- Joined
- Jun 13, 2024
- Messages
- 16
Newer member here, but just wanted to share my experiences with my first large late- a 1979 LeBlond Regal Servo Shift 15"x54". Information on these machines online has been a little bit scarce and troubleshooting has been frustrating, especially because most issues with these lates are electrical/hydraulic and I consider myself one baby step past complete novice in both of those categories. But here's a little bit of encouragement: if you take the time to work the problem step by step YOU CAN AND WILL SUCCEED (or at least learn something new along the way). This will be a little bit of a saga, but maybe this post will help somebody or encourage them to keep going on their machine that they just can't seem to get figured out.
I bought this machine at an auction from a complete machine shop closure, having never seen the lathe in person. My rationale is that if the whole shop worth of equipment is being taken out of service at the same time 1. the machines probably work, and 2. they're not just selling off their old worn out junk. I definitely tested that theory on this purchase and gave myself a pretty good scare in the process.
The first thing I did was reach out to LeBlond directly with the serial number, requesting any information they had on it. They responded quickly with a scan of the original purchase order, some wiring drawings, and said a manual would be $95. I had already found a scanned PDF online, so I didn't take them up on that. At least the relationship was started and I knew they would be available and ready to help if anything came up in the future or parts were needed.
Next, I sized and installed a new Phase Perfect Enterprise for the shop. Up until this point, I had been buying used Mitsubishi VFDs on eBay and installing one on each machine. The issue with the LeBlond is that it has 3 total 3 phase motors, so getting those wired up with independent VFDs and making the controls work as they should sounded like a complete machine rewiring job, which I am not confident in attempting. I decided to go with the Phase Perfect over a rotary phase converter primarily for the reason that the standby power usage is so much lower. I didn't want to have to flip another switch each time I want to quickly use a machine and remember to turn it off when I leave the shop. I hooked the lathe up to my new 3 phase power, flipped the switch, and that's when the problems started.
The spindle would turn on, albeit in the wrong direction, but it was stuck in a low speed and turning the servo shift knob would make some clicking, but no oscillating as I had seen in the videos online. I pulled out the wiring drawing, which had a description of what's happening with each major machine manipulation, which proved to be helpful. The machine needs to confirm zero speed before shifting can begin, which means the brake needs to be working, but I had noticed the lathe free wheeled to a stop when turned to "stop" on the dial. I opened the electrical panel and immediately noticed a missing fuse on what turned out to be the brake circuit. Why somebody would take that out and not replace it, I have no idea. Doing this made the chuck oscillation work when the speeds were changed, but movement seemed very weak compared to what I had seen online.
According to LeBlond's YouTube channel, two common problems with the magnetic brake are the DC rectifier and pad adjustment. The power to the brake unit needs to be between 48 and 60 VDC. I checked, and it was within spec thankfully. They also mentioned that for the brake to work properly there needs to be 18 thou or less gap between the hubs. Mine measured about a steak knife thickness. Turning the 3 Allen screws on the outside of the hub counter-clockwise pushes the pad closer to the magnet. This got the spindle to oscillate like I had seen in the videos. But still no speed changes. I know the unit shifts hydraulically, so I put my hand on the hydraulic pump and it was pumping fluid. I opened the top head cover and all I heard inside was some gurgling noises and no movement from the shift arms. There is a pressure test port on the servo shift manifold, where some apparently already have a gauge installed (according to the manual). Mine did not, but I cracked the plug and no fluid came out. I figured this meant the filter was plugged and planned to dig into that whole mess another day.
The next day I had an epiphany. Why was the oil in the headstock gurgling and bubbling when trying to shift? How could absolutely no oil come out of the pressure test port even if the filter was plugged? The oil looked remarkably clean so that didn't make sense. Wait... wasn't the spindle turning backwards? Does that mean all the other motors on the machine are running backwards too? Yes! The hydraulic pump was pushing fluid backwards into the headstock sump instead of the servo shift manifold. I checked the input wiring on the machine and, sure enough, the terminals were wired white, black, and red instead of the black, white, and red order I used in the rest of the shop. It looked like the wire was just a tad bit short, so I presume somebody had just done the easy/lazy thing and ran wires where they could reach. Problem solved? Not quite.
Now the machine was acting all sorts of weird. Things would turn on, trip out, make noise then nothing. At my whit's end, I grabbed my multimeter thinking I had blown a fuse, burned up a diode, or worse. Fuses were good, but reading line to line I would get weird readings. ~240V, ~110V, then 87V. 87, are you kidding me? Is this phase converter a piece of junk?? I know I had read that high leg delta needs to be measured from line to line instead of line to ground and I was doing that, so what gives? I went back to the panel and checked there and all of them were spot on at 240V. Then back to the lathe and the same thing again. As a last ditch effort, I shut off the master power and checked the line to the machine. Since Menard's and Home Depot don't stock standard industrial 3 phase twist lock plugs, I was waiting for those to arrive in the mail, so I had just hard wired from the box to a drop cord to the machine. 8 wire nuts and, sure enough, one had come loose and the wires weren't even making contact. I was sending 87V through the air! I fixed the connection, flipped the breaker, held my breath, and bingo, we have speed changes!!
The machine runs very nicely, and I'm excited to get it off the trailer and installed! The inside of the headstock looked pristine when I was in there, so I assume the previous owner had some rebuild work done on it. Just finished up the 3 phase wiring, drywall, paint, in what will be the back corner machining room of the shop, so the lathe will soon be home.
Hopefully this helps or at least entertains somebody. Thanks for reading, and feel free to reply if you have any feedback or questions about your own Servo Shift machine.
I bought this machine at an auction from a complete machine shop closure, having never seen the lathe in person. My rationale is that if the whole shop worth of equipment is being taken out of service at the same time 1. the machines probably work, and 2. they're not just selling off their old worn out junk. I definitely tested that theory on this purchase and gave myself a pretty good scare in the process.
The first thing I did was reach out to LeBlond directly with the serial number, requesting any information they had on it. They responded quickly with a scan of the original purchase order, some wiring drawings, and said a manual would be $95. I had already found a scanned PDF online, so I didn't take them up on that. At least the relationship was started and I knew they would be available and ready to help if anything came up in the future or parts were needed.
Next, I sized and installed a new Phase Perfect Enterprise for the shop. Up until this point, I had been buying used Mitsubishi VFDs on eBay and installing one on each machine. The issue with the LeBlond is that it has 3 total 3 phase motors, so getting those wired up with independent VFDs and making the controls work as they should sounded like a complete machine rewiring job, which I am not confident in attempting. I decided to go with the Phase Perfect over a rotary phase converter primarily for the reason that the standby power usage is so much lower. I didn't want to have to flip another switch each time I want to quickly use a machine and remember to turn it off when I leave the shop. I hooked the lathe up to my new 3 phase power, flipped the switch, and that's when the problems started.
The spindle would turn on, albeit in the wrong direction, but it was stuck in a low speed and turning the servo shift knob would make some clicking, but no oscillating as I had seen in the videos online. I pulled out the wiring drawing, which had a description of what's happening with each major machine manipulation, which proved to be helpful. The machine needs to confirm zero speed before shifting can begin, which means the brake needs to be working, but I had noticed the lathe free wheeled to a stop when turned to "stop" on the dial. I opened the electrical panel and immediately noticed a missing fuse on what turned out to be the brake circuit. Why somebody would take that out and not replace it, I have no idea. Doing this made the chuck oscillation work when the speeds were changed, but movement seemed very weak compared to what I had seen online.
According to LeBlond's YouTube channel, two common problems with the magnetic brake are the DC rectifier and pad adjustment. The power to the brake unit needs to be between 48 and 60 VDC. I checked, and it was within spec thankfully. They also mentioned that for the brake to work properly there needs to be 18 thou or less gap between the hubs. Mine measured about a steak knife thickness. Turning the 3 Allen screws on the outside of the hub counter-clockwise pushes the pad closer to the magnet. This got the spindle to oscillate like I had seen in the videos. But still no speed changes. I know the unit shifts hydraulically, so I put my hand on the hydraulic pump and it was pumping fluid. I opened the top head cover and all I heard inside was some gurgling noises and no movement from the shift arms. There is a pressure test port on the servo shift manifold, where some apparently already have a gauge installed (according to the manual). Mine did not, but I cracked the plug and no fluid came out. I figured this meant the filter was plugged and planned to dig into that whole mess another day.
The next day I had an epiphany. Why was the oil in the headstock gurgling and bubbling when trying to shift? How could absolutely no oil come out of the pressure test port even if the filter was plugged? The oil looked remarkably clean so that didn't make sense. Wait... wasn't the spindle turning backwards? Does that mean all the other motors on the machine are running backwards too? Yes! The hydraulic pump was pushing fluid backwards into the headstock sump instead of the servo shift manifold. I checked the input wiring on the machine and, sure enough, the terminals were wired white, black, and red instead of the black, white, and red order I used in the rest of the shop. It looked like the wire was just a tad bit short, so I presume somebody had just done the easy/lazy thing and ran wires where they could reach. Problem solved? Not quite.
Now the machine was acting all sorts of weird. Things would turn on, trip out, make noise then nothing. At my whit's end, I grabbed my multimeter thinking I had blown a fuse, burned up a diode, or worse. Fuses were good, but reading line to line I would get weird readings. ~240V, ~110V, then 87V. 87, are you kidding me? Is this phase converter a piece of junk?? I know I had read that high leg delta needs to be measured from line to line instead of line to ground and I was doing that, so what gives? I went back to the panel and checked there and all of them were spot on at 240V. Then back to the lathe and the same thing again. As a last ditch effort, I shut off the master power and checked the line to the machine. Since Menard's and Home Depot don't stock standard industrial 3 phase twist lock plugs, I was waiting for those to arrive in the mail, so I had just hard wired from the box to a drop cord to the machine. 8 wire nuts and, sure enough, one had come loose and the wires weren't even making contact. I was sending 87V through the air! I fixed the connection, flipped the breaker, held my breath, and bingo, we have speed changes!!
The machine runs very nicely, and I'm excited to get it off the trailer and installed! The inside of the headstock looked pristine when I was in there, so I assume the previous owner had some rebuild work done on it. Just finished up the 3 phase wiring, drywall, paint, in what will be the back corner machining room of the shop, so the lathe will soon be home.
Hopefully this helps or at least entertains somebody. Thanks for reading, and feel free to reply if you have any feedback or questions about your own Servo Shift machine.
