For a project I am building a large several tier, guess you could call it, tray for my grandmother with different inlays and decorative things cut into it. My question is in regards to clamping. I have to cut several circles out of 3/4 and 1/4 material that is 4" by 4", with patterns in them and I have to cut the circle completely out (with tabs). Rather than clamping down every 4" by 4" piece of material I have and swapping them out over and over, can I take a larger board (10" x 5" x 4/4) and cut inserts into them to put the 4x4 material in without having to clamp it every time? Below is a crude idea o what I was thinking:
The green stars would be clamping the ‘jig’ down but no clamps would be used at all on the cut out sections. I would simple put each of the 3/4 and 1/4 materials (the 4x4") into each of the grooves. Would that be sufficient to hold them down through the cutting process? Or would I still need to clamp them?
Thanks in advance.
Yes, locating your pieces inside the jig would be a good idea. It will keep the pieces from moving in the X and Y. However, something still needs to hold the piece down. If you use an up-spiral bit, it will tend to pull the workpiece up out of the jig. This might also happen when the bit is raised in the Z. Finally, you will want to do something to keep the workpiece from shifting inside the jig. You will likely still need to use something like a hold down clamp, double sided tape or some sort of wedging to hold everything completely still.
You might be able to create a similar type of jig that comes down over the top of the workpiece and has cutouts through which the bit can reach the workpiece areas that are to be machined.
I’m not entirely clear on what you’re trying to achieve, however I do understand the struggle in trying to clamps odd shaped things down…
I’m sure you’ve seen this previously, but don’t discount the option of using double sided tape.
I buy rolls of double-sided mirror tape (it’s a “foam” type of double-sided tape used for holding up mirrors, pictures etc) and often use that instead of clamping.
If you’re a little clever in where you place the strips of tape when affixing it to the table, you can have the tape assist in holding the pieces that have been “cut-out” - either by relying on the tape alone, or by using only a few tabs instead of lots and lots of tabs.
The work can be pulled off the table (sometimes it’ll need to be prised off with screwdriver) and the tape can be removed by “rolling” it off with your fingers.
I’ve used this for fragile & weird shaped bits (and gears) for wooden clock and I’ve done this for heavy work such as cutting out deep pockets to make one-piece ‘boxes’ out of aussie hardwoods.
Not sure if it’s and option for you or not…
There is a way to “clamp” things down without having to do tabs…
I use painter’s tape (blue tape) and super glue…
Apply blue tape to the waste board and the underside of the project piece.
Apply super glue to the blue tape on waste board, then set the workpiece on to the waste board.
This allows the superglue to adhere between the two pieces of blue tape, holding the workpiece in place, and by simply removing the tape, you end up with a clean underside of the workpiece when finished!