Hmm....

Discussion in 'My Shapeways Order Arrived' started by Datto, Aug 28, 2012.

  1. Datto
    Datto New Member
    Well, I got my long awaited HP Lovecraft bust today, and am disappointed. Again. I keep having terrible luck with FUD, and now the same rough, rough surface on Frosted Detail. I almost went with Black Detail this time, because luck had been better, I'm kicking myself for not doing so. I can't afford to keep ordering prints in every material in the off chance that I might receive an acceptable print. :cry:
     
  2. Brigadier
    Brigadier New Member
    I share your pain :( ... about 1-in-3 or 1-in-4 of the FUD prints we get have that nasty rough surface in really obtrusive places, and since we want to use them as production masters it makes them useless. What's especially frustrating is having a print made which is fine (no roughness, or at least it's in places that don't matter), making a few tweaks and getting a second print back of the same model which seems to have some nasty creeping skin disease !
     
  3. BillBedford
    BillBedford New Member
    You have two choices, but of which soften the white texture on FUD. The first is to soak the piece in dilute acetone or nail varnish remover. The other is to put the piece in and ultrasonic cleaner with very hot water. Both methods soften the white bits enough so that they can be scrapped off with a finger nail or wooden modelling tool. Acetone will soften the whole pice and it will take some days for it to 'dry' out completely and regain it's hardness.

    The existence of this surface texture is one of the reasons I don't think FUD is entirely suitable for direct sales to the public.

     
  4. Datto
    Datto New Member
    Brigadier, mine are for molding masters too. Bill, does this mean the surface roughness is not intrinsic with the print, but stuck to the surface?
    -Marc
     
  5. Brigadier
    Brigadier New Member
    The roughness is unfortunately part of the model, rather than something that has just stuck to the surface.

    On some models I've got rid of the worst of it with a bit of wet-n-dry paper, on others it's been in inaccessible places and beyond fixing. I always give the models a coat of gloss varnish as well before putting in the moulds, which helps to further soften down the effect (and helps free the model from the mould).
     
    Last edited: Aug 29, 2012
  6. BillBedford
    BillBedford New Member
    Yes. This texture forms were there is an vertical interface between the plastic and the support wax. What seems to happen is that the plastic leaves an overrun or smear going into the wax. So in effect each voxel of plastic has a microscopic spike which is surrounded by wax. The normal finishing methods don't clean the wax from around these spikes which is why when the wax is removed with either acetone or hot water the spikes collapse and can be scraped off with relatively soft tools.

     
  7. Datto
    Datto New Member
    Maybe we should start lobbying Shapeways to offer Blue poly-jet :D