[TowerTalk] Thrust bearing thread

[Jim Lux]

On 10/14/11 4:34 AM, w8zn at comcast.net wrote:
> It has been interesting seeing all the posts about this. The real question is why would you ever use a TB3 or TB4 at $161 and $185 (from 3Star) when you can have a REAL bearing for only $30.98???? Made with REAL steel, seals and a zerk fitting?
>
> Check out http://www.thebigbearingstore.com/servlet/the-88/2%22-Four-Bolt-Flange/Detail
>
> A nice  1" thick plate of Delrin with a two inch hole cut in it using a hole saw from your local hardware store works really well also - Delrin however is way more expensive than these bearings.
>

Delrin might even be overkill..   A couple slices from a 1/2" thick 
cutting board (or a 1" thick board) made of HDPE (aka poor man's teflon)


Almost any plastics supplier can supply it.  A quick google for HDPE 
Cutting Board turns up, for example, US Plastics a 1/2"x12x18" sheet for $11

That acetal/Delrin is expensive.. $100 for a 1x12x12 chunk... Acetal is 
nice to machine, though.  It's a lot harder than PE and it doesn't melt 
while you're machining it, but it's probably overkill for the radial 
load bearing application.

HDPE in 1x10x10 is $18, they also have UHMW PE, PVC, Nylon, 
polypropylene, etc.  They're all fairly inexpensive.

McMaster Carr also has this kind of thing, and really, really fast 
delivery, if you want to get working on it tomorrow.

For the impecunious among us, checking with restaurants who are throwing 
them away could probably get one for free.   (They have to dispose of 
them when the cuts and scratches get too deep to be properly 
sterilized).  The cafeteria at work probably has 200 of these boards in 
various colors stacked up in the kitchen.