First of all I tried to just order a new z truck and Carvetight Upgrade. LHR is currently out of both the old style and upgraded z truck assemblies (as of 5/2/2014.)

I read all the tips on removing the chuck with the z truck still in the machine- didn't work. I bent/broke flat wrenches and square drives made from screwdrivers, 1/4" inch extensions, grade 8 bolts, etc and heated it to 400 degrees according to a infrared temp gun and still wouldn't budge.

I decided to just go ahead and take out the z truck because regardless it had to come out if I couldn't get the QC off. I cut off the plastic shroud and all the moving collar parts with a cutoff wheel afterwards. I then cut as far into the QC as possible without damaging the threads of the shaft or nicking the z truck housing badly. I heated it to 800 degrees with a propane torch and voilą !!!

So it only took 800 degrees to free up my stuck QC chuck... but while removing the z truck (I have what seems to be an older Version A machine without any upgrades)
I broke the Z Sensor that sweeps past the Flag. I have Designer Version 1.187 but Im unsure whether or not I still need the sensor or if i can just leave it off the z truck since I already have it removed. Ive read other posts about it no longer being necessary but I was unsure if I needed to reconnect the cable and board or what.

Thanks for any help.