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Vibratory Tumbler finishing - Brass - Questions

BHolcombe

Aluminum
Joined
Apr 15, 2019
I am a furniture maker and typically make the hardware that I use. I've been making parts mainly from brass and always hand finishing. Hand finishing is occasionally problematic if I have parts with a lot of detail, so I've been considering moving to a vibratory tumbler to apply a finish to them and remove light machining marks (the kind that typically disappear with glass beading).

I've been looking at Burr-King 150 and Nova 251 machines. Both seem to be able to be used with 'flow-through' which I'm sure has advantages, but I'm unfamiliar with these systems.

I'm posting this mainly to see if I'm headed down the right path and also to solicit suggestions for media and other advice.

Thank you!
 
Send a few parts to the machine vendor, they will run them and suggest correct machine & abrasives.
 
Brass tends to run dirty, compared to aluminum, I actually have a different tumbler for it, so flow through is probably a good thing.

I find the round tumblers easier and more effective than the tub or rectangular type.

If you are deburring, it is not rocket science
 
I make batches of small brass parts, some with rope knurling or other decorative bits, and toss them into a small round vibratory tumbler with crushed walnut shells (lizard bedding from the pet store) and squirt in some Flits polish. Overnight they get a nice high shine.

epinuts11.jpg


If memory serves, the tumbler was about a hundred bucks on eBay - sold as a "pinball polisher"
 
eBay - sold as a "pinball polisher"

Recommend do not buy, looks exactly like one I tried and it fell apart faster than I could get use out of it. Every part I beefed up caused another to fail until the motor failed
 
I ended up buying a Nova 251 that was available locally. It came with a type of ceramic looking media, I've used it all day and so far it won't take out light machining marks (not from a step-over, but from the milling cutter) after 8 hrs or so.

I decided to grain the parts with 320grit on a surface plate like I normally do and throw them back in with a bit of polish in the mix, I'll run that for a few hours and see how it looks.

I batch pretty small amounts of parts, so I dont mind some manual aspect of this if it keeps the parts crisp looking. I'm considering a more aggressive media but it may round-over edges too much while in the process of removing the machining marks.
 
I make batches of small brass parts, some with rope knurling or other decorative bits, and toss them into a small round vibratory tumbler with crushed walnut shells (lizard bedding from the pet store) and squirt in some Flits polish. Overnight they get a nice high shine.

epinuts11.jpg


If memory serves, the tumbler was about a hundred bucks on eBay - sold as a "pinball polisher"

This is a very nice looking result!
 
I ended up buying a Nova 251 that was available locally. It came with a type of ceramic looking media, I've used it all day and so far it won't take out light machining marks (not from a step-over, but from the milling cutter) after 8 hrs or so.

I decided to grain the parts with 320grit on a surface plate like I normally do and throw them back in with a bit of polish in the mix, I'll run that for a few hours and see how it looks.

I batch pretty small amounts of parts, so I dont mind some manual aspect of this if it keeps the parts crisp looking. I'm considering a more aggressive media but it may round-over edges too much while in the process of removing the machining marks.

Vibratory finishing, by nature, is considered non-dimensional. It is not supposed to "remove metal". It is to deburr the edges and to enhance the surface that is already there. Yes, it will "blend" some machine marks, but don't consider it to remove metal.
 
That's becoming clear to me for sure after putting a bit of time on these parts. I'm wondering if I should not further work these parts before putting them into the tumbler.

I'm starting to think a process would be machine, then remove machining marks by hand using plate/paper, then moving to the vibratory tumbler for polishing. I'm wondering how far to take my finishing routine before the tumbler.
 
That's becoming clear to me for sure after putting a bit of time on these parts. I'm wondering if I should not further work these parts before putting them into the tumbler.

I'm starting to think a process would be machine, then remove machining marks by hand using plate/paper, then moving to the vibratory tumbler for polishing. I'm wondering how far to take my finishing routine before the tumbler.

What does a typical part look like? What kind of machine are you using? Manual/CNC?

There are lots of options for removing machining marks that can/should be used while the part is in the machine, generally much more efficiently than doing it by hand with sandpaper.

My personal favorite for most things is XEBEC... But they're pricy... Plenty of 3m and other brand brushes on MSC or McMaster that will at least give you an even surface finish before going into the tumbler.
 








 
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