How much motor Torque(oz) does Gecko G210 7A ?

[Calico]

How much torque does step motor available for 7A ?

Just wondering how big(oz) does 7A step motor which is available in the market ?
any sample ? url ? just want to know how much that motor cost.
I'm trying to compare using Servo motor, how much I can save.

regards

rud

[ger21]

You can get 1000 oz-in motors rated ~6a for about $300 from Oriental Motor or Sanyo Denki. 2000 oz from Sanyo Denki for about $600.

You can get 1300 oz motors for $195 from here http://www.seanet.com/~dmauch/Products2.htm

[Calico]

thanks,
i wonder how much table weight can be move with 1500oz ? 500pounds ?

rud

[JFettig]

Calico, wouldnt it be a better idea overall to go with servos for that size machine?

tormach.com has some larger steppers
homeshopcnc.com also has some I think

Jon

[Calico]

Jon, well the cost is the problem if I go with servo,
my question is... does stepper can handle that ?
what's the problem I might see if I go with stepper ?

rud

[Evodyne]

Look at Rick Lalonde's site at http://www.homeshopcnc.com. His 1200 oz/in Model # RHT34-1200 runs $155. I did notice they are temporarily out of stock right now.

[Calico]

yes outta stock, but ...
can somebody give me a figure....
what can 1200oz stepper motor can do ?
can it cut metal CNC mill ? do they using it for industrial CNC Mill ?
what about the speed ? i'm sure it can cut the wood CNC Mill easyly, is it ?

wow that 1200oz is cheap, if it's real 1200oz. I might get those if that thing can cut wood CNC Mill with 1meter Xaxis by 2meter Yaxis and 50cmZ axis deep.(all travel sizes)

can 1200oz do that ?

rud

[Evodyne]

Calico,

O.K.-a good place to start is to to look at Roton's site for ballscrews and such. Find their "Useful Formulas" section in the resources area.

The first formula given calculates the torque needed for a given screw to generate a given linear force. Note that units are imperial, not metric.

If I put in a load, i.e. 1000 lbf, and a screw lead, say 1 in/rev, and an efficiency of 100%, the calculator says I need 159.15 in-lbs of torque.

But 16 oz = 1 lb, so 159.15 in-lbs = 16 x 159.15 = 2546.4 in-oz!

Wow! That's a hefty motor. But in reality the screws can be purchased with different pitches (reduction ratios). Also their efficiency is never 100%.

So say I now use a real-world screw: 5 turns per inch, efficiency of about 90% (ball screw-lead screws are much less!).

Now the calculator says I need 35.37 in-lbs or 564.92 in-oz. This for a 1000 lbs of thrust.

With a further toothed belt reduction of 3:1 ahead of the screw you would be looking at 188 oz-in needed for that same 1000 lbf.

But beware: this doesn't mean you need a smaller motor! A stepper will generate its greatest torque (holding torque) when it's NOT moving. From there torque drops off with speed. So a 1200 oz-in motor will only generate varying portions of that at higher speeds. Ideally you would get a set of curves from the manufacturer showing torque vs. speed, etc.

See the Stepping Motor Basics White Paper at www.geckodrive.com for a solid introduction to steppers.

Hope this helps a little!

[Calico]

Evodyne,

sorry for late reply.
yessss it helps alot, not a little.

thank you again.

regards
ruddy

[Chris Duzak]

[QUOTE=Calico]How much torque does step motor available for 7A ?

Just wondering how big(oz) does 7A step motor which is available in the market ?
any sample ? url ? just want to know how much that motor cost.
I'm trying to compare using Servo motor, how much I can save.

regards

rud[/QUOT Go to ---- Bobcampbelldesign.com