[canman77]

Wizard and MARV: Thanks for the comments. Very informative. It is sounding more and more like a futile effort to do any kind of vacuum work holding for the cuts I am making...if I were simply engraving parts, it might be different. But I am in a semi-production environment and the goal is to hog parts out as quickly as possibly. If that means tabs, so be it. I suppose my goal now is to optimize my tab efforts. Nothing worse than the tabs breaking during cuts...or having to break off a million tabs after the cut..

Thanks again for all of the information. This is giving me a great starting point to do a lot of research and see what is actually feasible for what I want.

[MARV]

canman7, if you are trimming tabs by hand afterward, you may want to try to onion skin the whole part during your roughing operation and take a final pass (perhaps at a slower pace) and clean the onion skin out at the CNC. Keeps things a bit simpler when programming and you won't be exerting as much lateral cutting force on the work piece. And you may not have to do any hand work afterward. Just a thought.

[wizard]

Wizard and MARV: Thanks for the comments. Very informative. It is sounding more and more like a futile effort to do any kind of vacuum work holding for the cuts I am making...if I were simply engraving parts, it might be different. But I am in a semi-production environment and the goal is to hog parts out as quickly as possibly. If that means tabs, so be it. I suppose my goal now is to optimize my tab efforts. Nothing worse than the tabs breaking during cuts...or having to break off a million tabs after the cut..

Thanks again for all of the information. This is giving me a great starting point to do a lot of research and see what is actually feasible for what I want.

Gee I hope I didn’t turn you off to vacuum fixturing completely because it can have a use in a production environment. The problem is it has to be carefully considered. Sometimes it might even pay to have a custom vacuum box for a specific part run. This is no different that setups done on production mills, fixtures are designed for the part to be made.

Other things to consider are hard hold downs in areas that are known to be waste. You can run a couple of screws into threaded holes to supplement the clamping for rough milling and rely upon vacuum for final cut through. You can even use the vacuum to hold the part in place to “drill” the holes for those clamping screws.

In other words vacuum tables can be part of the solution or the whole solution. You don’t want to think in terms of all or nothing in production. Rather think about what is cost effective and minimizes difficulty on the floor.