How to attach/animate tank treads around wheels in assembly

orlando_lupone

Hi, I'm new to CAD and I've been trying to wrap tank treads around wheels and so far I haven't been able to find any resources on how to do it. It would look something like this (https://www.thingiverse.com/thing:15528). except that's not exactly what I'm trying to make because I only have one grooved wheel and four other smooth wheels. I was just wondering if anyone had any idea on how to do this. If it's possible if someone could also explain how to make the treads go around the wheels when animated would be greatly appreciated. Thanks in advance!

MichaelPascoe

If you are inside an assembly, you can mate the treads similarly to how @NeilCooke has done in this forum post.

imants_smidchens

For creating custom tread paths, you could try using a Feature Script I made recently: 
https://cad.onshape.com/documents/1be886df2e36b431c92b2d61/w/791200d47653055fd5d51eb7/e/2346394668da0ee679271f52?renderMode=0&uiState=61f427cf19430907be13b417
(for some reason I can't see the thingiverse object, but hopefully this is similar)
you should be able to click the [+] at the top and add the tool to your toolbar.

Unfortunately, creating animated chain links/treads is challenging at larger scales, and aside from using a ton of revolutes & tangent mates, I don't know of any way to do so in Onshape.

S1mon

If you're ok with faking things a little, you only need a few frames of different positions to animate a chain/tread.

Frame 0 is the starting position.
Frame 1 moves the chain by 1/3 of a link.
Frame 2 moves the chain by 2/3 of a link.
Frame 3 is the same as frame 0, and repeat...

You need at least this many frames to get the sense of direction correct (i.e if you just have 0 and 1/2, it will pulsate). You can add more in-betweens (e.g. 1/4, 1/2, 3/4) to make the movement slower/smoother.