14.2 second 1/3 mile? (oval)

[jhautz]

If your going for speed runs, Id dump the mechanical brake and save the weight of the servo and the mechanism. Your not gonna be beaking that much anyway so it probably wouldnt add much load to the controller. you just have to make sure the tranny doesnt have a 1 way in it somwhere that would prevent using the electronic brakes.

The wanderer motors of the same size and wind are smaller in diameter. The same internals, without cooling fins around the can. I dont know about the others.

Have you considered the emoli cells. They would make a nice compact brick and save a ton of weight over sub c's. But the lightest option would still be to find a lipo pack that would fit. Its gonna be hard to find them much shorter though if you want larger capacity cells.

hmm just thought of something. what about two 5s1p packs, one on each side.. the problem I see with that, is that the drive belt isn't in the center, and that would push the weight way to the outside.. almost to the full width of the car..
then again, they are alot lighter.. but then i could mount the rest of the elctronics realy low on the chassis in the center.

the front has a one way in it..
i'm not familiar w/ nitro, oneways, and or 1/8 onroad drivetrains.. the rear doesn't seem like a differential. if I hold the center drive train, and spin one tire, it's very tight, but opposite wheel doesn't move..
it all seems very weird to me, having so many drivetrain changes i'm not used to at once. how could I lock the 2speed to the smaller spur gear? it spins and does nothing.. so centrifical*?
the drivetrain also seems very tight. not sure if something's binding or not.

I bought the car as a display model, with the car, and nothing else. i don't even have an instruction manual! =\. the discount was worth it imho. I'll probably rebuild the car completely before I run it to check the drivetrain.

[coolhandcountry]

If you come up with a way to run the two speed. I would keep the mechanical brakes. It would requre a pinion make with two gears. I have seen a few around. You would have reverse then though. But who needs reverse if you can go 90mph forward.

Originally Posted by coolhandcountry

If you come up with a way to run the two speed. I would keep the mechanical brakes. It would requre a pinion make with two gears. I have seen a few around. You would have reverse then though. But who needs reverse if you can go 90mph forward.

I'm going to try and keep it as simple as possible.. making my own pinions doesn't follow that rule :)
also, this car has no reverse, and now that I think of it, if I don't lock the 2speed, then there's NO electronic brakes. when the spur spins in reverse, it free spins.. if I hold the spur in one location, the car will still rolls forward.. like a one-way 2speed..


question time!

I'm looking at two different batteries..

#1:
MaxAmps Lipoly 4200HV 5S2P 18.5V Pack = $184.99
* 4200mah Capacity
* 18.5 Volts
* 34mm X 98mm X 62mm
* Rated at 60 Amp Constant Discharge
* Rated at 80 Amp Burst for 10 seconds
* 495 grams
* Comes with Standard Taps
* TP Taps Optional

#2
TrueRC 5S1P 18.5V 4000mAh = $85
* 4000mAh Capacity
* 18.5 Volts
* 27mm X 145mm X 50mm
* Rated at 40 Amp Constant Discharge
* Rated at 60 Amp Burst
* 425 grams
* TP Taps Optional

I'll be running two packs in parallel, so the maxamps would be 120a/160a discharge, the truerc's would be 80a/120a discharge. the truerc's would also have lower cg, and be lighter. Do you guys think 80a constant, 120 burst would be ok? I'm thinking it would, but want your insight.

also, will the ThunderPower TP205 2s-5s balancer work with my 109d's?

if you guys think I'll be ok, I'll go ahead and get the truerc's. then I need a ubec, and li-saver.. anything else I'm missing?

very simple motor mount design completed:



only one other part needs to be designed for a completed conversion.. battery mounts. I've decided to make "trays" that attach to the center of the chassis under where the gas tank was, and span along the sides between the tires.. updates as I get em :)

[squeeforever]

Why not just run a TrueRC 5S2P pack? Or if you want to run 2 packs instead, a 3S2P pack and a 2S2P pack in series. Either way, its the same amount of cells.

Originally Posted by squeeforever

Why not just run a TrueRC 5S2P pack? Or if you want to run 2 packs instead, a 3S2P pack and a 2S2P pack in series. Either way, its the same amount of cells.

I'm mounting the batteries on the sides of the chassis. I need the weight to be even :rolleyes: .. which brings up my next question..

which keeps seperate packs in balance w/ eachother? in series or parallel? ie, if I run these packs in paralell, can I charge them in parallel? will the balancer work like this? sorry, never used my lipos :o


edit:
looks like I'm done for the night. I'm going to try and meet up with a buddy tommorow to try and get some of it cut.

[Batfish]

Originally Posted by A4DTM

which keeps seperate packs in balance w/ eachother? in series or parallel? ie, if I run these packs in paralell, can I charge them in parallel? will the balancer work like this? sorry, never used my lipos :o

If you have two 5S1P packs and want to run them in parallel, you should prep them first by fully balance-charging both packs individually. This means taking one pack, hooking up a balancer capable of balancing while charging (active balancer), then charging the pack fully. Repeat with the second pack.
The balancer will only work on 1P of batteries at a time. In a 2P (or more P) pack, you need two or more balancer leads (taps); one for each P.
Once both packs are fully balance-charged, you can use them in parallel in the vehicle and charge them in parallel. I would, for safety's sake, re-balance them (using the method from above) after about 5-10 charges. This is really just to make sure they stay in balance, which will help prevent damage from over-discharge or over-charging.
I actually have two new 4S1P 4000mah TrueRC 10C packs that I will be running in parallel, but it'll be a few weeks before I can get this done so I can't offer any pics or results at this point. I will balance-charge both packs fully, then wire them in parallel in the vehicle for 4S2P 8000mah. To charge them, I'll leave them in parallel and charge on my ICE at up to 8A (1C of 8000mah).

eh now that I think about it, I'll charge them seperately, but run them in parallel in the car.. so I'll be able to re-balance every charge. so can i assume 80a constant is sufficient?

[MetalMan]

80amps continuous would be enough for the batteries in that car.

*Update*

Nick is pretty busy so I thought that I would help out and update the post. The proto type pieces are going to be machined out of 6061 this week and the final pieces will be done out of 7075. This is a pretty crazy project and can't wait to see it complete.

Thanks,
-Joe

upsydaisy



huge thanks to crazyphantom for helping get this this far.

Hey,

No problem Nick. I think I am going to get one of those motor mounts machined just to put on my shelf. It looks SOOOO perdy.HAHA

What you guys think so far?

-Joe

[squeeforever]

Looks great! How much would it be to have one of those motor mounts machined?

Originally Posted by squeeforever

Looks great! How much would it be to have one of those motor mounts machined?

thanks.
I can't quote a motor mount right now, but this could possibly turn into a conversion kit at some point.. I'll lyk when this project's done.

got the parts today, and everything turned out great. nothing's mounted, because, none of the holes are tapped yet, as I havn't decided on screws.
the motor mount needs some filing, because the 540c's endbell has a slight lip by the bearing, and I completely overlooked it when I designed it. any future mounts won't have this problem.
now need $ to get controller, and then batts.

comments?