Well Chewed Chop

[idcook]

Shopsmith is where I buy my new quadrants. I have been able to recondition about 50% of the damaged quadrants and reuse them. I do not have any extra speed control assemblies for sale as I sold what I had last year. I have been slowly clearing my extra inventory as I am only able to rebuild a couple of local headstocks this year.

Thanks just the same Bill. Your knowledge base, contributions to the quality of discussion in these forums and to the membership in general has not gone unnoticed by me. But, still much the newbie that I was when I first arrived, I tend to read you more than speak with you.

I’ll appreciate the replacement for the roll bar and continue to watch and learn as well as I can.

Thanks again.

[idcook]

I'm certainly not suggesting you should do so since a replacement is better, but I was able to mostly bend and somewhat file a pork chop in almost as bad shape into fine working order. I going the metal the worm hear if made of "flows" well when tapped with into shape again. I used a hammer to tap a punch against the bent teeth. I was in the same frame of mind... Worst case I'd is have to replace it anyhow. The metal bent out of shape without cracking noticeably in the first place so it had to be soft.

I probably would have just replaced it but I too just saw the price for the whole unit.

I was surprised at how much better it moved after that and, this is important... adding Bill Mayo's free pivot pin replacement bolt. He kindly sent me one with a part I ordered.

Prior to that it was binding badly. Now it is smooth.

Thanks fitzhugh.

After the same suggestion was offered by JPG, I had considered bending, filing and tapping the chop’s gear teeth into place. However, beside my inexperience with the process, several of the teeth appear to have been somewhat thinned by whatever means they were damaged. Hence I don’t feel entirely confident that bending and tapping will prove as reliable a solution as I’d like.

I’ll likely order a new chop and then work on repairing the chewed chop to practice and be prepared should I find myself confronted with the issue in the future. If all goes well, and I should ever need it, I’ll at least have a reasonable replacement chop on hand.

[JPG]

Thanks fitzhugh.

After the same suggestion was offered by JPG, I had considered bending, filing and tapping the chop’s gear teeth into place. However, beside my inexperience with the process, several of the teeth appear to have been somewhat thinned by whatever means they were damaged. Hence I don’t feel entirely confident that bending and tapping will prove as reliable a solution as I’d like.

I’ll likely order a new chop and then work on repairing the chewed chop to practice and be prepared should I find myself confronted with the issue in the future. If all goes well, and I should ever need it, I’ll at least have a reasonable replacement chop on hand.

I do not know what bending and tapping will do for the quadrant teeth. Filing will remove that portion of the gear that will interfere with the worm gear after the quadrant gear is positioned correctly to it(re positioned by bending the leg on the speed control back to it's original position).

The contact between the worm gear and the quadrant teeth is a line. The quadrant teeth only need to be correct at that line. That line is located at the center of the quadrant gear teeth. The excessive wear occurs at an angle that deviates from that center.

Be advised that final filing can get tedious as you gradually remove material that continues to interfere. The straightness of the worm gear and the curvature of the quadrant creates tooth clearance requirement that is difficult to predict. One worm gear 'tooth' will bear against the front of one quadrant gear tooth and a second worm gear tooth will bear against the back of a different quadrant gear tooth causing a jam.

[fitzhugh]

You make a very good point that it just needs to contact at that line, which should be right down the center. In my case the teeth were bent enough that it included metal along the center line as well. I thought it looked like filing alone might introduce slop. Luckily it worked better than I expected though I would have been more concerned if it was a hard to replace part. Edit: to clarify, it may have been totally unnecessary, but it turned out fine in that case.

[idcook]

Hello JPG,

I also appreciate the center line to worm gear relationship. However, though the photo may not show it well enough, several of the quadrant teeth have a sort of "S" curve as well as a gouge toward the left center of each distorted tooth. The gouges leave me with the feeling that they might straighten well enough with bending and filing but part of each of those teeth would still be thinner than they should be.

So, basically, while the the thus repaired quadrant might work well enough, I don’t trust it to maintain its integrity over the long haul.

All signs indicate that a previous owner of this machine was a pretty haphazard about maintenance.

[JPG]

Hello JPG,

I also appreciate the center line to worm gear relationship. However, though the photo may not show it well enough, several of the quadrant teeth have a sort of "S" curve as well as a gouge toward the left center of each distorted tooth. The gouges leave me with the feeling that they might straighten well enough with bending and filing but part of each of those teeth would still be thinner than they should be.

So, basically, while the the thus repaired quadrant might work well enough, I don’t trust it to maintain its integrity over the long haul.

All signs indicate that a previous owner of this machine was a pretty haphazard about maintenance.

I think you are likely to feel greater confidence by getting a new quadrant. Do perform the Bill Mayo leg straightening and screw pivot fix also.

That said. I do not think the reduced thickness would matter as long as the worm gear continues to mesh correctly. If it once again goes to the left, then the reduced thickness would become an issue.

[billmayo]

I think you are likely to feel greater confidence by getting a new quadrant. Do perform the Bill Mayo leg straightening and screw pivot fix also.

That said. I do not think the reduced thickness would matter as long as the worm gear continues to mesh correctly. If it once again goes to the left, then the reduced thickness would become an issue.

I totally agree. Replace the quadrant. I have years of transmission and reduction gear experience in filing and lapping gear teeth along with the special tools needed for these tasks and am having only about 50% success rate reconditioning the damaged quadrants. I am always looking for damaged quadrants to practice on so do not throw them away. Thanks.

["Wild Bad Bob"]

Good to see ya Bill!