Bozo stopped by the shop today

ltlvt

ltlvt

H-M Supporter - Sustaining Member
H-M Platinum Supporter
Joined
Aug 29, 2019
Messages
999
Yep spent a couple of hours getting the cone gears off the cone gear shaft . They must all be removed from right to left to get to the farthest one on the left which is the one that drives the cone shaft. I ordered an 18 tooth gear about 3 weeks ago to replace what I thought was the last one on the left (the drive gear) Bozo likes to speed read assy drawings and the 18 tooth gear is really a 16 tooth gear and it is part of the cone shaft (not removable) . This is the gear that was the damaged one so I do not need the 18 tooth gear. So I've spent the rest of the afternoon doing the shop research to determine what gear cutter to use to re-cut the teeth on the shaft.

So here is the deal. The O/D of the gear is 1.110 inches. the number of teeth is 16. so not knowing what the DP is I did the math. I came up with a DP 16 14.5 pressure angle and cutter #2 from the 16 D/P set. Somebody want to check my math before I invite Bozo back over.

#Note to self: Stop trying to speed read.
 
A 16 tooth 16 D.P. gear has a theoretical O.D. of 1,125" so it looks like you're good. You're your own re: pressure angle.
 
RJSakowski said:
A 16 tooth 16 D.P. gear has a theoretical O.D. of 1,125" so it looks like you're good. You're your own re: pressure angle.
Click to expand...
When the gear started out new it probably was 1.125. I was thinking the same thing.
 
ltlvt said:
When the gear started out new it probably was 1.125. I was thinking the same thing.
Click to expand...
That surface shouldn't wear as it is never in contact with another surface in normal use. However, from what I have seen, the O.D. dimension hardly ever hits the theoretical. It is a non-critical surface regarding function so tolerances can afford to be looser.
 
RJSakowski said:
That surface shouldn't wear as it is never in contact with another surface in normal use. However, from what I have seen, the O.D. dimension hardly ever hits the theoretical. It is a non-critical surface regarding function so tolerances can afford to be looser.
Click to expand...
I will get to the repair sometime this week. What's the recommendation Tig weld back the damaged areas or braze them with oxy/acte.
 
RJSakowski said:
That surface shouldn't wear as it is never in contact with another surface in normal use. However, from what I have seen, the O.D. dimension hardly ever hits the theoretical. It is a non-critical surface regarding function so tolerances can afford to be looser.
Click to expand...
I understand that it is a design variable that can be used to deal with shaft-to-shaft distances. In some cases, the distance between shafts is inconvenient and cannot be changed. So you can adjust tooth length a little to make everything work out. Totally theoretical for me. Does this sound right to anyone in-the-know?
 
durableoreo said:
I understand that it is a design variable that can be used to deal with shaft-to-shaft distances. In some cases, the distance between shafts is inconvenient and cannot be changed. So you can adjust tooth length a little to make everything work out. Totally theoretical for me. Does this sound right to anyone in-the-know?
Click to expand...
You cannot change gear tooth length to compensate for a center to center mismatch. The O.D. of a gear can vary slightly because it doesn't mate with another gear. Just as you can decrease the diameter of a screw thread slightly and still have a working thread.

It's the pitch diameter that must be maintained to acceptable tolerances. A deeper root or a smaller o.d. just increases clearances althoughit can have an effect on tooth strength if it strays too far from the design specification.
 
You must log in or register to reply here.
Back
Top