What's new
What's new

Is spindle taper warming with HP TSC normal?


Hot Rolled
Nov 25, 2020
Riga, Latvia
I have been running a die job recently, and had it running with max RPM and TSC for like 2-3 hour straight and noticed that holder and spindle taper are warm to the touch. First I thought it I had some issues with spindle, and dropped RPM to 10k, then to 8, then to 6. Spinlde has a chiller and temp probe, had no alarms. However, my TSC fine filter was about same temperature as tool and taper. Running spinlde same load dry it was nice 20 degrees, both tool and taper.
It seems that having hight pressure coolant heats it up about 15-20C above ambient.

Is this normal? Should I be worried? Should I fix it and how?
If the tool and holder you are running the TSC through has a small orifice the pump is probably maxing out on pressure, but the tool can't move the volumetric flowrate that the pump is outputting so it has to bleed the excess off through the bypass valve. All that working of the fluid builds up heat in the coolant. Measure the coolant temp in the tank after a run, it's likely the same temp as the holder. Since you'd be blowing warm/hot coolant through the holder for hours at a time.

To eliminate the heat build up you can do a couple things, 1.) don't run the tsc for as long (duh), 2.) If you have the ability to control the flow output of your tsc pump turn it down some (Our fancy chipblaster unit is variable pressure and flowrate), or 3.) increase the overall coolant volume in the system so it doesn't heat up as much or just takes longer overall to heat up.

And yes the holder getting hot can cause accuracy issue since it's getting longer as it warms up.
I was running 1.5mm bullnose, so yeah, orifice is tiny comapred pump flowrate.
Tank temperature was about ambient, may be 2-3 degrees above.
Sadly my HP control is either on or off. Should I get something like cooling loop for this? Doing it dry is not really an option.
I may try heat soaking the tool before operation and measurement, it seems to get up to temp in 10-12 minutes.
Tank temperature was about ambient, may be 2-3 degrees above.
I was going to suggest a coolant chiller but sounds like it won't actually do anything.

Instead of running high pressure thru the tool, can you run high pressure through a coolant jet holder/collet instead?
Honestly, I want to know more about this 1.5mm bull-nose with TSC...

As long as the temp holds stable, your solution of heat soaking it before touch-off is probably your best bet. You'll probably still get some variance over hours, but you'll eliminate the bulk of it.