I'm putting this post here because I don't really know where the best spot might be. I have an Open Builds WorkBee machine that I have used for many years. Standard configuration and I'm using an original Black Box controller and use the Open Builds sending software. It has worked for me very well. Recently I had some concerns with the stepper on the X axis. It occasionally didn't sound "right" and I found that it was possible to turn the shaft even with the coils energized. I bought a couple of new Nema 23's. The ones I received were physically larger than the current ones. I replaced the X axis motor with one of the new ones. Originally I had problems getting it to work and Peter gave suggestions. Turned out to be a bad jumper cable I was using to temporary connect it. At the same time I purchased Spindle/VFD controller. The spindle was heavier than the palm router I had been using so I put the other new stepper on the Z axis. Checked the calibration of the new motors. All seemed to run fine. It was time for a new spoil board so I trammed the new spindle and surface leveled a new spoil board. I made a couple of Vcarve Inlay cutting boards that turned out great. A guy contacted me and asked if I could make some Whiskey Smokers as grooms men gifts for his wedding in a couple of months. I made 3 detailed tops on VCarve Pro for him to choose from. Down to the basement to carve them and this is where things went bad. All of the tops used a 7.5 degree, .01 inch, tapered ball nose bit. Finish time of about 90 minutes per top. About 45 minutes into the 1st carve I got some stepper chatter, lost positioning info, destroyed the carve. in short none of the carves worked. About half way through each one the same thing happened. If I stopped the machine, re-centered it, restarted it things would go fine for 45 minutes or so and then fail. At 1st I suspected perhaps electrical noise from the spindle/VFD especially since it didn't have a shielded cable. These are the steps I took to try to fix tings. 1. Replace the spindle wire with a grounded/shielded cable with drain wire and moved the VFD as far away from the computer as I could - no improvement 2. Put a power conditioner on the computer and Black box power supply - no improvement. 3. Temporarily replaced the Spindle/VFD with palm router - no improvement. 4. Checked all the linear rod bearings, retention clamps, nut blocks, Motor connectors, etc - no improvement. 5. Checked the stepper wire connections to black box. All secure, connector fully inserted - no improvement. 6. Removed the fan cover from the Black Box controller. Minimal dust inside cleaned it with compressed air - no improvement. 7. Temporary attached a 12 volt fan from a computer power supply to replace stock fan - no improvement. Ok about the only other things I can think of to fix this is to replace the Y stepper motors and/or the Black Box controller. Any ideas appreciated! - Mark -
Motors never go bad. Its always wiring. If joints look good, on a older machine cables can have breaks inside insulation (constant back and forth bending in strained spots and tight radius bends can fatigue the copper and cause breaks)
Thanks Peter. The motors that are giving me the issue, as far as I can tell appear to be the Y motors. Those wires never move but I was going to replace all the cables anyways so I will start there. More latter Mark
For Peter or anyone else who wants to comment on my post regarding loss of position after a period of time. Peter suggested that the issue could be a wiring issue. I always suspected that the issue was in the Y axis. I verified that by pulling the wire connector for the X and Z axis from the Black Box so now only the Y motors would run. Ran my tool path again and in about 25 minutes I started getting stepper chatter and lost positioning on the Axis. I have had this machine for many years so was going to replace all the stepper wiring anyway with shielded cables. About 30 minutes latter new shielded/grounded Y cables were installed and ready for testing. Ran the tool path and again 20-25 minutes into it I got steeper chatter and position loss so it wasn't a wiring issue. Just to satisfy my curiosity I replaced the Y steppers and got the same results. One last test, removed the Y motor connections and connected the X and Z motors to the the Y inputs on the Black Box. 20 minutes into the run the Z stepper became very unhappy with the signals it was receiving. Time for a new Black Box controller!
