J325 with BEI Encoders reused in retrofit

[lavrgs]

Tree used some BEI encoders that are difficult to find any datasheet for. The numbers on the case are 817-05-1019 CI;OB0068 S/N 106470 . These are the encoders that came on the Baldor motors and I assume they are original. ZPS was not able to ID them. They have 9 wires 5V,COM, A,/A B /B Z /Z and a BIG Ground wire.
They were used on a retrofit using Gecko G320 and Mach3. After reviewing the controls I had made some errors - left the jumper on the G320 between pin 5 and 7 meaning that any possible error correction was disabled. Before going to Retrofit 2.0 I wanted to get everything corrected since I would have to do it for a new controller. After removing the jumpers the machine was completely unstable - erroring for a variety of reasons ... so the plan is the shield all wires, do whatever I can to reduce noise and get the system operational.
Rather than go into the larger picture I want to ask about the encoder wiring. For some reason - which seemed to work, I used /A and /B. Now that I'm using A and B I have a runaway servo, so I will go back the way it was. I just doesn't seem right.
Any advise on removing the encoders would be welcome - there are three screws with triangular clamping items but I 'm guessing there is some set screw that holds the encoder to the motor shaft.

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[Jim Dawson]

Try swapping the A and B connection, that may prevent the runaway.

Yes, the encoder is connected to the shaft with some kind of clamping arrangement, could be a set screw or other type of system.

[lavrgs]

Thanks for the quick reply. I've swapped A and B as well as the armature connections. It did make the axis go in the opposite direction. I have since removed the belt so I don't have to scramble for the power switch...
I didn't take notes about why /A and /B were used but it was consistent across all three encoders.
I'm going to have to do some reading on checking encoders with an O'scope...

[Jim Dawson]

This might help you with the scope. https://doc.ingeniamc.com/venus/prod...oder-interface

This shows what to normally expect, any deviation is normally noise or a bad encoder. Is best to use a 4 channel scope if you have one, but a 2 channel or even a 1 channel can be used. Normally 5V pulses.

[machinehop5]

...not sure if this correct drawing for your Encoders. Hope it helps

[lavrgs]

machineshop5 Thanks for the info. It makes me wonder what I'm currently missing when I only use 2 legs of the encoder . The original industrial controls certainly were very capable. I've limped along with a hobby control, but as I mentioned earlier I want to try and getting it working before I do Retrofit 2.0 - the learning will be useful.

[lavrgs]

When I say I limped along I had to remind myself that I have completed some nice parts. This is an adaptor to mount a transmission into an International Harvester
https://www.cnczone.com/forums/tree/...r-project.html

[lavrgs]

This might help you with the scope. https://doc.ingeniamc.com/venus/prod...oder-interface

This shows what to normally expect, any deviation is normally noise or a bad encoder. Is best to use a 4 channel scope if you have one, but a 2 channel or even a 1 channel can be used. Normally 5V pulses.

I have some trace captures but I am getting close to sure the encoders arenot working properly. I tested the x-axis A, /A, B and /B ,of the four only one channel had a signal close to 5V, the others were approximately half and had a strange double step. I know pictures would help but I am almost certain that a "NEW BUILD" thread is in my future. I got a quote from DMM for three axis motor kit and when you consider everything is new and the cost of replacing encoders is approaching half the cost of the kit it becomes clear that modernizing is good...

[Jim Dawson]

The pulses are pretty clean, but I don't understand the double step on channel 2. Never seen that before.

Nothing wrong with DMM servos, I have 4 their 1.8KW units on my lathe and they have been working fine for a couple of years.

[lavrgs]

The encoders may be the last straw in considering a Retrofit 2.0. Most modern systems seem to push you toward a 2000 line encoder - e.g. Acorn I'm sure there are cheaper encoders available but starting with 3 Centroids they are approaching 1/3 -1/2 the cost of a DMM kit. DMM uses a callout that I have not seen 16-bit Absolute (65,535cpr) It sounds good but I don't have a frame of reference. CPR sounds like counts per revolution but how does that relate to pulses per revolution. Are they quadrature encoders or a different technology?

[Jim Dawson]

It's the same as a 4096 line encoder, when using differential quadrature. So 4096 x 4.

The actual output of the encoder into the DYN drive is gray code, but the encoder output from the DYN4 (or DYN2) from JP5 is standard differential quadrature.

[PCW_MESA]

I have some trace captures but I am getting close to sure the encoders arenot working properly. I tested the x-axis A, /A, B and /B ,of the four only one channel had a signal close to 5V, the others were approximately half and had a strange double step. I know pictures would help but I am almost certain that a "NEW BUILD" thread is in my future. I got a quote from DMM for three axis motor kit and when you consider everything is new and the cost of replacing encoders is approaching half the cost of the kit it becomes clear that modernizing is good...

The green trace looks like A and B (or /A and /B) are shorted together

[lavrgs]

That sound like more than 2000 9-). I'm ready to start collecting parts. I like to try and have everything ready to go. The DMM and Acorn is pretty well understood - possible grey area is the need for extra i/o. Centroid has an ETHER1616 expansion that I may leave room for, but I will have to research what it gets me. My main area that needs work is in the electrical controls - I 've started to peruse Automation direct to get a list put together. I like the look of DIN rails and wiring trough to keep things organized and secure.

I'm collecting layouts to use as reference to find appropriate parts - sizing contactors and such will be a first time experience. The machine is being run off a phase converter into a switch on the back cabinet - the only item using 220 is the spindle motor. Is that a candidate for replacement? I would jthink to leave it and possible add a contactor to shut it off. I see a diagram in my future...

[lavrgs]

The green trace looks like A and B (or /A and /B) are shorted together

The wires were all exposed - I could try putting some caps on. The encoder has Z and /Z so I should check those...appreciate the observation!!!

[Jim Dawson]

That sound like more than 2000 9-). I'm ready to start collecting parts. I like to try and have everything ready to go. The DMM and Acorn is pretty well understood - possible grey area is the need for extra i/o. Centroid has an ETHER1616 expansion that I may leave room for, but I will have to research what it gets me. My main area that needs work is in the electrical controls - I 've started to peruse Automation direct to get a list put together. I like the look of DIN rails and wiring trough to keep things organized and secure.

I'm collecting layouts to use as reference to find appropriate parts - sizing contactors and such will be a first time experience. The machine is being run off a phase converter into a switch on the back cabinet - the only item using 220 is the spindle motor. Is that a candidate for replacement? I would jthink to leave it and possible add a contactor to shut it off. I see a diagram in my future...

I have been through this a few times. Not too difficult.

Take a look at this thread for some good examples https://www.cnczone.com/forums/mecha...77816-cnc.html

[lavrgs]

I have been through this a few times. Not too difficult.

Take a look at this thread for some good examples https://www.cnczone.com/forums/mecha...77816-cnc.html

Excellent I started following SLODAT's J425 build a week ago. When I first saw the pictures of his cabinet I was floored - had no clue what any of that stuff was -I'm starting to understand what the items are - still have a ways to go. I received the basic info from DMM that shows items associated with their motors so I've put them on the shopping list. I'll have to grab the Acorn schematics and see what they have in line.
Thanks for your help - I see you're not to far away - I'm in Tualatin

Bill

[Jim Dawson]

My pleasure to help where I can. If you have questions I'm happy to help.

You're close enough for some hands on help if needed.

[lavrgs]

I decided to open the X axis encoder to see if I could find out what was wrong. I found the COM wire disconnected. I removed and replaced all the wires - I'm only using 5V, COM,A and B. The wire I used is a bit too large so I will try and find some 8 conductor wire and bring it back to the way it was in case I decide to sell my servo motors

[Jim Dawson]

That looks much better!

[lavrgs]

I'm wondering if CAT 5 cable would bo ok to use...