Duplicating a Gear...?
Duplicating a Gear...?
(OP)
I have a 88 tooth spur gear (6.190" diameter)and I'm wondering how I can duplicate this gear? I don't have any of the other gear specs. I have access to a CNC mill and a lathe, I just don't know the best way to duplicate this gear without any other gear specs.
Thanks a bunch for any assistance,
Jason.
Thanks a bunch for any assistance,
Jason.





RE: Duplicating a Gear...?
http://www.gizmology.net/gears.htm
Maybe you can calculate what you don't know...
RE: Duplicating a Gear...?
A more reliable way is measurement over pins. If you don't know the pressure angle, you may (not positive about this) have to take measurements using 2 different sizes of pins. Then you have to do lots of math. For reference books for the math see thread 406-146377.
Another possibility is caliper measurements over several teeth, and, again, lots of math.
RE: Duplicating a Gear...?
RE: Duplicating a Gear...?
I use the measurement over pins, no. of teeth, OD, Root dia, Base tangent length to arrive at a preliminary data. Using this preliminary data and making assumptions based on this data, I use Klingelnerg gear checker to check the profile and lead of the gear. By making calculations based on this data I arrive at a final data.
RE: Duplicating a Gear...?
RE: Duplicating a Gear...?
This is not a good idea to start a new post inside an other post. You already started a second new post.
RE: Duplicating a Gear...?
The first place to start is by measuring the base pitch of the sample. This is done with a good set of verniers and measured tangentially in the normal plane over a certain number of teeth. The number of teeth over which to measure is worked out by laying the jaws of the verniers over the "best fitting" number of teeth". By this I mean the number of teeth that allow the jaws to contact the tooth profile somewhere around the pitch line (about half way down the profile from the tip of the tooth) and not allow the tips of the jaws to make contact in the root area nor have them make contact right up on the tips of the teeth. Then take the next best fitting measurement either side of that; so if the first measurement was made across 10 teeth then take a measurement over 9 or 11 teeth, which ever fits best. Subtract the smaller measurement from the larger and what you have is the base pitch.
Let me know what you measure and I’ll let you know what to do next.
RE: Duplicating a Gear...?
RE: Duplicating a Gear...?
If it is the od, it looks like a 1.75 module
gear to me. I would start with the most
common 20 degree pressure angle and see
how it compares.