Brent,
You are a keen observer. Yes I have been doing some machine repair work for hire. I really like it.
I have no formal training in machine tool repair. I did work as a mechanic when I was in college, but I worked on semi trucks and other things with diesel engines. At my last real job we had an ace in-house repair guy so I never really did any repair work for them.
When I started the shop I had no money. So, I bought what I could afford. As you can see, that usually means machines that need some TLC. I bought them cheap and tried to make them go. Some have required more work than others. Buying broken machines and fixing them yourself is a fantastic way to learn how to fix them. If you need them to work to make money, you are pretty motivated.
I think I have learned as much about fixing machine tools in the last 6 or so years as I have about any other aspect of the business. It turns out I'm pretty good at it. It also turns out I like doing it more than I like running the machines...
Here is a run down of repair projects:
Tree J325:
New switches on the control panel. Y axis thrust bearings and re-balled the ball nut. Replaced spindle bearings.
Haas VF-3:
Tool changer carousel bearings. Orientation collar and shot pin. New spring washers in the draw bar. Had the spindle drive rebuilt. Replaced the DC power supply. New way cover wipers.
Mazak Slant Turn 15:
Major alignment including turret coupling, turret to X axis, head stock, and tail stock. Replaced the whole tailstock with a used unit (previous owner had torn out the hydraulics and made it manual). Replaced all the lube metering units. Hacked in some relays to allow bar pulling.
Tree VMC 1260:
Major rebuild of the way covers including spot welding new wipers and heat shrinking, straightening, and welding the covers (it has 8 covers
). New X axis thrust bearing. New servo drive contactor. Various pneumatic solenoids replaced. New spindle belts and cleaned up rusty pulleys. Recently did the spindle gear shift yoke as seen in the video above.
Mori SL20:
Turret coupling was packed full of crap. I bought it cheap because it would not hold size. It was easy to see why. Lined up the head stock and turret. I think that's it. Solid machine.
Bridgeport Romi PowerPath 15 (not shown in this thread):
Replaced entire 486 control computer. Rebuild the dynamic braking controller (board level repair). We'll see what else it needs when I get a chance to run it.
Tatung Grinder:
Hydraulic feed was all jacked up. Would not reverse table and would over travel. Spent about a week fighting it. Finally made a PLC logic truth table and narrowed it down to 1 wire that was not connected to ground
. Seller had no idea it wasn't working right
.
Victoria Drill Press:
Straightened bent spindle. Replaced stripped helical gears on the motor with a set of spur gears. Fixed power feed clutch.
Engine Lathe:
Replaced safety switch in the electrical cabinet. Repaired feed clutch. Fixed foot brake.
I'm sure there is more. I've owned at least 8 CNC machines now and never called in a service guy.
I like the machine repair side of our industry and I definitely see things headed more that way. The problem is I have gotten so wound up in production machining that I can't really cut that off.