Simple Machine (help and advice needed)

[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

[EddyCurrent]

Yes, that's a better design.

Only problem i envisage is the alignment of the gantry rails, do have a solution to this ?
Regards
Mike

You are right, maybe one rail could be welded and the other bolted to allow adjustment ?