Setting Up A Dividing Head Question?

tertiaryjim said:
Thanks for the pics. Whats keeping the blank from sliding off the shaft ?
Click to expand...

It's a hardened, tapered arbor used for turning. That gear blank is pressed on there tighter than... well, you know :D
 
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Well, I'm pleased to post that everything went perfectly this afternoon when I cut the gear. It was a very rigid set-up (even though it doesn't look that way), and cut every tooth smooth and quiet. Afterward I broached a 5/32 keyway into it, and sent it home with the prospective owner to try out. I'm very pleased with the results. Thanks everyone!

gear.jpg
 
planeflyer21 said:
Odd man out here...why not use the table as an indexer, disengaging the drive and rotate to each of the 37 holes in sequence and machine each tooth after locking the table each time?
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Not sure I follow you. I have a dividing head, but not a rotary table. I just needed to know for sure how many holes I needed to move for each tooth with a 40:1 ratio and a 37 hole dividing plate. The answer turned out to be one complete turn and 3 additional holes per tooth. Thanks!

GG
 
The next gear I'll be cutting will be a 47 tooth. Check my math (I'm a math flunkie, so bear with me) 40:1 indexing head with a 47 tooth dividing plate. 40/47 = 0.8510638298 * 47 = 40 holes per tooth. Let me know if this is correct. If I do this enough, I'll get the hang of it.

I really appreciate everyone's help. Thank you!

GG
 
GarageGuy said:
Not sure I follow you. I have a dividing head, but not a rotary table. I just needed to know for sure how many holes I needed to move for each tooth with a 40:1 ratio and a 37 hole dividing plate. The answer turned out to be one complete turn and 3 additional holes per tooth. Thanks!

GG
Click to expand...

My apologies. I said table.

I would be tempted to cut the gear using the degree marks on the direct indexing plate and the pointer (if your dividing head is so equipped), by disengaging the worm gear hub and using the spindle lock.
 
It's always a good idea to check your calculations by stepping through and just making a light nick on your blank, then count them for accuracy. Time consuming but safe. I remember in trade school a kid was cutting a gear, got nearly to the end and asked the instructor if he should finish up with one big tooth or two small ones.


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Congratulations on a great first attempt. I know many that did not do anywhere near as well as you did.

"Billy G"
 
Great job on the gear, I'm looking forward to giving it a try. Mike
 
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