Keeping Parts Dust-Free in CNC Production
Tips for keeping parts clean as they come off the CNC. October 27, 2008
Question
One of the things that really bothers me is the amount of dirt/dust off of the parts on the CNC. Both sides are dirty and it always seems the parts have a static charge, especially on melamine, which makes them hard to clean. When they go to the bander, we're just introducing more dirt into the machine. Anybody find a solution?
Forum Responses
(CNC Forum)
From contributor M:
Put in a ground rod within 6 to 8' of your machine.
From contributor S:
Depending on your production requirements, take a look at your tooling. For melamine my best solution to the dust issue is to onion skin all parts, first pass with a standard compression, second pass with a full upcut modified to bring back all but the bottom 1/4 inch or so by 1mm. This evacuates nearly all of the dust from the groove. It really leaves a very clean cut and virtually no dust at all.
It will cost me maybe 15 percent in run time on average for the second pass, since drilling is not relevant, nor dados, and I would onion skin all the small parts anyway. It's just a second pass on large parts that is added. The little dust left blows off with an air gun before the sheet ever leaves the router or the vacuum is ever turned off.
From contributor I:
That is a great idea, but why do you use a compression bit? Wouldn't a down spiral do the same thing in this case?
From contributor S:
In a sense, yes, but a standard compression bit is about 2/3 upshear and just a little at the top down. It packs less dust to begin with and makes less for the upshear to do. Aside from that, I rarely like to use a downshear over a spoilboard, as it generates more heat and results in less tool life. For example, if I am cutting MDF or shop grade plywood, I use a slow full upshear.
From contributor L:
Why would you put all that extra wear and tear on the machine? The extra time is not the only factor. Make a brush the width of your spoilboard, give your operator an air hose, tell him to blow parts off. It's a lot cheaper than the rails and leadscrews on your machine.
From contributor S:
My lungs and those of my coworkers are more valuable than the machine. I owned my own shop for 10 years, did well and kept the place pretty clean with a good dust collection system and attention to simple practices. It's really not that much trouble, expense or time. The people I work for now appreciate a clean environment and it is one of the best things about working for them.
Look, if I ran my machine anything close to even 40 hours a week, I am sure I could come up with other ways to get the dust up the chute and into the bags and reduce that 15 percent of machine time. Besides dust double passing also means almost never losing a part to movement. I'm not saying my way is the best for everyone. It's just what I do to get good results. Other people are out there doing different things to get good results too. Tooling strategy is only one aspect to exploit. Use it or not, but don't make the dust cloud I see more often than not.
Others use an air blast under the dust hood while the cut is being made. Carefully managed it can do a fair job when combined with a decent collection system that has proper flow.
