Tumble deburring

[Michael GilliganParticipant @michaelgilligan61133]

Your advice, please …

[Michael GilliganParticipant @michaelgilligan61133]

I have bought [cheaply] a small 'gemstone tumbler' machine, with a view to using it for tumble de-burring of small metal components. I remember being very impressed by the results that Kodak obtained using this technique on the levers for their camera mechanisms.

Does anyone have experience of machines and materials?

Grateful for any advice

MichaelG.

.

P.S. … it's an old 'Wessex Impex ATC Mark II' with one 'Add-A-Barrel' unit, and appears to have been very little used.

Edited By Michael Gilligan on 07/09/2015 20:41:48

[David Clark 13Participant @davidclark13]

What do you want to know?

Used to use special pottery shapes and abrasive compound. Possibly sand would be better with a small tumbler.

Search ebay for polishing compound tumbling machine.

Edited By David Clark 1 on 07/09/2015 20:41:40

[Michael GilliganParticipant @michaelgilligan61133]

Posted by David Clark 1 on 07/09/2015 20:38:27:

What do you want to know?

.

Speeds; Durations; Media … that sort of thing.

The gemstone tumblers run at around 60rpm for several days, and use grits … I suspect that this is too slow for small metallic parts; and I seem to recall Kodak using 'gentle' compounds like crushed apricot stones.

MichaelG.

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Edit: This is the most helpful website I have found so far.

Edited By Michael Gilligan on 07/09/2015 21:13:56

[jason udallParticipant @jasonudall57142]

The one we used at work..
Dry.

Drum about 18″ dia.

Porcelain tera hedra.thingy. about 8-9 mm on a side.
Parts 30 mm long by 4mm square

Typical time 1-2 hours (at least hour and get that lot out so we can get the next lot in..)
Rpm.. well about 1-2 rps.. so 60 to 120
We also had two sets of porcelain. .one in one being sorted from parts.

Most use vibratory tubs now.

Edited By jason udall on 07/09/2015 21:14:17

[Clive HartlandParticipant @clivehartland94829]

There is a difference between polishing tumbling and de-burring tumbling, firstly the burrs are nominally removed by the action of the parts banging against each other with the addition of a media that will also fill the spaces as they tumble. As David says you need a media as dense as the item so broken pottery maybe the answer. It can be quite noisy and needs to be done over a period of time and only experience will give you that time, perhaps 20 mins. cycles and check results. The volume of items is another thing as if you cram in items they do not move as much. Some I have seen only turn over the burr and it is still visible but squashed down. Others show marks on the surface as perhaps the media is too heavy for the job. Perhaps there are some ceramic cubes or triangular pieces so you will have to search for the media. Then there is the question, wet or dry.

[Michael GilliganParticipant @michaelgilligan61133]

Good baseline, Jason

Thanks for that.

MichaelG.

[jason udallParticipant @jasonudall57142]

Intended to build a vib. Unit one day…
Based on loudspeaker power amp. Oscilator
Stainless.can and either apricot/walnut. Shell media. ..
Haven’t needed one that badly yet

[Neil WyattModerator @neilwyatt]

Walnut shell chips are supposed to be excellent for polishing, rather than deburring. A good excuse to pig out without waiting for Christmas.

Neil

[Anonymous]

Posted by Michael Gilligan on 07/09/2015 20:16:15:

Does anyone have experience of machines and materials?

In a word no, but I shall be reading this thread with interest, as I have been looking at the process. I've identified a small machine, and media, but haven't quite had the pressing need yet in order to take the plunge.

Andrew

[steamdaveParticipant @steamdave]

Chris Heapy described an easily made rotary tumbler.

http://easyweb.easynet.co.uk/~chrish/cancelled%20account/tumbler.htm

He also describes various other interesting projects on his site. The techniques make good reading for novice machinists, too.

Dave
The Emerald Isle

[Michael GilliganParticipant @michaelgilligan61133]

Thanks for the input, folks

[Dave] Useful to know that Chris Heapy built something with roughly the size of barrel/drum that I have; and achieved good results with Walnut shell.

[quote, from 1996] So far I have only tried two polishing mediums, both donated by a friend. One is crushed walnut husks and the other is very fine (I mean really tiny) glass beads. I'm a bit wary of the glass but the walnut seems to work very well on brass (although it manages to get itself jammed into the smallest hole). [/quote]

MichaelG.

 

Edited By Michael Gilligan on 07/09/2015 22:33:16

[Clive HartlandParticipant @clivehartland94829]

There is a vibratory tumbler/machine used by ammo reloaders to clean and polish cases. This uses corn cob husk or walnut shell media. Cost about £50 I think.The name Lyman rings a bell as its been a long time since I did it.

Clive

[Michael GilliganParticipant @michaelgilligan61133]

Clive,

Thanks for the useful reference to Lyman

… and thereby, also to Raytech, and this excellent article 

MichaelG.

.

P.S. … [Brian] Approx. Internal dimensions are 4" dia x 4" long

Edited By Michael Gilligan on 08/09/2015 08:47:56

[donkeyParticipant @donkey]

a selection of media supplies are available from the FROST catalogue but very expensive and small quantities. not sure how big your tumbler is. (other stores sell media supplies but i have not found them yet. happy customer and user.)

brian

[KWILParticipant @kwil]

Micheal,

if you are in need of glass beads, try a local shotblaster, sorry, bead blaster, I do not know how well they work when just tumbled though.

K

[Ian S CParticipant @iansc]

Haven't got one at the moment, but have in the past. I used a paint tin about 6" dia, and rotated by a 1/6th hp shaded pole motor, these motors are not the best for long running(that's why I don't have one now) a 1/4 hp 1450 rpm induction motor will run for days. The drum should run at about 30-60 rpm. I used two rubber rollers, one driven, from a clothes wringer from an old wringer type washing machine, with the drum sat on top.

A hexagonal wooden drum is probably a better shape.  The foundry I use in Christchurch uses ordinary concrete mixers.

Ian S C

Edited By Ian S C on 08/09/2015 10:55:04

[Chris DentonParticipant @chrisdenton53037]

Glass beads and Walnut shells are availible on ebay.

[Cornish JackParticipant @cornishjack]

We used to use walnut shells for compressor 'washing' on our S&R Whirlwinds, so presumably suitable for precision items. How many days to Xmas??

rgds

Bill

[AjohnwParticipant @ajohnw51620]

Lucas used to do their 1/4" blade connector items in drums around 15" dia or so and about twice as long at something like 60 rpm, probably a bit slower with nothing other than the parts in them. Circa 2/3 full and inclined at some angle that also caused them to tumble. I'm guessing the sizes but wont be far out. They wouldn't have any interest at all in separating them from some sort of compound. They made them in enormous numbers on modified CVA high speed presses that had been speeded up. 240 / min if I remember correctly.

John

–

[Neil WyattModerator @neilwyatt]

Just bag up your unwanted walnut kernels and send them to the editorial office…

Neil

[Martin CottrellParticipant @martincottrell21329]

Posted by Neil Wyatt on 09/09/2015 14:08:05:

Just bag up your unwanted walnut kernels and send them to the editorial office…

Neil

The editorial office, collection point for nut cases. Mmmm, explains a lot!!

Regards Martin.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by John W1 on 09/09/2015 13:15:31:

Lucas used to do their 1/4" blade connector items in drums around 15" dia or so and about twice as long at something like 60 rpm, probably a bit slower with nothing other than the parts in them. Circa 2/3 full and inclined at some angle that also caused them to tumble. I'm guessing the sizes but wont be far out. They wouldn't have any interest at all in separating them from some sort of compound. They made them in enormous numbers on modified CVA high speed presses that had been speeded up. 240 / min if I remember correctly.

John

–

.

Thanks for that info., John … Very interesting.

Unforunately, I am most unlikely to be tumbling drum-loads of identical components … So I guess I will need to include some sort of medium.

MichaelG.

[jacques maurelParticipant @jacquesmaurel42310]

Look at the article: "The rumbling tumbler" in the Nov/Dec 1994 issue of MEW.

J Maurel

[Michael GilliganParticipant @michaelgilligan61133]

Posted by jacques maurel on 10/09/2015 07:10:10:

Look at the article: "The rumbling tumbler" in the Nov/Dec 1994 issue of MEW.

J Maurel

.

Many thanks for the reference [issue 26] Jaques

Unfortunately, he is working on a larger scale than I intend [e.g. he dismisses a 2.5 litre paint tin as being too small to be useful], and his experimental 'mediums' [sic] are proportionately coarse.

MichaelG.

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