Hey! This thing is still a Work in Progress. Files, instructions, and other stuff might change!

4:1 2 speed planetary gearbox

by BoilerPlateDan, published

4:1 2 speed planetary gearbox by BoilerPlateDan Jan 24, 2013

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Multi-speed planetary gearbox. Should be able to be scaled to reduce the size.


2 speed Planetary Gearbox

I set myself the challenge of producing a 2-speed planetary type gearbox and here is the result of a few nights tinkering.

A bit of info for you:
The design uses MOD 2 gears so it’s a little smaller than my last gearbox.
The ratios are 4:1 (or 1:4 depending on which way you mount it) and 1:1
The speeds are changed by pulling or pushing the M6 bolt which connects to the selector forks

I haven’t made it but it should be buildable. Some bits may need a little further tweaking or clearances adding.

My design is 6mm MDF (I know, it’s a pattern). You should be able to print it though with a bit of playing around.

For those who are looking to build this, you’ll need to look at the parts list (a jpeg has been uploaded). There are quite a few parts needed, perhaps someone can simplify it?

Unfortunately I can’t give you any step-by-step instructions. I’ve added a couple of exploded views which you should be able to work out how to put it together from.

Good luck!

I've just realised that the original parts list shows 4 no. 12 tooth gears (all the same). This isn't the case- there are 3 no. 12 tooth gears with a 6.25mm bore and 1 no. 12 tooth gear with a 6mm bore. I've changed the parts list and uploaded it as V2.

I've also uploaded the flat parts as requested. I've just dropped them onto a blank drawing sheet so you'll need to nest them to suit your machine/ remove the centre-lines etc.

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Is there a way to make this a 1:50 gear rartio?

There could be a way but it would involve changing the number of teeth on the gears and rings. Or you could couple it to a 1:12.5 ratio box to get your 1:50. It might be an idea to see what other boxes people are posting to simplify things for you

WOW.. this thing looks awesome.. any chance of uploading a dxf fileset of the pieces for folks with laser engravers.. I think it would be a great laser project.. thanks

DXF uploaded- I'll leave it to you to sort out the sheet format. Oh, and make sure you read the note about extra machining on the selector ring.

Hey... THANKS A BUNCH... looks like a number of folk have downloaded it.. cool... and thanks for what you do.