Hi, I know this sounds silly. But with an RC car do they make a holder or bracket to allow you to mount a motor and axle in order to allow both wheels to spin off the one motor. I’ve tried mounting a motor parallel but it moved around a bit in the model and was a bit average.
Just wondering if there is such a thing as a bracket that holds both the motor and supports the axle?
Hi Earnes,
What kind of motor are you using, do you have a link to it?
Typically small RC cars will use wheels that connect directly to the output shaft of the gearmotor. This is easy for mounting and adding additional wheels means just adding another gearmotor to the same or another motor driver channel.
For the second wheel you wanted to add, will it always be travelling at the same speed and direction as the existing wheel?
I’ve build a 4 wheeled robot where the two wheels on each side have 3d printed gears mounted to a gearmotor, then an intermediate gear between the directly driven wheel, and the free-spinning wheel. It’s quite tight getting the wheel and gear to fit on the single output shaft but it can be done.
Really appreciate your reply.
I’m building a steam paddle boat so wheels will turn slowly st the same time.
I actually need help picking a motor also but I’m trying to design a boat currently and would like to incorporate the design for the axle and wheels. I’d really love to have both wheels spin from the one engine.
Regarding KV I have no idea but If I had ro guess I’d be looking for a 27T motor I think?
I’m 100% new to this.
The paddle boat will be quite large. Around 65cm long and potentially around 2kg
Hi
I think I have seen somewhere small motors and gear boxes where the final drive shaft protrudes out both sides, presumably just for that use.
Cheers Bob
This sounds like it! I’ve been searching for days can’t find anything particular
So close!
Hi
Yes that is the sort of thing I saw. Also some motors have the shaft going right through. Would be a bit fast for your application but might be able to implement 2 identical gear boxes maybe.
Cheers Bob
Many of the chassis kits for cars have an option for locking the diff. For instance, for the TAMIYA 58584 TT-02D Drift Spec Chassis Kit there is:
Drift cars usually operate with locked diffs.
The problem will be finding just the drive shafts and differential, but they may be available as spare parts. ‘Locking diff’ or similar is the search term you are after.
Another option is to lock the diff with glue! See:
How To Lock An RC Car Diff The EASY Way! - YouTube
Hi Earnes,
Sounds like a cool project, I assume your steering comes from a rudder then not differential steering via the paddlewheels. A lot of small scale RC vehicles will use skid-steer/differential steering so I wanted to double-check that wasn’t a requirement.
This category on our site shows the 3 most common sizes of hobby gearmotors. We don’t typically carry the dual output shaft variety outside of the Tamiya gearbox kits you’ve already found but it might be helpful to compare the output speed/torque of each size so you can get a ballpark idea how what scale motor you will need. Then worry about the gear ratio later once you know the rough ballpark you need for power. I’ve never build a paddle boat before so I’m not sure how much force it takes to get them turning.
Is there another project or design you are drawing ideas from that could help us find some suitable parts?
Hi
Looks like that gearbox set up has 2 motors which puts you back to the same problem. I meant one gear box with the shaft protruding out both sides.
What would be wrong with the 2 paddles being connected with a single shaft right through the boat. This could have a tooth belt type pulley mounted somewhere conveniently along its length then the whole thing driven by a single motor with another tooth belt pulley attached. Or gears wheels maybe
Cheers Bob
Hi Bob. Yep this is exactly the setup I’m after, with the length of the shaft going straight through and driven by the one motor. My problem in testing has been keeping the shaft nice and tightly up against the motor gears, as slotting it into a 3D printed area seems a bit sloppy and I can’t get it to grip most of the time. So I thought it would be good if there was a mount that keeps the engine mounted and the middle of the axle mounted also which would ensure it is Al nice and tight and no slip for the gears to work well.
Hi Earnes,
Perhaps instead of trying to mount the gears to fit with perfect clearance you could instead use pinion gears between the gearmotor shaft and drive shaft with a timing belt? That may be easier to mount as you’ll have a bit more flex, if it requires further adjustment you could try and add an idler gear you can adjust the tension on to take up any slop.
That’s not how I designed my robot but it did take me 3 revisions to get the 3D printed gear dimensions dialled in enough that the drivetrain didn’t either lock up, or free-spin. It’s still not perfect so a timing belt may be the nicer way of doing it.
Hi
Just found this.
Is this more like it. Available from Core too. Nobody looked apparently.
Cheers Bob
Oh my, I somehow went straight past it. That is exactly what I need! Thank you!!!
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