PDA

View Full Version : Help.. Tiag mill has issues



MrRage
09-07-2005, 02:23 AM
Please excuse the spelling on my notes here but I’ve got a problem on my hands here. The Tiag mini-mill I’m working on has problems and I’m trying to isolate what exactly is causing it. The problem I’m having is that the bits that are in a collet or attached to the chuck vibrate around while spinning. It appears like the headstock shaft isn’t centered but I’m not sure. Here is a sketch I made that shows the problem. Its hard to tell if the headstock is vibrating where the collet is attacked, but then again the vibrations would be so small that it wouldn’t be noticeable.

I don’t believe it’s a bad collet adaptor because the chuck we have vibrates as well.

So what do you think is going on guys?

Diagram:
http://epyon.54.org:8000/~dustin/tiag.jpg

So what do you guys think it might be?

moto21
09-07-2005, 09:35 AM
Put a dial indicator on a couple points that rotate and check the run out. Im going to say that something is bent due to heavy cuts or shipping. Is the hole machine shaking or just the cutter. Also is this a new machine or has it been used for a while. tell us what you find and well go from there.

MrRage
09-07-2005, 11:44 AM
Just the very tip of the bit vibrates; the rest of the machine is rock solid. Just got it a few weeks ago and working with the vender I got it from about this issue, so I’m just trying to isolate the faulty component. I just got a dial last week so once I figure out how to clamp it down ( I’m so new at this I don’t even have clamps yet ) I’ll give that a shot.

awerby
09-07-2005, 03:09 PM
would you? The tapered part is supposed to point up - it nestles into the spindle bore. The stepped part fits into the hole in the closer nut. How are you mounting that chuck?

Andrew Werby
www.computersculpture.com



Please excuse the spelling on my notes here but I’ve got a problem on my hands here. The Tiag mini-mill I’m working on has problems and I’m trying to isolate what exactly is causing it. The problem I’m having is that the bits that are in a collet or attached to the chuck vibrate around while spinning. It appears like the headstock shaft isn’t centered but I’m not sure. Here is a sketch I made that shows the problem. Its hard to tell if the headstock is vibrating where the collet is attacked, but then again the vibrations would be so small that it wouldn’t be noticeable.

I don’t believe it’s a bad collet adaptor because the chuck we have vibrates as well.

So what do you think is going on guys?

Diagram:
http://epyon.54.org:8000/~dustin/tiag.jpg

So what do you guys think it might be?

MrRage
09-07-2005, 04:23 PM
Yeah its going in the right direction, tapered part pointing up. The chuck has an adaptor that threads onto the collet mount, then the chuck threads onto the adaptor.

awerby
09-07-2005, 04:50 PM
It sounds like you've got a bad bearing in the spindle, then. I can't think of anything else that would cause this vibration, assuming everything's tight. If the mill's less than 2 years old, Taig will fix it under warranty (they're pretty good about that). If it's older, this might be a good excuse to upgrade to the new ER spindle. It has a larger capacity (up to 3/8"), takes standard ER16 collets (metric and inch) and it's supposed to be more accurate than Taig's proprietary system. It doesn't handle Taig's accessories, like the chuck adapter, though.

Andrew Werby
www.computersculpture.com
Authorized Taig dealer

MrRage
09-08-2005, 12:57 AM
Everything is rock solid except the spindle. The spindle is oscillating approximately 0.001” according to my dial indicator. Not enough to see with the naked eye, but enough to cause the problems. I’m happy I got the dial indicator last week and had a chance to use it. By the time we get down to the chuck the oscillations are in the 0.00625” or so. Going to run another test tonight because we only logged the spindles oscillation and forgot to log the bits oscillation.

cartertool
09-09-2005, 07:54 PM
I agree with Andrew, if the mill is new (if not let me know) just send the headstock back to Taig, runout shouldn't be more than a few tenths. Some other questions:
Were you clocking the taper runout or the spindle OD runout?
How tight was the closer on the collet?
Did you check the collet for burrs, this sometimes causes a problem?
What diameter endmill/tool were you using and how long was it?
What speed were you running at (I'm suspecting some "whipping")?
The drawing shows a drill bit - if so these are notoriously not true-running depending.
Is the bit all the way in the collet?
Did you at any point mess with the spindle preload? It is possible something got out-of whack
Anyway, as I said, the factory will take care of it.