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Old 10-20-2015, 11:33 AM
SteinHDan SteinHDan is offline
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Join Date: Sep 2015
Location: Oslo, Norway
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Default Re: 90 ton 1/14 metal excavator scratch build w/embedded PC

The tracks are made of an industry-standard roller chain and track pads. The roller chain I'm using is a British Standard 08B 1/2" pitch chain, similar to the ANSI #40 chain. I'm using this chain as it is one of the more commonly used types, and thus the price is lower. It is a bit too big for this model. The 1/2" pitch means that every track pad is 25.4 mm long, and it should really be something more like 15mm long.



The "ears" are called attachments and there are various standard types. These ones are name "k1 attachments". There are wider versions that also can be used called "wk1". They have two mounting holes on each side. Search for "roller chain k1 attachments" on google to get more info.
- https://www.google.no/search?q=rolle...=lnms&tbm=isch
- https://www.google.no/search?q=rolle...=lnms&tbm=isch


I originally planned to mill all the track pads in aluminum. But then I though I just make some temporary ones on the 3D printer, and they became very tough, so now I'm thinking that I'll keep the plastic ones until they break (or maybe they won't break). It is also a benefit to be able to drive inside without scratching the floors.



The pads attach to the chain with two M4 bolts 10mm long. I chose a slotted head, as I think it will be easier to unscrew than philips or hex when the tracks get full of mud. On the other side I use two M4 locking nuts with nyloc locking mechanism.

Ebay links:
- Screw: http://www.ebay.co.uk/itm/261605587451
- Nut: http://www.ebay.com/itm/321386920963







I also overdid the width on purpose, but now I regret it a bit. I like the wide-tracks look, but I guess this is a bit too much. The real model in scale would be something like 60mm wide tracks. Mine are currently 70mm wide.







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