Quote Originally Posted by Ross77 View Post
Hi Vic.
Nice work, Looks very well thought out. I like the idea of using ali channel instead of the profile bars. There was a thread looking at an open source mid range Ali router machine and it looks like this could be it.....

not sure on your axis terminology but i take it by y axis you mean the longest axis? if so then you could use belts or wire to control the racking and stil use one ballscrew. If you increase the distance between the bearings then that will also reduce the racking but require longer rails or reduced travel.

My main concern is why use c channel for the rail supports if the ballscrew is in the middle? it would be much stronger to use rectanglar box section, I would at least provide support at the ends and mid point.


Hi
I get confused with the axis terminology, but I did mean that the Y is longest.

I havent got the model to hand at the moment (at work) but I think the bearings are about 270mm centres I'd like to keep it around 4ft cutting area and don't really want to make them wider if I can get away with it.

I'm not certain what you mean about controlling the racking with belts or wire ? do you have any links to something that has used something like that ?

The design started off using box section, I am aware that I might get some flex with channel, I have some ideas about strengthening it if I need to, the problem with box section is bolting the steel angle to it, you cant get to the nuts to tighten them up, I thought about using large self tappers but I think they might vibrate loose so I went for channel, it's a pretty strong channnel as it's meant for supporting the floors of trucks but your right, it will twist more than box.

Vic