[winzeracer]

Hi all,

I have asked various questions here and there but am now starting a real life build thread! The donor is a 2005 Track Magic shifter kart chassis. The goal is to keep it under 400 lbs with as much power as possible, so that it can hopefully go race against ICE karts. Here are my main parts currently being seriously considered.

-Agni 111rdr only 26lbs and max 45kw..ish hopfully 50kw with some cooling
read about it here, still a prototype http://endless-sphere.com/forums/vie...440&hilit=agni

-Solution Jr a bit under used for this application but full of modern features, and reliability that you find with a Kelly.

-For batts I am leaning toward the Haiyin Lipos( 3.7v 6ah 50C ) that Lithuimanics runs but am still doing more battery research. Battery musts are as follows: pack voltage will be 84-96v still working out what would be best for motor, probably 20-30ah and capable of 600amp burst which means High C Rate cells only.

I had a great talk on the phone with scotty449 the other day which was very informative. We discussed the possible use of an Ac-15 but at 46lbs i think it is still to heavy. Kleanspped build their eKart with AC and I am sure the regen is great but not sure if its worth the weight. http://www.kleenspeed.com/e-karts/


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

Thanks for your input in advance.

EDIT: I have decided to go with Turnigy Lipo 6s 35C-70C see page 3 for more on that.

[major]

Originally Posted by winzeracer

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

[winzeracer]

Major,

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

[major]

Originally Posted by winzeracer

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.

[winzeracer]

Originally Posted by major

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%...C%20Motor.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.

[major]

Originally Posted by winzeracer

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

[winzeracer]

Originally Posted by major

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?

[major]

Originally Posted by winzeracer

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

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

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

[winzeracer]

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?

[MalcolmB]

Originally Posted by winzeracer

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

There's this: http://www.diyelectriccar.com/forums...0-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.