CNC work holding suggestions

[Woodenspoke]

I am in the process of setting up for a small CNC project where I need to cut two pieces out of 1/2" and 1/4" aluminum. My CNC machine is small a Sig X2 type.

The first piece is an oval plate 1/4" thick with no holes. I have used wedges to hold 1/4" stock before, but I have not tried cut out a pattern from the center where the piece is released from the stock. I was planning on using my current wedge setup but I worry that the final cut may damage the edge of the piece when it releases. Should I worry. I was also thinking of maybe leaving a small connection point so the piece does not release fully? Maybe someone has a better solution as I have limited experience with different holding methods.

The second piece is a 1/2" by 1" bar stock that I need to make three holes and profile the 1/2" edge of the bar stock. Besides making it a two part procedure where I cut the holes then use the holes to clamp the bar, then profile the bar's edges. I would like to do all of the operations at once, but it would require access to all sides except the bottom. I am at a loss on this one, any suggestions?

I am using a jig plates now but I do not have a vacuum setup.

[neilw20]

Underneath I put a piece of stock so that I do not eat into my virgin table.
If z depth is accurate you can leave 2 to 3 thou and just break out when finished. that thin is usually small enough that deburring cleans it up perfectly.

Other wise cut down that far all the way round, and on the finish pass just leave 3 or 4 spots by a tiny Z move to leave it just joined.

An alternative is to glue the material onto the scrap underneath. Glued to fine chip board is perfect. Super glue is pretty good and a good shearing hit when finished shatters it from he baseboard. Acetone will remove the super glue remnants.

[Woodenspoke]

I put a piece of stock so that I do not eat into my virgin table.
If z depth is accurate you can leave 2 to 3 thou and just break out when finished. that thin is usually small enough that deburring cleans it up perfectly.

The glue idea is out as I have to do 25 pieces at a time. I do have a sacrificial plate above my jig plate as I have been cutting out holes in similar sized aluminum plate. I will have to see if I can get my setup to leave 2 or 3 thousands. For now I am relying on some simple programs to generate G code for the mill so any fancy moves may take a bit of programing training on my part.

[Woodenspoke]

No one else has any suggestions????

[lkenney]

Can you use pins to locat your stock? I would predrill locating holes in the waste or back of the stock. On the aluminum base I would drill and loctite in locating pins, they can be quiet small, then glue down material with super glue. The pins will help with the sideways pressure not breaking the glue bond and for locating the stock rapidly.
Eagle