Hardinge Lathe CNC Retrofit/Conversion

[Chaz]

So here I can define Input Parameters. P23_15 was set to 13 (Overheating) but I set it to 127 (Set to Null). The problem is that in the list below, its only P23_10 to P23_14, Ill double check but I dont believe any of them were set to 13 (Overheating monitor).

[Chaz]

Interesting that in the next section down it says 'add 128 to the number to make it NC type'.

The only other page I can see something related to motor temps is below.

My 'reading' of it is as follows ... not sure if that's correct or not.

P90_03 if its set to 0, it will Error and power off. if its set to 1, it will error but keep power on and 3 or higher it will 'no error, assuming it ignores' but offers limited torque %

[Chaz]

So SZGH have confirmed that its a NC contact.

The mapping goes to P23_25 (port MapToDi15). Ive been told to change this to 127 and disable it, I dont think you would know what port it was mapped to from reading the docs. Ill try that later and see.

[Chaz]

Parameter changed, it allows running but now comes up with Error 5, encoder failure. Its the same cable that is used for the Thermistor and a premade cable - cant help but think there is something wrong with this cable. Let's see what SZGH come back with.

If it was a simple DB connector, id put something together but this goes from a specific canon plug into a RJ45 (which in fairness looks good), so will test / check later. Might be a tuning issue - there's also some parameters that might need changing based on the manual.

[Chaz]

So parameter 14_x has a number of options. One of them is to disable the encoder or suggest that there isnt one there.

There is also encoder feedback on the spindle itself back to the main controller (not wired in yet), so this might be enough for now, can sort things like rigid tapping etc later.

[Chaz]

Ok, disabling the encoder stops the errors but the motor doesnt run well and doesnt speed up. It sounds like its single phasing but oddly when you press the spindle off button, it runs smoothly and then comes to a stop.

I've tried most of the encoder options, all of them give the same result, error after a few seconds.

There is a self test you can do which is is to set it into mode 2 which does a phase test (presume this is to check that the encoder and motor direction match). I had this working a few times whilst I was stuck with this motor temp warning but since then I cant get the test to repeat.

So will keep scratching my head, slow steady progress hopefully.

[Chaz]

I was writing some more than we had a power cut.

There is a viewable parameter called 'H' which shows the absolute position of the shaft. This isnt reading what I would expect. It flickers between, 1, 3, then 4096 then back. It's like it is on the index but ultimately then it doesnt seem to move when the shaft rotates.

I'm not sure if any of this could be due to the way that I am powering this (via a VFD via a choke) however when it stops running (after the stop signal) its ultra smooth.

Will keep looking.

[m_c]

Spindle drives are essentially a Servo drive.

They need to know the orientation of the motor in relation to the encoder, so they know exactly how to power the motor, which is done orientation/phase sensing to learn the position of the rotor in relation to the encoder.

Typically the drive needs to know the encoder count, then go through the learning process to learn the motor.
Not doing this successfully results in what you're experiencing.

Unfortunately, that's as far as my knowledge on the subject goes, as I've never actually used an unmatched motor/drive.

[Chaz]

OK, so major progress but sadly no go.

I checked the connector and rung out the wires from the cannon plug back to the RJ45 connector (but has 10 across, not 8). All looks OK.

I then found something that explains the issues, a loose wire inside the motor. Joy of joys, would explain why the encoder doesnt work properly and why the motor heat error is needing to be masked.

So soldered it back together, sadly no change.

I did figure out how to do the the Op = 2 run again, its all in the sequence. It trips out on an encoder error. I dont remember if it did this before or not as I was getting the over temp error but I think it did the same.

Its as if the encoder is simply not working. I can see no indication of a pulse or movement.





The manual refers to checking system parameters E04 but I dont know where / what that is. It does then talk about Parameter 14_1 onwards which are for the encoder, so must be related.

Ive tried to remove the encoder to see if all wires are there but struggling to get the rear case open.

[m_c]

So you get a bit of understanding of what the drive needs to achieve, have a read of the 3 Phase Brushless Motor Control on this page - https://www.dynomotion.com/wiki/index.php/SnapAmp_Info
It is Dynomotion specific, but it explains what the drive needs to achieve.

You just then need to figure out how to do it with your drive.

Having a quick read of the manual, E02 for motor poles, E04 to set the encoder lines.
The index offset might need a bit tweaking for smooth running, but I'd expect everything else to be automatically calculated after the phase detection has run.