[zaebis]

Folks,

I have been machinning lots of 0.1" - 0.25" alum plate on CNC mill making brackets and there has to be a better way to setup. I have 12x12 plates that I cut brackets out of. Then discard leftover stuff. Right now I position each plate on 1x2x3 blocks and clamp. It is a long process and the thing rattles as hell while being cut. Isnt there a better way to chop plates than that. I hear some use double sided tape to stick the plate to but dont see how this would work with coolant and all.

[DMF_TomB]

i use double sided tape 0.030" thick to hold sheetmetal to smooth plywood the type masons use for forms and is sometimes called sign board. it has a smooth laminate surface that tape sticks to well. i often have to use a hot air gun to pry up a corner and warm tape while prying to get it off.
.
a fixture plate that i show in a vise i often clamp pieces to it with 1/8" masonite paneling between so i don't cut into it

[Bob La Londe]

I always thought there should be an edge clamp you can use for sheet and thin plate that you could grip the edge firmly, place under tension with a screw or two instead of compression like with a vise, and then clamp down. In fact I might just have to build one. You wouldn't be able to cut edge to edge in one direction, but you can't in a vise either. Only way I know to cut edge to edge is by glueing down the piece.

I can visualize the clamping assembly to do it too. Just need to add it to my list of projects... right after flying car, but before personal jet pack. LOL.

[HorridHenry]

It is a long process and the thing rattles as hell while being cut.

And its going to be an even longer process cleaning up after the DS tape has stuck fast,

[txcncman]

When I can, I make a spoil plate out of say 1/2" aluminum, drilled and tapped in appropriate places for 1/4" screws (or smaller). Then I clamp the work piece long enough to drill the mounting holes and then screw it down and then finish machining.

[Bob La Londe]

When I can, I make a spoil plate out of say 1/2" aluminum, drilled and tapped in appropriate places for 1/4" screws (or smaller). Then I clamp the work piece long enough to drill the mounting holes and then screw it down and then finish machining.

Probably the best way if you are doing multiple identical cuts too. You can keep reusing your spoiler board.

[skray775]

Mitee-Bite Products Co.

Fixture and Edge clamps

I always thought there should be an edge clamp you can use for sheet and thin plate that you could grip the edge firmly, place under tension with a screw or two instead of compression like with a vise, and then clamp down. In fact I might just have to build one. You wouldn't be able to cut edge to edge in one direction, but you can't in a vise either. Only way I know to cut edge to edge is by glueing down the piece.

I can visualize the clamping assembly to do it too. Just need to add it to my list of projects... right after flying car, but before personal jet pack. LOL.

[annoying]

I always thought there should be an edge clamp you can use .........

yeah. They are already available

[Bob La Londe]

Mitee-Bite Products Co.

Fixture and Edge clamps

Can you be more specific? I do not see anything that places the work piece under tension and supports it above the table so you can cut through. MiteBite has a number of edge clamp downs, and cam type clamps, and a buynch of cute clamps but all the ones I have looked at place the work piece under compression. Not the best way to deal with thin sheet or plate as it will bow.

[txcncman]

Can you be more specific? I do not see anything that places the work piece under tension and supports it above the table so you can cut through. MiteBite has a number of edge clamp downs, and cam type clamps, and a buynch of cute clamps but all the ones I have looked at place the work piece under compression. Not the best way to deal with thin sheet or plate as it will bow.

With the Mitee-bite clamps, you would still want a spoil plate under.

[skray775]

Can you be more specific? I do not see anything that places the work piece under tension and supports it above the table so you can cut through. MiteBite has a number of edge clamp downs, and cam type clamps, and a buynch of cute clamps but all the ones I have looked at place the work piece under compression. Not the best way to deal with thin sheet or plate as it will bow.

Sorry Bob, I missed the "under tension" part of your post.

[Bob La Londe]

Sorry Bob, I missed the "under tension" part of your post.

Its an idea I came up with for doing things like button panels. I've played with it some, but my initial experiments slipped if I put to much cutting force on them. I have some ideas for good grip and tension, but haven't had the time to play with them yet.

[osphoto]

I have an aluminum spoil board/t-slot table.

To save my table, I place my parts on top of "plumbing" tape. I don't have the stuff near me to give an exact name, but It's this rubber tape I found at home depot/lowes. It has a nylon type back to it. It doesn't stick to anything unless it's under pressure. It's about a 1/32 thick and fairly cheap.

I place a piece of it under each of my bolt downs of my material and also place strips down to help support my material. This saves my aluminum spoil board, keeps my part from slipping to much and I can also set my cut values to cut beyond my material to help get clean cuts and of course through cuts.

Carpet tape is usable, harbor freight sells it the cheapest. About a $1.00 a roll when you can get it. It's been a while since I've bought the stuff, 6 rolls have lasted me awhile, but I rarely use it unless I'm doing small parts on aluminum when I need CLEAN cuts.

If you are cutting this aluminum and it's rattling, something isn't working well for you. My stuff doesn't rattle but I also use .25 & .125 inch bits.

[firecat69]

We use a vacuum plate for parts that are 1/4" thick and under. These are not the expensive ones requiring a vacuum pump. It runs on compressed air creating a venturi effect. You use a bigger aluminum plate with grids milled into it, and use o-ring material around contour of part. I was amazed at how well it held several different work pieces.

[Bob La Londe]

We use a vacuum plate for parts that are 1/4" thick and under. These are not the expensive ones requiring a vacuum pump. It runs on compressed air creating a venturi effect. You use a bigger aluminum plate with grids milled into it, and use o-ring material around contour of part. I was amazed at how well it held several different work pieces.

I'll probably have to buy a commercial one someday and study it. I tried a home made venturi plate and for a small part (1" x 3") I was not thrilled. I do have an idea for improving it though. To many projects not enough time.