Return to Level1Techs.com

RC car helps

OK simply put I know nothing about how RC cars work and to be honest Im sure I could put together something but it would be a pain in the ass.
OK here is the law out. Some peps and I are trying to build a popper scooper robot thingy. Sorta like a rumba except with shit. Proof of concept type stuff. Here is the thing tho no Lipos. So we are going to run this whole thing off a PSU or something. Easy 12V and 5V. Again proof of concept prototype stuff here. So I was big into the who RC plane thing a while ago and I still have some parts. 80 amp ESC, A Tacon big foot 870KV motor, and a smaller emax 1180kv outrunner. Great motors btw for flying.
This car needs to be going like idk 1 mph less? Rumba speed or whatever. My question is should I run these motors at like say 5V with some gear reduction or 12V(not for the emax) with a shit ton of gear reduction. I dont think Ill have a problem with putting in 5V or 12V into an ESC. I just have no idea if this is like way overkill and I need something else or if I can pull out a lot of gears.

Any ideas?

I would go for 14.4V (2 batteries @ 7.2V, oh yeah 12v psu) with gear reduction for torque and use a 4WD model. If you are essentially making a snow plow for poo you will want the front wheels putting power down. Also 4WD cars are a lot easier to control. I would suggest an on-road vehicle because for this application I think limited suspension travel and low center of gravity would be a benefit.

I get most of my R/C gear from Tower Hobbies, but beware. If you order from them they mail you catalogs for years. I throw them away before I open them and buy more stuff.

Associated 1/10 APEX Touring Kit $129.99


http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXGEHL&P=SM

Axial 1/10 RR10 Bomber 4WD Kit $359.99

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXGBAX&P=FR&gclid=Cj0KEQiA25rFBRC8rfyX1vjeg7YBEiQAFIb3bzDVu2XAtXRP4E8q3gyWYad69Ty4o5e-oAjPoesnEYYaAtj08P8HAQ

Team Durango 1/8 DEX8 Buggy EP 4WD Kit $499.99
Do you need 1/8 scale size? It will make prototyping much easier.


http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXEZYF&P=SM

1 Like

Well yeah I understand all that but out of the motors I have would it be better to run the 870kv or the 1180kv. I'm thinking 870kv just simply bc it's beefer. My question I guess is it reasonable to take one of these and expect to only 1 mph or less out of it with out getting crazy. And we plan to make all the transmission and drive trains. We have that capability.

1 Like

I changed to an Axial rock crawler because those things have bulletproof transmissions with low gear ratios. A lot of times they have steel gears and are simply constructed.

Have fun.
I was Fairfield County, CT R/C racing truck champion way back in 1992 and I just got this last year to get back into the hobby a little.

If you want 2WD I would suggest the classic (that I won my championship with) RC10T. The transmission is good and there are literally millions of custom parts (like steel gears in different ratios) for it.

Associated 1/10 RC10T5M 2WD Kit $279.99

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXEZUY&P=SM

Just random thoughts...

I know little of RC outside of 1980's tech, but your idea intrigues me. You can pop a roomba brain in it and have it track the whole lawn, but if it can track the source or the target then it saves a lot on power requirements and lets the energy go into scooping instead of driving... There is of course a large difference in the payload by breed. Hmmm, there are also grass length and weather considerations. I think that there is a roomba style lawnmower out there. If a scooper could be adapted to something like that you probably already have 18-19.2 volts on hand.

You are gonna have to get creative to go that slow. The rock crawlers can do it for sure. You can always tune the radio to make the engine go slow, but you will want the engine going faster for power and control, then gear it down to make torque.

It depends on the form factor, you can do a "gear" reduction very efficiently with a proper pulley setup since it's unlikely to need the quality of a gearbox just to slow down.

There are also relatively cheap stepper motors (or servo motors), I use some that have a 60 second rotation time.

1 Like

Tamiya makes quality small motors that run off of two AA batteries and would be perfect for your project. I'm talking about the ones into Mini 4WD cars. You could even buy one geared for power instead of speed and use a lot less gears and pulley to make it go slower.

Racing pack voltage is either 7.2V for NiMH or 7.4V for LiPo.
From there, it is all standard components.
Most motor controllers have 5V out for the reciver units, would look for those (medium price is 40€/$50).
Prices for model brushless motors are limited by the sky.

I am in Germany, so availability might be a problem. But these will give you an idea of what you might want.
2 channel pistol-grip remote
Racing pack
Brushless motor controller
Brushless motor

2 Likes

Well the point is this. You have a car that runs some sort of software. It can be GPS or pre defined path or whatever. That parts easy. It runs into something that goes into the scope it stops lifts the scope and puts it in a bag its carrying. Of course all the motors I have are slightly very much overpowered for the job. Can I do gear reduction yeah of course. Is it worth the head ache tho of building a gear box for these motors. That's what I'm not sure on. The car needs to be pretty slow like 1 mph less ish. There is plenty of stuff out there for how to go fast not so much to go slow. Plus no lipos we are just going to run it off a computer psu so it will be wall tether. Again proof of concept. The 5V out might be enough I think. Right? 12 would run these motor too fast and too hard. Well not the big foot tacon that one is a beast.

I know most of the lingo from RC the planes so KV and C and all that I'm good with but you don't want to run a prop that slowly that would be dumb. I can see a use for a shit ton of torque tho on a car. Just not finding anything useful as to how to run a high torque slow moving RC car. Torque isn't a thing that I care much about but if I'm going to use one of these motors I'll get quite a bit out of it.

Check out this guy. You may find a video that helps your project or a link to other resources. I'm not as plugged in as I used to be. Again, my first thought is look into a rockcrawler model. Those go very slow and have the torque to climb over anything.

Treads I didn't think of that. That might be better than wheels actually.

1 Like

Saves you the hassle of the steering mechanism. Just use one motor per track.

yeah thats true. looks like Ill need another motor and esc tho