After searching for a proper plate onto which I could fix the heat bed of the reprap I decided I would make it out of square tubing.
Here’s what I tried:
Aluminium profile at each set of linear bearings.
That was a bad (read stupid) idea because, not only did it limit my Y axis travel but it also allowed relative displacement between the two aluminium profiles because they weren’t connected between them. This caused issues when leveling the heat bed. The torsional stiffness of the bed while adjusting would lift one corner of the front profile and lower the opposite corner on the back profile. BAD.
One thing to note here is that where I am based, thicker plywood is not really available, which would have been ideal. I did try to use hobby plywood but that was a worse idea than the aluminium profiles. When the heated bed was turned on, the plywood quickly developed a beautiful arch. In hindsight, I shouldn’t have even considered using thing plywood.
An aluminium plate would also have been great but it would have also been expensive and difficult to cut nicely.
Therefore I decided to go with 12mm square tubing silver soldered together and then painted black to prevent corrosion.
After soldering the tubing, I drilled all the necessary holes with one side having a hole big enough for the head of the screw to go through and the other side just a pass through hole. Like so:
I also added aluminium tape over this structure to radiate the heat back to the heat bed. This decreases heating time significantly.