AC servo with 7i93 board

Tavares wrote: I'm thinking about the diameter of the ball screw. In the project I used ball screw of 16mm, I do not know if I need 20mm because it is a big machine 3000x2000.

ball screw : 1605 (16mm )

Tubes 50x50x15

Iam thinking in change the ball screw to 2005 or 2010, what u guys think? I want fast and Strong
and without spending a lot of money.

For that size you will need much more than 20mm if you plan on moving it fast.
1605 is not usable for that length as it will whip at roughly 80 RPM/400mm/minute and i have never seen 1605 longer than 180 CM.
Tubes 50x50x15 ???? What is that supposed to mean ? If it is 50x50x1.5 , that is also a NO in any way shape or form. You need much, much bigger and stronger and heavier tubes for a router. The least for that size of machine i would use is a 100x200x8mm.
With 2005 you can get only about 1000mm/minute on the long axis and 2000mm/minute on the short one. That is usable but to slow. Double that for 2010. Even those speeds are VERY generous.

Now if you can make or find rotating nuts, that will change everything as you can push that as fast as you want, since the screws are static.
In general for that size, you need at least 500 Kg of stuff as a bare minimum for something usable.

That is sad i almost buy the all stuff, nos i saw the biggest machines uses rack and pinion. I think i will need to build a smaller one to build a bigger with rack and pinion beacuse the mecanism os more dificult to build by hand.

The ballet screw os more plug and play.

You just need to make some nice holders for rotating nuts! They can run as fast as you can push them.
A while ago i did make a crappy one for testing and i could push it to 68 meter per minute on a 2505 screw with no load.

My milling machine was made with two rotating nuts and one rotating screw just because that was easier.
There really isn't any more engineering difficulty in a rotating nut setup than in a rotating screw.

Yup, the only difference, small as it might be, is adjusting the axial bearings. They are tricky b@$tard$ !

tommylight wrote: Yup, the only difference, small as it might be, is adjusting the axial bearings. They are tricky b@$tard$ !

You need to do that (or at least consider end-bearing backlash) with a rotating screw, too.

Car wheel bearing sets can work well for rotating-nut.

This one here (from my milling machine) uses double-row angular contact bearings but adjusts them as if they were single row .
The reason for that was that space was right and the double-row ones had a very small section not available in single row .

andypugh wrote: Car wheel bearing sets can work well for rotating-nut.

Oh yes, but oh no ! I could not find anything usable ( at that time usable was something that i could make work with 5 to 10 minutes work) but i had found a local dealer who carries a lot of bearings, a lot.
Thank you, Andy

tommylight wrote: Oh yes, but oh no ! I could not find anything usable ( at that time usable was something that i could make work with 5 to 10 minutes work) but i had found a local dealer who carries a lot of bearings

The last link of my previous post was to a supplier I use.
As well as lots of sealed and open angular contact bearings (and all other bearings) they have a section on wheel bearings:

There are some rather interesting things in "automotive special bearings" too:
simplybearings.co.uk/shop/Products-Autom...4747_5334/index.html

how are you guys!
Thanks a lot for the help!

I came to the conclusion of building a smaller machine since I have 3 stepper nema 23 and the tb6560 controller, I know it's bad but it works to make some parts.
I will use the same schematic of the initial machine but with a smaller size.
My question is what is the ideal size of the machine for the nema 23 motor using ball screw 1605 to cut aluminum even if takes 2 days cutting.

Maybe 1000x700

Motor:
57BYGH76-401A

holding torque= 18.9kgf.cm

Tavares wrote: My question is what is the ideal size of the machine for the nema 23 motor using ball screw 1605 to cut aluminum even if takes 2 days cutting.

Performance is not a matter of size. All that matters is rigidity. Chiploads in aluminum are a few 0.001in (0.025mm). The machine must be rigid to a fraction of the chipload, the holding of the work vs the motion of the tool. Otherwise you're not machining, and your creation is not a machine tool. The strength of the weakest members, and the backlash of the ways, are what determine the performance, not the size.