Denford Triac VMC with ATC Conversion / Fix

[Chaz]

In all honesty I've very little experience with IP-A or Analog drives or motors with Resolvers which will make a difference to PID setup.
My motors are Brushed DC with Tacho's and Real Encoders which makes a difference to your setup. My drives PID was set up already for the Velocity/Current and the IP-A Autotune did a good Job with position so little to no tweaking required.

I would think that because your drives where already setup then you'll be in a similar position with Velocity/Current setup in the drive so using the Auto tune in IP-A would get you close. Then it's just a case of playing with IP-A PID settings to get nice stable smooth movement.

Thanks. Considering the mill was working before, the drives should be setup correctly. The 'output' from the drive is as if it was an encoder. The drive takes the resolver input and converts it to encoder type for the controller.

I have a question too around cabling whilst I try and find out what could cause any funny issues.

I am using Cat 5 cable for the encoder and ref signals. So, its shielded, its 8 core + the outer core.

The drawings I have show that the -10 to +10V run in their own shield. Currently I am sharing this common cable for - 10 to + 10 plus the encoder feedback. Is this a problem? I dont mind splitting them but dont want to buy cable I dont need.

Thanks

[JAZZCNC]

Thanks. Considering the mill was working before, the drives should be setup correctly. The 'output' from the drive is as if it was an encoder. The drive takes the resolver input and converts it to encoder type for the controller.

Yes agreed but you'll still need to tune the Controller for position so use the IP-A Autotune and tweak settings if motors are twitchy etc..

I have a question too around cabling whilst I try and find out what could cause any funny issues.

I am using Cat 5 cable for the encoder and ref signals. So, its shielded, its 8 core + the outer core.

The drawings I have show that the -10 to +10V run in their own shield. Currently I am sharing this common cable for - 10 to + 10 plus the encoder feedback. Is this a problem? I dont mind splitting them but dont want to buy cable I dont need.

Thanks

Yes I'd separate them.

Also make sure your Grounding is correct and all Shields going to Star Ground point.!

[Chaz]

Yes agreed but you'll still need to tune the Controller for position so use the IP-A Autotune and tweak settings if motors are twitchy etc..



Yes I'd separate them.

Also make sure your Grounding is correct and all Shields going to Star Ground point.!

Not using 3 phase, I know that some will consider Neutral as Earth in single phase (country specific), is that the case here?

[Clive S]

Neutral is not earth In the UK the earth is bonded to the neutral in most cases but not always.
The ground in your case is a central point where all the screens and ground are connected together in one place (star point) and that point in connected to the general earth connection. This is to try and stop ground loops. ..Clive

[Chaz]

Neutral is not earth In the UK the earth is bonded to the neutral in most cases but not always.
The ground in your case is a central point where all the screens and ground are connected together in one place (star point) and that point in connected to the general earth connection. This is to try and stop ground loops. ..Clive

Ah, sorry, mistook 'star point' as the star of a 3 phase system which is commonly earthed. Thanks, understood what you explained.

Out of interest, my drawings show the encoder shield only being attached on side and from speaking to a colleague this morning, that seems common practice (not to earth both sides of a shield). Would that be correct based on the collective experience here?

[Clive S]

Out of interest, my drawings show the encoder shield only being attached on side and from speaking to a colleague this morning, that seems common practice (not to earth both sides of a shield). Would that be correct based on the collective experience here

Yes that would be correct. Clive

[GEOFFREY]

Been away for the past week (my Golden wedding aniversary celebrations?), so sorry to be harping back to one of the non technical points. If your motor is marked as 230v 3 ph you can almost certainly run that coolant pump on single phase. Set the motor block connecters to Delta and either use a vfd or trick the motor to run in quasi 3 phase using a couple of caps. I have been running 3ph motors on 230v single phase for over 20 years and have never had any problems. It may be neccessary to use a separate switched cap for starting. If in any boubt, cap values etc. you can PM me. Your project is looking great. Well done. G.