View Full Version : [Question(s)] How do I make sense of RC hobby parts?

11-01-2012, 12:47 AM
I've been having some robustness issues with my repurposed 10-year old RC monster truck. Surfing the various RC hobby sites, some of them list about half of the specs you'd want for parts (like, axle diameter, or whatever,) and half of them have no specs at all other than "fits such-and-such model truck" which is some other model they sell.

I would think that I can find parts for suspensions, steering/axles, and wheels/tires in the RC hobby community, but everything seems pretty disorganized, and not set up like, say, McMaster is for mechanical parts, or Digi-Key is for electronics. How's a person supposed to make any sense of that space? Or does it not matter? Given that the RC trucks seem to carry no more payload than a drawn polycarbonate chassis, perhaps the parts are just too flimsy? Also, it seems unlikely that I'll be able to find a RC vehicle with luxuries like wheel encoders, or even the ability to fit a suitable encoder, so I think I'm off to some other place to find those things...

Recommendations highly sought after! For example, if I have a 6 mm diameter D-shaped shaft, what's a good way to fasten a RC wheel/tire set to that, assuming I find one that fits through sheer persistence? (This might work: http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXXCC8&P=0 ? Or this? http://www.integy.com/st_prod.html?p_prodid=5559&p_catid=107#.UJIPn8WHJ8E -- how are these things fastened?)

11-01-2012, 01:11 AM
When I needed some strange parts, I just took the whole robot into the local hobby shop to explain exactly what I wanted.
After the initial WTF! followed by 1/2 an hour explaining how it works etc, they were more than helpful. You then get instantly recognised the other times you go there, as you will be known as "That robot guy" or something similar, & get pretty good service. :)
You might even be able to take your calipers in to measure parts they have in stock.....

11-01-2012, 12:51 PM
Buy stuff IN PERSON!? What is this, the twentieth centiry? :-) :-)

That's probably a good idea, though. There is a decent place (I've gotten some hinges and paints and stuff there before) nearby (J & M Hobby in San Carlos -- if anyone else happens to know a great place on the SF Bay Peninsula, I'd love a personal recommendation.)

Also, cantilevering the wheels straight off the motor shafts is probably likely to eventually wear out the bearings. That's why we have axles in cars (and, apparently, RC cars.) Is there a good solution for someone like me who wants both a motor-with-encoder-per-wheel and also want robust long-term reliability?

12-13-2012, 10:42 AM
It's no different in the automotive world. There's no master cross-reference list of what Ford parts go on Chevys or what Toyota parts go on Nissans. Nor do they tell you all the dimensions needed, for example, to swap a tie rod from one vehicle to another.

You have to work at it. :) I know from my FSJ forum that certain Dodge D60 rear axles and certain Ford and Chevy axles will fit without much modification to my Jeep and how to swap a Chevy, Ford, Cummins or other engines in if I want. At least in the auto world there's some crossover; the same Saginaw power steering pump was used on Volvos, Jeeps, GM, and others. The Delco-Remy alternator is in all kinds of GM and Jeep and others.

So, in addition to a visit to a *helpful* local hobby shop -- not all are -- I'd suggest visiting rctech.net and ultimaterc.com as good tech sources for parts swapping help. I'm using an ECX Circuit for my Data Bus rover and found lots of info on parts brand swapping on ultimaterc.com

12-13-2012, 11:45 AM
Thanks for those recommendations! Regarding the wheels, I found a helpful hobby shop at Allspeed Hobbies in So San Francisco. I now have some 6" monster truck wheels with 14mm hexes, 6mm center hole, and I'm in the process of making couplings from my 6 mm D shaft to that. The mill I usually use has been broken for the last month, and I'm anxiously waiting for it to come back online...