# ADC FB1-4001, Question about arcing/brushes



## DIYguy (Sep 18, 2008)

Hopefully MAjor will chime in. . . however, 10 degrees seems about right for a 144 volt application. Do you know your RPM upper limit and are you hitting it? Also, make sure the brushes are truly advanced... I mean in relation to rotation. The advance needs to be opposite to the direction of rotation....
As for the brushes...maybe running the motor with no load on a 12 volt battery for 24 - 48 hours will help to wear them in some more and develop a good film....


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## JulsJunior (Jan 14, 2011)

DIYguy,
It was probably around 2500-2700RPM at peak. Depends on the run/loading. 

The brushes are advanced the correct way as well.

I thought about running it for a day or two on a 12v batt to help get everything back to where it should be. I don't know if that will wear the brush down far enough to get a full contact patch again. Is there anything I can run with it to speed up the wearing in? Will that effect the oxide (film) layer that is on the comm? I just don't know what a truly 'bad' brush looks like, nor how quickly it will wear back into shape with the 12v method. I am lacking experience with electric motors in general. I've read just about all I could on these forums, but knowledge without experience can only get you so far.

I want to get this resolved because I want to push more amperage into the motor (800-900), but I want to make sure it is ready to take that burst of electrons for 12-15 seconds. I'm gona have to get my KW's back in amperage since I'm loosing 24 volts... but I also don't want a 150lb piece of junk at the end of the track...


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## DIYguy (Sep 18, 2008)

JulsJunior said:


> DIYguy,
> It was probably around 2500-2700RPM at peak. Depends on the run/loading.
> 
> The brushes are advanced the correct way as well.
> ...


Major is the best guy to answer this... however... Running it on 12 volts (don't go higher!!) for a day or two will help with the film. It likely won't get through the pitting completely. This is often caused from higher voltage and arcing I think. That said.... under 3000 rpm should not be a problem I don't think. Perhaps you could look into new brushes, there are different compounds some of which may be better for your application. 

The motor should also take 800 to 900 amps for this length of time. It is a good idea to use compressed air and blow out brush area after such an event and also to run at 12 volts for a while to re-establish com film. Do you have forced air cooling via an external fan? This would help to clear dust but also to cool down motor if multiple runs are required. I've pushed 1000 amps through my GE for short bursts like this. What kind of controller do you have? and what kind of batteries?


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## DIYguy (Sep 18, 2008)

There is a fellow on here named Jimdear2. He is a tractor puller guy. You need to hook up with him. He has a current thread (and others) on his big 13" motor/puller.


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## JulsJunior (Jan 14, 2011)

> Major is the best guy to answer this...


Yea I might send him a pm to glance at this thread. He seems very very knowledgeable.



> Do you have forced air cooling via an external fan?


Because of size/weight I was trying to avoid it. I am going to blow all the dust out after every run. I did not do that in the video, which may be the cause of the arcing more than any other factor.



> What kind of controller do you have?


WarpDrive 160v/1200amp. I went crazy with the controller because I didn't want to end up with something too small and go and have to buy again. I have the limits set lower right now.



> what kind of batteries?


Optima Red Tops 910CA. In the video I had 12 but in order to make weight I'm down to 10 

I would like to try and make the same KW number as I did at 144v. (~68.2kw) I think I can do it. Just as long as the motor doesn't mind. I might come up a little short but just so I'm close, I think I will remain competitive. Atleast until I can sell this battery pack and get some Braille AGM's and sell my motor and buy a NetGain Warp9. Should get 160v nominal pack (and make weight!) that I can pull 1000 amps out of. That will get me somewhere in a hurry. Unfortunately I didn't find the Braille's until a month after I bought the Optima's... DANG!

I have been in contact with Jim already. He has been helpful. However, I think Major is the person I need help from atm.

Thanks for the pointers DIYguy!


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## DIYguy (Sep 18, 2008)

Blowing out the dust won't prevent arcing... but it will help to prevent zorching (plasma event) which is the next step. Carbon traces and dust contribute to this. 

HAve you considered the Hawker batteries perhaps?


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## Jimdear2 (Oct 12, 2008)

JulsJunior,

I had some thoughts, some things to check (I really needd to do these myself during the after paint reassemble). Remember it just like a pro ICE assembly.
Every thing is clean, matched, balanced and triple inspected. 

1.) Put a dial guage on that comm and make sure it is true.
2.) Get a spring scale, check the tension of all of the brush springs, make sure there isn't a weak one.
3.) Put all of the brushes into their holders and make sure none of them are sticky. Use the spring scale and make sure the same force is needed to pull them out of theie respective holders. 
4.) Clean out the whole area. If needed polish the sides of the brushes with crocus cloth. No abrasives please.
5.) Watch that brush lead routing. No twists or strain.
6.) Is the angle of the brush holders perpendicular to the com on all pairs

I can't tell in the pictures, is that edge chipped and broken or burned)

Major is still your best bet, he may be out of town, he is involved with a couple of competition venues. He usually jumps right in.

Consider force feeding filtered air to boost the internal fan cfm. 

A wild thought came to mind a while back, One I just can't follow up on. Oxygen is part of the cause of arcs forming. I suggested flooding the area with a noble gas as a form of expansion cooling and arc suppression. It wasn't laughed out of the forum.

If all else fails find out if there is anyone building race motors (expensive and problematical, who do you trust.)

Jim Husted of high electric was a main man but I haven't heard about /from him in a while.

See the picture below, Hang this sucker on your tractor and go chase mini rods


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## JulsJunior (Jan 14, 2011)

> HAve you considered the Hawker batteries perhaps?


I looked at them some. They seem more industrial than high performance.



> I can't tell in the pictures, is that edge chipped and broken or burned


Yes two of the brushes (the ones held next to each other) Have chipped/broken/burned edge. I am going to inspect that brush holder tomorrow, and make sure it is holding them square to the comm. The other 6 SEEM fine. But I am not 100% sure what is good and what is bad. Could just those two brushes in bad shape cause all the arcing we see in the video? If so, that would be ideal, and answer a lot questions.

As far as movement and everything goes. The brushes fit fine and move freely, I had no problem removing them. The springs all FELT the same, but short of getting a spring scale on them I can't say for sure.



> Consider force feeding filtered air to boost the internal fan cfm.


I would rather not add another component to the tractor if I don't absolutely have to. Plus I would need a larger 12v source battery to run my electronics + a fan. And add a filter on top of that with a little duct work. Another switch and more wiring. All that is more weight, 5lbs is alot right now...



> I suggested flooding the area with a noble gas as a form of expansion cooling and arc suppression.


Sounds like it would work, but again its more components/complexity and weight.

I don't see why it can't take 144v and 800-900amps. All I really need to do right now is get this arcing under control and I think I will be just fine.

Maybe I have too much timing for the RPM/voltage I am running? Generally for EV uses, the motor's RPM is almost always climbing. Is it possible that if the RPM is falling with full power applied, the field in the motor does some weird stuff and that is causing the excessive arcing? The arcing seems to be worse towards the end, which is when its getting harder to pull and thus loosing RPM... I really have no idea what I'm talking about but it sounds good to me lol


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## DIYguy (Sep 18, 2008)

Some good ideas there fro Jim. When looking at gases, I'd only look at two of the noble gases. Argon and mayyyyybe Helium. The others are either too expensive or dangerous. I think being "noble" isn't the most important point, but as Jim mentions, the displacement of oxygen will help to keep the arcing more local. The cheapest and most readily available is likely Argon. (welding supply store)
I don't know of anyone trying this..but why not....? 

I've heard of ICE guys blowing off CO2 extinguishers to cool down intake air or intercoolers.... lol

I actually sprayed my entire inner brush holder gear and surrounding area with insulating varnish. It has an insulating value of 2100 volts per mil. I didn't get the best review when I brought this up a year and half ago or whatever it was.... but I later found out that some of the racing guys have done it/do it. The one argument was about shedding heat... or the possible thermal insulating effect. I think it's too thin to matter. I used Crown 6084 Rated Class F and flexible. 

You need to focus on the brush arcing though... and if you don't find any issues with springs you may just want to look at different brushes. 3000 rpm and 144 volts with 10 degrees advance should not result in much arcing. I went 13 degrees on my GE, but that was for 192 volts. (limited to 160)


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## JulsJunior (Jan 14, 2011)

Do you know of any sources that have different compound brushes for the ADC 9"?

I've heard of putting heavier springs in (twice the stock strength) to control the brush better. It increases wear but I could really care less (just as long as the dust is kept down by a better/harder? compound brush).

If I had to bump it a couple more degrees timing to solve the issue I wouldn't mind terribly. Give up torque<Zorch. Of course now I'm going down to 120v so I might not need to change anything and the arcing will lessen to acceptable levels.


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## Jimdear2 (Oct 12, 2008)

JulsJunior said:


> Yes two of the brushes (the ones held next to each other) Have chipped/broken <snip>/Maybe I have too much timing for the RPM/voltage I am running? Generally for EV uses, the motor's RPM is almost always climbing. Is it possible that if the RPM is falling with full power applied, the field in the motor does some weird stuff and that is causing the excessive arcing? The arcing seems to be worse towards the end, which is when its getting harder to pull and thus loosing RPM... I really have no idea what I'm talking about but it sounds good to me lol


One thing we have all missed here. _*Call the manufacturer*_, find out what the engineers recommend, maybe just a different brush material, maybe heavier spring . . .

Could be a simple answer

Another question, how did your motor end up already advanced. Did you order it that way? I'm very inexperianced here but I thought motors were wound to a voltage/current/rpm specification and brushes were neutrally timed so rotation could be reversed and advancing was a field expediant.

Jim


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## DIYguy (Sep 18, 2008)

I talked to two places when I was looking to replace mine. Jim Husted, and these guys http://www.manvillemotor.com/

I ended up getting OEM spec'd brushes locally.


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## DIYguy (Sep 18, 2008)

By the way... congrats on that tractor! That's some awesome pulling for your first time out! (or anytime) I'm no pro like Jim, but I actually know what is going on there. I was part of a pulling team many years ago with a Chevy big block in a 6000 lb econo class. We had a lot of fun then too! (but I always like the little ones...electric is the way to go!)


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## JulsJunior (Jan 14, 2011)

> Another question, how did your motor end up already advanced. Did you order it that way? I'm very inexperianced here but I thought motors were wound to a voltage/current/rpm specification and brushes were neutrally timed so rotation could be reversed and advancing was a field expediant


I honestly don't know, when I converted my ranger in '08 I ordered the motor from evparts.com and it arrived like that. Which was good, because at the time I had no idea about brush timing or none of that stuff. So happenstance worked in my favor. Unless it is technically neutral timed now... But I think the 400 miles @144v in the Ranger would have done some hefty damage to the motor if that were truly the case.



> congrats on that tractor! That's some awesome pulling for your first time out!


Thanks! I was actually thinking I was going to be over-geared based on the torque sheet I had and the calculations I did, turns out I was undergeared! So that is a big relief (I couldn't gear down any farther without redesigning half the tractor...). Guess I underestimated the torque these things make.



> electric is the way to go!


Once you get hooked, its hard to not mess with anything you can put batteries and a motor on!


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## Jimdear2 (Oct 12, 2008)

DIYguy said:


> By the way... congrats on that tractor! That's some awesome pulling for your first time out! (or anytime) I'm no pro like Jim, but I actually know what is going on there. I was part of a pulling team many years ago with a Chevy big block in a 6000 lb econo class. We had a lot of fun then too! (but I always like the little ones...electric is the way to go!)


 
DIYguy,

Thanks for the PRO comment, but JulsJunior is the PRO here, He's just starting a new direction and getting his feet firmly planted. I think he actually makes money at this, at some level.

Me, I'm just an enthusiastic amature having fun and spending money.

Jim


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## DIYguy (Sep 18, 2008)

I believe the ADC motors come advanced already. You can do a quick visual by eying up the center of the brushes with the pole shoe mount screws on the frame. If they are dead in line... it's neutrally timed. It should be 10 degrees shifted against (opposite) the direction of motor rotation. 

Did you say you had a tach? Have you verified it?


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## JulsJunior (Jan 14, 2011)

> You can do a quick visual by eying up the center of the brushes with the pole shoe mount screws on the frame.


Yea, in the pics of my first post it is, if you look at the end bell I have two sharpie marks showing the two centerlines.




> Did you say you had a tach? Have you verified it?


Nope, I don't have time to look at that going down the track


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## DIYguy (Sep 18, 2008)

JulsJunior said:


> Nope, I don't have time to look at that going down the track


Ya, I hear ya...but you may be turning a lot higher RPM than you think. (Maybe this is part of your gearing dilemma...?) Do you have a tacho-generator and if not how do you control RPM? 

Perhaps a large dial somewhere in your sight-line would be helpful? Something you don't have to actually "look" at...but can still see.


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## JulsJunior (Jan 14, 2011)

> you may be turning a lot higher RPM than you think.


I'm pretty confident of what I'm running. Attached is a spreadsheet with all of my possible gearing ratios I can do (hopefully you can open it). Just play with the RPM value and look at the MPH in column 'F' (That was my 'High Gear' in the video's, 'Low Gear' would have been Column C). If you watch my second run, You can see that the tires are hooked in very well. I would give it 3-4mph of slip/squat. Giving it any realistic amount of slip (and squat), you are still looking at an RPM value of right around 3000 RPM +- a few hundred RPM. I wouldn't think 3300 would (worst case realistic scenario) not be that high for this motor. Now if it were near 4000 I could believe we might see some arcing.

My tentative re-gearing ratios will be Column F, H, J, L (16,18,20,22 Top Shaft Tooth Count) This will def. drop my RPM (along with the loss of 24v...) But this should allow me to throw some amperage at the motor. And hopefully go faster. Not sure what RPM range I am looking at to get 800 amps into the motor with 120v source (minus voltage sag...) Again, I just don't have enough experience with this motor to even get a ball park. I know 20% loss of Voltage=20% loss of RPM. Which would make even more sense to gear up (to try and maintain my previous MPH). I just need to make it up with amperage.

I could share a spreadsheet of the logged Data from my runs (I didn't record the third run, I was too giddy and just wanted to pull ) If you think that would shed some light on the situation I can upload those when I get home from the shop.


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## badfishracing (Dec 4, 2009)

Julian,

Darin here. Are you measuring motor amps or battery amps? Does your controller log that data?

If it's motor amps, you can definately use some more gear.

If it's battery amps, then it's possible that you're overgeared. It's possible that the controller is in current limit at 900? amps, but to keep the amps down that low, the controller is limiting the output voltage.

I think when we ran the big 13 last year it was pulling about 200 battery amps, but was terribly slow, because it was limiting the output voltage to keep the motor amps down to 450, all because it was way overgeared.


Just a thought.


I was running a 32.2:1 ratio most of last year, my 3rd gear, stock bull gear. My best hook I pulled about 400 motor amps (contactor bypass, so motor amps was battery amps) and 120 volts, probably sagged down to 70ish volts.
When I tried a 2nd gear, about 70:1 final, in order to save the batteries from blowing, I hit the 6.5K rev limiter.

I forget what gear you said, but about 11:1 final? Wierd that I pulled 400 amps with a 32.2:1 and you pulled 650 amps with 3 times the gear? Or I need to find out what I'm doing wrong?


Darin Gilbert
BadFishRacing




JulsJunior said:


> Hello All,
> 
> I was wondering if someone could give me some pointers on my ADC 9". I'm using it in a garden tractor for pulling. I am not pushing a ton of amperage yet (550 mid track about 650 peak right at spin out), but on my first several passes it seemed to be arcing, possibly excessively.
> 
> ...


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## JulsJunior (Jan 14, 2011)

Hey Darin!



> If it's motor amps, you can definately use some more gear.


Yea that is motor amps, which was the same as battery amps. Which means the motor is limiting the amperage (back emf) not the controller.

High Gear in the Vid was 10.4:1. I'm thinking a 7.4:1 or 6.3:1 will get me closer to where my controller will limit amperage. I want to overgear so I can find my limit, that way I have a range of gearing I will be able to work with.



> Wierd that I pulled 400 amps with a 32.2:1 and you pulled 650 amps with 3 times the gear? Or I need to find out what I'm doing wrong?


What appoximate KW do you think you were running down the track?
I'm also running a 9".
I was around 68.2KW (This is with Voltage Sag, 105v*650amp(at spin out)=62.2) I was about 57KW mid track. That is the best way I can judge performance. Originally I was trying to figure rear tire torque (through the multiplication) to get my gearing, but the torque curve graph I had was unreliable or simply wrong. It makes it alot easier (and makes more sense) to just look at the energy expended. Whatever gets the most out of the pack as I go down the track is all that I really care about.

Take a look at that .zip file (excel file inside, or openoffice.org (free) if you haven't paid microsoft for their lovely.. excel program) I attached to my last post. You can edit it for your setup and compare it to what I'm running. Just change the reduction gears to whatever bull gears you are running.


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## MalcolmB (Jun 10, 2008)

Good advice Jim. I'll have to check all those points myself when I get round to firing (?) my motors up.



Jimdear2 said:


> Oxygen is part of the cause of arcs forming. I suggested flooding the area with a noble gas as a form of expansion cooling and arc suppression. It wasn't laughed out of the forum.


I can't find it now, but I did read a paper a couple of years ago that said that air, and in particular humid air, was needed to build up and maintain the protective film on the comm. An inert gas sounds like a good idea, but could lead to faster comm wear.


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## Jimdear2 (Oct 12, 2008)

MalcolmB said:


> Good advice Jim. I'll have to check all those points myself when I get round to firing (?) my motors up.
> 
> 
> 
> I can't find it now, but I did read a paper a couple of years ago that said that air, and in particular humid air, was needed to build up and maintain the protective film on the comm. An inert gas sounds like a good idea, but could lead to faster comm wear.


MalcomB,

That need was mentioned by the motor guy when they responded to the Idea the first time I posted it. He recommended that under any competitive circumstance, the motor should be run at 12 volts for a few hours after any competition to restore the finish to the comm.

I probably shouldn't have left that out, sorry.
Jim


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## badfishracing (Dec 4, 2009)

This just dawned on me. When my motor was in the bike, it was advanced. Moving it to the tractor, the rotation was different. I ran it neutral advance at lower voltages. When I moved up to 120V, I drilled another set of holes to get the timing advanced in the oppposite direction.
Backwards timing would definately cause a problem. Try running you ICE timing retarded instead of advanced!

Darin




JulsJunior said:


> Hey Darin!
> 
> Yea that is motor amps, which was the same as battery amps. Which means the motor is limiting the amperage (back emf) not the controller.
> 
> ...


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## DIYguy (Sep 18, 2008)

badfishracing said:


> This just dawned on me. When my motor was in the bike, it was advanced. Moving it to the tractor, the rotation was different. I ran it neutral advance at lower voltages. When I moved up to 120V, I drilled another set of holes to get the timing advanced in the oppposite direction.
> Backwards timing would definately cause a problem. Try running you ICE timing retarded instead of advanced!
> 
> Darin


This is what I was thinking earlier also. ... Just confirm it with rotation....


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## Jimdear2 (Oct 12, 2008)

DIYguy said:


> This is what I was thinking earlier also. ... Just confirm it with rotation....


Darin, DIYguy, Julian,

<*EDIT*> Julian, I got to thinking about this last night. You are probably too sharp to have let something like this get by you, but decided not to delete it JUST IN CASE. No insult intendid. Jim <*END EDIT*>

I think if you look at his first post you will see a picture of the brush end of the motor. Julian has marked the centerline of the fields and the centerline of the brushes. It shows the brushes are clearly advanced for clockwise rotation when looking from the brush end of the motor. That is the right direction of rotation for a stock transaxle.

Now we get down to it, Julian is driving the the input shaft of the transmission directly instead of through the bull gears which reverses the input rotation, which means he may have the motor turning *counter clockwise* when looked at it from the brush end. So unless Julian is using the reversed ring and pinion set some of the diesels use to allow him to run the motor clockwise, he may be turning the motor in the wrong direction and running with 10 degrees retarded timing.

Julian please check this, It's one of those things so easy to miss. I can almost even see it happening 

*Whoops, the the transmission runs in reverse. AH easy to fix, just reverse this and this, see all fixed.* *Now lets get er out and see how she goes.*

I sure hope its something that simple. Drill and tap four new holes and done.

Jim


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## badfishracing (Dec 4, 2009)

Ok. Looking at actual motor data, the 9" puts out more torque than the 6.7
, And there's a lot more torque at 650 amps over 400 amps. So you'd be making about 2.5 times the torque. That makes sense now.



badfishracing said:


> Julian,
> 
> I forget what gear you said, but about 11:1 final? Wierd that I pulled 400 amps with a 32.2:1 and you pulled 650 amps with 3 times the gear? Or I need to find out what I'm doing wrong?
> 
> ...


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## JulsJunior (Jan 14, 2011)

> Julian please check this, It's one of those things so easy to miss. I can almost even see it happening


I have not changed the direction of rotation of my motor from when I had it in the ranger. I'm 100% sure of this. I know its going the right direction and what Darin said confirms this:


> When I moved up to 120V, I drilled another set of holes to get the timing advanced in the *oppposite* direction.


He is running thru exactly one more set of gears. Which means our rotations will be exactly opposite. He is running his reverse (or the same direction as the ICE Cub Cadets) I run mine just like in a car. A car does not have a reduction housing on it... It has 2 shafts like my transmission has in my tractor.



> So unless Julian is using the reversed ring and pinion set some of the diesels use to allow him to run the motor clockwise


Incorrect, we make those for the diesels that run *thru* the reduction housing yet, and there motor's turn the same direction as a car engine would. The Cub Cadet's (with the reduction housing) our OPPOSITE from "standard". So I made it "standard" with skipping the reduction housing.

Also- I checked the comm and it appears to be within .0005" ( I would have to break out the .0001" dial gauge if this is not accurate enough) and all the springs are within an oz of each other.


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## Jimdear2 (Oct 12, 2008)

JulsJunior said:


> I have not changed the direction of rotation of my motor from when I had it in the ranger. I'm 100% sure of this. I know its going the right direction and what Darin said confirms this:
> He is running thru exactly one more set of gears. Which means our rotations will be exactly opposite. He is running his reverse (or the same direction as the ICE Cub Cadets) I run mine just like in a car. A car does not have a reduction housing on it... It has 2 shafts like my transmission has in my tractor.
> 
> Incorrect, we make those for the diesels that run *thru* the reduction housing yet, and there motor's turn the same direction as a car engine would. The Cub Cadet's (with the reduction housing) our OPPOSITE from "standard". So I made it "standard" with skipping the reduction housing.
> ...


Julian,

Whoops, got my direction of rotation mixed up, (see what happens when you get old) Should have rechecked my premise before I opened my dang fool mouth.

Sorry I couldn't come up with an answer. 

If it wasn't just one set of brushes it wouldn't bother me so much. But then I don't have a lot of motor experience. The very last thing I can think of is the brush rigging is not truly at 90 degree intervals. That might require motor disassembly to check, I don't know how easy ADCs come apart.

It could be contactng the motor mfg. next will give you all of the answers. 

Another Idea (don't hit me . . . don't hit me)
I'm not sure, but I think Killacycle runs ADCs. If they do maybe a call or mail to them might give you an answer.

Hope you have as much fun with electrics as I have, I'll sure be watchng the progress. 
Jim


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## JulsJunior (Jan 14, 2011)

> Whoops, got my direction of rotation mixed up, (see what happens when you get old) Should have rechecked my premise before I opened my dang fool mouth.


Hey no problem! I just want to make sure we are all on the same page. It's tough to fix something if we are talking about two different things.



> The very last thing I can think of is the brush rigging is not truly at 90 degree intervals.


I would find this hard to believe, it looks like it is all on the same backing. I would think this is a mass produced thing. I hate to take it all apart.

I think is what I might do is get two new brushes to replace the really bad ones, run the motor on 12v for 48hrs and hopefully the new brushes will be seated in good enough for a thrashing on the track. Perhaps the 120v will help reduce the arcing... However, eventually I want to get back to 144v or maybe even jump it to 160v.

Maybe Major will put his two cents worth in when he gets on next.


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## Jimdear2 (Oct 12, 2008)

JulsJunior said:


> I think is what I might do is get two new brushes to replace the really bad ones, run the motor on 12v for 48hrs and hopefully the new brushes will be seated in good enough for a thrashing on the track. Perhaps the 120v will help reduce the arcing... However, eventually I want to get back to 144v or maybe even jump it to 160v.
> 
> Maybe Major will put his two cents worth in when he gets on next.


Julian,

Sounds like a plan, if you get no or less arcing on 120 volt and it comes back at 144 you'll know where your at.

Just keep it clean keep it run in between pulls to recoat the com, and have someone watch or video the runs.

It still bothers me that it's only one set of brushes. Hopefully someone who knows will chime in. There might be a perfectly logical reason.

Jim


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## major (Apr 4, 2008)

JulsJunior said:


> Maybe Major will put his two cents worth in when he gets on next.


Hi Juls,

Been on the road. Read most of this thread. I'll post a few comments. Difficult to solve something like this from afar.

I wouldn't replace the two brushes. Just sand off the pitted area. Reshape. Use crocus cloth or get a dressing stone. Then reseat all the brushes. I would not do anything to the comm surface.

I'd run many hours at 12V to seat those brushes. And try to get some higher current by running the motor on the tractor spinning the wheels in the air. Try to get the brush face to 70 or 80% shiny.

Hard to say why a single brush arm pitted on the trailing edge and was apparently responsible for the flash over. Positive and negative brushes behave differently. I'd look for a reason the two brush arms of the same polarity might not current share equally. Maybe the cross connector from the A terminal or in the connections from it to the pigtails. Consider beefing up that area.

I think it unlikely one holder would be off-90. But it is possible. Check to see it is not loose.

Maybe a few more degrees of advance would help. 

It is possible a better brush grade (material) would help. It sounds weird, but possibly a higher resistance brush would help. Maybe contact a place like this. http://www.helwigcarbon.com/products/carbon-brushes/electric-motor-generator-brushes.html Also look at some the info they have on the site. 

Here's another http://www.morganamt.com/us/Products/Carbon-Brushes.htm

The other thing......This voltage and load condition may be just too much for the motor for the time period. You may be pushing it to the limit. Nothing wrong with that. You just have to try improvements and keep it in the best condition, and maybe get creative. Jim Husted can help build motors like this to make them more likely to survive. 

That's about all that comes to mind.

major


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## JulsJunior (Jan 14, 2011)

> Just sand off the pitted area. Reshape. Use crocus cloth or get a dressing stone.


I was wondering if that would work, there is so much of the brush left I didn't think replacing it was completely necessary.


> I'd run many hours at 12V to seat those brushes.


This may seem like a novice question, but I don't want to break anything. Would it be alright to run a battery charger in parallel with the 12v battery? That would be upper 13v low 14v or so. I know a little voltage can go a long ways with these motors. Not sure how many amps that 9" will draw with 12v going to it either. Hope the battery charger can keep up.


> Consider beefing up that area.


Sorry for my lack of knowledge, but I would guess you are meaning add another wire to carry more current? Or more specifically, add another wire to the other brush holder that shares the current with the one that is pitted badly. In an attempt to make more current go to the brushes that appeared good? I apologize for not fully understanding these motors and then wanting to make it high performance, it was one of those deals where I thought I had my head wrapped around it better than I did when I started this project. But I guess its the best way to learn, and I'm doing it in a hurry!

Thanks for the pointers major! Those websites have a ton of good information. Plenty of reading material for the next week


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## major (Apr 4, 2008)

JulsJunior said:


> Would it be alright to run a battery charger in parallel with the 12v battery?


Yep. I use one of those big ones with wheels that will charge at like 60 amps. I get the motor rolling with the battery and then clip on the charger. 13, 14 volts is o.k. Just watch nothing overheats on long run-ins, like the clamps or cables.



> Not sure how many amps that 9" will draw with 12v going to it either.


Maybe around 50A.



> but I would guess you are meaning add another wire to carry more current? Or more specifically, add another wire to the other brush holder that shares the current with the one that is pitted badly. In an attempt to make more current go to the brushes that appeared good?


Increase the size of the cross connector cross sectional area. Increasing the ampacity, or lowering resistance. And eliminating any possible current bottlenecks which would cause a high resistance point between the A terminal and the brush. Just a few milliOhms at 100s of amps can cause a difference in the current division between the parallel paths to the brushes 180° apart. And then carbon has a negative coefficient of resistivity so the high current brush gets hotter, lower resistance and hogs even more current. 



> I apologize for not fully understanding these motors and then wanting to make it high performance, it was one of those deals where I thought I had my head wrapped around it better than I did when I started this project. But I guess its the best way to learn, and I'm doing it in a hurry!


No apology required. Pushing these things to and beyond the limit is risky even for the experienced idiot, oops, I mean racer. And I guess pulling is racing. I'm impressed with your efforts. Keeping pulling ahead.

From Bowling Green Ohio, home of the Nationals, Pull Town 

http://www.pulltown.com/

major


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## JulsJunior (Jan 14, 2011)

Alright, this is the post we have all been looking for. Today I decided to pull the end bell off of this motor. It was bothering me that only 2 brushes looked bad given all the input on this thread.

So I got to wiggling each brush holder and paying close attention to the plastic ring they are all attached to. I wiggled the one with the bad brushes and sure enough, the bolt was backed off about 1 round. When I checked the first time they all felt 'tight' but upon closer inspection, there was noticeably more movement in the holder that had the bum brushes. It wasn't floppy loose but it wasn't like the other 3 either. This might explain the anomaly in the brushes. I would have to gander that it was like this since day one. I just never checked before this time or have had video of the comm arcing to worry about it. This is the most amperage I have ever pushed through this motor since I've had it as well.

I think this should answer most if not all of the problems I'm having. I am going to touch up all the brushes and then re-seat them. Try and give this thing a fresh start. We will just have to wait and see how it goes at 120v. I think for the first pass I'm going to run the same gear ratio, so in theory I will go ~20% slower but still pull around 550amps mid track and 650amps at spin out. Try not to abuse it too badly right away... If all looks good I will try and push it a little harder the next day. I think to play it safe I will set my motor amp limit to 800amps. Seems like alot to be 'safe', but sometimes you just have to go for it and see what happens. I wanna get back to the wattage I was running at 144v


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## Jimdear2 (Oct 12, 2008)

Julian,

I am *so* glad you took the time to pull that brush end bell. It really bothered me that only one set of brushes was acting up. I'm glad that major gave you something real to look for.

A couple of thoughts while you have the brush rigging in front of you.

Clean, insulate, clearance, insulate, reinforce, insulate.

Also can I suggest that while you have the end off, you look hard at making adjustible brush rigging. Take some photos and measurements. Lots easier then drilling holes into the frame.

Last thought, think about some kind of runaway protection. If you don't want a tach look into the adjustible NOX rpm triggers. the restof the circuit is simple a sensor like below and a latching relay or circut. Here is an example of a RPM sensor that should work on your motor. I noticed you have a dual shaft motor.

http://www.evolveelectrics.com/PDF/NetGain/Speed%20Sensor%20Kit.pdf.

Spend A couple hundred or a couple thousand, your choice. You know your eventually going to break something.

Cant wait to see videos of the next runs.
Jim


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## Jimdear2 (Oct 12, 2008)

JulsJunior said:


> I think this should answer most if not all of the problems I'm having. I am going to touch up all the brushes and then re-seat them. Try and give this thing a fresh start. We will just have to wait and see how it goes at 120v. I think for the first pass I'm going to run the same gear ratio, so in theory I will go ~20% slower but still pull around 550amps mid track and 650amps at spin out. Try not to abuse it too badly right away... If all looks good I will try and push it a little harder the next day. I think to play it safe I will set my motor amp limit to 800amps. Seems like alot to be 'safe', but sometimes you just have to go for it and see what happens. I wanna get back to the wattage I was running at 144v


 Julian.

Just a heads up. Are you removing any batteries from the rear, if you do then don't forget your tractor is going to be a bit lighter that may mean less load, fewer amps, less voltage sag, more rpm.

All this new stuff is so much fun, makes you think again.

Jim


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## JulsJunior (Jan 14, 2011)

> Last thought, think about some kind of runaway protection.


I got my brother on that. He is going to rig up a little micro controller that will sense the RPM off of a sensor we are making. When it goes out of value, it will trigger a kill switch that shuts down the controller.



> Just a heads up. Are you removing any batteries from the rear, if you do then don't forget your tractor is going to be a bit lighter that may mean less load, fewer amps, less voltage sag, more rpm.


I am taking the two 'stacked' batteries off by the fenders. So yes it will be in gross weight, lighter on the rear wheels, HOWEVER, the problem I am going to have is that I'm going to be light on the front. So when the front end is up I will lose hitch height. So by taking weight off the mid portion and adding it to the front, it will actually give me MORE FORCE down on the rear tires, because I will have an effectively taller hitch when my front end is close to the ground and not 3' in the air. More hitch height means more force. I will have about 2500 ft/lbs of torque on the rear tires from all the weight ahead of the rear axle when the front end is off the ground. So if I can keep the front end down (close but not on the ground) I will be essentially 'wedging' the tractor in to the ground by way of: Maximum hitch height (Force in the y vector of tension on chain), Leverage of weights on front weight bar, just enough rear tire torque to lift the front end about 3" off of the ground. At that exact moment you will be putting the most force (down) on the rear axle. And the rear tires will be able to take peak power. However if any one of these factors are incorrect, you can still compensate with body movement on the seat. You still have to hit the setup close enough so that it is "driveable."

So I will actually increase traction, which means more load, more amps, more voltage sag, and less RPM. You can effectively get more power to the ground (and out of the pack). Which means you should go farther if your batteries can take it 



> All this new stuff is so much fun, makes you think again.


Tractor pulling is a beautiful expression of physics. And it changes from hook to hook on the track. Just staying ahead of what the track is doing is very difficult, and then making the right changes on the tractor is a whole other can of worms!


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## Jimdear2 (Oct 12, 2008)

JulsJunior said:


> I got my brother on that. He is going to rig up a little micro controller that will sense the RPM off of a sensor we are making. When it goes out of value, it will trigger a kill switch that shuts down the controller.


Julian,

Glad to hear that, I suggest that you look at shutting down the main contactor instead. 

A number of people have had a failure in the controller that in essence shorts the power section and gives you the effect of full throttle. By shutting down the main contactor you also have the option of an included Master kill button. 

I prefer a manual disconnect (all my tractors have one) but finding a manul breaker that will take 800 DC amps is hard and expensive. A TYCO Killavolt will safely break 1000 + AMPS A FEW TIMES.




JulsJunior said:


> I am taking the two 'stacked' batteries off by the fenders. So yes it will be in gross weight, lighter on the rear wheels, HOWEVER, the problem I am going to have is that I'm going to be light on the front. So when the front end is up I will lose hitch height. So by taking weight off the mid portion and adding it to the front, it will actually give me MORE FORCE down on the rear tires, because I will have an effectively taller hitch when my front end is close to the ground and not 3' in the air. More hitch height means more force. I will have about 2500 ft/lbs of torque on the rear tires from all the weight ahead of the rear axle when the front end is off the ground. So if I can keep the front end down (close but not on the ground) I will be essentially 'wedging' the tractor in to the ground by way of: Maximum hitch height (Force in the y vector of tension on chain), Leverage of weights on front weight bar, just enough rear tire torque to lift the front end about 3" off of the ground. At that exact moment you will be putting the most force (down) on the rear axle. And the rear tires will be able to take peak power. However if any one of these factors are incorrect, you can still compensate with body movement on the seat. You still have to hit the setup close enough so that it is "driveable."
> 
> So I will actually increase traction, which means more load, more amps, more voltage sag, and less RPM. You can effectively get more power to the ground (and out of the pack). Which means you should go farther if your batteries can take it


I'm an old aircraft mechanic, weight and balance and moment arm have a lot of meaning to me. I won my class ICE ultrlight class for 4 years running until someone kept buying bigger engines.

I'm glad to see you have a firm grip on the these weighty methods. (sorry I just had to). Wheelies are fun and impressive and another (Not very good)way to control traction on a sticky track, but I know you generally don't win with wheelies unless you have so much power you just don't care



JulsJunior said:


> Tractor pulling is a beautiful expression of physics. And it changes from hook to hook on the track. Just staying ahead of what the track is doing is very difficult, and then making the right changes on the tractor is a whole other can of worms!


Most people you meet think that tractor pulling is simple. A rubes game, Podunck City.

That is until they try it. 

It is not a race, it is an expression of planning, forethought and preperation. You against the track prep, you against the sled operator. You get one try. No pratice laps, no heating of tires, no making it up the next lap. 

The feeling you get when you get just the right line, just the right pedal off the line, catch or miss all the sticky spots, or the soft spots, or the slippery spots. Feel those tires hook in, feel the steering go light and know you got the 1 to 3 inches of float you weighted for. Control that sucker when the dirt does you dirty. The ride may only be 15 seconds or so, but the planning can take hours and the track can change in minutes and you have to start over.

I'm not writing this for you, you're convinced. I just hope more people will read it and understand.

Sorry, us oldpharts do run on don't we,
Jim


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## JulsJunior (Jan 14, 2011)

> A number of people have had a failure in the controller that in essence shorts the power section and gives you the effect of full throttle.


I'm going to break the 12v source the controller uses to run the contactor. It is also the suggested way to shut off the controller in an emergency situation according to the NetGain manual. From my understanding it cuts the amps off when it loses voltage as well, so it shouldn't be too hard on the contactor. Even if it were full amperage, I think the contactor would still be able to overcome it, or if the power section short circuits, this will still remove power from the contactor.



> Most people you meet think that tractor pulling is simple. A rubes game, Podunck City.


Sadly this is true. Once you start pulling it doesn't take long, even with mild competition, to see that it is not all that easy.


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## Jimdear2 (Oct 12, 2008)

Julian,

The following is probably old news to you, but in the spirit of shareing and making sure no one gets hurt. Some of this stuff should end up in the formal rules for electric class tractors in general. You are one of the people who will have a big influance on those rules.

For motor runaway stopping, breaking the contactor apply ciruit anywhere should do the job. If it also cuts the controller out as well, all to the better. I suppose this will be added to your safety tether shutdown circuit?

What ever interupting setup you use, make sure it requires a *positive dirver action to reset*. You don't need some trackworker reseating your tether plug and suddenly finding to your dismay thing are working again. Remember There Is No Noise Even Though The Tractor Is Fully Functional

Don't know how you feel about the *BIG RED BUTTON* or *HANDLE. *There has been a pretty spirited debate off and on in the EV community about this.

I and many others feel there should be, a readily identified, positive, mechanically operated, disconnect for the high voltage. It should be located in a place accessible to both track workers and driver. Both my electrics have one, So does Darin's. The new one we are building has one. 

I think that it should be able to safely open a fully loaded high voltage, high amprage circuit, but the kind of switchgear that can handle that kind of amperage is very pricy. I think we should settle for just a mechanical disconnect on anything over 36 volts. We don't need dead trackworkers. Believe me a 120 volts DC *WILL KILL* you.

Now a question to satisfy my curiosity. What kind of pickup will you be using for your RPM sensor? We used an industrial prox sensor and two pole reluctor on the three tractors we've built so far. I has a Zolox Hall sender on my D&D motor that worked well until I accidently damaged it. I sent you a link to the one made for the Netgain Motors. That one should work turnkey on your motor because I noticed you hace a tailshaft. Something else?

You said your brother was going to make up a board with a Micro Processor on it to do the control function, could you give us any more information on the operation? How will you recognize the signal? Will your rpm limits be hardware or softwear?

I see I've rambled on too much again, Think about the above safety functions/equippment,

Have a great day,
Jim


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## major (Apr 4, 2008)

Jimdear2 said:


> Julian,
> 
> The following is probably old news to you, but in the spirit of shareing and making sure no one gets hurt.


Jim,

I'll follow up on this. When it comes to racing, my priorities:

1.) Safety
2.) Rules
3.) Winning

It ain't worth somebody gettin' killed or crippled.

In the TTXGP the "big red button" kills the controller and main contactor. And to verify that, there is a bright visible red flashing light "on" whenever the system power is such that the machine could be powered. I suggest this "on" flashing light. It is tested by the track safety official before each run.

On the main power circuit, if I was in the seat, I would have redundancy. Two main line contactors in the battery circuit, independent of each other. Each capable of breaking maximum V & I.

Regards,

major


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## Jimdear2 (Oct 12, 2008)

major said:


> Jim,
> 
> I'll follow up on this. When it comes to racing, my priorities:
> 
> ...


Major,

So in the TTXGP whenever the traction battery power is ON outside the battery case there is a flashing red light. 

*I Like It* (I'm always leaving the power switch on anyway)

Do you specify in the rules a location for the Big Red Button? Do you specify location(s) for the main contactor?

I notice a lack of comment on the mechanical disconnect. Do you feel that electrical control of the power disconnect is adequate?

Redundancy is always good. But there are two problems weight and cost. Two independant contactors at the $60.00 to $100.00 that the TYCO EV200 is currently going for isn't too bad, but when you get into BUBBA range OUCH. 

But I guess if you're going to play with the big boys you need to pay like the big boys.

Have a goooooooooood one,
Jim


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## JulsJunior (Jan 14, 2011)

> It ain't worth somebody gettin' killed or crippled.


 I agree! Quick question on these motors, my understanding is that the comm bars will "lift" in an over-rev situation. Does this mean they come flying out of the motor (danger to bystanders) or do they simply come up and pretty much destroy the brushes and all that stuff? It is tough to fully police the class if others start building these, so what we do with the ICE motors (due to the high performance mixed with homemade items) We simply mandate shielding in the areas where connecting rods and driveline components could exit the tractor. On my motor I shielded the cast aluminum fan, however, I do not know what might happen on the other end of the motor at high RPM's. If they do fly out of the motor, how much shielding would be adequate?

As far as the electrical safety, perhaps mandating a specific brand contactor that would be suitable for anyone in the class (something that would handle the loads I am running.)? I am running the Albright SW-201. I think that is sufficient... That way it is easy to tech and insure that (whether they have it wired right) it can break the load. We check that kill switches work before they are allowed to hook to the sled, so it would be easy to see if the contactor disengages when the switch is pulled.

Here are the current rules:
All other general rules apply.
H) Battery Electric powered garden tractors rules:
1. Motors must have a motor shield, minimum 1/8 inch
steel, 3/16 inch aluminum.
2. Each battery or battery pack must be secured with bolts
and/or straps commensurate with the size and weight of the battery.
3. Flooded batteries must be completely enclosed. AGM or
Gel batteries do not require this.
4. All traction wiring must be isolated from the chassis.
5. All battery packs must have over-current protection. Circuit
breakers or fuses permitted. Device must have a DC voltage
rating equal to or greater than the nominal pack voltage.
6. All tractors must have a visible indication of a ‘live’ tractor.
7. Traction battery pack must be physically disconnected
when switch is in the off position. Electrically or mechanically
operator contactor is allowed. The “kill switch” or safety contactor
may not routinely open or close under load. Semiconductors or
controller shutdown are not sufficient.
8. Must get power only from the batteries while the pull is
in progress (no Hybrid Designs)
H.) Weight is 1100 Lbs.


The rules I will be tentatively adding for next year:
A.) Rule Number 5 would require the fuse/circuit breaker to cut the pack in approximately 1/2 the voltage when activated. (I thought it was in there that way already, must have missed that).
B.) Batteries must be of lead based chemistry. <The reason for rule B, is that I don't want someone to spend a whole ton of money on some nice lithium's and ruin the class. Its no fun when it breaks the bank to go pulling... AGM should be sufficient to beat all the ICE motors anyway  

Obviously the rules are pretty minimal at the moment. Most all of them are safety. If you can think of something obvious I am missing please let me know. I can implement safety changes at any point in the season. I don't know of anyone building one that will be running it yet this year. So at the moment, I just have to make sure I don't kill anyone.



> What kind of pickup will you be using for your RPM sensor?


I think we are going to use an optio-interrupter that is looking at an encoder wheel I am going to make. The original intent of making it so accurate, is that we were going to actually measure and calculate the acceleration of the armature. So it could actually shut the motor off at any RPM, it just has to accelerate fast enough, and it would also have a maximum RPM cut off value as a back-up. However, we were having some interference with the controller/motor at low throttle (most amount of switching occurring in the controller/motor), so we are putting it into a shielded cable. At first we will probably just do a simple max RPM value, then work on calibrating it to the encoder wheel and setting up the acceleration cutoff part of it.

It seems like overkill, but its a good learning experience for my brother and it gives me peace of mind (kinda... just hope he does it right lol). But we are going to test it on the CNC machine where you can adjust the spindle speed +/- 1RPM. So it should be accurate enough for calibrating.


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## DIYguy (Sep 18, 2008)

JulsJunior said:


> I got my brother on that. He is going to rig up a little micro controller that will sense the RPM off of a sensor we are making. When it goes out of value, it will trigger a kill switch that shuts down the controller.


Hey Juls, just my 2 cents...but why use a micro controller as part of your tacho-generator? I'm not a big fan of over-complicating critical circuits (or most things  ) An inexpensive low voltage industrial proximity sensor is all that is really required. U definitely need rev limiting.

cheers.


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## major (Apr 4, 2008)

Jimdear2 said:


> Do you specify in the rules a location for the Big Red Button?


I think the TTXGP rules do specify the kill button and flashing light locations. Rules are available on their website.



> Do you specify location(s) for the main contactor?


I think the rules don't specify the physical location on the bike, but do for the location in the circuit.



> I notice a lack of comment on the mechanical disconnect. Do you feel that electrical control of the power disconnect is adequate?


I'm not sure the rules address this. But from what I see, most have a service disconnect, but not one which could be pulled by the rider or corner worker. IMO, this is adequate.



> Redundancy is always good. But there are two problems weight and cost. Two independant contactors at the $60.00 to $100.00 that the TYCO EV200 is currently going for isn't too bad, but when you get into BUBBA range OUCH.


The EV200 has an interrupt rating of like 2,000 amps*, 1 or 2 times. (From memory. Check the spec sheet.) With a redundant installation (like one in the positive battery line and the other in the negative or midpack), I feel this is enough. However, carry spares. Once you break full current you need to replace the contactor.

I worry about the Albrights. There the spec sheet has them rated at 48V, or 96V with the blowouts. The contactor looks robust and I like the idea of visual inspection of the contacts, however this negates the vacuum. But just the low voltage specification would have me, at the minimum, backing it up with a kilovac type rated for full voltage.

Be safe,

major


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## major (Apr 4, 2008)

JulsJunior said:


> Quick question on these motors, my understanding is that the comm bars will "lift" in an over-rev situation. Does this mean they come flying out of the motor (danger to bystanders) or do they simply come up and pretty much destroy the brushes and all that stuff?


Yep, it is possible the comm bars will exit the motor as high speed copper bullets during a catastrophic failure at speed. It is uncommon, but possible, and all it takes is one 

At minimum, some scatter shield should be in place to confine parts to within the vehicle or within the motor itself. The steel coverband which comes with most motors is sufficient.

major


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## JulsJunior (Jan 14, 2011)

> The EV200 has an interrupt rating of like 10,000 amps, 1 or 2 times. (From memory. Check the spec sheet.) With a redundant installation (like one in the positive battery line and the other in the negative or midpack), I feel this is enough. However, carry spares. Once you break full current you need to replace the contactor.


I was looking into this contactor:
http://www.gigavac.com/products/contactors/datasheets/gx200/comparison/index.htm

The link is the comparison page to an EV200. I like this contactor because it is sealed and also has a terminal cover. By the numbers it looks like it should work.



> It is uncommon, but possible, and all it takes is one


This is true, I will mandate a minimum of .03" Aluminum motor band around the commutator end of the motor. With ventilation holes allowed. We don't need anyone getting hurt and the insurance going up...

I appreciate all the input!


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## badfishracing (Dec 4, 2009)

Your rule #1 is 1/8" steel, 3/16" aluminum. I forget where this came from. 

I don't know if the NHRA rule is the same, but for the NEDRA Jr. Dragster rules, they require:
.024" steel
.032" aluminum
.120" lexan
over the motor. I think this is mainly for the commutator area.
I believe the KillaCycle has lexan covers, with cooling slots. I think this would be enough to slow down a flying comm bar.

I think my machine is lacking in this area.

Darin





JulsJunior said:


> I was looking into this contactor:
> http://www.gigavac.com/products/contactors/datasheets/gx200/comparison/index.htm
> 
> This is true, I will mandate a minimum of .03" Aluminum motor band around the commutator end of the motor. With ventilation holes allowed. We don't need anyone getting hurt and the insurance going up...
> ...


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## JulsJunior (Jan 14, 2011)

> Your rule #1 is 1/8" steel, 3/16" aluminum. I forget where this came from.


Yea, I know that is excessive (atleast for the comm). So I am going to state that the comm end only needs the thin material (NEDRA specs you posted). The 1/8" steel, 3/16" aluminum is the flywheel shielding required for the ICE motors. I know they have some sort of cast "fingers" on the ADC on the fan end bell, to act as a stopping force in the event that the fan would de-fragment in a high speed run away event. But I shielded mine to the aforementioned spec for the fact I didn't want to lose a leg if that fan decided to let go. I think I will mandate the flywheel shielding for that end of the motor.


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