QCGB gears broken, need buying advice

ARC-170

Jeff L.
H-M Lifetime Diamond Member
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Oct 17, 2018
Messages
920
WHAT I NEED
I have an Atlas Craftsman QCGB (fits a 101.27440) that has two gear assemblies with broken teeth. Specifically, #10-1552X (1/2" bore) and 10-1551X (5/8" bore). These are 16/32T assemblies that go on the two main shafts of the QCGB.

WHAT I'VE FOUND SO FAR
I've looked on Ebay and some people have it listed by the part number and others have it listed as a "tumbler gear", often without the bushing. They also don't all list the bore size. Seems many don't really know what they have. I've sent a few inquiries to sellers for clarification.

This one looks promising, but I can't tell if it's the correct one:

WHY I'M HAVING TROUBLE
Specifically, I can't tell if the teeth are the correct ones. Some gears have larger teeth than others, and it's hard to tell in pictures if they are the smaller or bigger ones.
I think I'm looking for the big tooth ones, right?

MY OPTIONS SO FAR
1. Do the bushings push out easily enough? I think I can get just these smaller gears, push out and reuse the bushings and bigger gears on my exiting assemblies and push on the smaller gears. I could make bushings, too; I have a lathe.

2. The other option is to pay what I think is an exorbitant price ($100-$120) for a properly labelled assembly that I know will work. And, they actually charge extra for shipping. However, tell me if my expectations about price are off. $200-$250 seems awfully high for two gear assemblies. These are just a little less than new, I think, though the prices I saw were older.

3. I have an email in to my sales person for Clausing to see if these are available new. It might still be better to pay for decent used, depending on the price and availability of new.

Your thoughts and comments?
 
Maybe someone can cut new gears from some 6061 or 7075 ?
 
Have you checked with Boston Gear? Maybe it's time to learn how to make gears.
 
mrpete222 (tubalcain) has a video (maybe a 2 part video) where he does a deep dive into this very topic.

In the video, he removes & replaces 1 or 2 QCGB gears. At one point, he learns from a mistake.

I hope you take the time and find this video.
 
I found the videos, but it is a Logan QCGB:


and

 
@erikmannie I don't see your dilemma - $120 for an assembly of gears is very cheap. It would cost you about $100 to have made one custom gear in my town. Go with the solution you know will work, preferably from the original manufacturer, or a parted out lathe identical to yours.

To measure the gears to find 3rd party substitutes is in another skill bracket entirely, and trusting random sellers to make is similar measurement is unlikely in the extreme. A substitute approach to the one I mentioned above will lead you down a path of disappointment and frustration.
 
Boston Gear didn't have anything that would work. I watched the videos and there was some interesting information about cleaning out the teeth and not using compressed air to clean a machine because the chips get stuck everywhere. Sounds like gears would be a lot of trouble to make, so maybe another time.

I decided to buy the gears. I found them both on Ebay for $237 shipped. They are the exact ones I need, I know they'll fit, so it's done. I wasn't able to find much, so I think buying ones that are available was a good way to go. The other sellers that had gears that *could maybe* work don't seem to know enough to give me any confidence I'll get what I need.
 
I got the new change gears in the mail. I thought it was interesting that the old ones were probably broken because they had less metal between the OD of the bushing and the ID of the steel gear. You can see the difference in the photos. Just something to be aware of if you are ordering these from a less-than-knowledgeable seller.
DSC00541.JPG
 
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