CNC Pressure Foot

[tri4sale]

Looking at adding a pressure foot to my ShopBot for cutting some small pieces, and this is only one I've found:

http://www.widgetworksunlimited.com/CNC_Pressure_Foot_br_for_ShopBot_PRS_p/cnc-pressure-sb_prs.htm

2 questions, first has anyone used this pressure foot and if so what are your thoughts?

Secondly, does anyone know of any other pressure foot designs out there?

thanks

[bill_l]

I've been using it for about 18 months. I double side machine numerous small parts with plenty of small holes out of 4' x 8' x.125" sheets of polycarbonate. The parts are tabbed but testing with both up and down cut bits without the pressure foot resulted in too much flex and damaged parts. The pressure foot was the only solution and it works great.

[knight_toolworks]

been using it for years. you still need some way to hold the sheet in place. I use it keep thin plastic from lifting up when I cut it. but there are other methods depending on what your cutting. what I dont like is the time it takes to get it up and running. depending on the material sometimes you can use a straight bit.

[coryatjohn]

Three words: Double Sided Tape.

[knight_toolworks]

Three words: Double Sided Tape.
well unless it is a 4x8 sheet. a compromise is to spray one side of the material or table with strong contact glue and then vacuum it down. that works well but it is a bit messy and it can get expensive. I use the foot when ti is the only solution.

[Chuck Keysor]

Hello Daniel. I tried using double sticky tape to hold down 1/4 thick, 4'x4' melamine sheets, on which I was doing V-carving. The double sticky tape simply didn't work for me at all. I should have gotten set up with a hold-down vacuum, but I didn't........ So upon recommendations from people here on the forum, I got the Widget Works pressure foot. On one level, for the most part, it did what I wanted it to......... but not quite the way I wanted.

It turned out that it was very easy to apply pressure to the foot, and have the two springs compress, and then for some reason the shafts that slide through the sleeve bearings would bind! So the pressure foot would not ride over bumps, but I had to use it more like a sewing machine foot, to simply smash the material down, with the springs collapsed.

I have attached two pictures, which I took earlier this evening. The first picture shows the springs extended as you would expect. But then I pressed on the foot with my hand, and without any tricks, the mechanism would bind up, leaving both springs compressed/locked/binding.

I was a bit annoyed, but as noted, by using it wrong, it more or less did what I wanted, though I think I got some scuffing by misusing the pressure foot.

I did try to lubricate the sliding mechanisms, but it didn't help. However, I never complained to anyone at Widget works, so I am not complaining about their service. They probably would have helped......... There is a Bible verse which goes something like: "Ye have not, because ye ask not".

So that is my assessment.......... Good luck, Chuckhttp://www.talkshopbot.com/forum/attachment.php?attachmentid=32993&stc=1http://www.talkshopbot.com/forum/attachment.php?attachmentid=32994&stc=1

[coryatjohn]

I suggest using a bit of teflon shrink wrap tubing on the shaft to take up the play and provide a dry lubricant. That would probably be a cheap and easy fix.

[Chuck Keysor]

Thank you John. That seems like a logical solution to remove the excess space between the shafts and the sleeve bearings. Chuck

[coryatjohn]

I love shrink wrap in all its forms... so satisfying to use.

[dlcw]

I've used the pressure foot a few times. The one thing I noted using it is, it will drag chips from your cutting into areas that haven't been cut yet. This is especially noticeable when engraving non-ferous metals (aluminum, brass, etc.). It would leave scratches all over the surface. I have a strong dust collector on my CNC but still wasn't enough to lift all the chips. I noted the same thing when trying to cut veneer. Left scratches on the surface. Not sure the solution to this problem.

[tri4sale]

thanks for the feedback, I'm about to order, but looking at the pictures and my PRS I just can't see how it mounts? Anybody got a picture of how it mounts, and how easy is it to take on and off?

[Chuck Keysor]

Daniel,,,,,,,, things aren't set up for me to take a picture, but I recall that attaching the foot isn't hard. However, I don't use the dust collection attachment, and maybe they both won't fit on at the same time. Chuck

[bill_l]

It attaches the same way as the dust shoe that came with your machine.