# PM Lathe Gear Question



## chiliviking (Jan 27, 2008)

Need some help from mklotz or others that have completed this lathe kit from PM Research. The gear at the front of the stepped pulley in headstock is giving me fits. The print calls for a 1-72 set screw placed in a .313 diameter hub placed at a 35 deg. angle. The hub has a .188 hole in it so that leaves .219 thickness in the hub. Triginomitry formulas tell me that with these dimensions the exit piont of the hole will be displaced by .153 from the entrance point. The gear is only .093 thick so the set screw hole will come out the side of the gear not in the center hole. One possible solution would be to forget the 35 deg. angle and drill straight in to the edge of the gear. Obviously this will weaken the affected teeth however on a model I don't know if this would be considered a problem. On the photo that mklotz posted of his lathe it appears that this may be the approach that he has taken. What do you think?


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## mklotz (Jan 27, 2008)

Yes, what they call out on the print is a bit over the top, IMO.  As you guessed, I simply drilled radially between two teeth. The backgear function on my model works perfectly so obviously this didn't matter.


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## chiliviking (Jan 27, 2008)

Thanks mklotz!!! Thats the way I will proceed. It's always easier to draw something on paper than it is to actually produce it in the real world.


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