Mitsubishi servo motor

Hi gurus,

I have my first encounter with a servo motor yesterday (a milestone). I was task to add the 200W, 3-P motor (HC-K series w/ amplifier MR-J2S-20A) to our existing machine which I did. Well ,it was just easy because I use speed mode only (for me, it was just setting an inverter).

I have observed the motor has small torque because when I try to exert counter force, it is not turning. When I check the setting, its set on 100% torque. Is there anyway that if I try to exert counter force with the motor it will still turn? What do I need to set? Tnx

Hmm

HP = .75 kW and = (Torque x RPM) /5252

A 200W motor is not going to have much torque. How much counter torque (and what are you referring to by term counter torque?) are you applying. What is the torque demand by the load?? Would need RPM of motor to advise further.

Dan Bentler

leitmotif said:

Hmm

HP = .75 kW and = (Torque x RPM) /5252

A 200W motor is not going to have much torque. How much counter torque (and what are you referring to by term counter torque?) are you applying. What is the torque demand by the load?? Would need RPM of motor to advise further.

Dan Bentler

Click to expand...

Hmm, is the formula supposed to be /9549 to have a torque in Nm? (please correct me if Im wrong).

By computation (using 9549), I derive the torque of 0.6366 Nm (given 3000 rpm max. & 200W), which will yield to 0.065 kgf(m). The distance r=300mm=0.3m, therefore the motor can rotate a 0.216 kgf (force) at 300 mm distance.

(Please correct my computation if wrong).

Is there a way to increase this?

leitmotif said:

Hmm

(and what are you referring to by term counter torque?) are you applying.
Dan Bentler

Click to expand...

My term counter force was referring to a force that restricts the motor rotation (sorry, if the term is self-made). I restrict motor rotation by holding the motor shaft by hand. By doing this, the motor hardly rotates but upon release it quickly rotates then goes back again to its original speed.

Quite often, these little servo motors will have a planetary gearbox between the motor and the load.

Brownhat said:

Quite often, these little servo motors will have a planetary gearbox between the motor and the load.

Click to expand...

Unfortunately, we fail to connect a planetary gearbox on our servo motor. Is putting a gearbox (increasing the ratio) the only way to increase its torque?

Anyway, is it torque or inertia that I need to increase?

My crystal ball is broken and I just cant see the machine from here. You gotta give us numbers to work with

Please list the following
1. Motor RPM, wattage HP frequency (better yet send photo of nameplate)
2. Description of driven load (conveyer pump crane or whatever)
3. Desired RPM of load and the torque demanded by load.

To determine torque demanded by load use
1 torque wrench and measure direcly or
2 a lever arm attached to input drive shaft and measure length from shaft center to point at which force will be applied. Now get some weights and determine how much force is required to make the machine move. RECORD this weight and multiply by length of lever arm. Correct to 12" or meter as you need.

Stalling a small motor like this does not surprise me at all.

Dan Bentler