Hi, I am a new member who has been forum stalking for a while. This is a great place to learn anything you would want to know about using a metal lathe.
I am retired and just recently decided, after COVID started, to take up metal forming. I refurbish musical instruments, brass and woodwinds, and make them available to kids and people getting back into music. The ones I work on are usually ones that technicians can't/won't touch because they have to make a living. It keeps me out of my wife's hair
So having said all that I needed to make a trombone slide lock for an "overseas" trombone that fits on to an existing male threaded fitting. I found all I needed to know here except that I kept making the part to big. I finally realized that I cutting the internal diameter of the female part the same size diameter as the male thread. BTW the size of the male piece was 20.5-.75 metric. So custom sizing. I needed to subtract the thread depth(.018 in., didn't convert to mm) from the (major) diameter of the male thread and make that(minor diameter) the diameter of the beginning "hole" of the female part. And do the depth of the threading to match that. It turned out great!!
I'm sure that was explained somewhere but I searched and only found talk about standard bolt sizes. I'm also sure that smarter guys would have figured that out from the get-go but mechanical knowledge was not my forte.
I thought I would post this rambling to thank everyone for their help here and maybe if a brand new person reads this it will make it a little simpler. Jeff(snorky)
This was also on the Harbor Freight 7x12.
I am retired and just recently decided, after COVID started, to take up metal forming. I refurbish musical instruments, brass and woodwinds, and make them available to kids and people getting back into music. The ones I work on are usually ones that technicians can't/won't touch because they have to make a living. It keeps me out of my wife's hair
So having said all that I needed to make a trombone slide lock for an "overseas" trombone that fits on to an existing male threaded fitting. I found all I needed to know here except that I kept making the part to big. I finally realized that I cutting the internal diameter of the female part the same size diameter as the male thread. BTW the size of the male piece was 20.5-.75 metric. So custom sizing. I needed to subtract the thread depth(.018 in., didn't convert to mm) from the (major) diameter of the male thread and make that(minor diameter) the diameter of the beginning "hole" of the female part. And do the depth of the threading to match that. It turned out great!!
I'm sure that was explained somewhere but I searched and only found talk about standard bolt sizes. I'm also sure that smarter guys would have figured that out from the get-go but mechanical knowledge was not my forte.
I thought I would post this rambling to thank everyone for their help here and maybe if a brand new person reads this it will make it a little simpler. Jeff(snorky)
This was also on the Harbor Freight 7x12.
