Some may be interested in doing such a job, I was handed one this morning and this is how I do it. It is only 12 parts in 360 brass hex stock and the time estimate from my employer is 21.45 hours for the lathe work. My methods may not be the same as how the guru Youtube "how to" video producers may do it but it works for me and the machines available.
The part is 23 5/8" long but the thread is only 10 3/8 long.
Sample
A sample was supplied by the customer.
Measure the sample Pitch Diameter over wires, the .25" lead is wider then the spindle on many micrometers so a .100" gauge block spans the 2 top wires.
My employer was not going to spend several hundred dollars on ring gauges for a small job so I made one at the lower PD limit that would fit the sample.
Face to length and center drill the threaded end, put the chamfer for the start of the thread on before the threading operation saving a tool change later.
The threading starts Monday, will update then.
Used a Vardex horizontal insert internal threading bar at 375 RPMs, will use a Kennametal Top Notch tool for the external threads, I suspect that it will have to be run somewhat slower.
This is done in a Romi/Bridgeport 15 X 40 lathe which is a sort of CNC Manual hybrid built in the 1990"s, these are very nice machines with VERY easy to learn conversational controls, knowledge of G Code is not required for the most part unless the work requires a feature that the conversational input will not do. They have a lot of safety features in the software that will not run a program if there are obvious tool conflicts or math errors. They are the perfect machine for a hobby shop but a bit to expensive even at 20 years old at $10.000-$20.000 used.
The part is 23 5/8" long but the thread is only 10 3/8 long.
Sample
A sample was supplied by the customer.
Measure the sample Pitch Diameter over wires, the .25" lead is wider then the spindle on many micrometers so a .100" gauge block spans the 2 top wires.
My employer was not going to spend several hundred dollars on ring gauges for a small job so I made one at the lower PD limit that would fit the sample.
Face to length and center drill the threaded end, put the chamfer for the start of the thread on before the threading operation saving a tool change later.
The threading starts Monday, will update then.
Used a Vardex horizontal insert internal threading bar at 375 RPMs, will use a Kennametal Top Notch tool for the external threads, I suspect that it will have to be run somewhat slower.
This is done in a Romi/Bridgeport 15 X 40 lathe which is a sort of CNC Manual hybrid built in the 1990"s, these are very nice machines with VERY easy to learn conversational controls, knowledge of G Code is not required for the most part unless the work requires a feature that the conversational input will not do. They have a lot of safety features in the software that will not run a program if there are obvious tool conflicts or math errors. They are the perfect machine for a hobby shop but a bit to expensive even at 20 years old at $10.000-$20.000 used.
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