G540 Stepper motor spec

[tumutbound]

I've found a stepper motor supplier with a motor that seems an ideal fit to a G540 (or 250/251).
The only specifications I've checked are Inductance (1.6mh) and Current (3.5A per winding). It's torque is 2Nm (283 oz-in)

Are there any other things to consider in choosing a motor?

I've attached the spec as a PDF.

[jalessi]

Tumutbound,

That may be the same company Keling distributes here in the U.S.


Jeff...

[Crevice Reamer]

That motor is 40 Volts max and should be a goer with 36-38V PSU.

$60 KL320-36 8.8A

$139 KL-3815 15A

http://kelinginc.net/SwitchingPowerSupply.html

CR.

[Kelinginc]

G540 Package

http://www.kelinginc.net/CNCNEMA23G540Package.html

G540 Motor specification:
http://www.kelinginc.net/KL23H284-35-4B.pdf

[tumutbound]

Originally Posted by jalessi Tumutbound, That may be the same company Keling distributes here in the U.S. Jeff...

Jeff,
Could be, the part numbers are very similar.

Price I was quoted is very good ($US25 per motor, quantity 10) but nearly doubles when freight is included.
I haven't gotten a quote from a US supplier as yet but I expect that the freight will be a bit cheaper but the motor dearer.

So far, I haven't found a motor that has specs to most closely suit the G540 drive (<2 mh inductance, 3.5A) so this one is looking good. At 2Nm, it should be powerful enough for a CNC router or a small mill conversion.

[Crevice Reamer]

John at Keling: You should be looking for motors like this for G540!!!! Of course you would also need a 40V 1.6 mH 3.5A 350-400oz motor for Z axis.

CR.

[Kelinginc]

Originally Posted by Crevice Reamer John at Keling: You should be looking for motors like this for G540!!!! Of course you would also need a 40V 1.6 mH 3.5A 350-400oz motor for Z axis. CR.

Thank you Sir

We have a 1.6 mH, 3.5A NEMA 23 motor (KL23H95-35-4B) in production. We have another NEMA23 Motor (KL23H84-35-4B ) with 2.5 mH. 3.5A in production for G540 ( we redesigned)

[Crevice Reamer]

Originally Posted by Kelinginc Thank you Sir We have a 1.6 mH, 3.5A NEMA 23 motor (KL23H95-35-4B) in production. We have another NEMA23 Motor (KL23H84-35-4B ) with 2.5 mH. 3.5A in production for G540 ( we redesigned)

VERY GOOD!

Glad to hear you are on this John. What Torque are these motors and when can we expect the little beauties to be available?

Any progress on a 600-700 oz N34 in G540 range?

CR.

[tumutbound]

Look forward to hearing about availability of these new drives.

[After receiving a reply from Keling overnight regarding the cost of shipping motors from the US as opposed to China, it's no contest on price. ]

[Jeff-Birt]

I'm at a loss to understand this mania to find a motor that is 'rated' at exactly the limits of a particular drive. The stepper motor is part of a system and you must consider the entire system when specifying such things.

The spec sheet on this motor actually tells you very little about how it will perform. Where is the torque/speed graph? Under what conditions was it tested? From an engineering perspective without 'all' the data you can't tell anything. To Kelings credit they were able to point me to their torque/speed graphs when I asked the other day.

The graph will give you an idea of how much torque is being produced at what RPM (and hopefully the disparity between full steps and micro-steps). For instance I was looking at two steppers the other day one was about 170 oz/in and the other was about 270 oz/in. The larger motor only produced more torque at speeds less then 100 RPM or so. Factoring in a lead screw ratio of 20:1, it shows that perhaps the motor can supply just a bit more torque up to (maybe) 5 IPM. It would have absolutely no effect on rapid traverse speeds.

You have to match the motor/driver/power supply to the rest of your machine to have a good working system. Just bolting up the largest motor you can find is not the anser.

[Crevice Reamer]

Originally Posted by Jeff-Birt I'm at a loss to understand this mania to find a motor that is 'rated' at exactly the limits of a particular drive. The stepper motor is part of a system and you must consider the entire system when specifying such things. The spec sheet on this motor actually tells you very little about how it will perform. Where is the torque/speed graph? Under what conditions was it tested? From an engineering perspective without 'all' the data you can't tell anything. To Kelings credit they were able to point me to their torque/speed graphs when I asked the other day. The graph will give you an idea of how much torque is being produced at what RPM (and hopefully the disparity between full steps and micro-steps). For instance I was looking at two steppers the other day one was about 170 oz/in and the other was about 270 oz/in. The larger motor only produced more torque at speeds less then 100 RPM or so. Factoring in a lead screw ratio of 20:1, it shows that perhaps the motor can supply just a bit more torque up to (maybe) 5 IPM. It would have absolutely no effect on rapid traverse speeds. You have to match the motor/driver/power supply to the rest of your machine to have a good working system. Just bolting up the largest motor you can find is not the anser.

Hi Jeff!

I am certainly not telling people to "bolt up the largest motor they can find." Quite the reverse.

We are hobby folk here, not necessarily engineers. We may have a different perspective on this.

Regardless of what the torque speed curve shows, if you drive the motor with a driver that has mid band resonance problems, it will never deliver best performance.

However, if you drive the motor with a Gecko, especially one with morphing, you are assured of best performance possible.

The G540 is the most powerful and cost-effective driver ever produced, but it is limited. The "mania" you refer to is simply us trying to find motors that operate well within the G540 limited envelope of 50V, 3.5A

CR.

[tumutbound]

I'm no expert on the subject of stepper motors, I've been basing my motor search on the recommended torque requirements for what I want to do, and the specs of the G540 (50V, 3.5A, <2mh inductance).
This was the first motor that met all these requirements.