Large robot or crawler track - 75mm wide tread

This is a track design for larger robots or crawler / caterpillar style RC models & vehicles etc.

It's designed to conform to ISO16a or ANSI 80 standard for 1" pitch roller chain, so should work with metal sprockets as well as suitable printed ones. The sprockets I'm using are based on someone else's design from Cults 3d, so I cannot share those. They are here:

https://cults3d.com/en/3d-model/tool/ansi-80-roller-chain-sprockets-with-hub

Two versions of the chain are included: One (my original) has “waisted” links like normal metal roller chain; the second has flat tops on the outer links and one side of the inner links, so plain rollers can be used as idlers rather than needing sprocket idlers.

Use whichever is appropriate for your requirements.

The chain is designed around metal bushes for pin positions in both the inner & outer links, and the rollers on the links.

The pin bushes are 6mm bore, 8mm o/d; one 5mm long one in each hole of the outer (tread) link walls, and two 10mm long ones in each inner link end.

The rollers are 14mm bore by 16mm o/d, 15mm long. Those slide on to the inner link halves before pressing the two link halves together.

The holes for the pin bushes will probably need cleaning out to 8mm with a drill bit, before pressing in the bushings. If needed, also clean out the larger holes in the inner link walls to 11mm to allow the two link halves to be pressed together.

The chain is built up by joining the completed links with 40mm long x 6mm diameter clevis pins, using a 6mm washer at either end then a split pin through the clevis pin to lock it. The split pin end should be trimmed to around 10mm and the ends folded back tightly around the clevis pin, once the track operation has been confirmed.

Clevis pins seem to be measured differently by different suppliers; the ones I use are 40mm along the 6mm part, to the tip. Around 38mm between the head and split pin hole.

The metal bushes are all from this store on Aliexpress:

https://teclachiara.aliexpress.com/store/230702

They are SF-1 series, sizes 0605 for the outer link sides, 0610 for the inner link pins, and 1415 for the rollers.

I made around 3m of this chain a while ago, for a big ongoing project. That was printed in PETG; use a suitable material for your application.

A carbon fibre reinforced type may be best for heavy duty or outdoor applications.

The new “proving” print on the Bambu X1C was in PLA as that's all I had to hand.