L gantry design with 2 aluminium beams bolted with T nuts inside...

[pierantoine]

Hello,
I'm starting the gantry build, i assume the 2 beams must be bolted one with the other, and i ve think that could be done with a t nut and a (minimum diameter) hole for the hex key, screws will be M8 Din 7380. The gantry is about 1m, 1 tnut every 10cm x 2 rows. the 2 beams could be positionned differently...

or is there any reason to not make holes (stifness...) and do that differently ?

thanks for your comments.

21479

[MikeyC38]

Hi Pierre

This is exactly what I did on my build (see my build here (http://www.mycncuk.com/threads/8206-Ar-last%21%21%21-Started-my-Gantry-3-Axis-CNC-Build)post #10) . My Gantry is 700mm wide so I think I spaced them at between 120 - 150 mm apart, drilled through the profile so I could tighten the bolts. I was using much heavier material than you are (4 kg/m) and only 80 x 40 profile. The L shape inspired by Jazz gives great resistance to torsion. What type of spindle will you be using? The spindle I have weighs over 2kg hence the use of the heavy gauge profile to resist torsion. I have some concerns about the thickness of the material you are using for your gantry if you have a heavy spindle plus the weight of your Z axis ballscrew, bearings and stepper/servo motor?

Kind Regards
Michael

[pierantoine]

Hi Pierre

This is exactly what I did on my build (see my build here (http://www.mycncuk.com/threads/8206-Ar-last%21%21%21-Started-my-Gantry-3-Axis-CNC-Build)post #10) . My Gantry is 700mm wide so I think I spaced them at between 120 - 150 mm apart, drilled through the profile so I could tighten the bolts. I was using much heavier material than you are (4 kg/m) and only 80 x 40 profile. The L shape inspired by Jazz gives great resistance to torsion. What type of spindle will you be using? The spindle I have weighs over 2kg hence the use of the heavy gauge profile to resist torsion. I have some concerns about the thickness of the material you are using for your gantry if you have a heavy spindle plus the weight of your Z axis ballscrew, bearings and stepper/servo motor?

Kind Regards
Michael

thanks !
80x120 profile
15mm ground aluminium and 20mm alum plate
2.2kw chinese spindle water cooled
i would buy the 3nm from zap or cnc4you if i had to rebuy instead of 4nm from cnc4you.

my log here
http://www.mycncuk.com/threads/8717-Aluminum-profile-and-alu-plate-1500mm-x-600mm-x-150mm-working-area-first-cnc?goto=newpost