New Machine Build- Are these sufficiant.

[Gaz.]

I have just bought stepper motors which have 872 in.oz holding torque. As i have no idea what this means, do you think they will be suitable for a 1200mm x 1200mm machine. Running ballscrew with approx 4mm pitch?

Any help greatly appreciated.

Also, anyone know of a place which sells supported 20mm guide rails cheaply. I already have the blocks.


Gaz.

[HereinCS]

Should be more than enough. As for the round supported rails, look at vxb bearings.

[UUU]

If you had a spanner (wrench) one inch long you'd have to pull 872 oz on it, to get that torque. Not realistic so...

If you had a spanner 10 inches long, you'd have to pull 87 oz on the end to get the torque.

I can't imagine anyone putting a 10 inch handle on their ballscrews and expecting to pull over 7 pounds force on it.

So, as has been said, more than enough.

[Crevice Reamer]

That's about twice what you need, but big motors run slow. You will have to carefully match your driver and PSU to get the best performance out of them.

I would recommend G540 with 381s:
http://crevicereamer.com/Page__57.html

CR.

[SatanKlawz]

Why buy stuff without even knowing what it is or if it is good or not? That just blows my mind......

[hemsworthlad]

Originally Posted by SatanKlawz Why buy stuff without even knowing what it is or if it is good or not? That just blows my mind......

Not that bind blowing really.? . . . It was probably cheap.!!

[Eurisko]

Gaz,

Don't let any negative comments discourage you! There are many people here who did the same thing you did - start accumulating router parts without knowing exactly how it would all come together. And I'm proud to be in that group.

The worst thing that can happen is that you end up with enough parts to build two routers. And that wouldn't be so bad, would it?

[75duster]

Hello,

I found the formula for "Push" . I'm new to building cnc myself.
In.oz X TPI X pitch / 8 .....correct?

872 x ? X (4mm converted = ) .1574 / 8 = lbs of push

What would the Thread Per Inch be?

[Gaz.]

I have 5 machines in total now ...Don't ask. (addictive isn't it)

I will just follow this up for other people with the same question...

The motors were more than enough, but i found that around 450oz motors run just as well on 5mm pitch ballscrews and have no trouble keeping up with the machine with bigger motors.

They are all 1350 X 1350 bar 1 which is 3050 X 2050 running on rack and pinion with 8882 oz motors, 1200ipm rapids

The smaller ones are built from ali extrusion (80 x 80) and 20mm supported roundrails. Kress 1050 routers which are pretty good and reliable with long term cutting.

The big one made of steel with HSR rails and blocks. 8hp water cooled router. (not tested under load yet).

But anyway, i will be uploading a video of the four 4 X 4' machines running at the same time cutting the same thing which is quite interesting to watch.


Gaz.

[mlabruyere]

and if you find you can't use them (want more speed vs power) there are plenty of folks around to buy steppers...you almost can't lose by buying something cheap enough.

I'm running my gantry CNC with about half that oz/in with 1/2-10 ACME 5 start screws (dual X, single Y) and have had great success. I can get rapids above 400 IPM....the long screws whip but I've had no problems...