Team Associated B5M R/C race car

I know I'm not racing, but I do want to take care of the batteries over the long haul. Alligator clips won't work with either of the batteries I have, and by the time I've built/purchased the right adapters to work with the Dynamite charger I'm in the same price ballpark as a charger that can balance and comes with the adapters. We'll see what the vendor has to say. If they won't take it back for exchange, I'll get the adaptors and cross my fingers.

I've shaved the plugs down on the server and the power box, but I don't have an appropriate plug to go into the receiver for battery power. I think I've identified it, I'll order some. The only shop that sells RC stuff in town is only accessible to me about 7 hours/week, and that won't happen again for another month.

Dear lord look at the voltage and storage on those batteries. I have some older ones that are like 800-1100mh and they were trick back in the day.

I have nothing to add but that this is very cool.

In reply to wearymicrobe:

Same here; I wish there were still racing around here, excepting of course that I have no idea where I'd find the time.

Yeah, if your charger doesn't have a balance function, you'll be fine. Mine does, and refuses to charge a battery without it. As a basher, it's overkill.

Edit- my friend Sam and his brother are big in the rc scene in Montana and have a great shop. I get all my stuff from them, and Sam is legitimately one of the nicest dudes i know. Check em out

They were the ones that helped me engineer the junk heap i built a few years back, and helped me stuff a huge motor in it later. They'll answer any and all questions we can't.

Link takes you back here. Is he at Stormer Hobbies? I think they're in MT.

I'm getting mixed messages. First, these LiPos are so volatile they have to be charged in a fireproof bag, outside, in a bunker, with the hazmat team on call. Or "don't worry about it"

Keith Tanner wrote: Link takes you back here. Is he at Stormer Hobbies? I think they're in MT. I'm getting mixed messages. First, these LiPos are so volatile they have to be charged in a fireproof bag, outside, in a bunker, with the hazmat team on call. Or "don't worry about it"

Don't worry about balance. Worry about them having an issue if there is some internal damage that is not known.

The charger is still smart enough to not overcharge or cause an issue without the balance part.

You should still charge in a safety bag.

It looks like you could get one side of an alligator clip into each hole on the battery and the other side of the jaw would be outside on the case the battery.

I don't think you need a battery plug for this receiver. The esc should have battery eliminator circuitry or BEC.

So the ESC provides the power to the receiver? This is my ESC. Specs says it has 6v/3A BEC. Good to know. So all I plug into the receiver is the steering servo and the ESC?

I'll still need an adapter to charge the battery in the transmitter, but I think I have some connectors coming that will deal with that. As soon as the servo tape and those connectors arrive, I'm ready to fire this thing up. Ooooooo, exciting.

Got enough parts in yesterday to allow me to finish the hardware build. It's a roller! It's got some crazy alignment, looks like 3 degrees of toe in back. I'm guessing that's for stability.

Also, it's suddenly quite large and solid. They look small and weightless in the videos!

rear toe will help forward bite and stability.

Yes, just plug the esc into the receiver and no need for a battery to the receiver.

IIRC, steering is channel 1, esc is channel 2. Its been awhile. It wont mess anything up if you switch them, it might just steer when you pull the throttle trigger.

Excellent. Thanks.

Anything I need to do to break this in? They're not new motors, but the trans appears to be and the slipper definitely is. Same with the rear wheel bearings.

IT'S ALIVE!

Powered it up last night and we have a functioning, remoting car! Woo! I didn't run it for more than a few seconds because I'm still waiting for a couple of connectors to charge the batteries, but it goes.

The steering servo was constantly making noise, though. Normal servo noises, but it almost never settled down. To be expected?

No reverse. I guess that makes sense.

I notice that one of the channels is brake "pressure", independent of the accelerator channel. What does the signal actually look like coming out of the receiver? I think it would be fun to add brake lights.

Some of the newer digital servos make noise all the time.

It could also be some bind in the steering assembly. The steering should basically flop around if you unhook the servo mechanically. If it does not, find the bind and fix it.

No reverse on racing type esc. I believe there are brake light kits you can hook up to the esc.

I think the brakes still go through the esc channel of the receiver.

I think I remember the steering being floppy, but I'll check. The servo just seems restless.

The ESC is obviously taking care of braking, but the transmitter shows channel 4 as a brake channel. That's why I was wondering about tapping right off the receiver. I'll do some prodding.

Thanks for the help!

It's been a few years since I dabbled with RC but I'm guessing the brake channel is there for a Nitro powered buggy that could run a separate brake and throttle servos.

There may be a way to enable reverse in your ESC, it can be nice if you aren't racing and will save you having to recover the car sometimes.

Adam

No reverse is a racing thing. Nitro cars had no reverse, so electric cars ended up not being allowed to use it (at least that is my understanding of how it came to be). Not sure how universal it is, but my ESCs can be configured to either disable reverse or allow it. When it's allowed, it generally takes two pushes on the trigger to get it to work. The first is braking, and as long as the car isn't moving, the second goes in reverse. It is a lot more fun when not racing to be able to back out of a lot of off track oopsies.

Looks like my ESC doesn't do reverse - there's no mention of it in the manual. I'll keep digging around. It sure would be handy given my skill level. At least the car can do a rapid power-assisted 180

Keith Tanner wrote: Link takes you back here. Is he at Stormer Hobbies? I think they're in MT. I'm getting mixed messages. First, these LiPos are so volatile they have to be charged in a fireproof bag, outside, in a bunker, with the hazmat team on call. Or "don't worry about it"

Hard shell= don't worry. They're at scheer brothers hobbies in Libby.

update-able to include reverse.....

It looks like this is a "tuneable" ESC. If you get the hardware link, you can program it to run reverse.

RC lighting (including brake lights) instructable.

Here is one way to get the brake lights to work if you are interested.

wvumtnbkr wrote: update-able to include reverse..... It looks like this is a "tuneable" ESC. If you get the hardware link, you can program it to run reverse.

Thanks! You had to dig pretty deep to find that 1.5 software version.

Aaah, so it looks like I can take brake light power off one of the motor wires. I'll play with that.

This is why I say be careful and use a bag of sand or a fireproof charging bag.

LiPos are flat awesome, just treat them with appropriate respect.

But don't worry about balancing

We have test drives! Twin rooster tails rock. This bugger is fast. Still some setup to do, the front suspension seems to have a bit of trouble keeping the tires planted. I've lowered the front and raised the rear as much as the current springs (used as per the instructions) allow. It looks to me like it needs thinner shock oil perhaps. I'd also be happy with slightly slower steering, I may be able to adjust that in the transmitter.

This also prompted me to blow the dust off my old Tamiya M2. Surprisingly fast, but without the suspension or handling of the buggy. Decent grip as long as the pavement is very clean.

Fun stuff. I do not anticipate any rabbit hole problems, this is pretty much exactly what I was looking for. Thanks again for all the assistance.

So, I should ask - any break-in or maintenance tips? What sort of wear should I watch for?

Battery question!

This happened today. The battery is substantially swollen.

Ready to self-destruct or OK to keep using? I'm pretty sure I know what happened - I had the B5M sitting in the car all day and it got pretty hot - including the aluminum floorpan that the battery sits on. I then proceeded to drive it enthusiastically in a big open lot where it got lots of WOT time. I didn't run it all that long, but I suspect the battery got very hot. I have not plugged it in to charge it.

It's done. Swollen batteries -- assuming they don't try to start a nuclear holocaust -- will exhibit odd charge and discharge behaviors.

As far as the break-in question, today's electric R/C products don't require any kind of break-in. This includes things like transmissions and driveline parts. Back in the old brushed motor days we would dunk an new motor in a cup of water and wire it directly to the battery to break it in. People stopped doing that by the late '90s. The nitro people still have to have careful break-in periods on their engines.