re: MuscleChuck - Quick Change Router Chuck

Well, I had to remove the Muscle Chuck from my CNC router.  It was causing serious vibration issues, especially when I use a long 1/2" bit.   The bit is over 3" long because I am carving a very thick piece from both sides that requires at least 1.5" of cutting depth.  I actually bought 2 of the chucks for different router types and had the same issue on the second one, even though  it was the first time I had used that chuck.  In fact, the vibrations seemed to cause that second router to over heat and caused its speed control to falter (speed was fluctuating or pulsing) and had to shut down the CNC job.  That router has only been used a few times with short runs so it is practically new.  After letting it cool down and running without a bit in it, the overheating problem seems to have gone away.  Switching back to the original router and its normal collet made the vibrations go away too, even with the long 1/2" bit, so I am pretty sure that the problem was with the chuck.   Fortunately I was able to finish the job using the normal collet with the same bit.

 I am not sure how you would over tighten the MC with a bit mounted in it.  It can only tighten down so far.  I suppose you could strip out the tightening bolt.  I suspect that my issues with having problems getting bits in and out of the chuck are related to the vibration issues when using the long 1/2" bits.  The vibrations may have somehow distorted the chuck, though I cannot see anything obviously wrong with it other than it is now impossible to put a 1/2" shank bit into it.   I can still put the 1/4" collet into it  since it is compressible but it does not slide in and out as smoothly as it did when I first got it.  

Long story short...If i were reviewing/rating it I would give it 5 stars for easy of use but I would have to lower it to 2 stars due to my experience with long bits on my CNC.