New Machine Design Advice

[EddyCurrent]

I think you've just described something like an XY Plotter, mybe the guts of this would do ?

http://www.ebay.co.uk/itm/CalComp-Mo...item19f29e9262

[cncJim]

Cheers Eddy - yeah I guess I did kind of describe a plotter! Thanks for the link - Might be a good place to get me started.

Still tempted by the delta type machine or some kind of 2 motor arm? Does anyone know of any resources that deal with Delta robot type calculations?

[EddyCurrent]

Does this give any ideas ?

http://orangenarwhals.blogspot.co.uk...-now-with.html

I used to have a similar thing years ago for a BBC micro only it was an input device. Two perspex arms joined with a potentiometer and both attached to a table with another potentiometer. As the extreme end was moved about over a drawing surface it created a digitised image on the screen. Mapping from the two pots. was quite simple using sin or cos calculations I remember.
So I was thinking about the reverse, two motors, one attached to the base driving a 'shoulder' the other driving an 'elbow' all moving in the horizontal plane over an A3 drawing area.

[cncJim]

yes! that's the kind of thing - Thanks!

I think the two motor arm idea would work very well - Also could look very nice/interesting. Also the entire arm could be positioned so that the view of the drawing area is clear.

Material wise, I will be looking at using brass (or aluminium) with wood for a kind of retro/steampunk look. Would be great to use something like servos but not sure they would be up to the job? Maybe small steppers might be better.....?