Pinion problems.

[BRIAN]

I am trying to cut .6 mod 8 leaf pinions.
.
The blank is .234" and the depth.059" as recommended in the article I am following.

but I am ending up with a flat top on the leaves.should I cut deeper to eliminate the flat? its difficult to see when its all setup.

the photo was taken on a USB Microscope at 20x.

Thanks in advance.for any help

BRIAN.

 

[cyrusb]

There are so many variables to contend with here, but I would say yes, cut till there is no land at the top. The gear is useless with a flat at the top. Is this flat consistant on all teeth? If not your blank is not running concentric. This is usually the case if you do not "round up" the blank in place on the rig you are using to cut the teeth. Having said that, if you are using a depthing tool to place the gears some inconsistencies can be tolerated.

 

[BRIAN]

Thanks cyrusb that is a great help, the blank is concentric, and I am very pleased with the result apart from this flat.
I did not notice the flat when I proved the gear on the depthing tool ( to happy just to have made a pinion) it only became apparent when the train came under load.
Thanks for the help. BRIAN.

 

[BRIAN]

I have made the new pinion and it works perfectly, the clock now runs without the ocasional tantrum.

Now I have to look for a nice piece of Walnut to replace the plywood mount.

BRIAN: