# mini tractor pulling



## Thunderbolt51 (Sep 15, 2009)

Hello all. I'm new here but have been considering for a few years now building an electric garden tractor puller for an Open Super Stock class. No one has built one as far as I know for this class but an opening was made in the rules, I can also run as Exibiton. Other ice tractors in this class are making around 70hp. or better (highly modified alcohol 1 and 2 cylinder garden tractor engines). 1100 lb. class including driver. I'm a shade under 300 lbs. so that leaves me 800lb. for the rest. 26x12x12 pulling tires, pulling track normally 200' sometimes 250', make from 2 to maybe 6 or 7 pulls at an event plus any slow speed driving around the pits to scales, track and return. Each pull may take maybe 15-20 seconds. I'm shooting for 96 volts or better depending on weight total using a Net Gain TransWarP 7" motor hooked directly to a narrowed 9" Ford rear end with pinion shaft mounted disc brake in a lightened 782 series Cub Cadet tractor. a 1000 amp WarPcore controller and Braille NoWeight 12V. AGM batteries or lightweight AGM Odysseys, 6ea.- 16V. preferred. Also need an on board batt. charger. I've got to weigh the tractor/rear end and wheels/tires to see where I'm at. Need help to determine what battery capacity (cranking amps, amp. hr. reserve) I need to make it thru the day. What kind of horsepower can I expect with this setup ?? Not sure on what gearing I need either, stock is probably around 3.50 or so. Also does the controller or other components need to have a seperate 12 v. battery to operate ?? Also need to hook up a breakaway switch for safety. What solenoids/fuses/contactors/etc. do I need ?? Thanks for any help I can get.

photo of tractor I intend to build;
http://www.flickr.com/photos/[email protected]/1683234462/sizes/o/

http://www.flickr.com/photos/[email protected]/1683240264/sizes/o/

http://www.flickr.com/photos/[email protected]/1682360271/sizes/o/

my Hub Garage;
http://www.hubgarage.com/mygarage/Thunderbolt51


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## Dennis (Feb 25, 2008)

Thunderbolt51 said:


> Hello all. I'm new here but have been considering for a few years now building an electric garden tractor puller for an Open Super Stock class. No one has built one as far as I know for this class but an opening was made in the rules, I can also run as Exibiton. Other ice tractors in this class are making around *70hp. or better (highly modified alcohol 1 and 2 cylinder garden tractor engines). 1100 lb. class including driver*. I'm a shade under 300 lbs. *so that leaves me 800lb. for the rest. 26x12x12 pulling tires, *pulling track normally 200' sometimes 250', make from 2 to maybe 6 or 7 pulls at an event plus any slow speed driving around the pits to scales, track and return.* Each pull may take maybe 15-20 seconds*. *I'm shooting for 96 volts or better *depending on weight total using a Net Gain TransWarP 7" motor hooked directly to a narrowed 9" Ford rear end with pinion shaft mounted disc brake in a lightened 782 series Cub Cadet tractor. a 1000 amp WarPcore controller and Braille NoWeight 12V.* AGM batteries or lightweight AGM *Odysseys, 6ea.- 16V. preferred. Also need an on board batt. charger. I've got to weigh the tractor/rear end and wheels/tires to see where I'm at. Need help to determine what battery capacity (cranking amps, amp. hr. reserve) *I need to make it thru the day. What kind of horsepower can I expect with this setup ??* *Not sure on what gearing I need either, stock is probably around 3.50 or so.* Also does the controller or other components need to have a seperate 12 v. battery to operate ?? *Also need to hook up a breakaway switch for safety. What solenoids/fuses/contactors/etc. do I need ?? Thanks for any help I can get.*
> 
> photo of tractor I intend to build;
> http://www.flickr.com/photos/[email protected]/1683234462/sizes/o/
> ...



You may not get the all day run time you need unless you got a fast charger, but if you have access to a power source and have a regular charger then 8 PC1500's (http://www.odysseybatteries.com/battery/pc1500series.htm) ought to do it for 20 second (could take longer) 200 ft pulls of maybe 1 to 2 at a time before normal recharge required depending on how long the batteries are allowed recovery time or you can simply keep them charged up every time you complete a run with a fast charger like drag racers do at NEDRA events after every run so you do not have to worry about run time then. The total weight of the 8, 12 volt PC1500's is about 400 pounds meeting a required minimum voltage of 96 volt nominal without including the effects of sag when the batteries are under load, but since these are high discharge type then the sag is far less than if you went with deep cycle golf cart batteries. 

You state that the class you are entering is 1100 LBS and the tires are 26X12X12 which I assume the first figure is the diameter which means your tire radius is 13 inches. If a pulling force of 1100 lbs from the tractor is needed to counter the sled that has the shovel thingy digging into the dirt (is that what the class is or is it tractor weight?) then the torque required at the output axles from the Ford differential will have to be about 1015 foot-pounds, but I would make it 1400 foot-pounds. 

The torque data of the Transwarp 7 only goes up to 350 amps. I would need to see some data up past this up to about 600 amps. I am showing how you can do the calculations so I will use a similar motor which will be the L91-4003 that has the data I need. This motor can provide 106 foot-pounds of torque at 600 amp draw if we are to believe this data: http://www.evparts.com/img/mt2114peakmotoroutput.PDF is accurate. We should use about 2/3 of this value for full load torque for the short duration of run time you have planned. So the full load torque will be 70 Ft*Lbs with a current draw of about 450 amps so the total gear ratio has to be 20:1. Peak torque to break static friction with 600 amps motor current limit will be 2,120 ft*lbs at the axle which gives us a pull force at stall of 1,957 pounds. 

The test data above in the link shows a test voltage of 120v - .03(450) = 106.5 volts (accounts for sag). The data shows that 46 HP is produced which with the included torque data is about 3,355 RPM from calculation. Since we have not changed our torque value, but have decrease our RPM, the voltage then is 96V - .03(450) = 82.5 volts which means the RPMs and HP are 2,599 RPM for same torque of about 72 ft*lbs and 35 HP. 

Top speed is approximately with final gear reduction of 20:1 and tire diameter of 26" is 281 feet per minute which in a 200 foot course should take about 43 seconds to complete one full pull. Since this will be full controller voltage then the battery current will equal motor current. According to the PC1500 datasheet the battery can provide 494 amps till 10.2 volts is reached for two minutes. We are pulling 450 amps for 42 seconds so we are well within the limits of run time for this battery for at least one pull.



*This assumes you are pulling 1100 pounds from start till finish which obviously is not the case because the sled gradually shifts the weight over the shovel that digs into the dirt so it will be less for the majority of the time till the the tractor gets to the end of the course. I am just giving you a worst cast scenario here.* 

I am not sure exactly what the time it will take to complete the course, but I can tell you it will be <43 seconds since that is the worse case if by some strange reason the sled puts a force of 1100 pounds from start till finish.


I have actually posted a sort of wiring diagram here: http://www.diyelectriccar.com/forums/showthread.php/electric-riding-lawn-mower-13510p4.html for lawnmowers that you could use if need be. Please though read the warning I stated because it does have a "flaw" that requires the controller to have a way to disable power to the motor if the throttle is pushed before power up because I did not take this into account since many controllers took care of this issue for me.

So in summary:

*Use 8*PC1500 batteries
Set motor current limit to 600 amps
Use 20:1 gear ratio for 96 volts
Call to get the data required for 600 amps for the Transwarp 7 or use the motor I gave an example of or go bigger if need be.
*


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## Thunderbolt51 (Sep 15, 2009)

Dennis, thanks so much for a detailed and quick reply. This is something that I've been looking at for several years now but am still trying to get my mind around all of it, so far, the confusion, cost and weight has put me off and not knowing the likely outcome, also there hasn't been any rule openings for EVs to compete. I'm not sure we're on the same page as to my needs., from your description it doesn't sound very feasable for me to proceed unless I understand this better, I'm not very good with numbers. Yes, the tire radius is 13". The battery tech has and still does confuse me with all of the variables. The class is 1100 lb. total vehicle AND driver weight, the weight transfer sled is probably around 5 or 6000lb., the first 50-70' or so is minimal resistance and then gradually increases until the weight box is entirely over the flat pan, it doesn't dig into the track but just becomes dead weight to pull.. With me being 300 lbs. that only leaves 800 lbs. total for ALL components including the tractor and 400 lbs. of battery weight on the wrong end of the tractor is totally out of the question hence my interest in 15-17 lb. AGM batteries, just the motor is around 110 lbs.. Also, if much heavier E-cars are being hooked directly to a rear axle with assumable stock ratios why can't I run the same thing in a lighter vehicle, the lowest ratio made for the Fords are 6.50 or 7.00 to 1 so 20-1 is out of the question. Also, I'd be a laughing stock if it took 40 seconds to make a pull that others in the class are doing in 15 seconds, why would I need such heavy batteries when at most I'd likely have four 15 second "blasts" down the track and maybe 5 minutes of very light usage just driving to and fro at an event.. Also not likely to have more than 2-3 runs back to back. Are you also stating that I don't need a 1000 amp. controller ?? Thanks again for taking the time to help me understand all of this. 


here's a battery I was interested in 6 ea @ 192lbs..

http://www.jegs.com/i/Braille-Auto/147/B1632/10002/-1&parentProductId=1250689

or 8 of these, even better because of weight, 136 lbs.;
http://www.braillebattery.com/index.php/batteries/b2317/

George


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## Thunderbolt51 (Sep 15, 2009)

after looking at Jimdear2's nice Cub conversion on another thread on here I'm going to look at this again with a different setup. What is the airfilter for, can't tell what it's hooked up to. although he states he's using 4 batteries I count 5, what's up there, 48 or 60 volts ??


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## major (Apr 4, 2008)

Thunderbolt51 said:


> after looking at Jimdear2's nice Cub conversion on another thread on here I'm going to look at this again with a different setup. What is the airfilter for, can't tell what it's hooked up to.


Hi Thunder,

Air filter is for a blower to force ventilate the electric motor, as it did not have an internal shaft mounted fan.



> although he states he's using 4 batteries I count 5, what's up there, 48 or 60 volts


Not sure, but it might be an auxiliary battery to run the fan and contactors, and stereo 

Regards,

major


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## Dennis (Feb 25, 2008)

> *The weight transfer sled is probably around 5 or 6000lb., the first 50-70' or so is minimal resistance and then gradually increases until the weight box is entirely over the flat pan, it doesn't dig into the track but just becomes dead weight to pull..* With me being 300 lbs. that only leaves 800 lbs. total for ALL components including the tractor and 400 lbs. of battery weight on the wrong end of the tractor is totally out of the question hence my interest in 15-17 lb. AGM batteries, just the motor is around 110 lbs.. *Also, if much heavier E-cars are being hooked directly to a rear axle with assumable stock ratios why can't I run the same thing in a lighter vehicle, the lowest ratio made for the Fords are 6.50 or 7.00 to 1 so 20-1 is out of the question. Also, I'd be a laughing stock if it took 40 seconds to make a pull that others in the class are doing in 15 seconds, why would I need such heavy batteries when at most I'd likely have four 15 second "blasts" down the track and maybe 5 minutes of very light usage just driving to and fro at an event.. Also not likely to have more than 2-3 runs back to back. *Are you also stating that I don't need a *1000 amp. controller ?? *Thanks again for taking the time to help me understand all of this.


If you are pulling 6000 lbs then you need to enter into a lighter class, especially if you plan to use a single gear ratio limited to 6.50 or 7 for a Ford 9" rear end with a Transwarp 7.

The time of 43 seconds is a non-realistic worst cast scenario of what it would take if the tractor was pulling against a pound force of 1100 from start till finish which is not the case. It is just to give you an idea of what it will take for that amount of pound force to pull against.

I choose the PC1500's to account for the fact that lead acids suffer greatly from the _puekerts effect_ which means the batteries stated capacity will not be the same for various loads placed upon a battery.

Electric vehicles are not being asked to pull their weight (fraction of or full) unless they start to go up inclines. Even if they do go up inclines they are more capable of handling their weight because of more gear ratios, bigger motors, and higher current limit. You though have limited yourself to ratios no greater than 7:1 and are using a Transwarp 7 instead of Transwarp 9 or larger which the 7 size will not be able to handle 1000 amps very well versus the 9 or provide near the torque as the Transwarp 9 for the same current demands.

So for the new ratio you will have a maximum pull force of only 7/20th's of what it would be from the 20:1 ratio, but you gain approximately 3 times more speed.


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## Thunderbolt51 (Sep 15, 2009)

Dennis said:


> If you are pulling 6000 lbs then you need to enter into a lighter class, especially if you plan to use a single gear ratio limited to 6.50 or 7 for a Ford 9" rear end with a Transwarp 7.
> 
> >There is ONLY one weight class - 1100 lbs., the 6000lb. is the approximate weight of the weight transfer machine (all tractor classes pull the same sled weight, the speed with which the weight box advances is what is different between the classes AND/OR where on the transfer sled the weight box starts out, faster classes start with more resistance or faster weight box speeds, momentum is the name of the game), initially you're not pulling all of that weight as there are wheels at the tailend of the sled where the weight box starts from that carry most of the weight so the resistance is minimal until the weight box starts moving over the sled pan. You haven't answered my question about why a heavier vehicle run on the street with this motor can eliminate the need for a transmission. I thought that with the superior torque from an electric motor that it would replace the need for so much gearing, hence faster wheel/ground speed.<
> 
> ...


sorry I mixed the reply in with your quote, see arrowheads above.

>yes, speed (momentum) is what I need. Also concerned about overspeeding the motor rpms. The tractor I will use for this setup as there is room under the footrests for batteries;
http://www.flickr.com/photos/[email protected]/2755110504/sizes/l/ <

Dennis, again I thank you and the others for your input. Geo


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## Dennis (Feb 25, 2008)

> You haven't answered my question about why a heavier vehicle run on the street with this motor can eliminate the need for a transmission. I thought that with the superior torque from an electric motor that it would replace the need for so much gearing, hence faster wheel/ground speed.<


The Transwarp 7 cannot be used alone as a prime mover for a vehicle unless it is light, like a Geo or it can be used for a tractor conversion like yours. Transmissions are needed so that the motor is not overloaded beyond the thermal limits too often. Sure you can run a motor beyond its ratings for a short time, but if this is continuous then you will shorten the life of the enamel that coats the windings and will eventually have motor failure caused by shorts. People tend to want to protect their motor by having at least 2 gears to choose from in a transmission like 1st for hills and 3rd to get up to highway speeds.

Of course someone could just use a huge motor like a warp 11 or 13 directly coupled to the rear end differential which they generate lots more torque per ampere than the smaller sized motors. These motors though cost quiet a bit more than simply getting an 8 or 9 and using a free transmission that came with the donor car. The performance crowd generally go for the 11's or 13's as they are more interested in sling shooting themselves down the quarter mile with a large EV grin on their face.




> I'm looking for realistic scenarios not unrealistic. I don't understand the part about pulling AGAINST an 1100 pound force, am I not pulling WITH an 1100 lb. force ??


I would have to know if the pound force the sled is putting against the tractor is increasing linearly as you drag it down the 200' strip. This makes it very easy to find the area under the pull force curve to get you an average pull force the sled will be putting against your tractor so I can get the new load point this would point on the motor so that I can get you an accurate speed. It will be near impossible to get this information. So I chose the worst cast scenario of your tractor having to pull against a force that is pulling in the opposite direction with a force of 1100 pounds. 

You state that the 1100 pounds is the tractor class so just forget about the 1100 pounds. At least you know what it would perform at if it had to pull 1100 pounds from start till finish. I know sleds gradually apply the weight as you go down the track.

The pound force is the horizontal force your tractor will exert against a body that has resistance. Say for example you hook up and pull against a body that puts up a resistance of 1100 pounds force, then your tractor is pulling with a force of 1100 pounds also. If the forces are unequal then you have acceleration or stall condition, when forces are equal you are at steady state like for example you reach a constant velocity.




> I need a scenario for batteries I may intend to run such as the Braille No Weights, say the 17 or 18 pounders. Weight, battery capacity, size, cost are the main considerations in order of importance, AGMs only not flooded cell, I may mount them on their sides


They are still lead acid except the electrolyte (the acid) is suspended in glass mesh. It does still suffer from the puekerts effect. I cannot come up with a real world scenario for batteries. You will have to take the plunge with real world testing or ask other members about how long they got in runtime under high demand of their AGM's.







> o.k., after looking at the fella who built the narrow frame Cub puller I'm now thinking of a different configuration with a 6.7" D&D 18hp. motor 72-120V. , http://www.cloudelectric.com/product_p/mo-es-31b.htm (I don't understand the efficiency rpms) in a similar setup only with 8ea. 12V. Brailles. Can this motor take short spurts of 1000 amps or what is the limit ??


If it is similar to the X91-4001 as it states on that site (http://www.evparts.com/prod-MT2115.htm) then it would be a poor choice based on the fact it has slow RPMs for the voltage you want which limits your gearing since speed is also important for you. So a better motor choice or similar one is the L91-4003 (http://www.evparts.com/prod-MT2114.htm) because it has higher RPM's which give you more gearing flexibility and if the data is to be believed here: http://www.evparts.com/img/mt2114thermaltests.PDF, it also seems to have higher thermal rating duty than the X91-4003 (http://www.evparts.com/img/mt2115thermaldata.PDF) or similar motor which is most likely due to its higher RPM's which allow the fan to move more air.

I do not recommend that you set the motor current limit to 1000 amps for such tiny motors or you run the risk of destroying 1000's of dollars worth of a perfectly good motor. Six-hundred amps is plenty for what you will need. That is 100+ Ft*Lbs of torque at 0 RPM for the L91-4003! 





> I'm now considering using the same I.H. Cub Cadet 3 speed transaxle only driving thru the upper main shaft of the tranny (1" splined shaft) instead of using the bull gear reduction unit as all the power goes thru a puny 5/8" input shaft with a 1/4 inch bolt, may get ratios to around 13-1 (tranny and rearaxle total without the bull gear reduction), it would also reverse rotation so that it'd be the same as an automotive rotation.. This will also allow me to mount the motor a few inches lower in the chassis for a lower center of gravity.


Thirteen to one is a good compromise between protecting the motor from overheating and going fast, so good choice.



> I also had the impression that the controller was the "weak" link and that the horsepower was limited by the maximum amps that it could deliver......yes ?? Another thought I've had is with the higher voltage battery pack (96v.) that it would be less drawdown on the battery capacity than with a lower voltage heavier battery pack like he's using - 48V. yes or no ??, would I be better off with a 72V. pack with higher reserves ??


If you want 96 volts then stick with that since you got more RPM's to work with than with 72 volts and indeed the current will be less if the motor is geared properly. Your batteries might get you more than one run time. Only real world testing will reveal if this is the case or not.

Remember to try to keep the RPM's at 6500 RPM's or less for 6.7 in motors (bigger motors have an even lower RPM limit) or use the setup Jimdear has which uses a tachometer as a control element to shutdown the controller if the motor goes above the RPM limit. The controller is the weak link if it is crappy like K*ll* controllers, which I'll let you fill in the rest.


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## Thunderbolt51 (Sep 15, 2009)

how much difference in rpms between 96v. and 120v. motor in either 6.7 and 8" ?? I'm now considering a 8" Impulse NetGain motor at 106 lbs., maybe it can pull a taller gear to make up for the 1000 rpm difference of the 6.7" motor. Also, how many amps can the 8" take at 96 and 120v. ?? Hope to weigh my tractor soon to see how much weight I have to "play" with. Thanks.


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## Dennis (Feb 25, 2008)

> how much difference in rpms between 96v. and 120v. motor in either 6.7 and 8" ?? I'm now considering a 8" Impulse NetGain motor at 106 lbs., maybe it can pull a taller gear to make up for the 1000 rpm difference of the 6.7" motor. Also, how many amps can the 8" take at 96 and 120v. ?? Hope to weigh my tractor soon to see how much weight I have to "play" with. Thanks.


When looking at the data for the warp 8 it seems to have relatively the same torque performance in comparison to the L91-4003. I would stick with the L91-4003.

L91-4003

400A = 60ft*lbs 
450A = 72ft*lbs 
500A = 84ft*lbs 
600A = 106ft*lbs 
750A = 150ft*lbs

Warp8

419A = 60ft*lbs 
463A = 70ft*lbs


To see how many RPM's the warp 8 will turn when producing an X amount of torque just simply multiply the ratio of the new voltage/old voltage to the old RPM's. Example at 72 volts - .03(463A) for 70 ft*lbs of torque is 58 volts and 96v - .03(463) is 82 so it will be 82/58 = 1.41 times more RPM's. At 70 ft*lbs the warp 8 is spinning at 2744 RPM so at the new voltage it is 3870 RPM.


The L91-4003 at 72ft*lbs at 96 volts - .03(450A) spins at 2600 RPM's from calculation of RPM from the data provided here: http://www.evparts.com/img/mt2114peakmotoroutput.PDF and then dividing by the ratio since they tested with 120 volts, but you want the data at 96 volts so it is 2600 RPM.


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## Thunderbolt51 (Sep 15, 2009)

what is and do I want advanced timing for my application ??


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## Dennis (Feb 25, 2008)

> what is and do I want advanced timing for my application ??


Timing advance is where the brushes are shifted such that the conductors in the armature (the rotating part) are energized before they reach the dead center of the field poles where the maximum magnetic field would be. This will cause the armature to have to spin faster (the details on why it does this is not important to this discussion). It also moves the armature magnet field lines which can reduce magnetic field distortion of the field poles caused by the armature's magnetic field which reduces sparking at the brushes (called armature reaction) that in turn can allow the motor to operate at higher voltages.

Timing advance though only works for particular load conditions and will not work at all load conditions, but this is a compromise the designers have accepted as they assume the motor will spend the majority of its time at the rated load condition to merit the use of timing advance. They cannot fit interpoles (which is another way of reducing or eliminating armature reaction) in small motors so they have to resort to timing advancement. Only the bigger motors like the 11's or 13's are practical for fitting interpoles inside.

For your application the warp8 and L91-4003 motors are most likely already advanced or they do not need the timing advance as they were designed to run from 96v - 120v (they can be ran less than 96 volts). So they will work as stock on your 96 volt setup.


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## Thunderbolt51 (Sep 15, 2009)

o.k., I like the 8" Net Gain Impulse motor, LogiSystems 750 amp. controller and if weight allows 10 Braille 12v. no weight AGM batteries @ 21lbs. ea.. and an onboard waterproof PFC charger, how does that sound to you ?? What other components are necessary ?? I don't see any solenoids or contactors for 120v. or high amps., do I have to run yet another 12v. battery (not in the series) to use the other components like the key switch, throttle, etc., fuses or circuit breakers ?? I need to have a kill switch incorporated into the system that's hooked up at the rear of the pulling tractor to a cable from the sled controlled by the sled operator that "pulls the plug" killing the engine, or motor in this case, if something is going wrong. Also seen a big red knob on the dash of the Cub puller (panic button disconnect ??) where do you get that ?? On my other pullers I currently use an Artic Cat snowmobile tether switch (normally closed) and an inline on/off toggle switch hooked to a Ford starter solenoid. Also what gauge welding cable should be used for 120v. and are there any advantages to using copper crimpon lugs or regular automotive battery post clamps ?? I also use race car power disconnect switches, are they suitable for 120v. ?? Thanks again.


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## Thunderbolt51 (Sep 15, 2009)

well, I finally weighed the tractor, it came in at 385 lbs. so I need to adjust my setup in order to make the weight break. It only leaves me 415 lbs. for everything else including motor and batteries, mounts, batt. cables, weight rack, hitch, wheelie bars, etc., maybe back to the 96v. setup, now also considering just building a tubular frame.


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## Dennis (Feb 25, 2008)

> o.k., I like the 8" Net Gain Impulse motor, LogiSystems 750 amp. controller and if weight allows 10 Braille 12v. no weight AGM batteries @ 21lbs. ea.. and an onboard waterproof PFC charger, how does that sound to you ??


I have heard LogiSystem controllers have problems with blowing the mosfets resulting in a dead controller and having jerky starts. Maybe they resolved this issue. 



> What other components are necessary ?? I don't see any solenoids or contactors for 120v. or high amps., do I have to run yet another 12v. battery (not in the series) to use the other components like the key switch, throttle, etc., fuses or circuit breakers ?? I need to have a kill switch incorporated into the system that's hooked up at the rear of the pulling tractor to a cable from the sled controlled by the sled operator that "pulls the plug" killing the engine, or motor in this case, if something is going wrong. Also seen a big red knob on the dash of the Cub puller (panic button disconnect ??) where do you get that ??


I would use two contactors rated at 500 amps continuous on the positive side going to B+ of the controller and one on the negative side going to B- of the controller of the 96 volt pack. You will need either a 12 battery that would be an accessory battery to power all the contactors and key power for the controller or use a DC-DC converter. For the fuse I would use a 250 VDC, 500 amp fuse for the main pack and a 5 to 15 amp fuse for the accessory battery.

Here is how I would do the kill switch and emergency stop button: where the two contactor coils have their minus sides tide together, put the kill switch and E-stop switch on that side. This will cause both contactors to open if you press the E-stop or if the guy in the sled pulls the string attached to the kill switch.

You will need a precharge resistor of 330 ohms, 10 watts on one of the contactors. I would put it on the positive side. 

For the start up sequence have it do the following: When you turn the key on it should switch on the negative side contactor and provide power for the controller key input, provide power for the safety switches to be activated by you on the positive side and power some 12 volt relay that has it contacts connected to the 12 volt battery that provides power for high demand devices like say head lights or any other high demand device you wish to have activated when the key is on if you have such accessories.

The will also commence precharging since the resistor on the positive side contactor has a complete path when the negative side contactor was activated. 

In order to activate the positive side contactor, have the following safety measures in place: the key switch, seat switch, foot switch (if it has one), and the throttle pot box switch all need to ON in order for the positive contactor to be energized. This will provide the safety measures needed to shut down the motor if you fall off or if something goes wrong and you or the operator are not fast enough to shutdown the motor you can by instinct of human nature immediately remove your foot from the foot switch and/or the throttle which would also shutdown the motor.




> Also what gauge welding cable should be used for 120v. and are there any advantages to using copper crimpon lugs or regular automotive battery post clamps ?? I also use race car power disconnect switches, are they suitable for 120v. ?? Thanks again.


For the main pack wires use 00 AWG. if the posts of the batteries are brass use tinned copper post clamps if lead then use lead post clamps.
Stick with 12 volt switches. 


Here is where all the above items can be bought:

Pre-charge resistor: http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=TMC10-330-ND

Fuse 500 amp: http://www.evparts.com/prod-FU9532.htm

Contactor: http://www.evparts.com/prod-SL2570.htm

00 AWG wire: http://www.evparts.com/catp13-Wire+&+Terminals+..htm

Tinned copper post clamps: http://www.evparts.com/catp5-Wire+&+Terminals+..htm

Pot throttle box: http://www.evparts.com/prod-PB2222.htm

The rest can be bought from automotive suppliers or are already on your tractor (the saftey switches).


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## Jimdear2 (Oct 12, 2008)

Thunderbolt51 said:


> well, I finally weighed the tractor, it came in at 385 lbs. so I need to adjust my setup in order to make the weight break. It only leaves me 415 lbs. for everything else including motor and batteries, mounts, batt. cables, weight rack, hitch, wheelie bars, etc., maybe back to the 96v. setup, now also considering just building a tubular frame.


Thunderbolt,

Hi, I'm Jimdear2, I Just bumped into this thread. Interesting . . . You have been given some very good information about needed components. 

To answer one of your questions . . the fifth battery runs the fan and relays. 

I think your weight goal is acheivable barely. But you will probably need to use much lighter batteries. I can suggest 13 or 16 amp hour Hawkers or similar. They can supply the needed power (just barely) for a 15 to 20 second pull at the voltage you are considering. The 16 amp hour go about 13 lbs each. Lithiums would alsobe nice 

With small batteries, A rehook or pull off ???? Good Luck

I question the ON BOARD charger. Is this a rules requirement. I recharge from a generator through battery chargers that sit on my trailer. Get rid of the weight if you can. If you need a fast recharge the AGMs I suggest can take quite a kick from a dump pack.

My first tractor is a stock narrow frame cub 100 with the stock cast iron grill and cast iron front axle. I went with a later model fender set because I like the looks.

Man that custom chassis you show in your first post is Pretty, but I'll bet its also pricy. 

I set this tractor up to, I Hope, start an electric conversion tractor class.

I'm using 48 volts nominal and 1150 lbs. as a limit for the class and also to be competitive with the stock up to 13 hp 1150 lb. ICE tractor class we have in our area. It has turned out well and is competitive with stock tractors as defined in our area. There appears to be a lot of interest.

The spectators love it, it is so quite they have to be told it is running. Just for fun next year I might put a phony exhaust pipe on it, tap the cooling fan air and put a bubble pipe in the phony exhaust pipe.

I didn't bother with motor size or battery size limits in my rules as they are going to be pretty much self limiting in this weight class. 

I'm using a $232.00 rebuilt Prestolite Hi Lo pump motor, running through a stock Cub three speed. I have a used 7245 Alltrax $220.00 and I have 4 used take out 40 amp hour High Rate AGMs from a UPS system they were $20.00 each I believe. 

I wanted to show that an electric could be competitive (we also have an outlaw run what you brung class) and reasonably priced. 

Interesting enough, I pull with the top third and am getting closer. I have run the tractor continuously for an hour before the voltage fell off.

My second tractor is a former "ultralight" 586 to 820 cc 1300 lbs. class tractor that I converted to electric. I set the tenitive rules limit for this class at 72 volts nominial 1300 lbs. again weight will limit batteries and motors.

This is probably closer to what you are trying to build. I have a D&D ES 15B motor and a Alltrax 7245 I am running 72 volts. I have got a lot more tuning to do. The best pull i've had was quite short for the class. Missed 1st place by only 30 feet. But I have a lot more tuning to do.

Our sled is much heavier then yours, it's about 9000 lbs. It has a drop pan, a rising tag axle and when needed, crank down cutter bars on the back edge of the pan. It can stop a 1000 HP supercharged 350 CI small block 1800 lbs. V8 mini. It will put bruses on your chest from the five point harness.

I'm an olde phart, it's late and I'm rambling. Feel free to contact me or ask. If I have an answer i'll give it to you.

By the way the tractor shown in my signature is the ultralight I am converting.


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## Thunderbolt51 (Sep 15, 2009)

Dennis, Thanks again for the great advice and knowledge you've been giving me especially the heads up on that controller. I was clueless on the other components, and how to hook it all up, you've saved me a great deal of time (money too) trying to figure this out safely. I'll be sure to pass along this info to other pullers also interested in a changeover, would love to see Electrics running amongst the sport. Thanks again, I appreciate it. Geo


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## Thunderbolt51 (Sep 15, 2009)

Jimdear2, greetings fellow puller !! Thanks for the comment on my puller, I do all the fabrications and paint jobs myself, I love to build hot rod stuff. My problem is that I have too many projects at various stages of completion and easily get side tracked with new ideas. yes, I agree about the on board charger, after weighing the tractor I realize that component weight is a REAL concern. I see that getting the right combo of motor/controller/voltage/amperage, a deep enough battery reserve wise and the weight issue and it's placement is not an easy solution. I'm also very concerned about the battery reserves lasting a sufficient length of time and having to constantly recharge after each pull, all I have to do with my ICE pullers is refuel and reweigh between rounds taking no more than ten minutes and the fuel can is very portable and easy to haul around, at 60 yrs. old I'm not excited about expending more effort at the pulls and also running a noisy bulky generator. Was hoping for enough gusto in the batteries to recharge between events not between rounds. Still the concept of EVs and possibly being one of the first to break into the sport inspired me to spend much time picturing it in my mind. I know I can build a super puller but not sure if it'd be worth the effort at this point in time relative to the financial situation the country is in now, it's tough trying to sell pulling parts and tractors that are in common use now, an Electric would be an oddball and tough to sell to anyone who doesn't understand it which is likely everyone. Also don't want no dog of a puller, the NQS Open Super Stock class ain't for no slouches (their only rule (so far) for electrics is nothing bigger than a 9" motor, I love minimal rules like this !!!), also have a similar local 70 cube class running against modified singles, twins, small sled and bike engines. Without any E experience I've no way of knowing which combo will actually do the job, just the knowledge of others willing to share but with different applications. The approximate price of around $5000 is on par more or less with a modified ICE powerplant. Question is, is it comparable performance wise ?? It also might be a bit anticlimatic without the heartthumping screaming noise of a racing engine to get everyone's complete attention. I'm now thinking about a lighter weight tube chassis, Half Pint style, have all the chassis and rear end parts just have to decide if I want to do it. Might also consider swapping out one of my 4 cyl. Super Modifieds but would rather do a G.T. instead. Our sled stops everything from Stock 1050 lb. garden tractors to 2000 lb. 375 cube Alky v8 mini rods on 31" tires, has hydraulic snow plow cylinders on the rear of the pan, can be adjusted when they kick in and you know it when it does. Thanks. Geo


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## Thunderbolt51 (Sep 15, 2009)

here's my Flickr album and some of the vehicles that I've built. http://www.flickr.com/photos/[email protected]/?saved=1

http://www.flickr.com/photos/[email protected]/sets/

http://www.flickr.com/photos/[email protected]/sets/72157602732369201/


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## Dennis (Feb 25, 2008)

Hello again, I have to amend some information I gave you on the lanyard switch and E-stop because re-activation of those switches will result in the tractor being active if all other safety features are active without warning so I am going to add a lock out that requires user action to reactivate the tractor to the active state. This will be achieved by using a DPST N.O. relay as a latch in which a push button is wired in parallel to two connections of one of the internal switches of the relay where one leg of this parallel connection will go to the positive side 12 volt wire after the key switch, E-stop, lanyard switch, and seat switch and the other leg of this parallel connection will go to one leg of the relay coil itself and to the main wire that provides power for the controller, indicator light, positive side contactor safety switches: pot throttle box and foot switch, negative side contactor, and to energize an accessory relay that has its contacts connected to the 12 volt battery for powering high demand 12 volt loads (use 15 amp fuse). Also the other internal switch of this relay will be used to provide a return path (ground) for both the positive side and negative side contactor.


So the KILL ALL switches that will kill ALL power to everything are seat switch, E-stop button (N.C. type switch), lanyard switch (N.C. type switch) , and key switch. If any of these switches are shutdown then in order to bring your tractor back into the active state the key switch must be on and you have to push the start push button.


The motor shutdown switches are the foot switch and the throttle pot box switch that will disable the positive side contactor if the throttle is not depressed or no foot on foot switch (this switch could also be used with a brake peddle that locks in when this peddle is not depressed, so you have no motor power if the controller fails short circuit and the tractor will not move) which consequently will prevent the motor from receiving power, but accessory power is still available and the controller is still on.

I forgot to tell you to use a form of voltage spike suppression for the contactors and relays which is needed to prevent voltage spikes from destroying sensitive electronics. For suppression, diodes are wired to both legs of the coils of the contactors and/or relays. The diode should be wired such that positive is going to the side that has the gray to white looking line and the negative to the black body side that has no line mark (diode is connected reversed biased). If the diodes are wired in reverse to this they will go up in smoke (forward biased).

For contactors use diode 1N5408 and for relays use 1N4007, both are available from a local Radio shack or can be purchased online from retailers such as Digikey. The DPST N.O. relay needed is available here: http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=PB298-ND


I have provided a diagram that I drew in MS paint on how to wire all this up:


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## Jimdear2 (Oct 12, 2008)

Dennis said:


> Hello again, I have to amend some information I gave you on the lanyard switch and E-stop because re-activation of those switches will result in the tractor being active if all other safety features are active without warning so I am going to add a lock out that requires user action to reactivate the tractor to the active state. This will be achieved by using a DPST N.O. relay as a latch in which a push button is wired in parallel to two connections of one of the internal switches of the relay where one leg of this parallel connection will go to the positive side 12 volt wire after the key switch, E-stop, lanyard switch, and seat switch and the other leg of this parallel connection will go to one leg of the relay coil itself and to the main wire that provides power for the controller, indicator light, positive side contactor safety switches: pot throttle box and foot switch, negative side contactor, and to energize an accessory relay that has its contacts connected to the 12 volt battery for powering high demand 12 volt loads (use 15 amp fuse). Also the other internal switch of this relay will be used to provide a return path (ground) for both the positive side and negative side contactor.
> 
> 
> So the KILL ALL switches that will kill ALL power to everything are seat switch, E-stop button (N.C. type switch), lanyard switch (N.C. type switch) , and key switch. If any of these switches are shutdown then in order to bring your tractor back into the active state the key switch must be on and you have to push the start push button.
> ...


Hi all Jimdear2 here,

Thunderbolts51, Wow those are some nice tractors, I'm afraid that mine are a bit more "Farm Implement". They do perform well though.

Dennis, A couple of points on your diagram. It is very complete and mostly usable. You have really covered all possibilities, but you may have gone a bit too far on the safety switches and complexity. Of course what is included is up to the indiviudual. But so many contactors and switches just create failure points in what can be a very dirty, violent and rough sport.

My personal systems:
Emergency Disconnect and Main Contactor

The ultralight uses a single combination Emergency Disconnect/Stop Button / Main Contactor unit from Curtis Albright. 

The Cub uses a Dedicated HV circuit Emergency Disconnect/Stop Button unit from Curtis Albright with a TYCO kilavolt main contactor 

Your emergenct stop button would not break the HV curcuit in case of a welded contactor. You REALLY NEED some form of mecanical Hi Voltage disconnect. You are constantly dealing with BIG amprage. This year I did not have a connection between the standard pull away lanyard switch and the mecanical disconnect, next year I will.

The second (B-) contactor for this application has two negitives, one is the extra weight (a very critical point), second it is redundant with a mechanical HV disconnect/emergency stop unit like described above.

The seat switch is a very bad idea in that these things have no suspension and can bounce violently. Many also have a perminantly mounted seat or use seat belts.

A body lanyard is redundant (unless rules require it) because the required tractor break away switch not only opens when/if the tractor should break away from the sled, it can be manually opened by ther sled operator if the driver should fall off. In 15 years of pulling I've never seen anyone fall off, although I'm sure it has happened.

Both of my tractors will probably have your latched start switch system incorperated by next year.

A critical High Voltage interuption circuit that you did not include is a motor runaway stopper. The system I use has already saved my motor once when I broke a differential. Basically it uses the shift light of a racing tachometer pre set to a safe maximum rpm to latch open a normally closed relay that carries voltage to the main contactor. The set up I have requires a OFF ON cycle of the KEY ON switch to reset.

The foot and potbox switches are just another redundant component that create a failure point. your choice on those, I personally do not like the constant cycleing of the main contactor. Many contactors have open contact points where dirt could be a real problem

A low power or power reduction switch for reverse is a plus. If your controller has it use it, if not you can switch a resistor into the pot box circuit.

Remember these tractors normally run in competition for just a few seconds and are normally driven by a very limited group. To many things to go wrong can be a nightmare when you are on the line broke and have three minutes to fix it.

These are just a few of my thoughts.


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## Dennis (Feb 25, 2008)

> Your emergenct stop button would not break the HV curcuit in case of a welded contactor. You REALLY NEED some form of mecanical Hi Voltage disconnect. You are constantly dealing with BIG amprage. This year I did not have a connection between the standard pull away lanyard switch and the mecanical disconnect, next year I will.


If you look closely you will see that the E-stop cuts off the relay which removes power form BOTH contactors. It is impossible to maybe very slim that both contactors will be fused. Fused contactors mainly occur when they make (come on) on high current beyond their rating. This is impossible for my setup as the negative side contactor comes on first and is not having to make on high current. Contactors can break more current then they make (come on) and have blow outs that use magnets to suppress arcs or if sealed use a type of gas that is very good insulator that prevents plasma arcs when they break (open). Also the positive contactor will not fuse as it makes because the throttle just begins to move and so the current is very low as well for it unless there is pre-charge resistor failure then in that case the negative side contactor will still be able to open for such an emergency.

If it is really necessary rule wise then some form of anderson disconnect connected to some device that you push to force a disconnect will work. 



> Dennis, A couple of points on your diagram. It is very complete and mostly usable. You have really covered all possibilities, but you may have gone a bit too far on the safety switches and complexity. Of course what is included is up to the indiviudual. But so many contactors and switches just create failure points in what can be a very dirty, violent and rough sport.


That is up to the user to decide how much safety they need. I tried to get all possibilities I could.




> A critical High Voltage interuption circuit that you did not include is a motor runaway stopper. The system I use has already saved my motor once when I broke a differential. Basically it uses the shift light of a racing tachometer pre set to a safe maximum rpm to latch open a normally closed relay that carries voltage to the main contactor. The set up I have requires a OFF ON cycle of the KEY ON switch to reset.


You can provide him with this detail if you wish. My latch relay can be used for this setup instead to shut off the tractor once the trip point is reached.




> The foot and potbox switches are just another redundant component that create a failure point. your choice on those, I personally do not like the constant cycleing of the main contactor. Many contactors have open contact points where dirt could be a real problem


Any switch that is mechanical type will fail eventually. Only electronic types will not fail from cycling near as much. The contactors I recommended him are sealed from the environment.


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## Jimdear2 (Oct 12, 2008)

Dennis,

Sorry If I seemed to come across as criticisizing your advice, wiring diagrram or component selection. As I said previously Thay are all exelent.

My interpersonal skills have never been one of my better traits.

I just offered a different look at the method of solving the problem of making one of these things go.

In my opinion (we all know opinions are worth what they cost) the system you have designed and layed out for thunderbolt51 is a bit too heavy and complicated for what he needs to accopmlish.

But let me restate . . .the diagram is good and quite complete and should in my opinion work fine with one exception. The wire you have labled as going to key switch input of controller, you should note that some controllers, Alltrax for one, require pack voltage not control batt voltage there and will need a switching relay. 

I do like the starter button to latch relay idea and will be using it next year.

I wish I had had someone like you to offer advice when I started. I didn't find this site until I was way into the projects. I bet I would have a lot fewer of those WHOOPS what did I get that for? 

Difference of opinions are what make things happen.

Be well,


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## Thunderbolt51 (Sep 15, 2009)

Jim and Dennis, Thanks again for your insight and knowledge, you both have some great ideas, I'm sure that others can benefit from your experiences. I'll pass this thread onto the Garden Tractor Pullers site. Yes, I believe in Keep it simple systems whenever possible, as Jim has said trying to diagnose a complex unfamiliar system problem on the line with only 3 minutes can have you pulling your hair out instead. Other pullers will frequently pitch in trying to solve a problem when they are familiar with the technology. It's good to see a well experienced puller already pulling an ev to know what you might run into. Thanks again to BOTH of you !! Thunderbolt.

internet's largest G.T. Pulling site;
http://sports.groups.yahoo.com/group/gardentractorpulling/

National Quarter Scale pulling series;
http://www.nqspulling.com/


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## TractorFan1407 (Feb 25, 2009)

Does naybody think that the electric tractor is a real posibility? I have seen on other forums that New Holland have developed a hydrogen based engine, but can this be extended to the tractor?


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## major (Apr 4, 2008)

TractorFan1407 said:


> Does naybody think that the electric tractor is a real posibility?


Sure, I have one. A small yard tractor. Works great. Battery powered tractors can do many tasks, but not pulling a plow over 200 acres.

major


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## JulsJunior (Jan 14, 2011)

Hi all! I was just browsing the forums looking for brush timing on a ADC 9". I happened to find this. I just finished my electric tractor last month and couldn't resist chiming in.

Here is the video of my first 4 passes:
http://www.youtube.com/watch?v=GFexW6m4vtE
The video details has my facebook album of my build.

I'm running a 9" ADC motor directly into the top shaft of the cub transmission. I made my own adapter bellhousing and couplings to meet the engine to the trans. I'm running the NetGain WarpDrive controller (160v/1200 amp version, but I now know I won't ever get there, better safe than sorry on the first attempt!) In the video it is still 144v but I am going to have to go down to 120v to make weight for the aforementioned 'Open Super Stock' class for NQS. I went with the red tops because of availability and relatively good performance/price. I converted a Ranger in '08 and that is how I got into the electrics. Now I took the ranger apart and built this little contraption.

My 'Low Gear' final drive is 13.8:1 and my 'High Gear' is 10.35:1 with an 82" circumference tire. My ground speed is in the video so you can work it backwards for RPM (not sure how to gauge tire slip, I would give it 3-5mph slip.

I am going to re-gear for our next event (February 11,12 in Sturgis, KY) and put high my previous high gear as my low gear, my new high gear is going to be 6.27:1, which I think will be too large for the poor little Optima's, but there is only one way to find out, try it!!  I will still have two other gears in between those two ratio's to try and nail down the right range of gearing.

I don't know a whole lot about these motors, but I get the mechanical side of things. If you look very closely on the video I think you can see some arcing (look right above/in front of my left foot). Perhaps it isn't really bad either, again, I don't know what I'm looking at exactly. I'm not exactly sure what my advance is. My question is: Is it centerline of the bolts on the side of the motor to the centerline of the brushes? This probably sounds like a simple question, but my strong suit is not electrical. I could tell you anything you want to know about an ICE motor tho... I tried to find the answer on these forums, but I couldn't find it. It does seem that 'major' knows his stuff tho!! Your talking way over my head on alot of those posts.

If you have anymore questions on my setup let me know. I would really like to see electric tractor pulling grow! Thanks for any input in advance!


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## Jimdear2 (Oct 12, 2008)

JulsJunior,

We have been following your build quite closely. I and others have reviewed both your videos and some pictures. As well as following the bench racing stories.

Would you believe the videos have made it to England.

I'm kind of jelouse bcause you seem to have got so very close to right on the first try. You made some nice pulls.

That tractor is going to supprise a lot of folks. I can imagin what you will hear from the other open class pullers. Up here we just started an electric class so no one gets bent out of shape.

Isn't it nice to sit there and listen to the crowd comment and the birds chirp as you go down the track. Just a HUM

I saw the arcing on your video and was going to suggest to Bad Fish Racing, whom I believe you have been in contact with, to let you know you need to do something there. 

The motor expert I follow is a guy with the handle major. You should go to the motor forum and ask for help on that motor, and how much advance you need for the voltage you run. Be aware that you WILL loose torque for every degree you advance. Makor is very good at helping out. Is is also involved with the electric road racing bikes.

Bad Fish Racing (BFR) and I have been slowly working our way into electrics for pulling, learning as we go. I've been running ICE ultralights for about 10 years and BFR has been drag racing electric motorcycles for a while with NEDRA. We're tryig to combine knowledge.

I believe you have seen my first electric, A yellow cub 100 that Jerry S and Mike B were using as a tow tractor last year at one of the indoor pulls.

Mike has asked a couple of times about building a NQS 'Open Super Stock' class electric. Maybe he and Jerry will do something.

A couple of questions:
The trans, are you using a Dart carrier and an aluminium case?. I see from your gear selections that you have discovered how to turn electric motor low end torque into wheel speed. 

Are you running any kind of overrev/runaway protection in case you break something under full load? Series motors will explode the comms if they get loose from the load. Does the Warp drive have something?

What kind of coupler are you using, custom or modified off the shelf. You said you made a custom front cover motor adapter. Did you machine something from billit?

You mention you used a motor from a previous conversion. I kind of figured from the performance that the brushes were well broken in. It took me almost two years of pulling to get my motor to the point that it is performing.

Next year I'll be running a P&S kit controller, I will have i44 volts and 500 amps through my little 6.7 inch Prestolite. BFR has been running 120 volts through his ADC on his stock narrow frame cub, but has had battery trouble. He pulls so much amprage he blows up batteries, kicks butt until a battery goes. Should be good next year. 

Instead of a 1100 pound open class, I have built a 1350 lb ultralight. to run with the local clubs. I is ment to be a dual purpose machine. We want to san drag it as well. 

It has a 13 inch GE motor, chain driving a Ford Ranger Diff that has been narrowed. The motor sits on top of the diff. I'll attach a picture. We have a 5:14 gear and any input ratio we want via chain and sprockets. We are on a set of 12 x12 x 26 used Lawntecs right now, (money you know). We will have a 175 volt 600 amp battery with a home made 300 volt 1000 amp controller.

So it looks Like electrics will kick some gas next year. You'll do in the open class. Boyh BFR and I will do in everything we thing up to 16 horse stock altereds and the ultralight should at least scare the motorcycle and four cylinder people. 

This is getting too long.

The pictures are of what we call the big 13. its about 80% done and we stuck a 72 volt 450 amp setup into it for the last pull of the year and had it geared for 175 volts and 600 amps. It moved but slowly.


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## JulsJunior (Jan 14, 2011)

> "Isn't it nice to sit there and listen to the crowd comment and the birds chirp as you go down the track. Just a HUM"


It sure is! So many people told me I should put a speaker with tractor noises, I told them I liked the silence haha.



> "The motor expert I follow is a guy with the handle major. You should go to the motor forum and ask for help on that motor, and how much advance you need for the voltage you run. Be aware that you WILL loose torque for every degree you advance. Makor is very good at helping out. Is is also involved with the electric road racing bikes."


Yea I have been reading vigorously tonite trying to soak up some info on the motor situation.



> "The trans, are you using a Dart carrier and an aluminium case?"


Aluminum Case, and our Billet Steel Carrier (Dart Replacement). With our heavy duty ring and pinion.



> "Are you running any kind of overrev/runaway protection in case you break something under full load? Series motors will explode the comms if they get loose from the load. Does the Warp drive have something?"


I know they will go crazy if something breaks, I haven't had a chance to rig something up yet. Based on the speed/power so far, I don't forsee the transmission breaking. Obviously I plan to go faster so I am looking into someway of limiting/cutoff RPM for the just in case situation. Any cheap and easy solution? (The WarpDrive does not offer anything that I know of)



> "What kind of coupler are you using, custom or modified off the shelf. You said you made a custom front cover motor adapter. Did you machine something from billit?"


Custom- Imagine a 'lovejoy' coupler with clearance and no rubber. And instead of interlocking you have a sleeve that "captures" the drive and driven end. I have a steel piece on the motor and on the top shaft. Then an Aluminum piece that goes over each steel piece and connects them. I have clearance in case my alignment is not dead on. I checked it when I pulled the motor and it look absolutely perfect. For the bellhousing I modified an existing program for our "Half Pint" drop boxes, so the bellhousing was actually pretty easy.



> "It took me almost two years of pulling to get my motor to the point that it is performing."


I put around 400 miles on the motor with no really high amperage (500 tops). However, I think I might need to replace brushes... Honestly, I couldn't tell you. 6 of the 8 look good (to my untrained eye), the other 2 could be better. I will try and attach a picture I took. Let me know what you think. (the top one is the questionable one, in case you couldn't tell lol)

Looks like the "big 13" ought to be a fun ride when its finished.


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## Jimdear2 (Oct 12, 2008)

JulsJunior said:


> It sure is! So many people told me I should put a speaker with tractor noises, I told them I liked the silence haha.


I keep threatening to get a recording of the flubber sound from the movie and as a special treat add a phony exhaust pipe with a bubble machine inside.



JulsJunior said:


> Yea I have been reading vigorously tonite trying to soak up some info on the motor situation.


You really need to put a post into the Motor forum asking major for help on this. The most common figure I hear for a motor running high voltage is 10 degrees advance. But check with him. He is aware of the tractor I sent him a link to the you tube video. You might look into the possibility of adjustible brush rigging. Jim at High Torque Electric made up a kit for some motors. We did out own version fot the Big 13. Brush advance allows higher rpm and produces less torque. Since we don't have a trans, we plan to try to use this to tune for loose and tight tracks, along with sprocket changes.



JulsJunior said:


> Aluminum Case, and our Billet Steel Carrier (Dart Replacement). With our heavy duty ring and pinion.


I sure hope we don't get into needing that kind of equipment for our cubs. We have gone over to hydro two piece carriers and fine spline axles for now. We will see how they hold up. It's good to know that kind of stuff is out there if we need it.



JulsJunior said:


> I know they will go crazy if something breaks, I haven't had a chance to rig something up yet. Based on the speed/power so far, I don't forsee the transmission breaking. Obviously I plan to go faster so I am looking into someway of limiting/cutoff RPM for the just in case situation. Any cheap and easy solution? (The WarpDrive does not offer anything that I know of) .


*"I don't forsee"* Famous Last Words ! ! !

We use a tach with a shift light to trigger a latching relay or latching circuit. The main contactor circuit runs through the normally closed contacts of the relay. 

We set the shift light trigger point to a high but safe rpm. Then, in a runaway situation, when the rpm reaches that setpoint, it trips the relay which latches open and shuts off the main contactor. We set this up to have to cycle the latching relay with a deliberete action to reset it so you don't get a on/off on/off. 

You can wire this up as part of the teather cut off circuit. 

If you are not running a tach, you can use something like a NOS rpm trrigger module. See the Summit or Jegs catalogs for these. 

For rpm signals, there are many ways to do this. I would need to know if you have a dual shaft motor. Some motor mfg.s have a kit.



JulsJunior said:


> Custom- Imagine a 'lovejoy' coupler with clearance and no rubber. And instead of interlocking you have a sleeve that "captures" the drive and driven end. I have a steel piece on the motor and on the top shaft. Then an Aluminum piece that goes over each steel piece and connects them. I have clearance in case my alignment is not dead on. I checked it when I pulled the motor and it look absolutely perfect.


The coupler sounds very strong (necessary). For now we are using just the old two sprocket wapped with double row chain type coupler. Noisy but strong.



JulsJunior said:


> For the bellhousing I modified an existing program for our "Half Pint" drop boxes, so the bellhousing was actually pretty easy.


Interesting, It sure is nice to have CNC stuff to do you precision stuff. I was lucky to have someone to help out there when we did the adjustible brush rigging

BFR is thinking of running a hydro diff with the motor driving the pinion shaft directly, or maybe driving the small reduction set. I don't know if the 6.7 inch AMD is enough motor even at 120 volts to do that. Trial and error. . . Trial and error. . . Trial and error. . .



JulsJunior said:


> I put around 400 miles on the motor with no really high amperage (500 tops). However, I think I might need to replace brushes... Honestly, I couldn't tell you. 6 of the 8 look good (to my untrained eye), the other 2 could be better. I will try and attach a picture I took. Let me know what you think. (the top one is the questionable one, in case you couldn't tell lol).


Again, get an opinion of someone like major or others with more motor experience then me. You might be able to clean up the brushes' again ask them. 

You *must* include a photo of the comm with the picture of the brushes. ANY damage there needs to be fixed. High rpm, high voltage, brush bounce, can equal.

*"ZORCH"*

new motor time. 

When you reassemble the motor, pay particular attention to flash over points. Those gaps that were good for 48 volts may not be for 120 volts, especially with brush dust and ozone. Insulate, Insulate Insulate. Filtered air and cooling the motor may not be necessary for the short runs of pulling but blowing all that crap out, just might be. Remember those tracks where the dust was soooooo bad you couldn't see 2 feet? They are still out there, need I say more?



JulsJunior said:


> Looks like the "big 13" ought to be a fun ride when its finished.


My partner, BFR has never had a real ride YET!!!!! I was hopeing to get him on my 120hp single engine ICE tractor last year, but the steering broke. (first time that thing let me down in ten years). 

The Big 13 is ugly right now. But with new fenders, a new seat, some paint, a pretty battery in a showy plastic case and a big fancy controller in a pretty enclosure should clean it up. I just grabbed a bunch of leftover stuff from the ICE tractors and through it on so we could see it move for the last pull last year.

Once we get the new battery in it . . . WOOPEEEEEEEEE, instant rush. I'm too old, fat and sick to drive it but I do _REMEMBER._ Plus we still have sand drags to look forward to. 

By the way, sand drags is the reason for the front suspension. I'll most likely run struts for pulling.


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