This is a fully printable Y carriage plate for mounting your heated bed. I adapted the Prusa i3 MK2 dxf file and modified it so that you can bolt on the arms in order to make this a fully printed part rather than having to rely on cutting one out of wood or having one laser cut or machined for you. It is 10mm thick, and the legs go in the slots only one direction each so that you cant mix them up and they use 3mm screws to bolt down. I printed mine with cubic infill to give it some additional rigidity, but it's a very solid piece once it's complete.
I adapted this version to use 4 lm8uu bearings instead of the 3 that are called for in the plans. However if you want to modify it back to a 3 bearing design, i'm including the sketchup file itself for your reference. I may improve this design by making it a little thinner so it's lighter. it comes in at about 159 grams. You can print this on a standard 200mm square build plate.
I also added additional 3mm holes for extra zip ties or screws for the bearings. Some of you like to use blocks so I gave plenty of options to tie them all down however you see fit.
May come back and add some lm8uu bearing brackets in the future if there is interes.
I printed this with .25mm layer height (since it's a large unseen part, you dont need to do fine details on this) and a .5mm nozzle on my Wilson II printer. I used a top/bottom thickness of 1.5mm and a wall thickness of 2mm, but this is way overkill. you can use a 1mm thickness all around to speed up print time. as is, i printed it in about 8.5 hours.
Setting to 1mm wall/top/bottom thickness it drops to about 6.5 hour print at 60mm/sec.
use 8x m3x12 cap head or pan screws with nuts on the other side to attach the legs to the body. Legs mate to their slots in only one direction flush and tight.