Steel Gantry Machine 1500x750x200

[JAZZCNC]

Do you think this long 1610 ballscrew will start whipping on X-axis?

I know silyavski told you No but he's Wrong it most definatley could whip at that length at higher rapid feeds. 20mm is much better screw to use at this length and won't cost much more in either Money or performance.

[Boyan Silyavski]

I know silyavski told you No but he's Wrong it most definatley could whip at that length at higher rapid feeds. 20mm is much better screw to use at this length and won't cost much more in either Money or performance.

Sorry, totally missed that 1500mm. I was thinking about something else. I will have to whip myself

[JAZZCNC]

Sorry, totally missed that 1500mm. I was thinking about something else. I will have to whip myself

Argh thought it was strange you saying was fine.. . Lol and Don't Whip your self get a nice fit blonde to do it much more fun..

[Boyan Silyavski]

I agree Dean. I was deep into reading about HF plasma grounding and just glanced at it and thought 1500 total length of screw -300mm in gantry legs gives 1200, minus more when he betters the design, so he could go away with that, cause anyways most people don't go faster than 10m/min in real life. And it was 1500mm travel , not screw length. I hope he did not order the screws. Anyways i will buy them from him if that mistake happened. its never a bad thing to have some extra ball screws.

[toomast]

No worry's mates! Have not ordered anything yet :) except the whipping blond...

[Sven]

I'd change the plate you have now for the Z-axis for a 80x80 steel tube and connect the dust collection to that.
That works really well.

Do put a brace between the mounting of the spindle and the oposite face, otherwise the mount may flex. Probably not as bad as my 35 mm high kress mount but still....

[toomast]

I'd change the plate you have now for the Z-axis for a 80x80 steel tube and connect the dust collection to that.
That works really well.

Do put a brace between the mounting of the spindle and the oposite face, otherwise the mount may flex. Probably not as bad as my 35 mm high kress mount but still....

I don't quite follow you. Do you have a sample picture how the 80x80 steel tube would work as dust collector?
Dust is the problem that needs solving in my design though. I was aiming for some simple bracket that holds dust extractor tube...some housing with brushes...I need to put it on the drawing.

For spindle mount I will order tha thick cast aluminium version. Nice and rigid I think.

[toomast]

I know silyavski told you No but he's Wrong it most definatley could whip at that length at higher rapid feeds. 20mm is much better screw to use at this length and won't cost much more in either Money or performance.

What would be the maximum length of 20mm ballscrew in this application? What would be critical length that needs rotating ballnuts?
Im thinking of getting more distance from gantry travel...

[JAZZCNC]

What would be the maximum length of 20mm ballscrew in this application? What would be critical length that needs rotating ballnuts?
Im thinking of getting more distance from gantry travel...

Oh very hard to answer because depends on the end fixing etc but I wouldn't go above 2000mm and at that I would have Both ends with Fixed bearings and slight preload on them. When I build 4x4 size machine I always use Fixed/Fixed end bearings as the slight cost difference is worth the extra support it gives.

[Gary]

To work out the critical speed of a screw there is a calculator on our site.
http://www.zappautomation.co.uk/inde...lculators.html

In the lower part of this page is a link for the calculator.