Imported Involute Gear Cutter Sets

You have done well Chuck. As a newbie you took nothing for granted. You read what we had to say, researched on your own and came up with a solution that fits your need. I believe you need not call yourself a newbie any longer. You have the process down pat. Congratulations.

"Billy G"
 
Billy,
You are too kind. I can look things up and figure things out. But I don't know squat about actually running the lathe and mill/drill I recently purchased. That will only come with hands on experience. The guys who have been doing this for years would laugh their backside off watching me futz around.
Chuck
 
Not on this Forum, we would lend some help and show you just how much you thought you didn't know. Back in my early days I felt the way you do. One of my earliest mentors told me this. Bill, you have looked at that lathe for 20 minutes now, put the stock in it and turn it on. Once you turn that switch you have done all the damage you can for now. That stuck in my head and the rest is history. Go for it.

"The other Billy G' LOL
 
Thank you Bill for following up on this problem.
I have been laid low with a particularly nasty virus for over a week so have been out of the loop so to speak.
The company that i got my original cutter from now has new stock but is still advertising both DP and Module cutter's
with the same numbering system . I have contacted them today and told them your findings ( not naming you ) I await there reply.
Brian. Module cutters from RGD.JPG Cutter numbers DP from RGD Tools.JPG
 
It's very confusing. I have a gear I need to fix and make one of . It's 34 tooth 10 DP and 14.5 . Which cutter should I look for ? Some cutters I see have just the tooth count and the 14.5 angle but no diametral pitch ? The metric I get with module s there all 20 DP.
 
All you need is the pressure angle (14.5*) and the number of teeth (34). You will need a #4 cutter. (English) If you wish to figure more info, Machinery's Handbook Edition (26) has all the formulas on page 2004. Other Editions will be close to that page. Just look up Spur Gear Formulas in the index of the Edition you have. I used 26 because it's the one at my computer.

"Billy G"
 
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I found only one cutter on ebay with those numbers but again it is in module. #4 10 DP 21-25 teeth is a metric cutter. If it were me and I had this problem the first thing I would invest in would be two sets of gear pitch gages, one DP and one module. Then you would know for sure what you need. I am by no means an expert on this subject. We had one but he left some time ago. Eric was the best I know on this subject as he did it for a living.

"Billy G"
 
With the gear pitch gages costing an arm and a leg,( it took me months to find one that was affordable) since you have the broken gear you can match it to drawings of full size gear pitches listed in Machinery's Handbook. In the 11th edition 3rd printing it is on page 700. If you don't have a Machinery's Handbook you can go to Rush Gear or a similar web provider of gears and use the gear calculator to work backwards to get the proper DP. Go to RushGears.com and click on custom gear builder. Enter the Number of Teeth and various Pitches until you get the Outside Diameter of the gear that matches the one that you have in-hand.
If you purchase a gear pitch gauge, some are 14-1/2 pressure angle only, while others are both 14-1/2 and 20 pressure angles. I've only made one gear so far but the gear pitch gauge has come in handy a number of times.
 
With all precision gages comes a price. A set of Fowler gages will come with a price tag of $190.00 0r higher. Almost always it will go over $200.00. Unless of coarse you go imported. The price will at times go below $100.00. India or China will be the choices.

A good Gear Tooth Vernier will also help, but again they come at a price.

If you have a handbook with thumb tabs go to the gearing section the full size profiles will be there.

"Billy G"
 
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What Billy G said is correct, I searched eBay and finally found a Boston Gear set of gauges for $49.00. On Boston Gear's site they have 14-1/2 and 20 PA on one set but the one that I bought is 14-1/2 PA only. I don't know if the set came this way from the manufacturer or if the seller split the set. (if you search for a used set be sure to search for "gauges" and "gages" )
 
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