Hybrid RC car build thread

This thread:

http://grassrootsmotorsports.com/forum/open-classifieds/wanted-rc-car-for-cheap/77271/page1/

Has netted me a serious project for Tunakid #1. He's five, and saves money from chores to buy things. He bought a RC heli for $20, and was given an RC plane ($20 indoor foamie) for Christmas. He wants to save for an R/C car. Looking around, I see no good RC stuff at that price point. Not even close. Jim sent me an older truck that he had put together a few decades ago.

Here is what we're talking about:

Apparently some Team Losi rear end (perhaps LTX?) and RC10T front end on a custom aluminum chassis.

It will need some work. Jim also sent along a hilariously complicated Ni-Cad charger, four questionable batteries, a Futaba AM radio (exactly like the old one I had), a few bodies, along with a pan car we'll save for another thread.

I aim to refurb everything (myself, it's going to be some trouble and the poor kid is only five), get him a shiny new body, and have him save the same $20 for that and give it to Jim's charity of choice, http://dutchcountryanimalrescue.org/ so he can 'earn' it. Over the next few weeks as I wait for various parts to arrive for the Tunatruck, I'll get this bad boy ready for him.

Hybrid...like a gas engine and an electric motor? Sounds fun, but maybe a little advanced for a five year old!

Bryce

Let us know what you need. I probably have enough stuff to build a few cars.

Rob R.

Well I am shopping now, actually, here is the list:

4-40 x 3/4" socket head cap screws (and other lengths if you have them)
4-40 x 3/8" flat socket head screw
1/8" e-clips
NiCad batteries OR NiMH with help on how to charge them with the super-fancy Victor HI-IQ Jr
Body clips
Leads to good looking stadium truck bodies
Team Associated dampers/rebuild kits

I OBVIOUSLY really want this body to fit. Thoughts?

My thoughts are that the shock towers are hard to clear. Usually stadium truck bodies have humps to clear them.

You MAY get away with running aftermarket body mounts BUT that might mean the boddy is WAY up in the air.

That is a cool body though. I think it will end up with a big gap under it and you will be able to see the electronics and everything else from the side.

wvumtnbkr wrote: My thoughts are that the shock towers are hard to clear. Usually stadium truck bodies have humps to clear them. You MAY get away with running aftermarket body mounts BUT that might mean the boddy is WAY up in the air. That is a cool body though. I think it will end up with a big gap under it and you will be able to see the electronics and everything else from the side.

You are indeed correct. Boo!!

Got any of the parts on that list?

Maybe battery stuff. i will have to charge them up and see if any are still good. Can you find an owners manual for the charger on the interwebs? If so, it shoudl explain pretty well how to use that charger. If you have any questions about charge rates or anything like that, I can probably help you answer them.

Whats wrong with the shocks that they need rebuilt? Are they leaky? If not, you just need some new good shock fluid. I have LOTS! I can send you some. I may have some shocks or a rebuild kit laying around. I will check.

I can send you some body clips most likely. Most of mine are painted.

I can also check on the screw hardware and e-clips. I probably have all of that somewhere....

By flat socket head screw, do you mean a countersunk screw? A flat one will actually be a challenge!

Rob R.

wvumtnbkr wrote: Maybe battery stuff. i will have to charge them up and see if any are still good. Can you find an owners manual for the charger on the interwebs? If so, it shoudl explain pretty well how to use that charger. If you have any questions about charge rates or anything like that, I can probably help you answer them. Whats wrong with the shocks that they need rebuilt? Are they leaky? If not, you just need some new good shock fluid. I have LOTS! I can send you some. I may have some shocks or a rebuild kit laying around. I will check. I can send you some body clips most likely. Most of mine are painted. I can also check on the screw hardware and e-clips. I probably have all of that somewhere.... By flat socket head screw, do you mean a countersunk screw? A flat one will actually be a challenge! Rob R.

Rob,

Yeah "flat" means countersunk in screw terminology, it's weird.

The shocks were stuck on the front, and when un-stuck, they sprung, but were sticky and definitely not damped. The rears were fine in travel, but no damping. If you think fluid is all that they need, I am game to try it, especially if you have fluid! What weight do you use for general backyard bashing?

The charger is weird. Internet sleuthing leads one to the originator, who is back in Belgium and out of the hobby. Apparently, there were several different chargers in the HI-IQ line, some of which have features others do not. Apparently, the interwebz have had success telling the charger that it was charging 2 NiCad cells rather than 6 NiMH cells, but the JR doesn't appear to have this capability. Dan0 is also sending another charger, an indi 16x2 pro, but it has the same issue; it was built in the NiCad era. All of the documentation just talks about NiCads. I have an E-mail into competitionx, who still exist (the folks who made the indi) so we'll see what they have to say.

Lemme know what you have for hardware, I went to Fastenal today and they have no #4 stuff in stock. $10 shipping for $2 in bolts!

My slightly less complicated charger is on the way, and there is a manual online for it.

http://notices.patrickmodelisme.com/telecharger/Integy/Integy_16X2-Pro.pdf

This forum is a good place to get info and some cheap parts as well.

http://www.rctech.net/forum/

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It'd look about like that. That is the exact body you're looking at (Proline C10 IIRC) on top of my T4. As you can tell it's not drilled for it or clipped in (This body actually came off my Rustler before it was well... you've seen that build thread). You would need extended body mounts to get it to lay flat, but it can totally be done. Traxxas makes some really nice shorter body mount risers. They ought to work well... If I can find my set I'll test it, and if it works, add it to the motor that I should have sent last week.

From what I recall people have said some charging of NiMh can be done with a NiCad charger. you generally want the pack drained (not half charged) and cool, so not straight from the truck used, then charged at a lower current and make sure the pack doesn't get hot as it charging (indicating it's overcharged).

The weird thing is that they do make "flat" allen head screws. They are usually used for pan-car motor mounts or sedans where there is something trying to occupy the same space. They are super tough to find. I think CRC used to make them for awhile.

I will see if I have a nihm charger. I might.

Tuna, I used to race for Associated and Protoform back in the day. I probably have some bodies and misc. stuff you can have. I'll have to raid my parents' basement this weekend and see what I have.

hrdlydangerous wrote: Tuna, I used to race for Associated and Protoform back in the day. I probably have some bodies and misc. stuff you can have. I'll have to raid my parents' basement this weekend and see what I have.

Since we're geographically similar did you run out at On Trax on 72? That's where this old truck cut her teeth, on their clay oval :)

And if you or anyone else has a mild motor you can send Tuna please do. The 12 turn hand wound triple in there is a bit of a battery eating high strung beast ;)

JThw8 wrote:

hrdlydangerous wrote: Tuna, I used to race for Associated and Protoform back in the day. I probably have some bodies and misc. stuff you can have. I'll have to raid my parents' basement this weekend and see what I have.

Since we're geographically similar did you run out at On Trax on 72? That's where this old truck cut her teeth, on their clay oval :) And if you or anyone else has a mild motor you can send Tuna please do. The 12 turn hand wound triple in there is a bit of a battery eating high strung beast ;)

I have a stock tamiya silver can an route.

Wow, guys, you're all awesome. I can't tell you how much I appreciate all of this.

I wanted to come and give a brief update on day #1. Tunakid got to see the box, although I only showed him the truck briefly as I don't want to give him any idea that it's ready to run. Here are the problems to correct:

Blown, worn or dry shocks
Missing E clip and stuck hinge pivot in the right front control arm
Broken rear body mount
Bent rear shock mounts
Weirdo alignment
Broken motor lead insulation
Missing wire insulation at the ESC/motor junction
No decent battery packs
No braking
Steering turnbuckles and bellcranks are loose and sloppy
Stripped front bumper/suspension screws

It's all very minor stuff, and will be attented do, along with letting Tunakid get a body style he likes.

I have a pic, and it's awesome.

That's Tunakid #1 on the box, with Tunakids #3 and #4 in tow, also very intrigued, but more with the box than its contents.

Again, thanks guys. This outpouring of support is totally unreal.

Why no braking? That is accomplished with the motor. However, if it is the motor that is not stopping, it is an issue with the ESC setup, the radio setup, or a malfunction of the radio or ESC.

Do you have a clear picture of the ESC and Radio?

Rob R.

wvumtnbkr wrote: Why no braking? That is accomplished with the motor. However, if it is the motor that is not stopping, it is an issue with the ESC setup, the radio setup, or a malfunction of the radio or ESC. Do you have a clear picture of the ESC and Radio? Rob R.

^This, there should be braking on it. Drawing a blank on the ESC right now but Im 90% sure it had braking. However, if memory serves there are adjustments to be made at the controller to determine the level of braking and also (again I could be completely off, haven't messed with that stuff for a looong time) its not like "toy" RCs where lack of throttle = brake. You have to apply negative throttle to activate the brakes.

I understand how it's supposed to work, and the ESC is an EXCELLENT Tekin unit. I have to see if the braking is not calibrated properly or if something more dire is wrong, but until I get a battery to hold a charge I won't know for sure. I have one battery with some hope.

I understand how it's supposed to work, and the ESC is an EXCELLENT Tekin unit. I have to see if the braking is not calibrated properly or if something more dire is wrong, but until I get a battery to hold a charge I won't know for sure. I have one battery with some hope.

In reply to Jthw8:

If that's the track in Browns Mills then yes, I did, but it was MegaTrak back then. It was a concrete tri-oval.

I know I have some stock 27 turn Reedy motors I can send out. Fine for back yard beating

As far as the brakes go, There should be dials on the speed control that you can turn using a small flathead screwdriver. There should also be trim adjustment on the controller.

The fets can go out on the brakes/reverse. If that is the case, I am sure I have an esc for ya.

Tuna, are you going to the barber race? What about any team mates that could get you stuff if you are not?

hrdlydangerous wrote: In reply to Jthw8: If that's the track in Browns Mills then yes, I did, but it was MegaTrak back then. It was a concrete tri-oval. I know I have some stock 27 turn Reedy motors I can send out. Fine for back yard beating As far as the brakes go, There should be dials on the speed control that you can turn using a small flathead screwdriver. There should also be trim adjustment on the controller.

Yep, that's the place, mom and 2 sons ran it as Mega Trak, mom sold it, sons got pissy and bulldozed the oval before the new owner moved in. They ran a clay oval for stadium trucks and buggies for the first year or 2 while they built a whole new banked oval, it was fast when it was done, lots of fun :)

And holy crap, you are older than I thought or you were racing at a very young age :) I was in my early 20s when it was OnTrax and I know I'm older than you.

I have this odd hint of a memory in the back of my head that says its something to do with that motor that prevents braking but I could just be imagining it, 'nother fun fact about that motor, it can and did melt a tamaya gearbox. The mutant truck I sent came about because I was po' and someone gave me a tamaya and I got into racing. I modded the crap out of that thing to the point where I was actually beating "real" trucks in heats. A few of the folks took pity on me when I finally melted the transmission and basically the truck was spares from a few other racers' trucks bolted to a custom aluminum pan.

wvumtnbkr wrote: The fets can go out on the brakes/reverse. If that is the case, I am sure I have an esc for ya. Tuna, are you going to the barber race? What about any team mates that could get you stuff if you are not?

Nobody is going that I know of.