At the begining there was darknes … and a X Axis … I decided to start with the X axis. Why the X Axis because it the object holding the extruder. Depending on the size of the bed and the size of the head, it determine the size of the X Axis, the Y axis and pretty much the size of the printer.
For the X Axis I decided to go for a 20×20 mm aluminium profile with 2 MGN12 rails. The rails are from Hiwin, a fairly good quaity rails. The rails are place on the top and at the back of the profile.I wanted to use two rails on this printer, as my personaly experience on a single rail printer shows that during the print, due to acceleration, collision and other forces, the rail tend to be put under a lot of constrains. These rails have really little tolrance when new and with time the tolerances increase. It will simply add up to the point where the print is going to detoriated by the rail movemenet. Putting two rails is a challenge as it is not easy to setup but the accruary is incredibly improved, even over the life time of the printer.
The one of the top will be carrying most of the weight, the one at the back is to help supporting any forces other than weight and to make sure the primary rail is not under too much stress. The second rail is placed at the back, where normally no one is going to see it.
Unfortunately, I was not able to create a picture of the objects from Blender, but that is on my todo list for the next development step and blog.