UHM…W, I call it. UHMW the wonder plastic.

I have decided to use UHMW, which is a hard plastic, to make the drive sprockets and track treads out of.  And other stuff later on.   You can get remnant/scrap pieces, ($1 per pound in my case), which is a very fair price… after all, it’s plastic, not lead.

Why UHMW?   It is a thermoplastic polyethylene.   It has the “highest impact strength of any thermoplastic presently made.”   It has very low friction (less than nylon and acetal, and is comparable to Teflon), is self-lubricating, and is highly resistant to abrasion. It is odorless, tasteless, and nontoxic.  It is also very resistant to water, moisture, most chemicals, UV radiation, and micro-organisms. *

Basically it’s super tough.   BUT, the other great feature, is you can cut it with most woodworking tools… about the only thing you don’t wanna do is sand it with sandpaper.    I was also able to get it in black, which is nice, will give the tracks a nice realistic look.

I got 1/2″ thick for the treads.  I decided I will cut them 1″ wide, and I think the 1/2″ will be perfect… I had originally said 1″ thick, but I think that is overkill… it would weigh twice as much, and would dig or catch more into soft ground, which should not be necessary.

For now, I cut out one drive sprocket, just need too clean up the edges a little:

* – Copied verbatim or paraphrased from http://en.wikipedia.org/wiki/Ultra_high_molecular_weight_polyethylene

Advertisements

2 Comments

  1. Can this be injection molded?

    • I don’t really know the process of making the UHMW, I think mostly it’s made into sheets, and parts are cut, CNC’d, etc. That being said, they do have a grade 2, which is where all the trimmings and stuff are re-melted down, and made into speckled colored sheets, so there is a process for melting it, I’m just not familiar, sorry.


Comments RSS TrackBack Identifier URI

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s