Question about wheel covers

[Mark Farris]

Hey all,
Up to this point the occasional cleaning of my X and Y rails and wheels has been sufficient for most of the jobs I have been doing. I am now cutting a lot of 3/4" HDPE for a very picky client who needs excellent edge quality. I have found that I need to polish the rails and wheels before every few sheets as ANY debris that finds its way between the rails and wheels causes a "nick" in the edge surface and ruins the part. My PRS Alpha is a 2010 model which was before they added the wheel covers, although there are small holes in the plates beside each wheel that appear to be in the right position for them. Question, does anybody know if those holes are for the covers, if by chance they are threaded and/or what thread they should be, and if anyone sees a problem with buying the covers with the rail wipers from Bishop-Wisecarver and would they fit? Your wisdom is appreciated. They aren't cheap at nearly $60 each and I want to make sure before I order them.

Thanks,
Mark

[Brady Watson]

Don't bother. It does nothing to mitigate the problem of the low rail height harboring chips. It'll work OK for a little while, but then get all jacked up with chips and the problem will return.

Instead, consider making yourself a couple rubber curtains that hang off the beam (at a 90 deg angle) and shield the rails from chips. You could probably make it out of sheet material, but rigid will get in your way. EDPM rubber like pond liner works well. I did this same thing on my PRT for the same reasons you mention.

-B

[Mark Farris]

Good to know Brady, that's why I asked. My initial thought was a curtain of sorts, I guess I'll go back to that. Although I have finally gotten the edge quality desired I think I'm pushing the limits of my Bot. Any little thing and it's gone. Thanks for your time.

[jTr]

Wiper covers do add the benefit of a light wipe-down and simultaneous oiling of the rails, which I've been given to understand optimize performance and longevity, if you keep the wipers dampened. While I do not cut any of the described material, virtually all wood dust is very well managed by these simple covers, and the rails look highly polished, like new all the time (6 years for my machine). No argument against Brady's advice, other than to say they appear to be doing a good job and I don't feel the idea of installing a set should be completely disregarded.
They simply need augmentation with the curtain idea in an extreme situation such as the HDPE shavings. Was surprised to read that your machine did not come with them, and I'd never run mine without, after seeing how well they work against average everyday sawdust.
Curtain first to solve immediate issue.
As soon as budget allows, I recommend you get a set of covers.

jeff

[nat_wheatley]

I used hard felt, pushed against the rail, and it works well. It was Gary Campbell's idea. Reply#7 on this post shows how mine is attached:

http://www.talkshopbot.com/forum/showthread.php?11114-New-Version-Rail-Wipers&highlight=rail+wipers

[Brady Watson]

There's not much to the wheel covers. The profit margin on them is insane...

FYI - you can download the CAD file for the wheel covers (which retail anywhere from $35-50 EACH) directly from the BWC website. It would be easy to 3D print and possibly machine your own - you can even do your own design.

The pre-tapped holes in the PRS gantry plates are either 2.5 or 3 mm - I don't remember off the top of my head...so don't go jamming SAE threads in there unless you re-tap them.

Yes - the covers are good and useful if you do the maintenance....which means oiling them and replacing the felts as required. Having traveled to every state in this country (and beyond) I can honestly say that very few even clean their machines & way less do proper maintenance on them.

PRS got the covers on the #3 Y rollers shortly after the switch from early PRS #2 Y rails. The #2 covers on the gantry side plates came much later and I'd imagine there are many on here who didn't get them.

-B

[gundog]

Check out this old thread I hope the pictures still work I got a notice a while back from photo bucket about having to pay for them to host pictures it worked for me but it was my account. http://www.talkshopbot.com/forum/showthread.php?288-Rail-sweepers&highlight=rail

[Ken Sully]

I got a brush from John Deere used in a corn planter. Cost 6-12.00 can't remember. Our brush will do all of the wheels. Used a bolt with fender washer to capture the brush. Works fine

[Mark Farris]

Mike,
Your pics are basically what I had in mind. Just ordered brush stock and will post pics when I get time to fabricate them. Thanks all for the responses.

Mark