Any experience with polishing WSF polymide yourself?

Discussion in 'Finishing Techniques' started by TOM_TOM_TOM, Apr 18, 2013.

    TOM_TOM_TOM Well-Known Member
    Has anyone tried polishing WSF polymide yourself?
    I'm going to be polishing 50-100 parts each month, and am looking to buy a small 10-12" diameter vibrating tumbling machine like the ones you can find on alibaba or here

    But I'm not familiar with the polishing media. I know that the 3D print services uses ceramic, but there are different shape, sizes, and types.

    I've seen balls, triangles, 1mm to 12mm diameters, and non-abrasive, abrasive types.

    Does anyone have a clue about what's best to use?

  2. gibell
    gibell Well-Known Member
    The SW polishing media sometimes gets stuck inside my parts. So I can tell you that it appears to be ceramic, a cylinder 4-5mm in diameter and nearly 10mm long. It seems to be rather smooth, so I'd guess non-abrasive. Photo attached.

    Let us know how it goes, I am interested in doing this myself too.

    Last edited: Apr 19, 2013
    TOM_TOM_TOM Well-Known Member
    I'm thinking to get this tumbler:

    This TopShot CTI 3500 also goes by the name of SmartReloader 747. Most of these are sold through gun shops for cleaning bullet casings.

    It's 42cm in diameter which is pretty large. Most others are about 30-35cm or even less. I'm trying to decide between this one, and the Lyman 2500, which is smaller. The issue is that if both have the same motor power, the larger one has less vibrating force compared to the smaller one as it has to move more material.

    But the smaller ones may not be able to submerge my parts completely in the media. My parts are about 115mm x 80mm x40mm. Most of these machines have a center column dividing the tub, so you'll have to divide the diameter in half and subtract a bit to get the maximum sized parts you can fit in them.

    As for the media, I've found some cheap ones, 25kg of ceramic triangles for 70 Euros, or 1kg for 5 Euros.

    The sizes are 4x4mm, and comes in 3 different abrasive strengths. I have no idea what strength to get, and I was hoping for something smaller and more round, like 2mm or 3mm. But other shops sell 1kg bags for 15 Euros.

    The ones you've found in your part from Shapeways look something like this: ikschleifkoerper-kvsacc.html

    Or maybe porcelain polishers tifte-porzellan.html

    Here is more information about shapes and sizes. ramic-media/

    I was thinking this first pass with the ceramic triangles would be an aggressive grind to get rid of the stepping lines, and then maybe it would be good to make a second pass with these round porcelain balls. However, these things are really expensive at the only one shop I could find that sells it. rkugeln-porzellan-3-mm.html

    Although, it would be much easier to use one type of media and dump the parts in one go. Changing media and cleaning up would be a hassle.

    I can't speak German, so my searching abilities are limited. Unless anyone knows where else to get these things in Europe?
    Last edited: Apr 20, 2013
  4. AmLachDesigns
    AmLachDesigns Well-Known Member
    Google translate will get you quite a long way, perhaps...
  5. gibell
    gibell Well-Known Member
    Exact stats on the SW polishing media (shown above):
    Diameter = 6mm
    Length = 14mm (tip to tip), 9mm (face to face)

    I should also caution you that these are from a year ago, and it is possible they have switched to something else by now.

    In my experience it is quite difficult, if not impossible, to completely remove the print stepping lines. You can certainly smooth them out so you can't feel them, but they are always there visually.
    Last edited: Apr 20, 2013
    TOM_TOM_TOM Well-Known Member
    Last edited: Apr 20, 2013
  7. fly2future
    fly2future New Member
    anybody know of what type of tumbling machines shapeways is using? I need to do this in house to speed things up, waiting a few extra days for tumbled parts is not possible. maybe a larger heavy duty machine is best.. any suggestions?
  8. gibell
    gibell Well-Known Member
    There was a photo of one of the SW machines in their blog (link below), but I don't think you can read any brand names. Let us know if you find out and if you buy anything. I am also interested in doing my own tumbling! er-in-action.html

  9. MrNib
    MrNib Well-Known Member
    Last edited: Dec 11, 2013
    TOM_TOM_TOM Well-Known Member
    There are several machines you could use. I saw a few at trade shows. One of the big companies is called rosler. The big round tumbler in the shapeways video could be from 10,000 to 15,000 euros. I was offered a small trough for 5,000 to 7,000 euros but that is way out of my budget.

    I did get a cheap 125 euro tumbler used for cleaning bullet casings, and 50 euro pack of 25kg ceramic media, which I mixed with a little bit of water, but the motor was only 50 watts. The expensive machine I was offered was 400 watts. With my cheap tumbler I was only able to grind away some of the stepping lines but it came out fuzzy. Shapeways uses a 2 step process, first with grinding media and second with polishing media. I might be able to get a good finish if I could test it out with some polishing media but rosler will only sell me large quantities and they're quite expensive. They did polish a part for me as a free test using the trough machine they offered me, and they did tell me the media type and compound they used. It came back quite smooth, although the surface did look a little bit micro dimpled. They only did a one step process. They used a triangular shaped ceramic media. But shapeways and I.materialize uses cylinders with chamfered ends.

    I dealt with the local contracted distributor for rosler so maybe you can contact your local dealer and ask them about it. If you happen to get some of the polishing media, maybe you could send me 5kg and let me test it out on my cheap tumbler.

    Another option are the polish guys who sit on the periphery of the trade shows. They may let you buy smaller amounts but there is the problem of shipping costs for such heavy media.