Let's Make Robots!

Gears and gearboxes. What do you want for your robot?

Sometimes when your building a robot you will need gears. Although there are plenty of ready made gearboxes on the market they will not always fit your needs. I have been looking at puting together a collection of gears, shafts and even small bearings so that you can build you own gearboxs.

I started off with the green bevel gears shown below, they have big, strong, chunky teeth that are hard to break. These allow you to have a 90° output.

I have now found some gears with slightly bigger, stronger teeth (0.6 pitch instead of 0.5). The yellow gear shown in this photo allows you to adapt from 0.5 to 0.6.

What else would you want in a set of gears?


At this stage I am trying to keep this kit relatively cheap so some things like metal gears are out. What I have so far:

  • A selection of plastic gears including worm gears and possibly linear rack.
  • A range of suitable shafts to suit the gears.
  • Aluminium mounting plates with holes spaced to allow various gear ratios to configured.
  • Small 90 degree brackets and screws for mounting the gearbox.
  • Motors to suit (common types so they are easy to replace).
  • A couple of small drill bits for changing the gears from press fit to free spinning.
  • Some small bearings to reduce friction.

Although it hasn't been mentioned yet I have recently designed some new, low cost, quadrature encoders that use hall effect sensors and work with both 3.3V and 5V systems. I think a couple of these could come in handy.

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I pulled out my old Mr Basic to take look. I think you hit on a good idea here, as the Tamiya dual gearbox could use some competition. 

I thought this would be a good product to test the market with as many robots use a skid steer system. Once I have the kinks worked out I have some ideas for what in my mind would be the "Perfect Robot Gear Box".

Probably getting away from the original remit but also a thought for universal joints might be in order.

maybe some spacers... and definitely a servo hub adapter.

A servo / hub adaptor for what? What size spacers? I often use washers for spacers.

I have used continious servo in two projects, and each time I thought how to speed it up a bit :D, so the idea behind the hub was to use the gear box to gear the servo output up a bit, maybe 1:2 or something... Torq should be enough... Just an idea :)

If you want to gear a servo output "up" to be faster then you just need to screw a large gear onto a round servo horn and put a small pinion gear onto the shaft.

A new magnetic clutch I have designed can be used on continuous rotation servos for this purpose as well which would also protect your servo gears. The first kit to be released is only designed for 8g & 9g servos but if it is popular then we will make one for larger servos as well.

I recognize that. sometimes would servos may run slightly faster.

One of my problems isn't the gears (although worm gears, and bevel gears are a bit mroe expensive than I like).  I have a hard time making the actual box that will contain the gears, the gearbox itself.  Having a modular gear set with axels is great, but if you don't have something to stablize everything..

I would think that 3 size gear boxes, (small/medium/large) that can be easily modified to adapt to individual applictions would be worth the cost of a few molds.  Even if the boxes are just 3 pieces that snap together to form a box.

I've started designing a box using laser cut panels but it is easier said than done to make a truely versatile box. In Australia I used Aluminium "C" channel for simple gear boxes.