Monday, 9 August 2010

Rejuvenated Bed

I put new PET tape on my heated bed at the beginning of July. Since then I have printed 15 Mendels on it, but on the last few I was getting problems with the parts not sticking. That is after about 700 hours of printing and ~15kg of plastic. I occasionally swab it down with Isopropanol to remove grease from finger prints, but Isopropanol is not a solvent for ABS. This evening I tried cleaning it with acetone instead. It dramatically increased the grip level, restoring it to new and making the parts hard to remove again! ABS must leave some traces behind on the surface of the bed and the acetone removes it.

So it looks like PET tape is almost fully reusable. It tends to get the odd blister where the corners of big objects overcome its adhesive and picks up a few scars from the odd accident with a knife. Apart from that it just needs cleaning with acetone about once a month.


  1. I do the same thing, but with kapton, IPA before every print, Aceton once a while. And I dont have any issue of kapton loosing properties over time, well I didnt print 15 kits on one sheet of kapton but after printing 18kits on two printers I think I can say this :-) Guess it depends on kapton batch (I have cheap chinese polyimide form ebay)

    Btw what do you think about my design ??

  2. Interesting, I would never have considered acetone through being worried about it eating away at the PET or Kapton. You learn something everyday.

  3. prusajr,
    I must give Kapton another try sometime. It seemed to fade after two or three prints with the reprapsource ABS. It lasted much longer with normal ABS though.

    I like your heater design. I think PCB is the way to go. I will try one, but the postage is too much to order on its own, so I will wait until I order my next batch of plastic.

  4. AKA47,
    I didn't notice any dissolving of the PET. I swabbed it with cotton wool and it didn't become sticky to the touch.

  5. Acetone should not dissolve PET due to the types of bonding in the plastic and the lack of an -OH (alcohol) group on the Acetone. So it seems you chose the perfect solvent for the job as it dissolves ABS but not PET.

    On a side note, isopropanol does have an -OH group and so if exposed for long enough I'm guessing the PET might dissolve.

    Also if your ever after a solvent that only dissolves oils, but not most plastics, give hexane a try.

  6. Disregard the hexane comment above. Further reading suggests ABS will dissolve quite well in hexane!

  7. it seems like you have had auktions closing and you talk about multiple childs. could you expand a bit please of the ecomonics in your factory?

    im sure you have some calculations as to print time, power consumption, plastic and setup time.

    what are you getting out of your home factory?


  8. It takes me about 48 hours to print a Mendel. That means I can print about 3 a week if we don't go away for the weekend. They auction for £203-460. The plastic costs ~£15, the electricity about £1 including the PC. The setup time is about 20 mins for each of 11 builds. It takes me 1.5 hours to drill out the holes. My wife packs them and takes them to the post office. eBay take 10% and PayPal 4%.

    It is good money, but the prices are falling rapidly, so it will soon be below the rate at which I am prepared to work in my spare time, so I might get back to development again then.