Simple Machine (help and advice needed)

[JAZZCNC]

Hi Gregor,

Looks nice and sturdy and there's no reason why you can't use 50x50x40 but I would say if you haven't already bought the linear rails then don't buy round rails.
Profiled linear rails have really come down in price in the last year or so and it's not worth buying the round type IMO. They simply don't compare in performance and accuracy.

Get the rest of machine designed then well take another look. Don't forget to think about cables runs and Home/limit switch mounting etc.

[Gregor]

Thanks for the advice JAZZ ,I think I will get 60x60 box for the side rails and use 50x50 for the cross sections and end rail.I plan on just using angle for the cable tray and also it will give some protection to the ballscrew I have put it in the drawings.I plan to make the gantry out off the 50x50 box as I don't mind welding do you think this would be ok? or a waste off time doing.I haven't ordered any rails yet
Cheers

[EddyCurrent]

. . .but I would say if you haven't already bought the linear rails then don't buy round rails.
Profiled linear rails have really come down in price in the last year or so and it's not worth buying the round type IMO. They simply don't compare in performance and accuracy.

I've just used some 20mm supported rail for a non cnc job, it was the first time I'd used them and it will be the last, as Jazz says, use Hiwin type rails every time, use 20mm all round.

[Gregor]

Hi EddyCurrent
I haven't ordered anything yet still messing about on sketchup lol.But I will take you and Jazzcnc advise and get the Hiwin type.Heres my first Attempt at a gantry It took me five hours to do this on sketchup I don't know what I was doing but I kept deleting parts off the sketch.

[Blackrat]

just another +1 on the hiwin rails ...

for the price difference it IS money well worth it !

for the gantry , dont have the gantry side like an upside down T as it offsets the spindle too much and the spindle will go quite a bit over the tables surface. using a L shape might be better and reduce the amount you go off the table (unless you want to ofcourse)

[EddyCurrent]

for the gantry , dont have the gantry side like an upside down T as it offsets the spindle too much and the spindle will go quite a bit over the tables surface. using a L shape might be better and reduce the amount you go off the table (unless you want to ofcourse)

Yes, the spindle should be inside the footprint of the 4 gantry bearings, this is the key diagram; http://www.cncroutersource.com/do-it...NC-router.html

[Gregor]

Thanks for the advice would this be a better design.

[mekanik]

Hi Gregor
That setup would ensure you get the Z axis very close to the gantry and the motor should be positioned as near to the centre of the X bearings as possible.
Only problem i envisage is the alignment of the gantry rails, do have a solution to this ?
Regards
Mike