Small Gantry Router

**mike os** · 19-12-2014

Gantry 3

Steel ends, aluminium box and plate gantry beam, all bolted
This checks in at a more reasonable 40kg

**mike os** · 19-12-2014

Am I worrying too much over the weight?
Which design is heading in the right direction? or am I going the wrong way?

on all the above the COG is low and just forward of the middle of the gantry beam

**EddyCurrent** · 19-12-2014

Only the first version has a space for the Y ball screw I think. One good thing about aluminium box section is that it's quite accurate dimension wise, I put my rails top and bottom and using a vernier the distance between them was the same right across the gantry.

**mike os** · 19-12-2014

Hi Eddy

I thought if I used either of the others the ballscrew could go at the back? (behind the gantry beam...or should it be as close to y axis rails as possible?)

It is the dimensional accuracy that is tempting me with the aluminium section... one less thing to think/worry about, and a 15kg saving on weight cant hurt... or will the extra mass help with damping?

would a bolted aluminium gantry be stiff enough for light aluminium/brass work?

**EddyCurrent** · 19-12-2014

The ball screw on my machine is behind an L shaped gantry and it works fine. I fitted a plate to the front, it's all bolted and glued and I think it's stiff enough to cut aluminium okay. There are other designs on the forum more suited to metal, silyavski for example has a nice design; http://www.mycncuk.com/threads/6457-...9577#post59577

I don't know if you saw this, if you are doing calculations, it's a pity more people didn't contribute;
http://www.mycncuk.com/threads/7155-...6572#post56572

**mike os** · 19-12-2014

yes I saw both of those, and like both designs, I spent several weeks reading various design/build threads before I started, but for a first build I am finding is a bit much to remember everything

will have another read of silyavski's post... my concern there is welding introducing unwanted distortion but think I might be able to come up with a suitable compromise

**mike os** · 20-12-2014

gantry based on 200x100 RHS, pretty much all bolted.... this has the benefit of simplicity, which I always like, no need to weld any of the joints, just weld in bolting plates to the ends, only drawback is closeness of y axis rails hence the layout

can I use hiwin rails in this configuration?