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Air purging a fixture

Cole2534

Diamond
Joined
Sep 10, 2010
Location
Oklahoma City, OK
I have some parts that I routinely make and I use the same fixture each time. It's accurate and reliable but collects chips in some spots that if not removed won't allow the next part(s) to properly seat.

My machine has an air solenoid with plumbing to the enclosure. I'm wondering if I can use that along with some porting basically air blast the fixture for say .5s after the last op finishes.

Seems straightforward, but are there any pitfalls? Is this common in shops or does my fixture just suck?
 
Sure you can do that. I've seen lots of videos where they use an air or coolant blast to clear chips. It's always a good idea to clean manually with an air gun when swapping parts though.
 
I have found that coolant or water works way better at cleaning chips off than air, and it's quiet. A large part of good fixture design is avoiding features where chips can collect.
 
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A large part of good fixture design is avoiding features where chips can collect.
I agree, it's the true art of this beast. I'm holding onto 0.400" of a 3/4" hex, axially with a vertical orientation. It's a steel part in aluminum jaws with 0.75" projection above the jaws. There are features on the opposite side of the hex that need to be concentric to .005" but I'd really prefer .002".

I don't see where I could add any relief to the fixture without sacrificing rigidity/strength.
 
To be honest, after fixturing and programming for production for 25 years now I am still learning quite a bit. I switched over to using water in a 5 gallon bucket to clean my fixtures around 6 years ago and now that I have my new Brother with a garden sprayer, and two tables so the fixtures stay on the table, I use that to clean my fixtures just like you do with air. I think the density of water vs air has a lot to do with it, it just works sooooo much better. As far as fixture design I would have to see it, the part, and the stock to properly respond.

As far as the coolant stream not allowing chips to get where they shouldn't we all know better. But with proper fixture design generally the chips should be easy and fast to clear once the part is removed. Most of my fixtures don't need washing down on every cycle so it is possible. It is not only fixture design but programming too. Try to finish with ops that don't create many chips and machine in the direction so coolant delivery washes the fixture and parts as well as possible while doing the last ops.
 
Coolant washing is a good idea but I feel using coolant AND an air blast may be better. The wash down will allow a quick air blast to more easily remove any stray chips, shavings, or crud from the reference surfaces. When building/designing progressive stamping dies I sometimes ground internal passageways for air jets to eject a part and/or accumulated metal debris from the various stations. No harm in trying what your imagination conjures, not trying is the only failure.
 
I had an injection mold years ago from which the parts would not reliably drop, so I had some air channels cut in the gibs the side actions ran in, the thought being to blow the parts out. Given the law of unintended consequences, the air blast actually caused a venturi effect that held the parts IN rather than blowing them away. Air blast was indeed the solution, but from an entirely different angle. I know that chips are heavier than plastic moldings, but be forewarned.
 








 
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