Small Gantry Router

[Clive S]

more questions..... have I got this right?

ballscrew sizes... fixed & floating bearing for mounts (BK & BF?)
x axis approx. 1000mm between bearings, 20mm screw, 5mm pitch, critical speed about 2000rpm = 10m/min?
Y axis approx. 780mm between bearings, 16mm screw, 5mm pitch, critical speed in excess of 3000rpm=15+m/min
z axis approx. 400mm between bearings, 12mm screw.. critical speed<6000rpm

does this look ok?

It probably would be Ok with 16mm screws all round but in general for wood 10mm pitch would be used for x and y and 5mm pitch for Z ..Clive

[EddyCurrent]

If you order ball screws then refer to the 'standard machining' diagram and request dimension F = 30 mm, this will give you enough length to fit a pulley otherwise it's a bit short.

[mike os]

no where near ordering yet,,,, lol, I wish

I put 5mm pitch as it seems to be used a lot, any thoughts on 5 or 10mm pitch? not really worried about rapids as only a small machine

[EddyCurrent]

I was recommended 10 mm pitch for X and Y and 5 mm pitch for Z, I use a 1:1 ratio pulley/belt drive and it works very nicely.