So, now that I have my mini-cnc, I have this project of building a bigger machine ( with a moving area of about 90x40x15 cm ).
To do so, I want to use the openstructures framework, but also contraptor, thus the idea of a 2cm-based contraptor clone. Work name is «contrapteur», that's how you would say contraptor in french if it were a word :)
I already found a source for ( cheap I think, 1euro/m ) aluminium angles, 20mm sided, 2mm thick ( so 1/10 instead of 1/8, but I find contraptor parts heavy ( especially the finished mini-cnc is very heavy ) ) here : http://www.leboutte.be/catalogue_FR_Metaux_aluminium_corniere.html
I'm still searching for cheaper, I'll call local sellers when I get the phone installed.
So angles will be 20mmx20mm, 2mm thickness, with 5mm holes.
Here is a first draft:
Any idea, comments and critics are more than welcome.
I want my big machine to be belt-driven, with X supporting Z supporting Y.
I don't see how any of the contraptor moving elements could work of the X axis :
- http://www.contraptor.org/make-sliding-elements : too much friction, I think it would work good for Z like in the mini-cnc, but not for X
- http://www.contraptor.org/make-linear-bearings : the rails are at least 40cm away, that's very far for these, I don't see how to make it work.
- The beta elements in vitaly's photostream seem nice, but I don't krow enough about these.
At first I tough about using something like this or this but they are expensive, and not very contraptor-y.
So I started designing something that works a bit like these, but can be made with contraptor components.
It's based on very tiny ( 5mm ) bearings :
Bolts not pictured here, but of course every bearing is supposed to be attached with 2mm bolts.
For a rail bar with a 10mm diameter, the bearings fit just exactly inside the U element, and there is room at the bottom to support the rail so that it does not bend.
Do you think this would work ?