Tracked vehicle

Don DIY
https://www.youtube.com/watch?v=HYLazxjcFLk   http://youshouldbuildit.blogspot.nl/p/blueprints.html

https://www.youtube.com/watch?v=YJXprgSDJ6Y blueprints

RC model plans(tanks)
https://www.rctankwarfare.co.uk/forums/viewtopic.php?f=150&t=13714 from RcHobby:Forums

http://www.scaledtanks.com/news.php linked from Tankman101 youtube videos.

ducks Garage
https://www.youtube.com/watch?v=J9at2aWAwZs making idlers and sprockets. Cuts a precision circle out of 2cm steel over six hours with setup.

= steel tracks = https://www.youtube.com/watch?v=4JfcQxwWHJY  How to build steel tracks

https://www.youtube.com/watch?v=xICesaqfiIo 2/5 tiger tank tracks (25mm square tube)

Tankman101
https://www.youtube.com/watch?v=U_2gYZAa10g badger mk1 tracks, make steel wheels with flat bar 150mm hose clamp tack weld by tankman101. Combine this idea with Thai ground robot. Drill 10mm spaced holes around flat bar that has been wrapped over 5mm steel disk. Wrap solid cut piece of scrap tire around this flat bar and countersink holes for M6 bolts.

Links
http://www.mitosal.com/
 * https://grabcad.com/library/my-chain-1
 * https://grabcad.com/library/crawler-track-system-02