The Thing-o-matic (TOM) is full of surprises.
Probably the biggest shock I experienced was having my very first build stick like it was supposed to, and then peel off like it was supposed to, on not only the first try but on all subsequent tries. The new belt that Makerbot is including with the TOM kits worked perfectly. It’s a pre-made affair that appears to be two layers of plastic tape that were wrapped around a pipe of the appropriate diameter.
That being said, the belt gradually warped. After a couple dozen rotations (not every build was allowed to progress to the eject stage) the belt had a small section that would lay flat, but was mostly waves so big you could surf ’em.
It got to where the surface of the belt was rising up many milimeters, which made it useless for printing on. The Makerbot support team indicated that the belt might have been too tight, which put too much force on it and stretched it out into a funky shape. They have yet to get back to me regarding how exactly I’m supposed to adjust the tension of a belt on the Automated Build Platform (ABP).
Since I didn’t want to go back to an old and busted option like the lowly Heated Build Platform (HBP), I took advantage of the old style DIY belts they were kind enough to include with the kit. After fighting with the assembly process I eventually got an ABP with a flat belt again. Unfortunately the belt refused to associate with ABS. I tried sanding the surface (in one direction), and I tried degreasing it with windex and other products … but nothing really worked. I had moderate success with just centering the kapton tape so that the build started out on it. Kapton seems to be a reasonably good build surface.
All this time I was bouncing around from forum to wiki to email trying to figure out if anyone had solved this adhesion problem. The best I could gather was that some people had a problem with the exact same kit and some people didn’t. That implied there was a variable involved in using the kit that was being missed, and so was randomly popping up to cause trouble. A conversation with Makerbot’s support led me to suspect it might be that each side of the DIY belts had a different surface, one was Jekyll and one was Hyde. But, in this case, they both looked exactly the same. How to tell them apart?
What I discovered was that you can find out which side is which with a sharpie. The side that won’t be a good surface for printing also is not a good surface for writing.
the bad mark is on the outside surface
The side that the sharpie ink can stick to is the side the plastic will stick to.
the good mark is on the inside surface
The belt I had put together first randomly had the wrong side facing outwards. It was 50/50. I couldn’t find a mention of this difference between the two sides in any of the build or troubleshooting documentation, let alone a method for telling them apart. If other people try this fix and find it consistently successful we can add it to the build instructions so that this problem never appears again. The last thing anyone wants is a 3d printer that would work if only the freakin’ plastic would stick. I haven’t tried this method on anything except the belts from Makerbot, but it seems to have something to do with the inherent properties of the surface of the plastic, so it might work generally (it verified that the pre-made belt is a good build surface).
Let me know whether or not this works when you try it.
printthat 