Back Cutting Gear Teeth

Sorry Tony! I should have looked closer at your profile!

The slippage over time is due mainly to the wearing of the bushing that the spring loaded gear slides in and out on. Also, misalignment is compounded by another pair of thrust washers in the clutch hub. The teeth typically don't become misshapen and never do they shear off. The force upon these the gear and plate isn't monstrous I know they are hardened as a hand file is completely ineffective.

Thank you for the preface, I know my machine is a for the shade tree type like me. I did discover that this machine has rigidity issues especially after watching a real Bridgeport in operation.

You are correct that it wouldn't take more than a few degrees. The harder you push, the more they would lock together. It's also important that they release easily or there will be more serious trouble!

One gentleman suggested that the back cut start part way down the tooth face. This would leave some part of the original manufacture. Here is a quick drawing he did to illustrate.

I appreciate you guys putting some thought into this. Also, I was looking at this to do the cutting if a jig was made to hold each of the parts.
http://www.grizzly.com/products/Chain-Saw-Sharpener/T23108

under cut.JPG
 
I think you may be on the right track with the sharpener idea. You would have to modify for indexing. You might give a Dremel, or a die grinder with diamond blade a shot to see if it will cut and then work up a fixture. Still have an ankle that gives me grief from an incident in my youth involving, a Sportster, tennis shoes, and tequila. Mike
 
I picture a sharpener like one used for table-saw type blades they have both a grinding wheel that can cut bevels and a method of indexing the blade to the next tooth.

Obviously it would be heavily modified with a new arbor of the proper diameter, indexing stop, and for guiding the grinding wheel to what would be the side of the saw-blade not the periphery.....and at the required angle.

I wonder if a jig to use in an abrasive chop-saw could work.

A few links to get the idea across:
http://woodgears.ca/table_saw/sharpening_jig.html
http://www.harborfreight.com/120-volt-circular-saw-blade-sharpener-96687.html

-brino

EDIT: I forgot to say, Welcome to the site!
 
OK, so for $100 I bought a Northern Tool Chainsaw Sharpening machine. There are similar and cheaper on eBay but I want to be able to take it somewhere if/when it breaks.
I have removed the clamping fixture altogether. I have ordered an aluminum drops assortment on eBay. I have also ordered a couple 3.5" round billets to create a stand of sorts to hold the parts.

I have an idea about indexing. The number of teeth is 9 so it's not easily divisible in relation to the gear teeth or the holes in the ratchet plate. I am thinking about turning a ratchet plate upside down on a hinge of sorts with a small section removed where the grinding wheel will enter. I can lift up the hinged ratchet plate, turn the part and drop the indexing plate again. I will have to hold the part so it doesn't back away from the grinding wheel. I will need to be sure to leave the top most part of the tooth in tact or the indexing will change as the teeth shape change.

I will make two versions of part holder so that the cut occurs at the same swing angle and depth for both pieces being that they are different heights. I should be able to set the depth stop and leave it.

Should I try to dress the wheel so that it has a flat bottom compensated for the cut angle?


IMG_4870.JPG IMG_4872.JPG IMG_4873.JPG IMG_4874.JPG
 
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