Posted: Thu Oct 28, 2010 1:30 am
billmayo wrote:mickyd wrote:
The worm gear rides up on the side pf the quadrant teeth and will bend the worm gear shaft when forced to do this action. Otherwise the Speed Control handle set screw will badly scored the worm gear shaft if the worm gear is jammed on the top of the quadrant teeth. The only time this occurs is when the quadrant teeth have been badly worn on one side or broken on that side. This also bends the leg on the backet holding the quadrant allowing the quadrant teeth to wear on the outer edge.
I have been replacing the quadrant roll pin with a #10-32 X 2 1/2" allen head bolt, 2 star washers and a thin Nylock nut after straightening the bracket legs. I have a computer file and pictures plus these parts (free) for this change if anyone is interested. I have been doing this change for around 6 years and over 75 Speed Control Assemblies without any returns or futher quadrant damage at this time.
I have a lengthly soapbox discussion available as to why this occurs but I find just fixing the problem is quicker and my opinion is best saved for another day and subject.
1) The roll pin ALLOWS the leg bracket to bend.
2) Turning the dial too fast towards slow(or the floating sheave[motor shaft] is sluggish due to crud buildup) will put stress on the leg.
3) Turning the dial too far towards slow.
The leg bending causes the worm gear to become mispositioned off the center of the quadrant gear. This causes abnormal wear because the teeth do not mesh properly. This in turn increases the torque required to turn the dial. All that is a downward spiral to needing a new speed control(or Bill's fix).
That be my HO!:)
And YES your 'fix' does wonders for correcting all the problems above(except the cruddy motor shaft).