I also had the same problem with my 5 year old WES51. After about 2 years of operating, the barrel would "wiggle" out of the handle causing much grief thru either the barrel wiggling out or loosening the barrel nut causing a non heating tip. I have been successful in "pushing" it back inside the handle. And about 2 years ago it would wiggle out even when cool. Pushing it back in has caused the wires to break at the strain relief. It appears that the hi-temp plastic used does breakdown when it is left on for extended periods on hi-temp selection. Looking into it further, I noticed the 'spline' rib cuts are lengthwise and not around the diameter. I tend to perceive this like a car drive shaft that can slide in and out but the spline prevents twisting. IMHO, if they were anticipating on the cheap they could just as easily cut the grooves around the diameter to prevent any type of removal. Although that would defeat the ability to replace the heater or temp probe unless they implemented a type of 'clamp' (clamp, screw, BNC style socket, etc.). Of course they would have to increase the price of the unit appropriately. I have ordered a replacement PES51 pencil, and I am going to modify the new one so this does not happen again. FWIW, I personally would not mind paying an additional $20 USD if the said designed clamp does what it is supposed to do and does not break upon the first heater/temp probe replacement.