Need some final decisions before start building…

[irving2008]

Your original plan was to weld 2 bits of 100*100*3 together to give 200h*100w gantry. You then decided for some reason to use 2mm wall section which is lighter but not as rigid. I'm not saying anything about what you should do, just that you can't make random choices without understanding the impact of that decision. You reduced the weight because of limitations elsewhere (although weight can be beneficial against resonance) but you did it in a way that reduced rigidity and it's not clear you understood that.

[Boyan Silyavski]

3 kw spindle better but not with that gantry sides. Look at my build log #70, same simple gantry sides but much stronger.

Gantry should be at least 2x 100x100x3 , 150x100 is not a good measure to fit the bearings and at the same time have long Z travel. , try to use only one type of profile, at least thats what i do here, cause i buy 6m lengths.



Now to your "big" problem.
Dean told you already. Dont go with big screws cause you will not be able to rotate them.

So Definitely go with 2 x 3nm/1610 running 70V. Will warn thou that at 1750mm length with 16mm screws your at the point when whip at higher feeds can cause problems so you may still need to limit motor tuning to lower rapid speeds.?
Also the mounting and alignment will need to be perfect, which it should be anyway, but if your off just a little then this is amplified at this length which can introduce whip and resonance.!

If you feel adventurous mount the long screws both sides fixed mounts , but it must be perfectly aligned. It will lower the eventual whip even further.


I dont know what calculations you make but if you do it correctly it will move even faster than you think.