hi all,

Am pushing some ideas around on the back of a fag packet- doing some blue sky thinking whilst pushing my performance envelope- etc etc more generic management speak-!

for my gear reduction for the 8 x 4 router- am looking at probably around a 3Nm stepper, running to a 16t timing pulley- to a timing belt- to a 60t pulley with a 20t pinion running on a rack- if that makes sense-!

so questions are-

1/ is a 3 (ish): 1 ratio the best- or is 2 better?
2/ whats the best belt width?
3/ hows best to keep tension/ the pinion on the rack
3/ has anyone come up with a slick way of mounting all this stuff in a nice dust free casing?! am looking at obviously trying to support an 'axle'/ bearings for these and have seen some on other machines but can't find an off the shelf bolt in solution....
4/ would you do the same thing on the 'Y' axis as well?

so far have decided on the hiwin type linear guides/bearings so one each side on the 'x' with the above rack to drive, and for the 'y' probably 2 hiwins on the top and one on the back maybe? probably mounted on an ali extrusion say 80 x 120 again on rack & pinion?

'z' i'm thinking of a ball screw linear table type thing- are these eay/ cheap to build or is it best to purchase an off the shelf type?- But will the 'z' want reduction?

hope to be in a position to start me build in the next couple of weeks so if anyone knows of a cheap but good source for

1/ the hiwin
2/ the rack
3/ the pulleys
4/ steppers/ drives/ etc etc
5/ decent maybe water cooled spindle with a vfd

have been looking around at the usual places zapp etc etc but just on the off chance wondered if there was a guy in a shed somewhere selling them off cheap-!

Gonna start me Cad drawings off and see how i get on...

George