Attaching wheels to servos

Community General Discussions
1

I have got hold of a couple of these...

https://www.robotshop.com/uk/parallax-futaba-continuous-rotation-servo.html?gclid=CMSn9fuQyscCFSsEwwodRLEBEw

 

but want some advice on how I attach wheels to them as the holes on the servo spindles(?) are about 2-3mm wide. Can you buy screws that small?

 

This is my first ever build so I am completely new to all of this.

 

 

2

Servos and wheels

Most wheels on robots are not driven by servos but by motor gear assemblies.

Take a look at Actobotics, they have all kinds of couplers and wheels that willl fit on servos:

https://www.robotshop.com/en/catalogsearch/result/?q=actobotics

3

Attaching wheels to servos.

I can think of 4 methods.

  1. Get wheels with holes that match the spacing on the servo horns. Generally I use small wood screws but you can drill and tap the horns for   machine screws.
  2. Get wheels with the servo spline builtin nd secure with a single screw thru the servo shaft.
  3. Get a round servo horn and use double sided tape to glue the horn to the wheel. 
  4. Get metal servo horns with threaded mounting holes.

If you do get different servo horns make sure you get the correct number of splines!

4

Many thanks for the

Many thanks for the information, I’ll check out the link also. :slight_smile:

5

5. 3D print the wheels.

5. 3D print the wheels.

6

Small Screws

I have zero experience attaching wheels, but at this point I have an enormous amount of experience in attaching other things to servos.

In the US, small screws are hard to find. Some hobby stores (that have RC parts) and a good Ace Hardware or a Do It Best Hardware have some of the smaller sizes. Home Depot and Lowes stop at #4. You would need a #2 to go through most of the plastic servo horns (+1 if you have the round ggallant talks of) after you drill them out. Easier to find is metric machine screws, 2MM x 19MM are fairly easy, longer is harder. The RC stuff is largely SAE (society of automotive engineers and not metric) and #2 and #4, mostly #4. Microcenter may have collections of small metric hardware. Cheap metal servo hubs (note the spline count as there are both 24 and 25 splines) can be found on Ebay (I think they take 3MM). 

also:

https://www.boltdepot.com/

I buy this stuff as I find it, not as I need it…

Not everyone has a 3D printer, yet…