Originally Posted by
RedneckPhysics
On my shop's 770, I see a bit under 0.0002" TIR at the spindle taper, BUT the TTS system ER-20's give me anywhere from 0.0003" to 0.0025" TIR at the cutting plane, depending on the assembly and insertion angles of the collets and holders. I've had parts turn out like that when I forget to map or match the cumulative runout values on a new cutter.
That's a bummer that you're already starting out with such a high runout at the taper... definitely not acceptable in my opinion. (Kindly) request a new spindle cartridge under warranty!
I would send them those part pictures, along with a video of you measuring the TIR of your spindle taper and tool. I find videos have the highest impact value with Tormach CS, as they're easy to understand, quick to watch, and provide a lot of information, such as making sure you did everything correctly in measurement, for example. I find those always get the best responses!
Hope that Helps,
Mike
PS: The Runout tolerance on the Certificate of Inspection for the 1100 is 20um "near" the spindle, and 30um at 100um away, as measured on a precision R8 calibration bar, I assume.
Same specs for the 770's spindle as well. In my case, the spindle was factory checked to be 10um and 30um respectively.
So, you might be able to interpret a 0.0008" runout on the taper face as out of spec, as I couldn't imagine a scenario where that much runout (if it's 100% angular and radial, and not caused by an error of the bore's shape itself) wouldn't cause an issue when measured anywhere outside of the spindle.
Have you measured at multiple depths on the taper itself, and compared the runout measurements with respect to angle at different heights? Might not be able to tease out much due to uncertainty in the tenths range though.
Also, sorry if I missed it, but what values did the inspector state on your machine's certificate?
Final thought: The short R8 collets that Tormach sources for TTS are mostly crap in my opinion. I recently re-ordered after springing the original (fantastic collet, by a different manufacturer), and ended up having to order 4 in total, before I found one that worked to my satisfaction.