Frame and mechanical build - Print bed

Before drilling or preparing the print bed check the sizes are correct.

I asked for my mdf to be cut to 225mm x 225mm and 140mm x 225mm at my local B&Q. For some reason they took it the 225's as 275...


Drilling (corners) - page 39

Its pretty straight forward however if you want to be precise there should be a 42.5mm gap on both sides of the 225mm plate (when drilling the 2nd set of holes).


Drilling (belt clamp) - page 49

First follow the alignment steps from pages 41 to 43.
Once its aligned jump to page 49 and follow the steps.

Doing it in this order means you don't have to remove the print bed with the bushings glued on. Otherwise you have to be extremely careful both when drilling the belt clamp holes and when removing and reattaching the bed.
I had to re-glue one of the bushings on eachof my first 2 removals (the 2nd was due to the bed being the wrong size) which is another step and another wait until its set.


Glueing - page 43

Skip if your not using PLA bushings

I found it best to line the bushings up at either the front or back of the frame. This way when you join the bed and the bushings you can use the horizontal bars to ensure the alignment.


Top print bed surface

Before attaching the top print bed you need to apply some form of printing surface. You could print directly onto mdf or glass however you'd have 2 big issues; damage to the surface (160C+ plastic and the mdf or glass aren't the best of friends) and grip.
To solve this most people with either kapton tape or blue scotch tape.
Kapton is slightly better, but costs considerably more for similar width tape.
Blue scotch tape has a surprisingly good tolerance to heat, is cheaper and is more widely available.

When applying it to the top print bed on mdf its best to apply a few layers in criss cross pattern. One layer horizontal, followed by one vertical. About 3 or 4 layers should be enough. This stops the tape peeling the mdf or removing the tape below when removing prints.


Attaching the top print bed - page 101

If your springs are fairly weak its best to have at least 5mm of thread sticking out. Otherwise as the bed sets in there is a good chance it will sink on one or more of the corners.

If you have m3 nylock nuts this is definitely the time to use them. I found standard nuts loosen extremely easily during printing and the bed will need constant levelling between every (even the small ones) print.