Almost 2 months ago Ed and Keith talked me into going to Ed's ShopBot camp, even though I didn't have a ShopBot or any plans to have one.
One thing talked about for more than 1 hour was vacuum and holding parts down to cut them using vacuum. I had messed with vacuum tables a little in the past, but mostly for metal cutting, and it always worked with limited results.
So, several weeks ago, I throw a sheet of Ultra Thin IPI plastic in (Rowmark color doesn't match customers spec), and I had 500 tags to engrave and then kiss cut. About 1/2 way through, I glanced over and found my work floating inside the cabinet and the laser kept on going
About that time it hit me that I had a vacuum table and wasn't using it as such. So I took a couple of pieces of scrap material I had, put a new sheet of Ultra Thin down, and then blocked off all the area around the material. Man, did it suck that material down!
Worked like a champ. A week later, I had a job that called for some material I already had in stock (IPI bowed up material), and I put it on the table, turned the exhaust on, and then blocked off the open areas on the table with some sheet vinyl scrap I had. Again, pulled 1/2" bow right out of the material.
My machine is running right now on a piece that's got a huge amount of material removed. Did one last week and fought it, as it's so much removed that it wants to bow. Did it just now and used the vacuum technique learned in ShopBot Camp, and danged if it didn't keep the material from bowing up while cutting out that large area.
It's so simple and one of those "Dohhhh" moments. I thought I was smarter than that, but apparently not. So if you are like me and you have been staring at the open honeycomb pattern, stop and cover those things up and watch it suck the material flat down on the table.
Try it, you'll like it.
Thanks Ed, and thanks ShopBot guys. You really helped me with my laser work!