[Ken_Shea]

Any suggestions on holding a 14"x10" x1/8" thick aluminum plate to a milling machine table, I want to contour mill the outer dimensions?

With my experience I do not mind saying I am a bit nervous about the thought of CNC milling that close to my table, is there a good inexpensive underlayment that could be used?.

Thanks
Ken

[wms]

Ken,
You could use another piece of alluminum or even a sheet of plywood.
Or cut the part to with in .010 - .015 of full depth and the remove the scarf. ( that will pucker the old bum)

Or you could hang it off the back or front of the table and cut one side at a time.
Best to use something under it.

[Ken_Shea]

I like the plywood idea Ward, I have had too many puckers in my life I have some nice 1 3/8" thick stuff that I think will work just fine.

Thanks

[cncadmin]

You could contact cement the alum to the plywood that is attached to the table.

[Ken_Shea]

Paul that was exactly what I was considering but did not know for sure if it would be Ok, but that stuff really sticks will heat allow removal and then some minor clean up?

Ken

[hardmill]

Originally posted by Ken_Shea
, is there a good inexpensive underlayment that could be used?.

Thanks
Ken

Try a piece of plexi-glass and use double-sided tape
to hold them both down.

Works like a charm

PEACE

[cbcnc]

Hi,

MDF is more consistant than regular fir plywood. Though birch or a finish grade plywood would be OK. You could double face tape it to your table. I don't think it would stand up for long if it were getting wet with coolant. Maybe use a Castrol Lube Stick?

Chris

[Rekd]

I have a 60 gallon lag-lead vacuum system with lines going to all 5 machines. I use vacuum for everything I can. All the flat plates, alum castings, everything. I make all my own vacuum fixtures. I even have them running on the rotabs. (The rotabs have a Gerardi tombstone on them the width of the table with a tail rest, it's like a tombstone on a horizontal, only laying down, about 9" above the table)

If you do this sort of thing often, vacuum is the way to go. Otherwise, put a plate down, plastic, wood, alum, and tape it down or use toe clamps or both.

'Rekd teh vacuum sucks

[Rekd]

...here's a very basic vacuum plate for doing 8 weld covers at a time out of .040 thick alum 4047. I mill down and leave .002" of carrier to seperate parts after they run. No clamps used, just vacuum.

[Ken_Shea]

Very interesting Rekd, I recall reading something about that elsewhere (maybe on this board) and totally forgot about it, might be a little much for this single fun project yet very useful down the road. Where can I get ideas on the design?

CNCzone is one very, very informative site, I only wish I had more expertise to share on it instead of just taking.

Thanks much
Ken

[Rekd]

Here's another one I used on the Gerardi's for doing alum castings. The one on the left you cant see because it is inside the casting. All vacuum here as well, no clamps at all.

[Rekd]

Originally posted by Ken_Shea
Very interesting Rekd, I recall reading something about that elsewhere (maybe on this board) and totally forgot about it, might be a little much for this single fun project yet very useful down the road. Where can I get ideas on the design?

CNCzone is one very, very informative site, I only wish I had more expertise to share on it instead of just taking.

Thanks much
Ken

There are some web sites out there for basic vacuum setups. Only problem is I dont' like the waffle-board fixtures everyone seems to be hell bent on using. Biggest thing is setting up the vacuum system. The fixtures should be easier. I'll try to look up some info after Ozzfest.

'Rekd teh Inebriated

[SRT]

Rekd,
I make and use my own vacuum chucks also. But up until now I've only used them stationary. The rotary table vacuum set up is very interesting. I guess the vacuum line attachs to the tail stock end with a swivel of some type?

[Rekd]

Originally posted by SRT
Rekd,
I make and use my own vacuum chucks also. But up until now I've only used them stationary. The rotary table vacuum set up is very interesting. I guess the vacuum line attachs to the tail stock end with a swivel of some type?

For now we just use a service loop. These Gerardis (5 of them), are too hard to drill. But eventually we will put holes thru the ends and tie them in with swivels. I can swing 180's all day in either direction without worrying about the vacuum lines, but this will not always be the case I'm sure.

'Rekd teh Hot Chips + Plastic Vacuum Lines = pucker-factor; 3

[DLMACHINE]

I place 1/8 piece of acrylic under the aluminum then clamp to table,In my drawing I break the contour into 4 parts.Machine 2 opposite sides then stop move clamps to machined sides and then machine 2 remaining sides.Beware of tool paths but this is easy and cheap for single projects.