Tormach PCNC 770 Reassembly
To say I underestimated the total time to completely disassemble, move, and then fully reassemble the Tormach PCNC 770 is an understatement.
Also I would like to acknowledge a big thank you to Rob, the gentleman whom I acquired the machine from, for his help and support on this journey.
Prepping the PCNC for rigging into the vertical position
Troubleshooting
My first error was not realizing the machine does run on standard household voltage but it requires a 20 amp outlet. (More on this later). When we finally got the machine upright and on its base and went to plug it in this outlet & amperage mismatch became apparent and halted us dead in our tracks on our quest to turn the machine on and bring the machine back to life. – If only it were that easy!
Some of the lubrication oil lines were either pinched or damaged during disassembly and transit and were replaced. This was relatively straightforward and easy.
The engine hoist procured from harbor freight worked spectacularly for the heavy lift elements of the assembly. I don’t need the engine hoist any longer but it was so handy to use I may hold onto it for bit longer.
Rigging the PCNC 770 onto its base
After a few months of post winter procrastination I had an electrician come out to install the required 20 amp outlet and fired up the machine. Everything worked fine except the spindle would not spin when commanded. After some initial troubleshooting I misdiagnosed this issue as a faulty C2 contactor and replaced it with a brand new one. Unfortunately this did not solve the issue.
The spindle failure troubleshooting threw me for a loop and I ultimately had chatGPT make me a comprehensive voltage test point checksheet which helped reveal the spindle door latch safety interlock as the culprit. The spindle door latch wiring had come loose assumingly during transit and was not working correctly and in turn preventing the sprindle from rotating. Fortunately this was an easy fix to reconnect the wiring spade to the terminal and restore its operation.
I thought we were out of the woods after restoring spindle operation, but I was sorely mistaken. The next gremlin in the machine was that the spindle would actuate and then mysteriously trip the breaker after the spindle would be commanded to stop. I was completely stumped on the root cause for a day or two. More troubleshooting (and some luck) revealed the next culprit. I had asked for a 20 amp outlet and circuit breaker be installed previously but I didn’t realize the electrician had specifically installed a GFI breaker at the panel and this is absolutely incompatible with the Tormach PCNC 770. After the electrician returned and changed out the breaker to a normal one we solved the breaker tripping issue.
Z Axis Troubleshooting
Next, for some strange reason the Z axis’s movement began to stall and squeal when commanded to raise or lower. I initially misdiagnosed this as a lubrication or gib issue. Turns out, the Z axis brake had gone faulty so I had to order and replace the Z axis motor/brake assembly which was another fun adventure in the wiring cabinet. Routing the Z axis motor cables down through the machine internals and into the electrical cabinet was an exercise in patience, dexterity, and determination.
Now with the C2 contactor replaced, the spindle door safety switch latch repaired and the Z axis motor replaced the machine was back to full working order!
I have to give credit to Tormach for making their machines friendly for field troubleshooting and repairs and for providing ample written and video documentation to support these endeavors.
Enclosure
To fully waterproof seal the Tormach PCNC 770 enclosure to the base I used 3 tubes of Sikaflex Polyurethane Sealant. You could probably get away with doing this with 2 tubes if you are doing this in one go or are judicious with your sealant use. Be cautious, the sikaflex sealant is extremely sticky and seems to get on everything and everywhere while you working with it. You probably want to wear sacrificial clothes when you do this evolution. (don’t ask me how I know)
Tormach PCNC 770 enclosure build
Tramming the vise
Next steps are to load the tool holders that came with the machine into the Autodesk fusion CAM tool library and cut a soft jaw block as a demonstration project. Fingers crossed we are done with any more troubleshooting!