Kuhn drill electric meter problem

[melted welly]

Got a Kuhn venta p/h drill with a metering unit problem.

the motor is surging and stop/start. It is impossible to calibrate, don’t trust it to use either.

metering unit had all new bearings in sept last yr and then drilled 400ac no problem. I can turn it easily by hand with the calibration slide moving it’s full length. However as soon as I move the calibration slide with the motor running, it cuts out. If I tap the shaft with hammer it cuts out, and when running it doesn’t sound steady.

I’ve 2 motors, one a year old, and the “spare” about 8 yr old. Both behave the same. Have had the short drive shaft off and ujs are free, it is sliding in and out nice and smooth too.

Check the motor in the diagnostic page and the voltage chart is fluctuating, think this should be stable? Wires appear all good, no frays, contact cleaned all connections.

bit lost now. Anyone any ideas?

 

[KB6930]

Did someone not have a very similar issue a year or so ago on here sorry can't remember who but I'm sure I remember it

 

[melted welly]

Did someone not have a very similar issue a year or so ago on here sorry can't remember who but I'm sure I remember it

Probably me! 🫣

got sorted, the tiny speed sensor on meter unit needed adjusted 1mm closer to the gear.

Temperamental b###h, uncanny how it can tell when it’s a holiday weekend

 

[KB6930]

Probably me! 🫣

got sorted, the tiny speed sensor on meter unit needed adjusted 1mm closer to the gear.

Temperamental b###h, uncanny how it can tell when it’s a holiday weekend

Yeah I've had a puncture today and the sprayer is stopped due to an oil leak always happens on a holiday

 

[Fraserb]

We had a similar sounding issue on our lemken a few years ago and turned out to be the ground wire going to the motor had rubbed through and was touching the frame of the drill.