Sturdy and Fast all Steel CNC , my first build

**Boyan Silyavski** · 08-02-2015

The key there is to leave possibility for alignment.

I mounted the plates so all bolts touched the holes from one side, and as they were laser drilled they were more or less straight. But later i drilled the holes 1-1.5mm wider. So at the moment of mounting i had not only the margin of the hole itself , but of the widened hole. So its easy to adjust cause there is space that allows it.

The other key is to have 2 precision squares and 1 straight edge. So at all times you can check and assure perfect fit. You can not measure how perfect, but if you insist and try that no visible gap is left at any place, you will finish with very precise machine. And not be lazy, cause you need sometimes to check a simple thing 10 times untill you are definitely sure its straight.

And when i say check, i mean check with strong led torch

**toomast** · 20-03-2015

Silyavski, do you think 10mm steel is minimum for Z axis?
I hink that I will at least try to build my Z axis from steel. If I dont succeed that I will go for aluminium :)

**Boyan Silyavski** · 20-03-2015

Steel is cheaper, faster and easier if you don't have a mill or other cnc. 10mm steel and that having in mind the way i did it, where the rails and the rectangular bars that the rails lay on, play the role of ribs that strengthen all. You will be surprised how flexible is 10mm of steel if not strengthened by bracing plates that provide strength in contrary direction.

I managed to mill with that Z/180mm fully extended/an aluminum plate- 1.5mm deep pass, and lack of cooling and proper bed fixture was the problem to go deeper per pass.