Bridgeport BOSS R2E4 Conversion - DC3IO - 411 and No Motion on any Axis

[Bridget]

Howdy there. I just purchased a secondhand R2E4. The previous owner redid the controls to all Centroid/Ajax in ~2005, and in around 2015 it ran into a fault and he didn't have time to look at it, so it sat unused for a decade. I've now purchased it and am attempting to get things running again. Here's where I currently sit (system specs/info/pics are at the bottom):

The mill is currently wired into 240V single-phase, as I am still waiting on a rotary phase generator to come in. That said, the control side of the mill does boot fine. As far as I can tell, as long as the machine is started with the estop is pressed, I should be able to at least jog the axes (at least, in theory - please correct me if this is not correct!), but of course not use the spindle, because everything aside from the spindle uses normal single phase power.
However, when I attempt to jog any of the axes, I get a 411 <axis> axis(<#>) full power without motion. This applies to all three X, Y, and Z axes. I have checked and verified that my board (DC3IO) does have the proper power - I even swapped out the ATX power supply with a known working one just to be extra sure. I've also checked all of the fuses in the machine and although I did replace one fuse (not on the DC3IO board though - in my mains cabinet) right when I got the machine, it has not re-blown and I don't believe it was related. However - the VSU light on the PLC is off! PLC OK is on, as is XVCC, and as are the +5V, +12V, and -12V lights. Putting a DMM probe on the motor ground/motor voltage pins gives me some interesting results, but I'm also not entirely sure what to actually do with the information I get. If the control PC is on, putting my positive lead on Vm and negative on COMm gives me ~-110 volts DC (yes, negative). With the PC off, this drops (raises, technically) to ~-52 volts DC. This doesn't seem right to me - but - I also am very new to all of this. So I'm wondering if that's actually just normal behavior, to have higher voltages or weird voltages on those motor outputs when the motors aren't actively being moved. My thermal cam also does not show any blatant hotspots on the PLC.

I've also noticed that the DF (drive fault) light is on - but from what I can tell, that's supposed to be on? (which is odd, because at least in my mind, drive fault LED on --> there's a drive fault, but I digress).

That said, here are the system specs that I am aware of, at least.
System info: Intel Pentium 4 Processor, BIOS date is 2001. CMOS battery is dead but that I do not believe should matter, because the system still boots fine.
PLC board: DC3IO
System version: CNC10 Mill v1.51 Uniconsole-2
Software last update was Thu Aug 11 2005, so my assumption is this is around the date the conversion kit was installed.

Pictures:

And now for some pictures. I tried to get as many angles as I could inside the cabinet. Whoever wired this up last time did a very messy job - there's a lot going on (and it's one of my goals to fix!). I don't really know most of what I am looking at but I've done my best to ensure all of the connections are snug. That said - when I received the mill, I noticed that the bottom right relay was missing 3 screws - they must have vibrated out over time, as I did find them down below. I also found a diode similar to the yellow one on the bottom left relay, as well as a blue wire looking similar to the others installed - so part of me is wondering if the relays need to be hooked up differently, but that is (at least for now) above my head so I am hoping someone can help me figure that out!

My report is attached - both the .zip and .txt.

Thank you for any help y'all can provide; I appreciate it. Really hoping I can get this thing working! It's worth noting I have access to a full range of electronics diag equipment (DMM/scope/etc), so I should be able to take any measurements as requested.

[cncsnw]

Measuring from VM+ to the adjacent VM- terminal (not to chassis ground!) you should see ca. +110VDC when the emergency stop contactor is closed, and ca. 0VDC when the emergency stop contactor is open. If the emergency stop contactor is closed and you have positive voltage applied to VM+ and VM-, then the green USV LED should light up.

It is very suspicious that you have a blue wire on VM- (the upper terminal), and a white wire on VM+ (the lower terminal). The more common convention is to use solid Blue for the plus side, and white (preferably with blue stripes or tape) for the minus side.

Wiring VM backwards used to be a death sentence for a servo drive, but the DC3IO might be able to tolerate it. Put the positive wire on VM+ and the negative wire on VM-, and try again to move the axes.

You should be able to trace the VM+ and VM- wires back through the emergency stop contactor to their source at a rectifier assembly (bridge rectifier and capacitor). Maybe the rectifier is hidden behind the DC3IO unit?

The green "Drive Fault" LED lights up when there is no fault, and there is valid fiber communication from the CPU10 board.

[centroid467]

Marc, I see one of our rectifier assemblies in the first picture. It looks like a white wire is going to the minus terminal but the wires should still be traced back to it all the same.

I agree that the positive and negative VM wires are crossed and there is a reasonable chance that it has survived the reversed VM.

[Bridget]

Hi All, @cncnsw,

That does seem very odd to me as well. I did run out there and take a few more pictures just now, and I'll add them to the photos album from before - check out the last 4 pics. I think I am going to swap the wires like you suggested, but just in _case_ it was done properly before I want to make extra sure before I potentially fry anything!

Google failed to add the pictures in order, but if it's showing the same order on my end, here's what I've added. I added pics #26-29, the order should actually have been 27 -> 29 -> 28 -> 26. (I am trying to number them in what order they're in, for future reference when I add more pictures). 27 & 29 are tracing the white wire - you can see it go into the mains cabinet and into a fuse, and from that fuse into the negative terminal of the large capacitor assembly (seems suspicious to me!). The blue wire, in pictures #26 & #28, you can see goes into a relay. I *think* that that specific relay is the one that's controlled by the e-stop, so that would make sense. That all being said - do you guys think that's enough data to say I should reverse the two wires?
Sidenote - turns out the blue wire had a cut in the insulation right near where my fingers are grabbing it in pic #28. Glad I found that - I'm going to be rewiring this all with fork connectors once they arrive from Amazon later this week anyways.

Certainly very interesting to me if these wires are reversed given that the seller mentioned that it did run for a while before faulting like this. I'd have to assume maybe he accidentally reversed them at some point in time while trying to fault-find, because the computer does show it as being on job ~20,000 - so it definitely did run for some time!

[centroid467]

Yes, you should reverse those wires at the DC3IO and leave the rest as is.

Well, do that after replacing the segment(s) with damaged insulation and installing the new terminals.

[Bridget]

Alright, good news and questionable news.

I swapped around those two terminals, and after powering everything back up, the USV light comes on! Hitting the cycle start button did actually start moving the Z axis, although something seemed off in its movement - it would turn a little bit, jiggle back and forth and make a sort of grumbling noise, and then repeat. But, it was actually moving the toolhead up, and continued to do so until it hit the endstop, after which the machine stopped. I did manage to get a video of this happening, and I added that to the photos album. So I think Z-axis seems to be halfway there. Also of note - I can spin the Z-axis pulley by hand while the machine is on. This of course causes a motor runaway and forces me to restart the machine (I didn't do it on purpose, I promise). I can't recall as it's been a few years since I have worked on servos - but when the machine is on, wouldn't I expect it to hold the motor's position (i.e. I shouldn't be able to move the motor by hand)? Or am I thinking about it wrong?

The X and Y axes though are acting oddly. Trying to manually feed them with the control panel does actually make noise - but it's not a normal motor turning sort of noise (at least, I think... worth noting that this is my first CNC, so I don't actually know what they sound like - but I *do* know what motors are supposed to sound like, lol). Both X and Y make some sort of gurgling noise - almost like the sound of passing fluid through a pipe - which is very odd to me - I don't believe I've even got the oiler hooked up just yet so they certainly shouldn't be doing that. I can attempt to take a video of the noise later today if my description isn't doing enough justice - just let me know. That all said - the X and Y axes do *not* move when they make this noise - I cannot manage to move them. It continues until I hit the e-stop. And I *think* the X axis was hitting a 411 again. Apologies for the somewhat scattered data here - I'm running downstairs to the garage between work breaks so I can only do so much! Thank goodness I usually can work from home.

It's got life! Much more confident now that I can get this thing running again, hopefully with the help of some kind internet strangers!

[centroid467]

When the servos are enabled, they will resist changes in position. If the servo was off (e-stop engaged or power released from the drive) then it would spin freely.


After writing all of the stuff below, I realized that your first step should be to unmount or uncouple all of the motors from the machine and jog them without any load in continuous mode. This will help narrow down where the problems lie.



I would check to see if there is something loose in the Z-axis assembly. This machine has a manual knee and the quill is Z axis, correct?

If Y makes noise but does not move and does not give 411 Full Power Without Motion, I would check the coupling to the ballscrew and make sure the screw can rotate.

X may be more difficult to figure out but here are a few things to check:
1. Motor rotates but the encoder does not. The encoder will be under the cap on the back of the motor and maybe the setscrew that couples it to the shaft is loose.
2. Motor tries to rotate but the load does not move. X axis may be binding or seized and the motor cannot move it. Try to manually move the axis by rotating the screw or ballnut. According to a manual I found, the screw is stationary so try the ballnut.
3. Motor does not rotate and the 411 Full Power Without Motion alarm happens pretty quickly. This is indicative of damage in that axis on the DC3IO. We can repair that kind of damage pretty quickly.

[Bridget]

Alright, I come bearing more good news. Turns out that some of the issues I alluded to in my previous post were of the PEBCAK variety. Call it a case of RTFM, maybe...

I forgot to hit the button to switch the control panel from incremental to continuous mode. So when I was trying to jog the axes, they were moving in such tiny increments that I didn't think they were actually moving. I only had the thought to actually hit the continuous button when I opened the axes up and saw the belts moving ever so slightly.

So - that being said. In continuous (and incremental) mode, I can jog all three axes in both directions, which is terrific! I find it hard to believe that the sole fault in the machine was that the motor power was wired backwards, because again... it ran for many years before breaking. So my thought is either:
A.) The screws holding down the motor power wires had vibrated loose some time ago and when the previous owner opened it up to fix that, he put them back backwards on accident and introduced the fault, or
B.) There's something else wrong with it.
I am guessing B.) is much more likely... which brings me to the issue that I now face. When I hit the cycle start button, I expect the machine to home itself (if I am correct - please correct me if I am wrong here!). It starts by moving the Z axis up until it hits the endstop - but then it stops entirely with an (entirely understandable) "407 Z+ limit (#6) tripped". But what I'd expect it to do (at least, if any of my 3D printer knowledge transfers whatsoever) is to then try to home the X and the Y axes. But instead, it just says "Limit: job cancelled" and refuses to do anything when I try to press cycle start/home again. Is this normal behavior, or is it supposed to move Z until it hits its limit and then continue on to move X and Y after that? Otherwise I'm not sure how else I would be able to set the machine home.

On a related note, what's the best place to read about the full functionality of the CNC10 software, and of the control panel and all of its buttons? There are definitely a few buttons of which I am unsure what they do, so I suspect reading through a bit would help me figure out quite a bit more.

I suspect that the whining noise I spoke of earlier was actually just the motors holding their position. It only starts once I've jogged a motor once and only stops once I hit e-stop, so that lines up pretty nicely.

P.S. Yes, the machine has a manual knee with a Z-axis quill. Not really sure what was going on with Z earlier but it seems to be much smoother now - but I will keep an eye on it. You also mentioned finding a manual somewhere - would you be able to point me towards that? I struggled to find all that much documentation (free documentation, that is) for the R2Ex mills.

[centroid467]

Alright, I come bearing more good news. Turns out that some of the issues I alluded to in my previous post were of the PEBCAK variety. Call it a case of RTFM, maybe...

I've run into plenty of PEBCAK errors myself. Glad that was all that was wrong with running the motors and moving the axes.

On a related note, what's the best place to read about the full functionality of the CNC10 software, and of the control panel and all of its buttons? There are definitely a few buttons of which I am unsure what they do, so I suspect reading through a bit would help me figure out quite a bit more.

Scroll down this page (https://www.centroidcnc.com/centroid_di ... nuals.html) for CNC10 manuals. It seems like we have the manual for V2.70 listed here. The manual for the version you have installed is most likely on the computer.

*EDIT* Looks like in V2.70 the operator's manual can be accessed from F5 CAM -> F4 Help.

P.S. Yes, the machine has a manual knee with a Z-axis quill. Not really sure what was going on with Z earlier but it seems to be much smoother now - but I will keep an eye on it. You also mentioned finding a manual somewhere - would you be able to point me towards that? I struggled to find all that much documentation (free documentation, that is) for the R2Ex mills.

This Maintenance Manual is what I was looking at. The site is not secured so view at your own risk: https://manuals.chudov.com/Bridgeport/R ... -Lloyd.pdf


As far as your homing issues go, read through the CNC10 manual and then go to the main screen and press ALT + I to bring up the PLC Inspector. Identify which input bits correspond to your limit and home switches and verify that they are behaving as expected. That would most likely be red for not tripped and green when tripped.

[cncsnw]

You should also try lubing and cleaning the Z+ limit switch. Start with WD40, finish with electronic contact cleaner.

Your control is set up to home using the switches. It homes Z+ first, using "M92/Z". Your control is configured in the normal manner: INP6 is both the Z+ home switch and the Z+ limit switch.

When you home with M92, you get a one-time pass to trip that limit switch without triggering an error. Any other time, a tripped limit switch during an automatic cycle is an error, which cancels the cycle.

You must make sure you are clear of all limit switches before you try to start homing. Select Slow, Continuous jog mode and jog each axis until it is obviously not tripping the limit switch. As centroid467 suggested, you can use the Alt-i display to verify that all of the first six inputs are green (closed, not tripped).

If you then press Cycle Start to find home, and it ends with a "407 Z+ limit (#6) tripped" error, it is because the Z+ limit tripped; then cleared as Z moved back down away from it; but then tripped again. This kind of failure to get a clean break is usually a sign that the electronic contacts in the switch are dirty, or perhaps that the switch is mechanically loose on its mounting.