Need advice using vibratory tumbler- no experience!

Considering using a small vibratory tumbler to get a pre-plate finish on small banjo parts. (washers and bushings). They are mostly brass, some steel, made on my DSM turret lathe or manual lathe, usually 10 - 100 pieces. I hone the tools for best possible finish, and take care to avoid or minimize burrs. My larger parts get a final buff with tripoli for nickel or gold plating

Would a small (.1 cu ft), inexpensive tumbler do the trick?
What sort of media would one recommend? Dry or wet?
Is it possible to get mild de-burring without dubbing over nice crisp chamfer edges?

Most anyone who reloads their own ammunition will use a tumbler to clean their brass prior to reloading.

The most common media are corn cob or crushed walnut. They're both very mild so it's unlikely they'll have much if any de-burring effect but they will give a nice shine.

Personally I don't wet tumble with stainless pins but everyone I know who does swears by it. It takes half the time to get twice as bright a finish and with less dust and mess overall. Your initial investment is higher but over the long run it's cheaper and better results.

Should work well for small parts. Do not mix different materials and parts - works best when all parts are the same. I was using only liquid media. The degree of deburring can be controlled, but depending on part original finish and geometry, sharp edges might get a bit rounded.

Any help? Rabbit Vibrator and Other Vibrators Battery and Operating Instructions | LeLuv

re tumbling with crushed walnut shells
Use a mask when opening the tumbler
If it's an open barrel, have an air filter system going.
Made the mistake of opening the tumbler when it had the walnut shells and the dust dropped me like a punch in the chest
Hacked for a good hour afterwords

We use the 2 sizes of tumblers made by Dillon, the reloading people. Their tumblers now say not to use with liquid, so we back the screws out and seal with silicon seal. We have used them for 25+ years. I have bought a couple of the small industrial units, but the Dillons last a fairly long time and are about 1/3 the price. We use ultra light ceramic media from U M abrasives with a liquid compound. The amount of liquid you put in changes the speed and aggressiveness of the cutting action. I would advise getting one of the 2 Dillons and experiment till you get what you want. If you go big time then get an industrial unit.

Years ago I climbed onto eBay and grabbed a cheap-o "Pinball polishing" tumbler. It was about eighty bucks and although it was cheaply made I found it worked great for about a decade before my batches of things got bit too big for the bowl.

Here's one: SMALL METAL PARTS VIBRATOR POWER SHAKER TUMBLER TOOL POLISHER POLISHING PINBALL | eBay

Pet shops sell crumbled walnut shells for hamster bedding - I use them with "Flitz" polish and get great results on brass and aluminum especially. It works wonders on handfuls of old banjo hooks an nuts! I don't mix hard and soft metals to avoid lotsa dings and things. I use my buffer with Menzerna compounds on bigger parts, esp. steel and stainless rather than tumbling.

Got a really great result on a vintage replacement part I made for old Gibson L-5 tailpieces. I wanted the look of a slightly worn vintage gold plating, so I gave the brass parts a super high polish, dropped ten of them in my pants pocket and carried them around for a few days. The resulting nicks and dings were just perfect! I asked the plater to be sure not to buff anything at all, and the parts came out of plating with just the right look.

Here's way more on that, with a pic or two:

192s L-5 Tailpiece Bar - Frank Ford's Corner - Accessories - Gryphon Stringed Instruments

look at sending them out. I'm sure you'll be shocked at how cheap it is to have it done, and you don't need to deal with the noise or the mess.

I use stainless media with water and a bit of dawn soap for cartridge cases now after many failed attempt at corncob and walnut media. I deprime them and besides cleaning the cases inside and out they also clean the primer holes.
I haven't tried it for our small parts deburring, using ceramic tetrahedron instead. One thing, the wrong media will destroy threads!

very funny Limy, have we begun drinking over there? (assuming we had stopped!!)

the overview, for those new to vibratory finishing, there are 4 basic types of media used in them for metal finishing, in order of aggressiveness,

1) hard ceramic media, basically like throwing rocks in with the parts, but do come in various grits,

2)cast abrasive "nuggets", pyramids or cubes of plastic with (varying) abrasives mixed in. the plastic can also vary in hardness.

3) burnishing shot, usually steel or preferably stainless steel, that come in various shapes and sizes, from balls to flying saucer like shapes, to tiny needles, to accommodate parts with corresponding degrees of nook and cranny-ness. these always have a mirror polish (when new). this produces the classic "tumbled' finish on mass produced jewelry.

4) dry media, usually corncob or walnut shell, and often used with rouge, as a very light cleanup and polish. this is the media for processing used brass cartridge cases that many are familiar with here, and is not really an industrial metal finishing process.

(for lapidary applications, stone finishing is accomplished wet with a load of stone, usually of the same type, either rough, or preformed to some extent, and bulk abrasives, such as 80 grit silicon carbide, and step finishing down to a polishing media, but that is a different animal.)

the first three metal media are used with a "bath" that is usually water with additives (surfactants and or soaps). for maximum effectiveness the heavier industrial units have a "flow-through" setup that allows the metal removed to be "settled out" and the fluid returned. that prevents it from becoming a useless paste that gums up the action.

the degree to which the details are "blurred" or rounded over of corse varies with the aggressiveness of the cut and the time processed, and must be balanced with the work needed to accomplish the necessary finishing and deburring. having parts with a decent surface finish and only light burrs, using the least aggressive media, and not working it longer than needed will produce the crispest edges.

for finishing most of the machined parts we commonly would encounter in the 1/4 to 1- 1/2" range, with a decent quality finish from the last cutting step, I would think a medium grit plastic media would be a starting point.

for soft-ish metals (brass, nickel silver), small parts for musical instruments, I might try a burnishing media first, (I.E.,shot tumbling)

wow! didn't mean to get that long winded.. but hope its helpful..

cyanidekid said:

very funny Limy, have we begun drinking over there? (assuming we had stopped!!)
)

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I couldn't help myself - and it is Christmas.

Assuming I don't fall off the wagon before , come 1am May 1 2018 I'll have been dry 30 years

just a note on the burnishing shot, the parts have to be made of a metal softer that the shot, so, not good for alloy and tool steels etc.

good on ya Limy!

Would a small (.1 cu ft), inexpensive tumbler do the trick? Yes

What sort of media would one recommend? Dry or wet? You are asking for a pre-plate finish. Normally the proper media for this is a plastic media with very little abrasive in it. Always wet.

Is it possible to get mild de-burring without dubbing over nice crisp chamfer edges? It won't do a lot to them.

When they come out, the parts won't look good to the eye. But they are perfect for painting/plating/polishing.

I own a Thumler's Tumbler UV-18. http://www.thumlerstumbler.com/industrial.html
It is big enough for me, but small enough to put away on a shelf. I have a few boxes of media but generally use green plastic pyramids about 5/16" on an edge. I generally shave off some slivers of an old soap bar and add a pint or so of water.

Media can pack up inside holes and stop circulating. This means you should either use media too large to fit in holes or small enough so no dimension is larger than 1/6th or 1/8th the size of the hole or other interior feature. (not industry numbers, just my own rule of thumb).

I learned a great deal from an old book I found called "Handbook of Barrel Finishing" by Ralph Enyedi. Handbook Of Barrel Finishing: Ralph Enyedy: 97812582459: Amazon.com: Books It is not a modern book but it provided me with a lot of the basics.

I have to admit I tumble parts more for cleaning and derusting than for deburring. YMMV.

metalmagpie

Thanks for all the advice, very helpful. Sounds like the plastic media might be a good first choice.

The "Handbook" is at my local library, I'll definitely check it out.

One question just occurred to me - how do you separate all the little brass parts from the media? Steel I cold use a magnet, but brass?

We bought plastic media for doing preplate (anodize) tumbling on delicate aluminum parts. One operator did a batch in the ultra light weight ceramic by mistake and it worked even better no plastic residue to get off the parts. I have one each, 1 cubic foot boxes of blue and green
I think (I am color blind)of V-cut cylinder shaped media, never used it again since the "mistake". If shipping from here is cheaper than buying new I would be glad to give it to you. We will never use it again.
Each batch of tumbling has its own way of running, some parts come across the surface and we pick them off, some stay below the surface and we skim the media off by hand till the parts get concentrated. You will figure it out. Dillon has some separators for cartridge cases if the size of your media is way different than your parts. We never use the one I bought. One of the tumbler makers sold an "Inseparator" screen for dropping in the tumbler. if the parts were different size from the media it is supposed to separate automatically. Who knows it could work.
Make sure to size the media so it does not get stuck in an holes in the parts. I just though out a batch the 25 percent of the media had gotten too small and got stuck in parts. Took 25 years to wear it out.

Media type, size, abrasives mixed in and amount of water and soap make a difference.
Wet or abrasive mixed in systems need to be flushed clean every few runs.
This mixture decides how much you remove, what finish you get, how small of corners the media get into, and important to me how it keeps the parts in suspension.
(Not good if carbide inserts hit each other and you might not want your parts "polishing" each other.)
Power input also matters and on the small bowl types you can vary the off center weight or speed of the motor.
Certainly many variables and a art type thing so expect some trial and error.

You want deburring and polishing? The two are sort of different uses, depends on the burrs I guess but polishing setups tend to leave polished burrs and deburring setups tend to leave a matte finish.
Maybe two little guys?

Have used the little round guy when dollars were real tight and if your parts have holes you can "fixture" them on a loop made of welding wire.
For my use I like this style which is a bit different but pricey, nice thing is that tell them what you want and they will spec a mix that works:
http://www.vibrodyne.com/

For sure a small inexpensive one will work and leave your corner chamfers in place.

For getting your parts out the media should be much smaller that your parts.
On a small unit you can remove and dump the bowl into a screen over a bucket or tub to separate if they are free tumbling.
Same deal here with parts hitting each other and leaving small nicks, go somewhat slow.

You will love these things once you get the process nailed.
Bob
.........(You might also hate them on the day it goes to poop due to an oops, you scrap $8000, get fired from your job and end up a dishwasher at $2.20 per hour.....(BTDT)).

FredC, thank you for the generous offer, I've sent you an email.

These people may be a bit closer to you.
Vibratory Finishing Machines | Tumbling Machinery | Deburring Equipment

richard newman said:

Thanks for all the advice, very helpful. Sounds like the plastic media might be a good first choice.

The "Handbook" is at my local library, I'll definitely check it out.

One question just occurred to me - how do you separate all the little brass parts from the media? Steel I cold use a magnet, but brass?

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Remember the bad old days when pot had seeds in it? Remember how you were taught to get the seeds out? :-)

metalmagpie