Thread: Gear tooth rounding

I have a gear cluster away being shaped at the moment, is a fairly tight stack of three gears about 1 inch spacing between tooth flanks and the center gear has rounded teeth to aid shifting. (Its from the norton box of a DSG) The gearcutter does not have a tooth rounding machine and their VMC has backlogged work for ages so im going to have to do it either by hand (Unattractive as its tough material and i dont want to scuff all the teeth faces up)

Or look for a manual mill setup. I was thinking of using a dovetail cutter or woodruff cutter to just nip in there on each tooth the only downside is the rounded end would be a flat face rather than smooth curve but i dont see that being a huge problem.

its a cluster of a 26, 24 and 22 tooth 10 Dp gears

If the 3 gears are separate pieces I can ask about doing it at work, we have a tooth rounding machine. Even if they're assembled we might have something that will get in

G/day Ralph, you could grind a form tool out of hss and fly cut the radius, or do it in a shaper

cheers, shed

Hi Ralph, is it the ends of the teeth you're wanting to round off as in a U? I can't see how you could do it with a Dovetail cutter? What you'd need is something like a radii tool or using something like diegrinder to shape the ends.
Kryn

Unfortunately the gears are all one piece and it's the middle one, so a shaper is probably out. Thanks for the offer Elan!

And kryn hole in one, I am happy with just two flat angled facets instead of a nice U as. It's just to make meshing easier when stationary, these gears are not changed while running.

Can you post a pic when you get it back from cutting so I can show the guys?

Absolutely. It's going to be a little while though unfortunately, everyone seems backed up with work.

Originally Posted by caskwarrior

I have a gear cluster away being shaped at the moment, is a fairly tight stack of three gears about 1 inch spacing between tooth flanks and the center gear has rounded teeth to aid shifting. (Its from the norton box of a DSG) The gearcutter does not have a tooth rounding machine and their VMC has backlogged work for ages so im going to have to do it either by hand (Unattractive as its tough material and i dont want to scuff all the teeth faces up)

Or look for a manual mill setup. I was thinking of using a dovetail cutter or woodruff cutter to just nip in there on each tooth the only downside is the rounded end would be a flat face rather than smooth curve but i dont see that being a huge problem.

its a cluster of a 26, 24 and 22 tooth 10 Dp gears

Indexing head top a rotary table. Use the indexing head to change between each tooth and the rotary table to mill the radius. Use a tiny slot drill to do the milling.

So I got this done, somewhat crudely but it gave a nice enough result. Most of this was just set up by eye as it's all non vital.

The dividing head was tilted back 15 degrees to give the tooth slope and was rotated off the X axis by the pressure angle (20 degrees) so that the 5mm ball nose end mill was traversing along the tooth flank.

Deburring was fairly annoying but the smresults are nice enough, it's off getting case hardened now.

Need to get a photo of the finished result when I gets back as none of those show it deburred.

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