I was having trouble getting the first layer to stick so I mounted an acrylic bed. I had to move my Z end-stop up, so at the same time I mounted the Z end-stop on an adjustable riser, so that I could fine tune my Z offset.
With these two tweaks I was able to get a really good print of belt-width-adjuster_1off.stl
The trouble was that it stuck to the acrylic too well, and was near impossible to remove, in the process of removing it I completely wrecked the underside of the print.
I have been told that a good material to print onto is scotch blue tape, so I am going to try that next.
Giles Bathgate 
Blue painters tape works great for PLA but not really for ABS. Try double stick scotch tape for ABS.. works for like 1-5 prints per cover.
Everyone I talk to gives me different advice. Okay with this double stick tape do you leave the cover on, or do you remove it so that the sticky bit is exposed.
We first started with double-sided sticky tape, and we’d stick a layer of duct tape on top with the sticky side facing to the print just for good measure. that would hold OK, but large prints would definitely curl.
then we moved to an acrylic bed, and prints would adhere sometimes, but sometimes also not adhere at all and curl (or break off entirely).
then we moved to a heated acrylic bed (~60°C). this worked *too* well, and the prints were near impossible to remove — particularly failed prints, that were only one or two layers. sometimes if your print was tall enough, you could just ‘snap’ it off and hope it didn’t break.
then we covered the acrylic bed in kapton, and heated it up to 120°C. this worked pretty well, but warped the acrylic table.
then, finally, we have moved to a large aluminum table covered in kapton at ~110°C. so far this is working beautifully, and the prints come off very easily.
For the time being, I am trying to find a solution that doesn’t involve a heated bed, but my ultimate goal is to have an alu heated bed coated with PET or Kapton Tape
@GilesBathgate The tape I’m talking about is this:
There is no cover.. You just apply that to the acrylic bed (well, I had an acrylic bed on the makerbot I was using), tightly (no bubbles), and ABS will stick down pretty well (until you get to large pieces, at which point you either need to switch to PLA or get a heated bed).
Really I cannot urge you enough to get a heated bed. I spent months trying to do without and failed . The first time I used a heated bed I got a large print with very little curling first time.
My heated bed has NO control software. it just used nichrome wire between two steel sheets (insulated with kapton tape). Just use about 6 ohms of wire and assemble. Connect directly across 12volt supply. Measure the heat the bed reaches. Reduce the wire resistance if you want to increase the heat. I ended up using a couple of wire lengths in parallel and around 5 ohms. bed runs at a steady 110 degrees.
Don’t worry, I have already been urged, I am just in the process of researching the simplest solution and sourcing the parts. You can follow the discussion I was having with nophead If you don’t believe me 😉