M
mjolner
Guest
Hello everyone, what a wonderful forum this is! (Long time lurker...)
I am working on a project and am down to the last few dozen operations; and one of them is stumping me.
I have a steel gear, 0.173" i.d., and am trying to fix it on a nominal 3/16" brass rod, that has an actual diameter of 0.188".
This has to be a firm attachment, as this gear will drive the rod, rotating another fixed gear.
That's the other problem, the second gear is plastic, about 0.125" thick, with a bore of 0.125".
I could either ream that out to match the brass rod and use some sort of epoxy, but that seems messy and unlikely to hold up to the torque.
Another option would be to cut a slot in a section of the brass rod, and another slot in the bore of the plastic gear and insert a square key.
That seems like the best option, the challenge there is the tiny dimensions of such a key and slots.
Back to the first problem - the steel gear with the 0.173" bore.
I'm thinking I can turn the 0.188" brass rod down to a diameter that would allow a press fitting of the gear.
But to what diameter?
And could/should I use heat to expand the gear and then slip it onto the cold shaft, making a much tighter fit?
I've never press-fit a gear before, so all opinions are helpful. Thanks!
-Kris
I am working on a project and am down to the last few dozen operations; and one of them is stumping me.
I have a steel gear, 0.173" i.d., and am trying to fix it on a nominal 3/16" brass rod, that has an actual diameter of 0.188".
This has to be a firm attachment, as this gear will drive the rod, rotating another fixed gear.
That's the other problem, the second gear is plastic, about 0.125" thick, with a bore of 0.125".
I could either ream that out to match the brass rod and use some sort of epoxy, but that seems messy and unlikely to hold up to the torque.
Another option would be to cut a slot in a section of the brass rod, and another slot in the bore of the plastic gear and insert a square key.
That seems like the best option, the challenge there is the tiny dimensions of such a key and slots.
Back to the first problem - the steel gear with the 0.173" bore.
I'm thinking I can turn the 0.188" brass rod down to a diameter that would allow a press fitting of the gear.
But to what diameter?
And could/should I use heat to expand the gear and then slip it onto the cold shaft, making a much tighter fit?
I've never press-fit a gear before, so all opinions are helpful. Thanks!
-Kris