Re: CNC/3D too ambitious?
I put my hand up - confused minutes and seconds. Never was very good at time-keeping...
What also made me wonder, though, is that when I'm sitting watching the wheels go round on the printer, it doesn't seem that fast and I think Clive is right - acceleration is very important as 3D printed components are generally fiddly little things and the extruder is changing direction a lot. I found the same effect doing some fairly fine engraving with the router - I traded acceleration for speed in the settings and the overall cut time reduced significantly. As far as the OP's question is concerned, I think that that is going to raise some interesting design trade-offs with regards to things like pitch of leadscrew/ballscrew.
Re: CNC/3D too ambitious?
Acceleration for 3D printing seems to be the keyword, which is one of the reasons 3D XYZ mechanisms are light and nimble. You don't need the power to push a cutter through a material, you are just squirting out plastic, icing sugar, chocolate or whatever. I just think that a hybrid machine would be the ugly son of widely different parents.
Cheers,
Rob
Re: CNC/3D too ambitious?
its looking like its going to be just a decent DIY CNC which il try and adapt for some 3d printing. I'l see how i get on :)