View Full Version : Beam choice

27-01-2015, 09:59 PM
Planning to build a gantry type machine. Before the construction goes on, would like to know the opinion of specialists. My machine has a beam of 2 meters long. What would be the most appropriate profile when you consider that the spindle weighs 12kg.It should be fast sheet cutting machine - the cutting speed of about 10000 mm/min.



27-01-2015, 10:11 PM
I use TBR20 rails.

27-01-2015, 10:14 PM
There's a spreadsheet here that might help, you need to study it for a while first.
You don't want to be using the C channel, it twists too easy.

31-01-2015, 05:23 PM
I've found this forum severe counselors. I would like to know the opinion of everyone present cnc design. Would be interested in the strength of the gantry and also the weight. My plan is to use 100x150 3mm thick square tube. Is it strong enough, if it is 2 meters tall / wide? This is a rack and pinion driven. It is planned to use for wood milling. It would be nice if I could use it for milling aluminum.


31-01-2015, 09:10 PM
Is it aluminium or steel ? if it is aluminium I would go to 6mm thickness, if steel you might consider 5mm thickness.
I can't be certain but according to the spreadsheet it looks okay. If you filled it with epoxy and filler it would be stronger and would not resonate anywhere near as much as an empty tube.

31-01-2015, 09:23 PM
with the round rails it will be fine IMO ...

but if you had square rails then id go thicker

+1 on filling it, mine has made a massive difference ... there is no ring when hitting the beam