gear rack

[Mike Windsor]

I have an older PR style shopbot , and I'm upgrading the rails using 8020 extrusion and BWC rails . On the old unistrut rail the gear rack was held on with double sided tape . I'm trying to figure out how to hold the rack on my new rails . --are they screwed onto the rails on the new PRT machines ? --how far apart would the screws be ? ---do they use tape as well ? Thanks for any input .

[bleeth]

They still use double sided tape but make sure you get the right stuff. It's a 3m product that is extremely high tack.
I have a bit in my shop and if you e-mail me I'll check the model #.
I got it either direct from the 3m store or RS Hughes. It's pricey.

[gc3]

http://www.cncrouterparts.com/rack-c....html?cPath=21

seen these?

I would think the 3m tape and end bolt attachment like on the uni would work. look on ebay for jimmystractor or similar name...has the tape cheap, i got 2 250' rolls $12.95 ea http://shop.ebay.com/jimmystractor/m...id=p4340.l2562

post photos, i would like to see as I have a pr also

[MogulTx]

It is tape, I think and the only tape that they would dare to use for this- to the best of my knowledge- is 3M's "VHB" tape. VHB stands for Very High Bond. Once it bonds- it does NOT come off. Comes in different thicknesses. You want fairly thin because movement will cause wandering in the rails, and that is not what a CNC needs.

I used RS Hughes, as well. Good source. Not the cheapest in teh world, but a very good supplier of various materials for me.