Harman Combustion fan blade removal

[rickwai]

If you have worked on many Harman stoves you know the set screw on the comb. fan blade rarely comes loose. Everey once in awhile it will with out persuasion. normally I heat the collar with a torch which ruins the allen wrench after a couple on times. Yesterday i heated collar cherry red and allen wrench just rounded off along with the set screw stripped out. I did not have my dremel to cut the fanblade and shaft so I thought I was sunk for the day. Then I thought well maybe I could try drilling it? I used a 3/16" approx bit and it naturally wants to go to the joint between collar and shaft. I quickly figured out that the collar is a pretty soft metal and drilled thru quickly. I put some side pressure on the drill bit and it cut clear thru the collar. the I went to opposite side and drilled thru and blade came loose. 10 min. tops and blade was off. I always replace the blade when replacing motor anyway and I keep all the blades on the truck. Even after 14 yrs of working on stoves I am still learning