# Silent Scream build thread



## major (Apr 4, 2008)

winzeracer said:


> *However I am interested if anyone has experience with Agni's and what their pitfalls are?*


I've never used one myself, but I have seen many Agni fail on the track. Main problem is comm and brush burnout. Also problems with rotor to shaft coming loose. This experience has been on eMotorcycles where they often used two motors. 

With eKart racing, a lot of the teams using brushed PM motors had durability trouble. AC drives prove more reliable and stronger performance-wise even though a few pounds heavier.

I don't know what your intended venue is, but you should buy a spare Agni or 2


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## winzeracer (Apr 3, 2012)

Major,

What types of motors does your team use? What are the advantages/disadvantages of them?


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## major (Apr 4, 2008)

winzeracer said:


> Major,
> 
> What types of motors does your team use? What are the advantages/disadvantages of them?


Our bike used AC induction first season and then went to Remy IPM, up in the 100 to 160 kW range. The eKarts (both of them) run the AC15 package but are limited by series rules to 14 kW for the 100 lap race. Without the power limit rule, the AC15 could exceed your stated kW.


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## winzeracer (Apr 3, 2012)

major said:


> Our bike used AC induction first season and then went to Remy IPM, up in the 100 to 160 kW range. The eKarts (both of them) run the AC15 package but are limited by series rules to 14 kW for the 100 lap race. Without the power limit rule, the AC15 could exceed your stated kW.


Where can you buy remy's at? Trying to find more info on them but thier website is not particularly helpful.

Have you ever burned up or over-speed any AC motors? Is this common when using AC for race applications? I ask because it does not seem to be something that is easily repaired. One other AC question it is hard to find data on what is different from an AC-9 and an AC-15 are they actually different motors? Or just diff controllers? If you look here http://www.evolveelectrics.com/High Performance AC Motor.html it looks like there is more than just controller difference.

You got me with that buy a couple extra Agni's tho, those puppys are not cheap it is not likely I can afford an extra or two. Trying to balance the weight so that the kart still turns nicely with EV motors build for small cars can be a challenge.


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## major (Apr 4, 2008)

winzeracer said:


> Have you ever burned up or over-speed any AC motors? Is this common when using AC for race applications? I ask because it does not seem to be something that is easily repaired. One other AC question it is hard to find data on what is different from an AC-9 and an AC-15 are they actually different motors? Or just diff controllers?


Remy is big for a kart and with controller would bust your budget.

The Curtis has 300 Hz limit, so 9000 RPM max for the 4 pole motor, which they are. As induction motors, they have a die cast aluminum cage over steel core rotor. It likely could stand 20,000+ RPM. They are equipped with thermal sensor and I have seen thermal cutback on the track making enhanced cooling methods used. 

Actually the induction motor (AC15) is much, much easier to repair than an Agni. And I think the AC15 motor is same size as AC10. Don't know about AC9. And AC20 is about 1.5 to 2 inch longer than the AC15. Of course a variety of choice with Curtis 1236/8 family w/r/t voltage and current.

The wound field motors can tolerate overload and abuse a lot more than PM motors, especially brushed versions. AC PM (or BLDC if you like) can work better, but look at what Ripperton went through with his. The PM motors boast better efficiency and lighter weight, but that doesn't do much good when they are in pieces lying on the track.

I'm sure a lot disagree with me. I speak from experience of hard racing. Casual users may do just fine with 'em


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## winzeracer (Apr 3, 2012)

major said:


> The wound field motors can tolerate overload and abuse a lot more than PM motors, especially brushed versions. AC PM (or BLDC if you like) can work better, but look at what Ripperton went through with his. The PM motors boast better efficiency and lighter weight, but that doesn't do much good when they are in pieces lying on the track.
> 
> I'm sure a lot disagree with me. I speak from experience of hard racing. Casual users may do just fine with 'em


Just read half of the ripperton novel, lots of motor nightmares and crazy custom magnets, sounds a little intense. I have a couple more years in school before I will understand all of that. The lighter PM motors did have me going untill I read all of that. Now I am not sure what I want to do.  I guess I am still stuck between Agni 111rdr and AC-12 or 15. If it was not for weight I would jump on the AC bandwagon.

But thanks for the great suggestions, i will keep reading.

Do you have any links on these AC-15 eKarts?


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## major (Apr 4, 2008)

winzeracer said:


> Do you have any links on these AC-15 eKarts?


http://www.diyelectriccar.com/forums/showthread.php?t=74048 

My report this year. It contains a link to previous thread showing kart details.


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## winzeracer (Apr 3, 2012)

Well I have been learning more about the AC-15 setup key points of this setup are:

-82ft/lb torque
-46 lbs (motor)
-Quality Controller with decent software
-Regen
-Reliability ++
-possibly easier to work on than Agni
- cheaper than Agni with Soliton Jr ( though I may use the 1000 amp Revolt)

This is what the Agni 111rdr has going for/against it:

-~65ft/lbs (estimated from 95r specs might be hopeful  )
-26 lbs
-no regen
-does not have matched controller ( less reliabilty more room for error)
-more money in motor/controller combo

But that extra 20lbs (5% of total weight) really gets me. I mean in a 2500lb race car this would be 125lbs. Ask any racer if he wanted to shed 125lbs he would immediately grab his wallet! I just like the idea of having a lighter more nimble car.
I get that it looks like the stronger case is for AC but I am having a tough time making the jump. Any thoughts that may sway me on way or the other?


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## MalcolmB (Jun 10, 2008)

winzeracer said:


> Any thoughts that may sway me on way or the other?


There's this: http://www.diyelectriccar.com/forums/showthread.php/luigi-goes-electric-fiat-500-r-65753.html

and this: http://ideas.egrandprix.com/viewtopic.php?p=85
(just scroll through to read comments by Cedric Lynch, designer of the Agni motors).

Like Major has pointed out, the Agni is less forgiving of racing abuse, but they've learned a lot from their racing participation. They had a problem with brush quality, which they've now sorted out, and the brushes on new Agnis are said to be carefully matched to ensure consistent wear.


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## major (Apr 4, 2008)

winzeracer said:


> But that extra 20lbs (5% of total weight) really gets me.


You know? The experience I related previously was with motorcycles using 2 Agni motors.


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## winzeracer (Apr 3, 2012)

So I have decided to stay with DC for now. So the next debate begins

Soliton JR VS. Kelly PM regen ( http://kellycontroller.com/racing-controller-kdh12101e24-120v1000a-pm-with-regen-p-757.html )

I really like the relaibilty modern interface of the soliton but there is no regen.

The Kelly is not my favorite b/c they are just not great quality thus why I would way over size it and go with the 1000a even though I would only ever max out at 600a. But having an "engine break" may be a great advantage on the track.

What are your thoughts?


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## winzeracer (Apr 3, 2012)

winzeracer said:


> So I have decided to stay with DC for now. So the next debate begins
> 
> Soliton JR VS. Kelly PM regen ( http://kellycontroller.com/racing-controller-kdh12101e24-120v1000a-pm-with-regen-p-757.html )
> 
> ...


This was answered in the controller section. See link if you are interested.
http://www.diyelectriccar.com/forums/showthread.php/soliton-kellyi-75741.html

On another note the motor is on it's way from the UK!


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## winzeracer (Apr 3, 2012)

New motor Pics! Serial #15


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## Karter2 (Nov 17, 2011)

Winzeracer,
What class of racing are you intending to run in with this kart ?
( Ignoring any problems with being allowed to run by controlling bodies !)
50 kW is a lot of power on a kart, right up there with the top 250 "gearbox" class, which is a rare class to find anywhere.
Most common kart classes are the 125cc "TaG" class who run at around 25 kW, so i dont imagine they will be too keen on you joining in ( highly unlikely anyway as they have very strict tech regulations which you cannot meet)
So, where will you race ?.. do you have an Ekart series in your area?,....or will this just be a fun ride ?
...and if it is just a fun ride, why are you intending to carry so much battery ?
Weight is a killer on a kart,..as you noted with your concern over the motor weight,... but here you are planning to haul around a truck load of CALB ???
Why didnt you look for a lighter pack chemistry ?


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## winzeracer (Apr 3, 2012)

Karter2 said:


> Winzeracer,
> What class of racing are you intending to run in with this kart ?
> ( Ignoring any problems with being allowed to run by controlling bodies !)
> 50 kW is a lot of power on a kart, right up there with the top 250 "gearbox" class, which is a rare class to find anywhere.
> ...


No CALBs that was my old design, new design is going to use turnigy nanotechs or hayin, both are lipoly. Not sure if it will fit into any class, it is really a research and learning experiment, for building an actual race car. I don't know of any ekart series in my area, but there might be one. Do you have an ekart? What are the specs?


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## Karter2 (Nov 17, 2011)

Ahh !.. Nanotec.. good move. ( better than the Haiyin too !)

no, no Ekart here, but several ICE karts , Ebikes, and several planned Ekarts !
The problem with Ekart is finding somewhere to race as tracks & clubs are reluctant to let "unusual" kars onto their tracks ( PL insurance etc) and also the battery run time issue.
Even with a lower powered Ekart ( 10-15 kW ) you still need a large and expensive pack of lipo to have a 20 min run time, 
You also need access to a decent , reliable, power supply at the track and a fast charger ( more expense), to recharge.... or another pack to swap in, ... to get you back on the track within an hour or so.
All in, not a very appealing option when a $300 ICE motor and $10 of fuel can keep me racing all day at the track without having to haul batteries, chargers , etc around.


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## winzeracer (Apr 3, 2012)

Karter2 said:


> All in, not a very appealing option when a $300 ICE motor and $10 of fuel can keep me racing all day at the track without having to haul batteries, chargers , etc around.


Yep, ICE racing is spendy, EV racing is just GREEDY! haha. This thing will be a beast when complete. It may just end up being for exhibitions, who knows. If you build it they will come right? I will have a quick charger for the track, and will rent a generator for the day when taking it out.


In other Silent Scream News...

I have been working on the motor mount design, and have a friend that works at a high end race shop with a CNC, so this will be one functional and cool looking mount, plan to have the new Winz E-Racer logo on it ( not yet in existence). It will be a great learning experience to go to the shop and help (watch) programming the CNC.


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## winzeracer (Apr 3, 2012)

Preliminary motor mount with slot for chain tensioner. Still need to add holes to the outer ring for outer motor bolts. I am thinking 1/4" aluminuim, any reasons why I should go to 5/16" aluminium?


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## winzeracer (Apr 3, 2012)

Here is the Video of the Motor Bracket programed into MasterCam, please ignore the Starbucks girl and terrible music in background 

http://youtu.be/7Fn9XoknDPY 

My friend Josh that is helping with the CNC work has a car that could be appricated even by EV Heads

http://youtu.be/7BcQqegUjtM 

We will be cutting the bracket out on Thursday. I also ordered half of my Turnigy Nanotech 35C constant batteries so that I could start putting together one of the modules for one side of the car.


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## winzeracer (Apr 3, 2012)

I recived my first batch of batteries for my right bank which will be 18s4p 66.6v 20ah, my left bank which I will purchase soon will be 12s4p 44.4v 20ah, for a total pack of 30s4p at 111v 20ah, these packs are rated for constant 35C I will never go over 30C MAX, I wanted to have plenty of "buffer" since these rating apply for RC cars. The continous rating for the Agni 111rdr with liquid "mist" cooling is 30kw which at ~100v and 300 amps I would only hit 15C. I also recived my HVC/LVC boards from Patrick at Methtek.com 

I am planning on building 12 or 14 gauge steel boxes to hold the lipolys and HVC/LVC system, I am building my own copper busbars for paralling the High Voltage. More on that later... I will also be buying a PL8 or 2 for charging and testing batteries.
Here are some preliminary battery pics.


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## Karter2 (Nov 17, 2011)

Looking good.!
What on track run time are you expecting from that pack ??
Chargers ??PL8's are V nice but also V spendy ! 
+ you will need some beefy 24v power supply to feed them.
Also it will still take 2+ hrs to recharge the 2kW pack
Why not just go for a direct high power "Bulk" charger, or even make one from server power supplies. Cheaper and more powerful.


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## winzeracer (Apr 3, 2012)

Karter2 said:


> Looking good.!
> What on track run time are you expecting from that pack ??
> Chargers ??PL8's are V nice but also V spendy !
> + you will need some beefy 24v power supply to feed them.
> ...


I am not sure about runtime yet, I can add more kwh if needed, the PL8 will just be for testing and charging at home. I am leaning toward the the 10kw EMW charger for bulk charging at the track. I still have more research to do on bulk charging and on the 10kw EMW charging, I plan on reading the very LONG thread on this charger soon.

Do you have a build going on? Have any Lipoly experince?


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## ricklearned (Mar 3, 2012)

I have two meanwell 48v 10 amp chargers running in parallel giving me almost 115 volts. I went with this approach because it was cheap and I could get some experience before investing in an expensive charger. I also have a PL8 and it I like it very much.


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## winzeracer (Apr 3, 2012)

Rick,

I have been following your progress, looks like you are making great headway! I am headed out of town for a couple Weeks but I still want to come down and check our your car. Thanks for the tip in the Meanwells, for now I will just charge with PL8, relatively small pack in comparison to a normal car so PL8 will suffice untill I learn more about bulk lipo charging.


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## Karter2 (Nov 17, 2011)

winzeracer said:


> Do you have a build going on? Have any Lipoly experince?


 Several Ebikes in various states of use.
I run 10s 3p Turnigy Lipo, and mostly bulk charge to 4.1 v/cell, but monitor all cells using cell logs.
I Ballance charge only if a cell gets much more than 50-75 mV out of wack.
If lipo is new to you, make sure to read all the "care" advice and find a fireproof place to store /charge ...just in case !
Its very unforgiving to an innocent mistake !


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## winzeracer (Apr 3, 2012)

Karter2 said:


> Several Ebikes in various states of use.
> I run 10s 3p Turnigy Lipo, and mostly bulk charge to 4.1 v/cell, but monitor all cells using cell logs.
> I Ballance charge only if a cell gets much more than 50-75 mV out of wack.
> If lipo is new to you, make sure to read all the "care" advice and find a fireproof place to store /charge ...just in case !
> Its very unforgiving to an innocent mistake !


Where do you store your lipo?


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## Karter2 (Nov 17, 2011)

winzeracer said:


> Where do you store your lipo?


 In a steel box, in outdoor garage. ( no cars in there either)


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## winzeracer (Apr 3, 2012)

Karter2 said:


> In a steel box, in outdoor garage. ( no cars in there either)


Hmm, I think I am going to go get a steel box and a welding blanket after work.  Thanks for the tip.

I would bulk charge at the track and every time the car came home it would get balance charged. So, say They were charged a max of 5 times at the track, would you still recommend using cell logs? even though they would get balance charged every 5 charges? And have HVC/LVC to keep proper voltage ranges.


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## Karter2 (Nov 17, 2011)

No , i wouldnot expect the ballance to go off much after 5 cycles, or even 10 or more , but charge ballance is not the only concern. 
Its wise to have some means of quickly checking individual cell voltages...or at least voltages of paralleled cells, even when not charging . Cell logs are good for that . ( Battery Medics are also an option)
Lipo is good, but not infallible.
EG. Most Turnigy lipo users expect to have a 5% ( 1in 20) failure rate in new packs ! ...so expect to find duds and order spares !
One bad cell in a series string can cause a major event both during charging and also during discharge.
Make sure you check, test, and cycle, each "brick" before you assemble the full 18s 4p pack. Look for any weak cells with uneven voltage profiles.
Also make sure your packs are well supported on the kart with some form of vibration absorber material.
A kart has no suspension and everything onboard is subject to major shocks.
Even industrial AGM lead acid batteries fail rapidly on karts due to vibration...you dont want any damage to that lipo pack whilst on the track !


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## winzeracer (Apr 3, 2012)

Karter,

Thanks for all the input. I have decided on a battery goal, of 20 minutes runtime, 20 minutes charge time. For this I think I will run 30s5p for 111v 25ah, which will give me a bit better run time and the cells will run lower C rate discharge for better longevity and stability.

After some more advice from Jozzer, I will probably run 40kw max with liquid spray cooling into the motor. So roughly 400 amp max for now( maybe push it harder after lots of testing) So that would be only 16C discharge. I am still happy with my battery choice, I would not feel comfortable pushing the 20C non nanotech's that hard.

For charging I would like to charge at 80 amps ( 3.2C) with the 10kw EMW charger.

As for pack construction, I am leaning toward a thin outer steel box with a layer of Anti-Vibration Flame resistant material that I found. Possible with an inner steel box and have the "bricks" individually wrapped in fiberglass (welding blanket) material. This way if one cell gets overcharged, or over discharged by mistake it will not send the entire pack up in smoke. This may be overkill but it will be safe and I hope effective at keeping the driver and bystanders safe. I bought some copper bar .75" X 1" to build buss bars out of, I want to leave the factory bullet connectors on the batts so that I can balance charge with the PL8 ( I ordered it ut they are out of stock) when at home. I will have short pigtails off the bullet connectors to the bussbars. *I will probably go with some high quality terminal end ring connectors and bolt them to the buss bar. Will I end up with too much Resistance through the ring connectors? The ones I am looking at are copper however they are still crimp connectors. So I have some reservations about them. Any suggestions on better connectors? * I though about trying to mate bullet connectors to the bussbars like Jozztek's but it looks labor intensive, and buying all my bussbars from Jozz would cost around $500, I bought my copper for $80.

Well that is enough for now.


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## Karter2 (Nov 17, 2011)

winzeracer said:


> For charging I would like to charge at 80 amps ( 3.2C) with the 10kw EMW charger..


 What will you power that charger from ?.
..few kart tracks will have a 10kw ( 3 ph ?) supply available , and that would be one large genny to carry with you !


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## winzeracer (Apr 3, 2012)

Karter2 said:


> What will you power that charger from ?.
> ..few kart tracks will have a 10kw ( 3 ph ?) supply available , and that would be one large genny to carry with you !


Yes it will be a large generator, with a 240v 50a outlet. I will rent it from a tool rental company for the day, since they are about $3k-$5k to buy.

I have also ordered some 5.5mm an 6.5mm bullet connectors to test and see how I might mount them directly to the copper buss bars that I am building. I am hoping that they will provide low resistance and thus low heat at bussbars. I am also looking into other BMS options.


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## winzeracer (Apr 3, 2012)

I have been working on the pack design, for more on that see Lipo Pack Build in batteries and charging ( http://www.diyelectriccar.com/forums/showthread.php?p=315115#post315115 )


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## winzeracer (Apr 3, 2012)

Here is my first attempt at bussbars with 6.5mm bullet.connectors. More on this later.


EDIT: I am going to drill these out on the CNC for better accuracy, hand drilling was not lining up perfectly. I have a date with the CNC machine tommarrow for the Motor mount and the bussbars Very excited about this!! Pics on that to come soon.


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## winzeracer (Apr 3, 2012)

So the motor mount is now complete! And is is pretty bad ass, those machines are truly amazing. Notice in the close up how great care was taken not to cover air holes into the motor. I built the chain tensioner slot into the mount. BIG THANKS to Josh Ogle Fabrication for making this come true.


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## ricklearned (Mar 3, 2012)

That is some nice CNC work.


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## winzeracer (Apr 3, 2012)

ricklearned said:


> That is some nice CNC work.



Thanks Rick. I did the 2D profile in AutoCad and the Josh put it in Solidworks and we did some nice work under the motor to allow maximum air flow into the motor. I am very happy with the results. I will get it bolted up to the frame this week. Also this week I should make good progress on the Battery Pack. We also punched all the holes in the bussbars with the CNC and I fitted the connectors into them. I have some high temp silver solder to make sure that the bullet connectors stay in place. My steel battery boxes which I had made by one of our fabricators at work will be delivered on Monday. What I really need to do now is test and cycle all the cells and group them by IR and Capacity, the ones that are the closest matched will go into each 5p module( maybe 6p) there will be 5 modules dispersed on the kart.


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## pitts12driver (Jul 22, 2009)

Hi there -

I've been down this path. I converted a CRG Kali last year using an reinforced Agni 95, 72V 32Ah 38120P cells, and a Kelly controller. I built custom kevlar battery boxes, and it came out great.

It will easily outrun a Rotax 125 - have never run it against a shifter. I had to talk my way onto the track. About the only place it's been welcomed is at an autocross event.

Fun, expensive, but looking back on it, I'm not exactly sure why I built it!

Adam


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## winzeracer (Apr 3, 2012)

Pitts,

Kevlar hmm... cool idea I may look into that. I had some steel boxes built at work but they were to heavy ( which I kinda knew would happen). I was going to go Aluminium but I may look into Kevlar. Where are you located would be great to run them head to head one day.  

I am building this as a fun project to learn lots about High Performance Ev's at the fraction of the cost of full size Ev race car.

Do you have pics or a site that I can check it out?


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## Arlo (Dec 27, 2009)

Very nice work!


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## winzeracer (Apr 3, 2012)

Thanks Arlo! I am working on the Carbon/Kevlar battery boxes now( Thanks to Pitts for the idea). Pics to come, though I have another thread for the pack build in the Batteries and Charging section.


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## winzeracer (Apr 3, 2012)

Well I am certianly a composite amature, here is what I have learned so far. The basic process for building a custom Caron Fiber or Kevlar peice is:

1) Build a foam block of the shape you need, for me this was my batt box
2) Then Fiberglass that box
3) the fiberglass then becomes your mold for the CF

So far I have not been able to get past the first step  
The first mistake I made was I bought a 2 part foam a boat store, this foam does not melt with acetone, which is the easy way to remove the foam from the fiberglass. So that was a hundred buck down the drain. Then I bought sheet foam at Home depot which does melt with acetone. I spend 3-4 hrs shaping the foam, and had some divots I wanted to fill. I had read that you need to paint the foam first or the bondo will melt the foam, so I used spray paint which I thought I had read was ok, however spray paint contains acetone, which of course melts the foam. Then I tried to save that but just turned the whole thing into cottage cheese. So If you are attempting this yourself, realize that there is a steep learning curve.

I will qualify this with the fact that I have been working on cars all my life and am fairly savy but I had ZERO composite experience. I am determined at this point to get this to work. More to come.


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## Duncan (Dec 8, 2008)

Hi Winz

Something you should be aware of 
Carbon Fiber is only stronger/lighter than fiberglass IF you can maintain a good fiber/resin ratio which is almost impossible in a wet lay-up
(You may have notices carbon fiber does not "wet" as easily as glass)

S- Glass and epoxy will give a better weight/strength ratio - and its a lot cheaper!

Kevlar is not as strong as glass - but it is tougher - 
basically in use it's weaker but in case of an accident it will absorb more energy as it fails
Not sure that is useful in your battery box


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## aeroscott (Jan 5, 2008)

If you use epoxy it won't melt the foam , stronger too. When you have witted out the cloth put in a plastic bag , then a bleeder cloth then another plastic bag tape this up to a vacuum cleaner . google, vacuum bagging , peal ply, amine blush , epoxy safety . with bagging you can do some nice work


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## kerrymann (Feb 17, 2011)

winzeracer said:


> Well I am certianly a composite amature, here is what I have learned so far. The basic process for building a custom Caron Fiber or Kevlar peice is:
> 
> 1) Build a foam block of the shape you need, for me this was my batt box
> 2) Then Fiberglass that box
> ...


If you are only making a one or two parts you do not need to make a separate fiberglass tool for the part, you can just seal and release the foam (called a master). But in your case the fiberglass will be good practice before you make the part. You also don't typically melt the foam master away unless it has trapping features. Just put a few degrees of draft on the sides and seal and release the wax which gives you more material options for the foam master. If the part/tool is stubborn then water and or air forced between the part and master should pop it out. 

Also one general note is that I understand to cool factor for CF but it's not the ideal for a batter box and it has a steeper learning curve as it doesn't wet-out as easily as FG. CF is conductive so I highly recommend a ply or two of FG or armid (kevlar) as a non-conductive barrier.


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## madmike8 (Jun 16, 2011)

I do some r/c planes out of foam. You can use minswax water based polycrylic out of a spray can or brush on. If you use the spray can on the foam then fog on the first couple coats and then you can spray normally. Btw normal household spackling works good to fill dents and doesn't eat foam... Cheaper than bondo too...


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## winzeracer (Apr 3, 2012)

I did have a bit of success with the fiberglass mold, and it was a good learning experience. I played with a piece of the Hybrid fabric, felt pretty strong with just wet layup, I would like to vac bag it but its not really going to happen for now. As for the bit about CF being a conductor, alternatively I would have built the boxes out of AL so not really an issue my cells are all insulated with plastic wrap around the 6s Bricks anyway. But thanks for the heads up, I had considered it but it wont be an issue.

I am back in school now so the project moves REAL slow, but it looks like I am going to be running the Synkromotive Controller, should have funds to buy in a few more weeks or so. The Soliton Jr was not going to fit. I will be charging at HIGH rates with this controller, from an external battery pack and some sort of inductor between the external pack and the controller. Should be able to charge at 15-20kw( at the track ) This eliminates the need for large generators and for the EMW 10kw charger. I will just need to charge up the external pack at home, and take it with me to the track. The external pack will need to have atleast 10kwh so that I can get a few charges at the track.

I think this is a much more efficient and elegant solution than large gen sets and high kw chargers.


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## major (Apr 4, 2008)

winzeracer said:


> ......I will be charging at HIGH rates with this controller, from an external battery pack and some sort of inductor between the external pack and the controller. Should be able to charge at 15-20kw( at the track ) This eliminates the need for large generators and for the EMW 10kw charger. I will just need to charge up the external pack at home, and take it with me to the track. The external pack will need to have atleast 10kwh so that I can get a few charges at the track.





winzeracer said:


> I think this is a much more efficient and elegant solution than large gen sets and high kw chargers.


Or you could use an easily removable battery on your cart and travel with 2 spares  Do all your charging off-cart. Don't have to mess with a real big battery and high rate charger. 3 or more batteries for the cart gives you spares in case of a failure and the ability to try different batteries. 

Removable batteries also are safer to charge and make service easier. Your plan to dump charge will be a big PITA


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## winzeracer (Apr 3, 2012)

major said:


> Removable batteries also are safer to charge and make service easier. Your plan to dump charge will be a big PITA


Yes this would be the best and optimal solution, but I would have to spend another $5k on batts to have 3 total packs, don't think 2 packs would do the job, because I would still have to quick charge the 2nd pack to get back out on the track in under 30min. So yes it will be a bit of a PITA, but will save at least $3k from the money pit 

When I build a full size race car I will likely use the swap method. One day I will be out of school and actually earn decent money!! For now I have to play with the mini version.


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## winzeracer (Apr 3, 2012)

Well, thanks to a combo of major's advice and the fact that Synkro does not really have customer service, the Synkro controller is off the drawing board, along with its quick charging solution. This left me to find more batts, got lucky and met a contact that had some damaged Electrovaya modules, which have some bad cells in them. I have ordered parts to build a cheap micro spot welder ( batt tab welder) to repair the modules.

Hopefully I will have 3 or more swappable packs.

With the Sjr out for size reasons and Synkro out, I had only one choice, a Kelly that could run this motor without too many thermal issues, so I purchaced the KDH12101E rated at 120V and 450amps continuous with regen from Jozztek who had a better deal than Kelly!

Next big purchase will be the 10kw charger.


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## winzeracer (Apr 3, 2012)

It seems that there was a miscommunication at Jozztek and the Kelly that I ordered was USED, though it was thought to be new. It was used in that it was installed but did not work so Jozztek sent it back to Kelly to get fixed, after seeing what they did to this controller, I completely lost interest in Kelly. This brings me full circle back to my controller of choice the Soliton Jr. I had ruled it out on size basis, but since it really is the best controller for the application I will just have to make it fit somewhere. I found that Jim Husted has the best price on the Junior so after I save a few more duckets I will order it up.

EDIT: Jim Husted is no longer on Evnetics Dealer List, looks like Ev-Propultion might have the best deal since I wont have to pay sales tax on it.


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## DanGT86 (Jan 1, 2011)

I may have missed it but what were the concerns about the synkro that caused you to give up on it? 

Do those bullet connectors thread into your copper or do they just press in and then get soldered?


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## winzeracer (Apr 3, 2012)

DanGT86 said:


> I may have missed it but what were the concerns about the synkro that caused you to give up on it?
> 
> Do those bullet connectors thread into your copper or do they just press in and then get soldered?


Dan,

The Synkro controller is great, however the company only has one employee/owner from what I understand and he does not have the time to provide customer service, a simple question took 1-3 weeks to get an answer. I value customer service because this is not a typical conversion. 

The bullet connectors are press fit into the bussbars and will have a small bead of solder at the base to make sure that they cannot fallout during expansion and contraction of tge metal.

Not much progress to report, school and life are in session at the moment. I made the Zero South Biodiesel Electric Hummer build team and so my EV time has been shifted to that build also. I hope to purchase the Sjr in January then this build will make larger strides, I am at a point where I need to have the contoller to consider mounting and weight distribution. Once I learn Solidworks I will just so this in the model but untill then I.do not want to commit to permant locations of other components.


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## DanGT86 (Jan 1, 2011)

I hear you on the customer service thing in general. As far as synkromotive goes I was really impressed with the customer service. I was in portland on vacation and called Ives from Synkro to see if I could look at a controller in person. He met me at his personal residence on a weekend and let me drive his truck to demo the controller. It was a really positive experience. It did sound like distribution and sales were not his main focus at the moment so I see why you would want to go with a controller from a company that is so active on the forum where you get quick responses. 

Looking forward to seeing more on your build. I have been looking at doing a motocross bike with similar power levels using turnigy lipo and methods boards.


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## DIYguy (Sep 18, 2008)

FWIW, compared to EVnetics.... no one else even has customer service.  I know that's a bit of sarcasm. . . but I'm telling u, my experience (and a few other's) I've read about, was exemplary. In fact, probably the best I've ever had with any product.


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## winzeracer (Apr 3, 2012)

Ya I heard a couple stories of Ives going out of his way to help people out ect.. But I any one man manufacturer just can keep up. I don't blame him he is doing what he can as a one man band, and I ask lots of questions, which is kind of a PITA if you don't have a department dedicated to such questions. I actually really like the controller, just didn't work out. 

Dan: What motor are you thinking of running?


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## winzeracer (Apr 3, 2012)

DIYguy said:


> FWIW, compared to EVnetics.... no one else even has customer service.  I know that's a bit of sarcasm. . . but I'm telling u, my experience (and a few other's) I've read about, was exemplary. In fact, probably the best I've ever had with any product.


Yes, I am not even a customer yet and have always had quick and detailed service, which to me has a great value.


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## winzeracer (Apr 3, 2012)

Well it has been awhile but I have good news! This week I received my 10kw charger kit, and my Soliton Jr.

Hers is a Mock up photo, it was too large to upload http://www.winzeracer.com/photos.html


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## winzeracer (Apr 3, 2012)

I have been looking at how to mount the controller, I wanted to keep it light and also adjustable, since it is behind the seat in case the seat needs adjustment for weight distribution or comfort. So I decided to use the same method that seats are mounted to the kart, using theseseat mounts , if they can hold a human in place they should do fine with the controller.


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## winzeracer (Apr 3, 2012)

Hey Everyone,

I finally have all of the parts to build my EMW Charger, here are parts that I have added to the liquid cooled PFC version with IGBT upgrade.

-Swiftech 240mm heat exchanger with integrated resivor and pump
- 240v 50a Flanged twist lock receptacle
- 12v 60 watt power supply
- Anderson Powerpole connector for DC out
- Bud Industries 10" X 17" X 5" Alum enclosure

Here is a pic, more to follow


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## winzeracer (Apr 3, 2012)

Quick Pic of Sjr in its final resting place!


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## DanGT86 (Jan 1, 2011)

No offense but I don't think that newspaper is going to be strong enough to hold it.

Seriously, that thing is going to be crazy fast!


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## winzeracer (Apr 3, 2012)

DanGT86 said:


> No offense but I don't think that newspaper is going to be strong enough to hold it.
> 
> Seriously, that thing is going to be crazy fast!


Haha, funny guy! Ya I am pretty excited about it. Here is a vid of the chassis prep, so you can see what is under the Soliton
https://www.youtube.com/watch?v=DB9TvV1Sz2s&feature=youtube_gdata_player

I also found a local hackerspace, that has a laser cutter that you can get trained on and then use for pretty cheap. I will be making the plexiglass lid for the charger and custom fan grills with my logo in them


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## winzeracer (Apr 3, 2012)

Here is the Charger Lid cut at the local hackerspace.


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## winzeracer (Apr 3, 2012)

Photos updated on my website. Never seen before footage! haha

http://winzeracer.com/photos.html


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## winzeracer (Apr 3, 2012)

Still working on the Charger, progress has been a bit slow as I am getting married in 3 weeks from today!! At any rate I picked up a little elec scooter 48v. I was testing it (not very carefully) with a couple of my nano-tech batts and accidentally shorted out two of my good batts Anyway it will make a good pit vehicle at the track.

I have also been thinking about trying to take the kart (when finished) to EVCON 2013 in Missouri ( INFO here http://blog.evtv.me/evccon/ ) but logistics from Los Angeles are a bit of a nightmare. I am going to look into shipping the Kart, and driving, see which one costs less. Would be fun to race it against other electric cars and see how it does, it will have a nice power to weight ratio!


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## winzeracer (Apr 3, 2012)

I am now a married man! My lady and I had an amazing ceremony in Sedona over the weekend. Now that the wedding is over. I should be able to get things moving along quicker. I am currently cycling batts for the pack. I bought a 12s lipo charger so that I can keep moving forward without having the EMW charger finished. 

I also bolted up the rear axle, brake and hub. As well as the motor mount and motor. I still need to fett the brushes and advance the timing.

New pics soon.


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## winzeracer (Apr 3, 2012)

New Tillett Racing seat, dropped over 3 lbs off the kart. Also have a Tillett Chain Guard on the way from the UK.

Been mocking up the battery modules, I got some polypropylene u channel which secures the 6s bricks nicely, and spaces the bricks to provide airflow between then to keep temps down. It looks like each of the 3 44.4v 25 ah modules will be under 20lbs each for a total pack weight of 60 lbs which was my target. I tested all the 6s bricks and some were no up to specs and a few had bad a bad cell, So once the new 6s bricks arrive and are tested. I can then group the bricks into matched parallel groups and finish the battery modules.

After the kart is running I will do a further weight reduction by rebuilding the side pods and battery mounts which should shave another 4 lbs.


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## winzeracer (Apr 3, 2012)

Ok all cell Testing Done! I used my PL8 to charge all cells at 15amps to 4.2v and discharged all cells ( in 6s Bricks) at 40 amps to 3.3v I then grouped them in parrellel groups to with in 30 mAh of eachother. Here is the data:


( did not keep proper cell formatting)

Cell ID	Group 1 or 2	Module A, B, C Cells CAP OUT
45	1	B	4498
52	1	C	4556
53	2	C	4574
51	2	B	4581
1	2	A	4599
54	1	A	4604
50	1	A	4616
20	2	A	4646
10	2	C	4652
3	2	B	4659
23	1	C	4675
6	1	B	4685
24	1	C	4692
11	2	A	4716
28	2	B	4720
13	2	A	4724
26	2	C	4754
4	2	C	4756
41	1	A	4764
42	1	A	4778
7	1	B	4781
22	1	B	4784
2	1	C	4798
25	2	B	4807
30	1	A	4809
43	2	B	4810
8	2	C	4811
29	1	C	4828
40	1	B	4832
44	2	A	4894

Attached are some pictures, I then built blocks of 44.4v 25Ah ( 10 6s bricks) So each 44.4v 25Ah module is 12s5p. There will be 3 of these on the kart for a total of 133.2v nominal 25Ah. I separated the cells with polypropolene spacers to give the right dimensions to fit into the boxes and provide airflow between cells. I have also changed all 4mm bullet connectors to 6.5mm bullet connectors for good measure.

I also installed the chain and sprockets, as well as bolted up the brake pedal.

Should have this thing running in about 2 weeks!!


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## Karter2 (Nov 17, 2011)

impressive pack !

I hope you dont intend to go down to 3.3v regularly !
That would drastically shorten the life of those cells.


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## winzeracer (Apr 3, 2012)

Karter2 said:


> impressive pack !
> 
> I hope you dont intend to go down to 3.3v regularly !
> That would drastically shorten the life of those cells.


No I will only be discharging to 3.55v, just went to 3.3v because they were under an 8C constant load and wanted good capacity for testing.


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## Karter2 (Nov 17, 2011)

Brock,
Sorry, i meant to ask if you recorded the IR (Internal Resistance) of each pack and cell. ? Its simple to do during a discharge cycle and is one of the best ways of monitoring cell/pack condition to predict problems and match packs.


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## winzeracer (Apr 3, 2012)

Karter2 said:


> Brock,
> Sorry, i meant to ask if you recorded the IR (Internal Resistance) of each pack and cell. ? Its simple to do during a discharge cycle and is one of the best ways of monitoring cell/pack condition to predict problems and match packs.


I do not have them all in a spread sheet, I monitored them as I did the testing on the PL8, so I have them all in the saved graphs from the PL8. I can get you all the values if you are interested. They were all between 1.5mOhms and 2.1mOhms. As long and painful as testing all the packs was I really learned a lot about the cells, for "cheap" high C-rate cells they are pretty impressive. holding between 4.5Ah to nearly 4.9Ah at an 8C constant load. I was able to see the "Lipo Cliff" in realtime on the graphs (and numbers) at about 3.6 volts where the cells begin to become unbalanced. I also found that after Hobby King came out with the A-Spec Nano's that they must have stolen all the higher cap cells for the A specs. I had to buy 5 extras after testing to replace cells that either had low capacity (higher Rint also), one cell died, I killed one with a balancer, and had one that seemed a little puffy. These 5 replacements were more consistent than the previous batches, however they were consistently lower at nearly 4.5Ah on all 5 packs. I suspect that they saved the lower Rint, and higher cap cells for the A-specs. So now if you want the good cells you have to pay about 30% more, for nearly what the older regular Nano-techs were. But I dont have any A-specs, the this is A-speculation


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## Karter2 (Nov 17, 2011)

No No, all good if you have recorded the IR data for your own future reference as it is a good way to monitor cell deterioration over time/cycles.
1 -2 mOhms is excellent performance, what was the highest ?
I havent used a PL8, but i suspect it may be deriving the IR during the charge cycle like most chargers ? do you know how the PL8 does it ?
I prefer to calculate the IR from a discharge test ( at working current levels) using the voltage sag.
Its usually a little different to "charge" IR figures, due to the higher current levels.


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## winzeracer (Apr 3, 2012)

Karter2 said:


> No No, all good if you have recorded the IR data for your own future reference as it is a good way to monitor cell deterioration over time/cycles.
> 1 -2 mOhms is excellent performance, what was the highest ?
> I havent used a PL8, but i suspect it may be deriving the IR during the charge cycle like most chargers ? do you know how the PL8 does it ?
> I prefer to calculate the IR from a discharge test ( at working current levels) using the voltage sag.
> Its usually a little different to "charge" IR figures, due to the higher current levels.


Yes the PL8 calculates R.int on charge condition. I just made sure that they were all in the same range, I have been told that you can only take the PL8's internal resistance calculation with a grain of salt.


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## Karter2 (Nov 17, 2011)

you can easily do a quick "discharge IR" check on a pack or two for comparison to the PL8 results.
simply hook up a cellog and note the pack & cell voltages with and without the discharge load.. then a simple calc of Volt drop/Amps =IR .


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## winzeracer (Apr 3, 2012)

Well I was hoping to be done and testing the Kart by now, however the battery packs did not go together very well. This whole business of "Spaghetti Junction LiPo" kinda sucks! I had all 3 sub-packs nearly done, but had problems with wires not reaching where they needed to go. Also the assembly process was a bit hazardous. I made safety caps for the bullet connectors, which worked alright, until the last sub-pack assembly when one accidentally came off, and I blew a hole in the aluminium box that the batteries were in. This caused a cell to go bad. I was really quite unhappy with the construction method I choose, it was just turning out sloppy and unsafe. I will NEVER F**K with bullet connectors and buss bars ever again.

So, back to the drawing board. I have now designed the pack that I should have started with. Here is a screen shot of it in Solidworks. 

This design will now only have 2 sub-packs each at 66.6v 25Ah.
This will make all the HV safe, I will put a cover over the bussbars later. This also gets rid of all soldered bullet connectors. For connecting the pack to the karts HV system I will use bussbar mounted Anderson PP180's. This will make nice easy connections, be safe and reliable. New connectors will all be hydraulically crimped. I will machine the 3 spacers out of Delrin, these spacers allow some airflow (4mm space) between batteries, thus fans could be added later if needed. 

I am much happier with the new design. I priced out materials and I will be about $250 to construct the new boxes. I guess this is the price of learning never to mess with spagetting junction lipo.


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## Karter2 (Nov 17, 2011)

?? odd.. Bullet connectors have insulating housing normally to prevent shorting etc. Were you using them without the housings ?

What will you use to connect the pack tails to the buss bars ?



> ... I will put a cover over the bussbars later...


 I suggest you do that sooner rather than later !


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## winzeracer (Apr 3, 2012)

Karter2 said:


> ?? odd.. Bullet connectors have insulating housing normally to prevent shorting etc. Were you using them without the housings ?
> 
> What will you use to connect the pack tails to the buss bars ?
> 
> ...


The 6.5mm bullets I used did not have housings. http://www.castlecreations.com/products/ccbullet.html

I will be using 10 ga crimp ring terminals to connect the packs to bussbars, should be much cleaner and NO solder


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## winzeracer (Apr 3, 2012)

Hey All,

I am finaly back to working on the kart after a long hiatus due to work. I am still fussing over the battery pack. Here is a thread from Endless Sphere all about the lastest on the battery pack.

http://endless-sphere.com/forums/viewtopic.php?f=14&t=56732&p=854764#p854764

It turns out that the spacers I made to separate the 6s bricks would have likley caused chafing in the pack. So I got the kart running with a small 12s1p 5ah pack to see how hot the batteries would get at high current levels. They did much better than I would have thought. So I do not think that having the airgap is needed and would probably be more of a PITA than they are worth. More details on that in the above link.

Here is a pic of the kart while I was testing it at about 25% power. It was great to get in the seat!!!

It felt pretty fun at 50v 150 amps. Can't wait for 100v 400 amps  

First time out I had the rear axle set as low as possible, and had I was dragging on any slight imperfections in the asphalt, so I raised it up about 1/2" and it was much better. Every guy walking his dog and driving by stopped to check it out. One guy said "Aren't those thing usually gas powered?" Gotta love comments like that, meanwhile I had that EV grin on  

The next big milestone will be beating my S4 in a 0-60mph test. There will definitely be a video for that. 

Brock


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## winzeracer (Apr 3, 2012)

I finials got the kart running! Here is the first test ride with about 33kw. More details to follow. 

http://www.youtube.com/watch?v=1xgzKbHK0j8


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## DanGT86 (Jan 1, 2011)

That is awesome! Nice helmet

Glad to see it up and running. 33kw sounds completely insane on something that small. Congrats. Look forward to hearing more.


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## Arlo (Dec 27, 2009)

I think those motors are limited at an output ~30hp... But I set Brock up with a guy looking to push them past their limits.


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## johnws6 (Jul 11, 2013)

Awesome build, congrats.


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## winzeracer (Apr 3, 2012)

Thanks guys. Ok time for a LONG overdue update I am just going to put down everything I can remember since I have no really updated this thing in quite a while.

First off I am nearly done with the final configuration of the battery pack. It is currently 42s5p which is broken into 3 sub-packs. (SEE PICS)

There is two subpacks, one along each side of the seat. Each of these packs are 12s5p. The third subpack is under the steering wheel where the gas tank used to be, it is 18s5p. I designed the aluminium boxes in Solidworks and had them lasercut, I had never bent sheetmetal before but after fully designing them in 3D I did not think it would be that hard. I made some extra pieces to practice on, and bought a little 24" box and pan brake for $300 on ebay. (SEE PICS)

The bending went fairly well (SEE PICS) it was much easier than I thought it would be. However without having taken a Solidworks class and being able to build the boxes in 3D first I would not have been able to do this. I have all of my Online SW class files it is almost 3GB file, PM me if you are interested in the file, it is complete with video lessons.

I also have been trying to learn electronics and microcontrollers. About a year ago I bought a prototype Arduino shield for EVs that never ended up going into production. It has inputs for two current sensors, four inputs for thermistors, it can retard a 0-5v throttle based on temps or current, it also has a Real Time Clock and an SD card for logging all the information. I will also use it to control a pump or solenoid for motor cooling. It also outputs the data to a screen.

I also have a friend that is a brillant programmer and we are working on an Arduino ethernet logger for the Soliton, more on that when it is up and running.

Since the 33kw test I tested again at 42kw. The kart was incredibly fast, however I was having a little too much fun doing doughnuts and drag racing, and burned up the stock brush holder. I did not have any temp sensing during this run and it simply saw to much current for to long and burned up. (SEE PICS) I have ordered a new brush holder, and will file the brushes down and salvage them. I will also need to clean up the commutator face. Major pointed out that he told me this would happen, and it did, in retrospect I would probably went with a PMAC motor. I am liking the EMAX motors lately.

I also bought a prototype brush holder (SEE PICS) that is claimed to push much more current and thus make more power. I have not yet run the new brush holder and have been warned by Steve Labib(Jozzer) that though this brush holder may input more power It may not OUTPUT more power. So I will be taking the kart to a Dyno in a few weeks and test BOTH brush holders.

And last but not least, my friend that helped me CNC mill the motor mount also used to build titanium bike frames, and has some titanuim tube left over from back then. So him and I are thinking of building a titanium frame, this would shed about 30-40lbs with a lightweight axle as well. I am going to do some weighing this week and determine what I would need to drop to get down to the weight of an ICE kart (~390lbs with driver) I think I might be able to trim some fat, and be competitive with the ICE karts in the same weight bracket.


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## johnws6 (Jul 11, 2013)

Looks pretty good, for the battery boxes are you planning to line it with something non conductive, or wrap the batteries themselves in a protective layer? I only ask since I did something similar a few years back and one of the packs ended up developing some slight wear and shorted out on the aluminum battery frame and started a fire. 

Since then, I usually insulate them with high density polyethylene and haven't had any problems. 

Great build so far, keep us updated.


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## winzeracer (Apr 3, 2012)

johnws6 said:


> Looks pretty good, for the battery boxes are you planning to line it with something non conductive, or wrap the batteries themselves in a protective layer? I only ask since I did something similar a few years back and one of the packs ended up developing some slight wear and shorted out on the aluminum battery frame and started a fire.
> 
> Since then, I usually insulate them with high density polyethylene and haven't had any problems.
> 
> Great build so far, keep us updated.


Yes the batteries are well insulated and protected from chafing with Gorilla Tape and Coroplast. Chafing was actually the reason that I abandoned my last battery box design, when it was pointed out to me over on Endless-Sphere that I would have lots of rubbing with the delrin spacers that I had made. 

Hope that nothing or no one was seriously injured during the fire.

Brock


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## winzeracer (Apr 3, 2012)

My friend and I also worked on the Arduino Soliton Ethernet Logger yesterday and tested grabbing the UDP packets from the Soliton, and storing them to SD card. We were able to store the raw data in Hex and now just need to decode the Hex to values. I am fairly excited about being able to log all this data with such a small device, since you obviously cannot have a laptop with you on the Kart.


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## winzeracer (Apr 3, 2012)

Just got done weighing the kart with all components it is 245 lbs, I also weighed myself with the same scale, I was 200 lbs. Looks like we both need a diet, I learned from my Uncle that it is much cheaper for me to loose weight than my car. Haha. So if the Kart looses 35lbs with a titanium frame and axle, and I loose 20 lbs, I was 165 about a year and a half ago so 20lbs should be pretty easy. Than would be at 390 lbs total, which was my original goal.


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## johnws6 (Jul 11, 2013)

winzeracer said:


> Yes the batteries are well insulated and protected from chafing with Gorilla Tape and Coroplast. Chafing was actually the reason that I abandoned my last battery box design, when it was pointed out to me over on Endless-Sphere that I would have lots of rubbing with the delrin spacers that I had made.
> 
> Hope that nothing or no one was seriously injured during the fire.
> 
> Brock


Wasn't a bad fire, just a quick burst of smoke. Polyethylene is a lot easier to work with than aluminum though so I do most of my electrical enclosures with it. It's also relatively cheap in price.


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## winzeracer (Apr 3, 2012)

I played with the High Pressure cooling system this weekend. I went and picked up a paintball tank with 4500psi compressed air and managed to hook it up with a older NOS tank which I used as water tank. It all worked ok, just to heavy and bulky. I am going to try CO2 next as it has better cooling, I would have to change tanks more (less CO2 in a tank), though I may not run water if the CO2 cools the motor well.

If I don't care for this mess I will just pick up a 100-200psi methanol injection pump and run that, however for this setup I would need an aux battery to help out my little Vicor DC/DC. Also this may not atomize the water well. I will let you know how that works out.

Brock


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## johnws6 (Jul 11, 2013)

winzeracer said:


> I played with the High Pressure cooling system this weekend. I went and picked up a paintball tank with 4500psi compressed air and managed to hook it up with a older NOS tank which I used as water tank. It all worked ok, just to heavy and bulky. I am going to try CO2 next as it has better cooling, I would have to change tanks more (less CO2 in a tank), though I may not run water if the CO2 cools the motor well.
> 
> If I don't care for this mess I will just pick up a 100-200psi methanol injection pump and run that, however for this setup I would need an aux battery to help out my little Vicor DC/DC. Also this may not atomize the water well. I will let you know how that works out.
> 
> Brock


Do you have a way to measure the temp on parts of the motor? I was thinking of going with the Agni 95R ( instead of the D and D 15-6 ) motor but am concerned about the motor overheating. Maybe a laser thermometer can be used to monitor the temp of the motor and mount a display on the steering wheel? 

Perhaps forced air cooling can be directed through to the motor itself? Would have to see the math on how much air cooling would be needed though but might be lighter than hauling a tank around on the kart.


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## winzeracer (Apr 3, 2012)

johnws6 said:


> Do you have a way to measure the temp on parts of the motor? I was thinking of going with the Agni 95R ( instead of the D and D 15-6 ) motor but am concerned about the motor overheating. Maybe a laser thermometer can be used to monitor the temp of the motor and mount a display on the steering wheel?
> 
> Perhaps forced air cooling can be directed through to the motor itself? Would have to see the math on how much air cooling would be needed though but might be lighter than hauling a tank around on the kart.


Yes there is a thermister that comes on the stock brush holder I have an arduino unit that reads the thermister and prints to a screen that will be in view of the driver. The arduino will also be able to retard throttle or turn a pump or fan on if the motor gets to hot. However I am running a motor that is rated for 35kw for 10sec, and pushing it to 45-50kw so it gets much hotter. I have been thinking about an airscoop, I designed this one (SEE PIC) yesterday.










I have a friend that does air intake development at K&N Engineering I am going to have him take a peak at the design and recommend any changes based on air flow dynamics. 

You are right I really do not want to carry a tank around so I am looking into other options. We will have to see what happens.

I took the kart out on Tuesday and it did quite well at 45kw with the Prototype brush holder. Motor was cooking though with 95 degree ambient temps and no real cooling. I was only running it for 3-5 minutes and letting it cool. Had a great time drifting around. 

https://www.youtube.com/watch?v=3EV21UJJ950&feature=youtu.be

One last thing, I read over on Endless Sphere there were guys that tried IR temp sensors and the lens always gets dirty rendering it useless.

Brock


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## Karter2 (Nov 17, 2011)

You may want to consider an auxiliary cooling fan..small only a few 100 watts... which would be more effective for continuous positive cooling.
Its common practice on high power motors to keep the windings cool.
But i suspect your brush holders will have much of the heat concentrated very locally to them, and it will be difficult to control that..


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## winzeracer (Apr 3, 2012)

Karter2 said:


> You may want to consider an auxiliary cooling fan..small only a few 100 watts... which would be more effective for continuous positive cooling.
> Its common practice on high power motors to keep the windings cool.
> But i suspect your brush holders will have much of the heat concentrated very locally to them, and it will be difficult to control that..


Yes the localized heat is the part that I was trying to get at with the pressurized water.


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## BrianMay (Mar 23, 2013)

Can you talk a bit more about the performance you got out of the 111R? I ordered one myself, still on the sketching point though...I'm converting a 1991 FZR1000


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## winzeracer (Apr 3, 2012)

BrianMay said:


> Can you talk a bit more about the performance you got out of the 111R? I ordered one myself, still on the sketching point though...I'm converting a 1991 FZR1000


Brian,

I never did put the kart on the dyno, so this is all just from "feel". To be honest with you, knowing what I know now, I will NEVER used a brushed motor again. Too much headache worring about burning things up, granted I was running with max power at 45kw. The motor was strong, and would be fine if I could have kept it around 30kw with a fan. This kart is fun, with a hint of scary, I was looking for scary with a hint of fun. I was told back in the first posts on this thread not to use an Agni and I ignored what Major said. I learned alot, it was fun, the motor runs strong as long as you do not overpower it and you have a fan( or good airflow) to cool it. You will notice that others will use an Agni for a build, then nearly all of them(including Zero Motorcycles and private builders) go to a brushless setup.

Also I had to stop using my Soliton Jr, it did not control the motor well. I sold it and now have a Kelly HPM14701(IIRC) . The kelly definitely controls the motor better and is regen capable, though I have not used this yet. The kelly is a little more jumpy of the line than the Evnetics.

Good luck with your build,
Brock


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## major (Apr 4, 2008)

Hey Brock, & Brian,

Brock lumps all brushed motors into a single category with his statements. My warning was for brushed PM motors, not all brushed motors. Had he used a wound field brushed motor, and one which was apply sized, he would undoubtedly be singing a different tune. However the AC packages may, and probably do, give you superior performance for a given motor mass unless you be a drag racer 

major


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## BrianMay (Mar 23, 2013)

I already have the 111R (which is an exchange for my previous 95R) and the kelly (the "race" type ones,1200A peak just to be on the safe side) and the A123 pouch cells so this is the way I am going anyway...it will be, most of the time a (hopefully) fast daily commuter so I think I'll be ok  don't want to hijack your thread anymore...thanks for the tips


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## winzeracer (Apr 3, 2012)

Right on, no worries, hijack away this thread is pretty much done, I still have the kart but have moved to new builds.

Major, thank you for the clarification


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## JCC (Mar 19, 2015)

Brock,

I noticed in your motor mount design that you had a slot for a chain tensioner, but in later pictures, it seems the tensioner was not included. Did you not get the functionality you wanted with a tensioner?


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## winzeracer (Apr 3, 2012)

JCC said:


> Brock,
> 
> I noticed in your motor mount design that you had a slot for a chain tensioner, but in later pictures, it seems the tensioner was not included. Did you not get the functionality you wanted with a tensioner?


Hi,

Unfortunately the tensioner was to close to the rear Sprocket to be useful.

I sold the kart to an EV WEST employee so it will live another life as an EV. 

Thanks,
Brock


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