DC Motor Torque

[value1]

Independent of the actual JRK PID settings it's certainly worth having a read here.

[motiondave]

try 4/4 , 0/3 , 4/4 and reduce max acceleration, max duty cycle, and max duty cycle when feedback is out of range from 600 to 450.
On input tab, tick the box "never sleep (usb ignored suspend).
Once that is set, get back to me.
Cheers, David.

[floriske]

Thanks to the both of you! That should give me a good base to start with!

[Michael]

then as I have run wipers in the past from large passenger vehicles and now I run these big worm gear motors.
Let me tell you, the big motors KICK WAY MORE than any wiper.

Hi,
I agree with you. I did make my first Testrun with the new big Motors and they are much stronger than my old Wipermotors .
My Motors are from Lemac and have 12V / 180W / Rated Torque 5,5 NM / Current at rated Torque 15A / Peak Torque 64 NM / Gearbox ratio 25:1 / Speed 177 rpm.
Here you can find a Datasheet: http://www.lemac.com/datasheets/pml-wbm.pdf

[value1]

Attached a file where you can calcultate the performance curves of your motor: torque, power output, efficiency etc.
You'll need to measure the current and rpm unloaded ILeerlauf/IM1 and nLeerlauf/n1.
And you measure the current when stalled IM2 and n2=0.
Alternatively and prefereably IM1/n1 and IM2/n2 are measured inbetween.
The calculation will give you a table with Current, Speed, PowerIN, PowerOUT, Torque and Efficiency.

[Michael]

Thanks,
in the Link of the Datasheet of my motors you can also see these curves in a diagramm.
How could i measure the unloaded rpm?. I think the best way, turn on the motor and than manually count the turns in 1 minute.

[motiondave]

Just for reference, I run my JRKS at 30 amps continuous, not peak, peak is close to 38 amps.

So that would be a lovely 21Nm then!
Anyway: how do you measure the amps the jrks are gulping? I haven't found a gauge that can measure such high currents reliably and accurately (and affordably).

I actually had to set max current to get an idea. The JRKS will handle 49 amps for 6 seconds. I set the max current at 35 amps at one stage, so the motors were sucking over 30 amps easy. Thats with harsh motion.
A current shunt setup on the 12 volt power line with a multimeter would give you and idea and average. If you want exact figures, you need a scope.

[motiondave]

Thanks,
in the Link of the Datasheet of my motors you can also see these curves in a diagramm.
How could i measure the unloaded rpm?. I think the best way, turn on the motor and than manually count the turns in 1 minute.

Look at the chart and estimate

[motiondave]

@motiondave:

I've just ordered the motors and gearbox from ebay and was wondering what PID settings you are using to "tame" your motors? (PID is new to me so any "Reference" is good to have)

If you are using jrks 4/4 0/3 4/4
Reduce max duty cycle, max acceleration and max duty cycle while out of feedback to 350 from 600. If its too soft, work up the numbers from there. Also set max current to 0 meaning unlimited

[Inside]

Augh.

Are these motors available anywhere in the US?

I've been trying to find a seller in the US for either the lemac or the dayon motors that motion dynamics sells.

Surely there's somebody who sells something like that?!