replacing speed dial and pork chop assembly.

[woodmeister]

I have replaced a few of these but ran into a problem. the shieve was stuck in high speed and the crank would not crank. The owner must have turned in while motor was not running.
I replaced the larger belt thinking it was the problem, but it wasn't due to wear anyway. I had to compress the large spring in motor bottom pulleys and put a wedge between after putting the belt in. I then put the upper sheive on(one with clip that goes onto the port chop part. I put the speed control back in and put clip back on and took the wedge out and started it up. The crank turned a little hard even after lubrication of dial, and places on shaft as in normal lubrication. It turned it on and motor seemed to run ok but the dial still turned hard. I replaced the speed dial assembly and pork chop and still the same but not as much resistance. I checked out the area where roll pin goes in as per Bill Mayo (RIP) and no distortion in that area. The crank assembly and pork chop turned freely when I inspected it outside on bench. Questions:
What could it be? Belt to tight? gears are not worn or shaft bent.
Is there and easier way to put new belt in and not having to compress the large spring?
Any help appreciated

[dgreen810]

I bought a Mark VII last summer that had a Mark V motor on it that had the same problem you describe. The guy had cranked it up to fast with the motor not running. I took it apart chucked the worm gear shaft up in My Jet mini lathe and found it was bent. I straightened it as best as I could and re-installed it. The speed control works OK now but it is still a little tight in one area.

Don G

[woodmeister]

thanks for responding. I took the worm gear etc out and it works freely with no worn gear or screw. I put it back in and it is tighter than I would like and I can't figure out what is causing the resistance.

[JPG]

thanks for responding. I took the worm gear etc out and it works freely with no worn gear or screw. I put it back in and it is tighter than I would like and I can't figure out what is causing the resistance.

Interference between the worm gear and the porkchop teeth. This can be caused not only as described by a bent worm gear but also improper shaped pork chop teeth(smushed?) The interference can be observed by looking at the teeth from the side with a bright light on the opposite side. You must look at a slight angle that aligns with the porkchop tooth angle. The contacting surface is a line on the porkchop tooth. There MUST be a slight backlash or it will bind. More than one tooth simultaneously contacts the wormgear and they must all have backlash. Realize when there is no backlash the worm gear is contacting the front face of one porkchop tooth and the back face of another(typically next tooth).

Judicious filing of the porkchop teeth will provide clearance(backlash).

When correctly done finger turning of the shaft will move the porkchop full range.