npolanosky
Cast Iron
- Joined
- Apr 9, 2016
- Location
- USA, FL
Hi there,
I picked up a used 1993 VF-3 for basically nothing because it wouldn't change tools.
Replaced O-rings in the TRP, replaced some air lines, cleaned the crap out of the whole thing, and boom- It's ready to rock and roll. A killer deal at twice the price, the previous owners had just given up and bought a new VF2SS to replace it.
The last issue I have left is that the spindle gets hot pretty quickly at anything over 2500RPM or so. I haven't measured it with the temp gun yet, but after a few minutes at 4k I can't touch the upper-inside of the taper for more than half a second or so. I've run a similar vintage VF1 for the past 2 years, and even after heavy cutting at 5k for hours it's nowhere near this hot.
I suspected a lube issue at first since the lubrication system was full of sludge. I replaced metering valves and tubing, cleaned the bijur oiler tank, etc. I've got good clean oil in it and it's definitely reaching the spindle. I put a bit of oil in the spindle manually too, just in case it was extra dry. The axes weren't being lubricated properly, so I figured it couldn't hurt.
It's still getting very hot though, and seemingly faster than before. Doing more reading, it looks like over-oiling is just as bad or worse than running too dry, and therefore adding oil manually was stupid.
How should I rectify this, and what should I check? Should I turn down the regulator for the spindle air/oil system (the one that's normally at 15psi or so) and just let it run at S300 or so for a day? Is it possible something else is causing the heating? Or do these 7500RPM spindles just run hot?
I picked up a used 1993 VF-3 for basically nothing because it wouldn't change tools.
Replaced O-rings in the TRP, replaced some air lines, cleaned the crap out of the whole thing, and boom- It's ready to rock and roll. A killer deal at twice the price, the previous owners had just given up and bought a new VF2SS to replace it.
The last issue I have left is that the spindle gets hot pretty quickly at anything over 2500RPM or so. I haven't measured it with the temp gun yet, but after a few minutes at 4k I can't touch the upper-inside of the taper for more than half a second or so. I've run a similar vintage VF1 for the past 2 years, and even after heavy cutting at 5k for hours it's nowhere near this hot.
I suspected a lube issue at first since the lubrication system was full of sludge. I replaced metering valves and tubing, cleaned the bijur oiler tank, etc. I've got good clean oil in it and it's definitely reaching the spindle. I put a bit of oil in the spindle manually too, just in case it was extra dry. The axes weren't being lubricated properly, so I figured it couldn't hurt.
It's still getting very hot though, and seemingly faster than before. Doing more reading, it looks like over-oiling is just as bad or worse than running too dry, and therefore adding oil manually was stupid.
How should I rectify this, and what should I check? Should I turn down the regulator for the spindle air/oil system (the one that's normally at 15psi or so) and just let it run at S300 or so for a day? Is it possible something else is causing the heating? Or do these 7500RPM spindles just run hot?
)
