Ideas on how to hold a small part?

[bobmoore]

The parts in your pictures do not look like 1.5 inch thick material. You would have to run with an 1/8 bit because of the thin slot on the right side. UHMW is a bear to run with such small dimensions even with thinner material. I would say no quote if you're busy or time and material quote to verify process. Be safe with that project because I think things could get out of hand quickly.
Bob

[Burkhardt]

One more idea....
- Screw the somewhat over-size blank down on a piece of scrap plywood at the corners (double sided tape in between optional).
- Cut only the side with the arches and detail first (open vector)
- Lay a thin piece of wood on top of the still attached part and hold it down with 2 or 3 screws through the arches' openings. Large washers instead of the wood piece might work as well.
- Cut the part free along the straight back (another open vector tool path).

[gbradley]

Thanks guy's for the input. I did try cutting this part with the use of vacuum, and gasketing. I made a fixture to cut two of the parts pictured, and I will say i did cut two of the parts in the picture @ 1.5 UHMW, not the 1/2" red shown in the beginning of the thread. The process I have to cut this now is to rout out most of the material with a 1/2" up cut bit, and on one portion of this part has a .15 cut in it so i have a long reach .125 up cut bit to handle that. With the last cut I use a .25 up cut bit to rout through the rest of the material. I have never cut UMHW before so I have that learning curve to deal with. If i am going to do this job I am not going to use our big regen blower for this job I am going to use the 1/4hp rotary vane pump we have and use .03 thick, medium density gasket material to get a better edge on the part.
Bottom of vacuum fixture.jpg
Top of vacuum fixture.jpg
fixture.jpg
PART1.jpg
PART2.jpg

[scottp55]

Pretty NICE George considering thickness/nature of material and small vac area!
Congrats
scott

[gbradley]

Thanks Scott!

[James M]

George,

What brand of long reach 1/8" bit did you use?

Thanks,

James

[joe]

Wow, I amazed at all the options on this topic.

Here's what I do when I need little, itsy bitsy, delicate letters. After securing the substrate, route the letters deeper than they need to be. Then take the substrate over to the band saw, set the fence to the desired depth and push the piece through. To keep the letters from fall out, I use a little masking tape on the back.

There have been times when I needed several copies so I route extra deep. Then push the substrate through twice. It's so easy and fool proof.

[gbradley]

James


Sorry I forgot to answer you question about the bit.

long reach .125 bit.jpg

[bobmoore]

Sorry if I am wrong but I think this is an advertisement for vacuum fixture supplies or these are some extremely expensive little parts.
Bob

[gbradley]

No advertisement! I have never cut UHMW and it seems like I could come here and ask for an idea on different techniques on ways to cut.