Purchasing Gears

I had to buy a bunch of gears and I learned the cheapest routes to get them.

Boston gear does not sell direct. After waiting a couple of days someone will finally contact you to tell you that and suggest you buy locally from your bearing supplier (who also sells gears). The price you get locally will be about $80 higher than any online price.

Find out the number of the gear you need from Boston gear (in your case it might be a GB34) Then search Amazon to see what their lowest price is but don't buy it yet. https://www.amazon.com/Boston-Gear-...D=41u%2BJ6c-0gL&preST=_SX342_QL70_&dpSrc=srch

Go to https://www.mrosupply.com/ and search there.
https://www.mrosupply.com/gears-gear-rack/change-gears/35188_10128_boston-gear/

Typically MROsupply will have the best price, but not this time. Amazon sells it today for $12.
 
Bob Korves said:
No worries, Mike. I am going to try to fly cut the gear out of bronze to replace the stripped Micarta one. I have everything needed on hand. Tiny teeth, 48DP, 96 teeth, 2" pitch diameter...
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All was going well on this project until I looked up the dividing head setup needed for the 96T gear. Turns out it cannot be done with simple indexing with my dividing head which uses the standard B&S 40:1 ratio and dividing plates. 96 teeth requires differential indexing, which I do not have. None of the store bought gears available were really close to what I needed, and the ones that might be usable are stupidly expensive for this little project.

So, a question. I found that I can divide to 48 divisions using my dividing head as intended, which is half of the needed 96 divisions. Is there a reasonable way to cut two 48 tooth patterns on the same blank, separated accurately from each other by half a division, without fancy pants measures?
 
Bob Korves said:
All was going well on this project until I looked up the dividing head setup needed for the 96T gear. Turns out it cannot be done with simple indexing with my dividing head which uses the standard B&S 40:1 ratio and dividing plates. 96 teeth requires differential indexing, which I do not have. None of the store bought gears available were really close to what I needed, and the ones that might be usable are stupidly expensive for this little project.
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That is why I went electronic. http://www.liming.org/millindex/
 
I was planning to make the gears that I would need to be able to cut metric threads on my lathe. I need a 32, 44, 52 and 54 change gears. I will also need one change gear stud with a spacer. When I figured out the time and trouble to make a gear cutting fixture, buy the cutters and the stock for the gears. Plus an allowance for screw ups. This was not going to be an easy undertaking for an inexperienced newbe to machining. As a cross check to my insanity to try to make my own gears I checked on Ebay for the cost to buy the gears and quickly came to the realization that I would be way better off buying the gears. So I am going to buy the gears. I'll check whatever other sources I can find to try to get the best price. Gears on Ebay look to run from $20 to $25 per gear including the shipping.
 
Amazon sometimes has fantastic prices on certain Boston gears- maybe clearing old inventory?
 
Bob Korves said:
Is there a reasonable way to cut two 48 tooth patterns on the same blank, separated accurately from each other by half a division, without fancy pants measures?
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Pretty recently, there was a thread where a fellow was using a printed wheel with divisions as his indexing guide for making gears. It consisted of what looked like a piece of plywood, a shaft, a pointer, and a wheel that he'd printed off the computer with the number of lines he needed, equally spaced. There was another gentleman who was adamant that the work couldn't be done without differential indexing, but the fellow doing it seemed pretty satisfied with his results. So yeah that may be more time, or less accurate, than your project demands...I don't know. But it seemed a pretty simple set up, and it was endorsed wholeheartedly by the person who had done it. I know I could print off a wheel with 96 equally spaced divisions in about 5 minutes. So long as you have a way to tie the indexing portion to the work, and a way to lock rotation, it seems plausible to me.
 
jwmay said:
Pretty recently, there was a thread where a fellow was using a printed wheel with divisions as his indexing guide for making gears. It consisted of what looked like a piece of plywood, a shaft, a pointer, and a wheel that he'd printed off the computer with the number of lines he needed, equally spaced. There was another gentleman who was adamant that the work couldn't be done without differential indexing, but the fellow doing it seemed pretty satisfied with his results. So yeah that may be more time, or less accurate, than your project demands...I don't know. But it seemed a pretty simple set up, and it was endorsed wholeheartedly by the person who had done it. I know I could print off a wheel with 96 equally spaced divisions in about 5 minutes. So long as you have a way to tie the indexing portion to the work, and a way to lock rotation, it seems plausible to me.
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Thanks, jmway for the kind offer. It could likely be done with far fewer than 96 divisions on a 40:1 dividing head, and the plastic would probably work OK for a one off project that is staying in the earth's atmosphere. However, I have dropped that approach to the project and am looking in different directions now. A stepper motor made into a universal dividing plate interface to fit the dividing head would probably also work, and would be really versatile, but is way ahead of my skills and again, not worth the effort for this one scrapped project...
 
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