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Author Topic: csmio/ip-a + Mach 3 servo problems  (Read 5684 times)

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Offline LesR

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csmio/ip-a + Mach 3 servo problems
« on: December 17, 2019, 01:16:02 PM »
I decided to upgrade my Bridgeport Interact 1 mk2 to a more modern control and chose a csmio/ip-a controller.
I already have a Mach3 licence so it made sense to go that way.
Things were going to plan up until I wanted to test the three axes.
I have changed the old sinusoidal encoders on all three axes to AMT103 units with differential drivers and they all work fine, giving correct readouts per mm of movement.
The servo +/- 10 volt inputs are fine when unconnected and just sit there dithering slightly with tiny interference voltages. However, when I connect them to the csmio/ip-a and power up, immediately each of the axes makes a bolt for one end of travel and causes an ePID fault warning.
I have played about with all the settings and still nothing. Just full speed movement for a very short time before trip out.
To try another system, I have got a 30 day licence for CS Labs own software but sadly the same thing still happens with that.
I know that others have done similar to me and wonder what I am doing wrong please?

Les
Re: csmio/ip-a + Mach 3 servo problems
« Reply #1 on: December 17, 2019, 05:02:41 PM »
Hi,
sounds to me like you have the encoder reading 'upwards' in one direction whereas the servo rotates 'downwards'

Try reversing the main pos and neg power feeds to the servo.

Craig
'I enjoy sex at 73.....I live at 71 so its not too far to walk.'

Offline LesR

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Re: csmio/ip-a + Mach 3 servo problems
« Reply #2 on: December 18, 2019, 11:41:41 AM »
That is one thing that I have not tried.
Unless it would be the same as reversing the encoder direction in the software?
Which only makes the test axis shuttle violently back and forth until it trips.
Re: csmio/ip-a + Mach 3 servo problems
« Reply #3 on: December 18, 2019, 11:49:44 AM »
Hi,
reversing the servo direction OR reversing the encoder direction have the same effect.

If the servo moves back and forth.....then its trying to do the right thing whereas if it moves violently to one
end of an axis without attempting to reverse, that is a symptom of when the ecoder and servo directions are
crossed.

It sounds to me like you have had the correct directions when the servo moved back and forth but
you need to tune it. Try to start with small or no I or D, just P alone. I and D components can very
quickly cause instability.

Craig
'I enjoy sex at 73.....I live at 71 so its not too far to walk.'

Offline LesR

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Re: csmio/ip-a + Mach 3 servo problems
« Reply #4 on: December 18, 2019, 12:20:49 PM »
Thanks,
I'll give that a go in the morning.

Les

Offline LesR

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Re: csmio/ip-a + Mach 3 servo problems
« Reply #5 on: December 19, 2019, 12:49:20 PM »
I went back to basics today. I disconnected the x axis and tried it with a 1.5 volt battery on the analogue input, the cable sheath earth was joined to the machine earth.
It works fine. That led me to think about the connections to the csmio/ip-a board. I tested the ground terminals on the analogue output connector and found they didn't have a circuit to 'real' earth.
So, i disconnected all the cable screens from the terminal block and connected them to machine earth.
As if by magic, all now works fine. Each axis was automatically tuned with the plug in tuner and everything works fine now.

Tomorrow I try to make the spindle work......

Les
Re: csmio/ip-a + Mach 3 servo problems
« Reply #6 on: April 24, 2020, 07:24:06 AM »
Im going through the same process as you.

How far have you got?

Ive tuned my axes so far. Homing routine next.

John

Offline LesR

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Re: csmio/ip-a + Mach 3 servo problems
« Reply #7 on: April 24, 2020, 11:35:00 AM »
Mine is fully up and running now. Once I sorted the earthing thing, everything works fine. The spindle caused no problems at all.

I didn't bother with the handwheel, I use one of these instead https://www.cnc4you.co.uk/Motion-Control/WHB04B

Les
Re: csmio/ip-a + Mach 3 servo problems
« Reply #8 on: April 24, 2020, 04:52:19 PM »
Can I ask you how you dealt with the Bosch drive enable signals?
It would be good to use these when jogging or running a program
like the old Heidenhain did.

Ive just got them turned on continuously for now although i am
using 'DC Interlock' for 'machine enable' which seems to make sense.

Also did you use the NC home switch signals? They seem quite German
to me. If there is a fault its just going to slam into the limit and cut off
FC5. It says 'Reference Pulse Suppression' on the drawing. Im not sure
what this means?

Im attempting to attach the diagram for the bit I'm talking about...

John

Offline LesR

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Re: csmio/ip-a + Mach 3 servo problems
« Reply #9 on: April 25, 2020, 06:11:44 AM »
I'm trying to remember!
I only did this before Christmas and have already lost it...
There are two sides to the controls, 110v and 24v DC.
All the limit switches are 110v and are the "last chance" cut off.
The enable signals and DC interlock, I have wired to the CSMIO so that Mach 3 controls them. Then you can set soft limits in Mach 3 and everything behaves like it did before. You can run to the end of travel and it will stop before hitting the final buffer of the 110v system. It will not trigger a reset and you can jog back off again, as before.

The pulse suppression thing is for the Heidenhain control. It is not needed now. You get your reference from the encoders on the servo motors and ref via mach 3 and CSMIO.
I assume you have changed the encoders on your existing motors? Or you had more modern motors than me?

To power my 24v side, I did away with the ancient basic regulator fitted and put in one of these (or similar) https://www.amazon.co.uk/Surom-Universal-Regulated-Switching-Computer/dp/B071W121H7?ref_=fsclp_pl_dp_4  It even runs from 110v.

Les