How much Torque is required when cutting?

[Regnar]

I hope I am asking this in the right section but here we go.

I am looking at the Keling KL34H280-45-8A Stepper Motor,

http://www.kelinginc.net/KL34H280-45-8A.pdf
http://www.kelinginc.net/KL34H280-45-8AT.pdf

I am still in the planning stages but I would like to do a 3.1 to 1 belt drive with a 20 tooth pinion.

If I have done my math right I should end up with a almost 1:1 with the steppers rpm and 3 times the torque at rated speed.

Now for a few numbers, I would have

Stepper RPM-------Stepper Torque-- Pinion Torque--Table Speed(est)
150rpm------------594oz------------1841oz--------150ipm
300rpm------------580oz------------1798oz--------300ipm
600rpm------------509oz------------1577oz--------600ipm
900rpm------------410oz------------1271oz--------900ipm
1200rpm-----------311oz------------964oz---------1200ipm
1500rpm-----------254oz------------787oz---------1500ipm
1800rpm-----------198oz------------613oz---------1800ipm


This was all caculated from the torque/speed chart.

My question is will the torque and speed meet the Mechmates need with the above setup? I have never cut at a significant speed and dont have a clue what is required for cutting.

Would anyone object to this stepper motor and setup. In my mind it sounds good but then again what do I know.

[Gerald D]

Consider that a 20 tooth pinion which has a 20 diametral pitch has exactly a half inch radius. Therefore, a 613oz.in torque on a 20 tooth pinion is going to give you 1226 ounces of linear "pushing" force at the cutter, which is 76 pounds, which is plenty for a typical bit in a hand pushed router.

[Castone]

I have the 640 oz Keling steppers, with beltdrives. no problems so far and I am very happy with them.

[Regnar]

Leo, are you running them 3 to 1 or are you doing a different setup. Thanks guys for the responses. I feel very comfortable with the mechanics but unsure of the electronics that need to be put in. Thanks again. Russell

[Castone]

Yes, I am using the 3 to 1

[kostis]

So, why do you use beltdrives in your machines?

I now build my 1mx2m cnc and I have 640oz-inch steppers with G203 and ballscrew 2510 and I plan to put them directly to ballscrews....If I put belt drive I will have decreased speed right?I do not want to decrease the speed...

Will I have any problem with this?

Kostis.

[bradm]

Kostas, this forum generally only handles the specific MechMate machine design.

The answer to your question is that the MechMate uses rack and pinion, and thus gearing/belting down the motor makes sense. With a ballscrew, it wouldn't, since the ballscrew naturally does that. Whether you will have problems is a question for another forum, I think. Good luck with your build.

[kostis]

Ok sorry then,
thanks for clearing this out Bradm...
Good luck to you too...:)

[oopz]

Kostas, this forum generally only handles the specific MechMate machine design.
bradm: So therefore a kind of --Back to basics -- :) I´v like to know how G540(+motors) and Linux has worked on your MM over time.
( Im a Mach3 and G203 person.) The reason why is simple I decided to go "THAT path - G540 and Linux" on one of the slanted machines I´m building:D.

I know that its a learning curve on everything new thing you have to learn, so
" Lets Start NOW!! " :)
If you wounder in what build it will apear etc..Its this machine you can see grow in this moment taking its shape in my building three below.
http://mechmate.com/forums/showthread.php?p=38897&postcount=25

Feel free to answer either in the three above or here !

So if you have same advice or what to avoid etc or likewise let me know.

/oopz

[eesanopi]

I have the 640 oz Keling steppers, with beltdrives. no problems so far and I am very happy with them.

Leo, I have this motors too, but not running yet, how fast they can perform with 3:1 reduction?

Edgar