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Cutting 11.5 TPI threads
- Thread starter LROYSON
- Start date
- Joined
- Jun 7, 2013
- Messages
- 10,101
Likely a 23 tooth gear on the change box would do it.
- Joined
- Jun 7, 2013
- Messages
- 10,101
I suppose that you would have to make one.
Here is my text that I wrote up for cutting threads not listed on the quick change box.
Special threads may be cut by substituting a gear with the same number of teeth as the TPI desired on the QC box input, the tumbler gear and lever on the QC box are set for the for the number of threads as there are numbers of teeth on the stud gear. The levers may be set to cut multiples or halves of the QC box drive gear, and also the QC box range gear may be used to arrive at the correct pitch.
Here is my text that I wrote up for cutting threads not listed on the quick change box.
Special threads may be cut by substituting a gear with the same number of teeth as the TPI desired on the QC box input, the tumbler gear and lever on the QC box are set for the for the number of threads as there are numbers of teeth on the stud gear. The levers may be set to cut multiples or halves of the QC box drive gear, and also the QC box range gear may be used to arrive at the correct pitch.
You could 3D print such a gear using PLA or PETG. I have 3 such gears in my lathe and they are doing great over a year know. If I eventually break them, I even don't replace them with the POM gears I made but again with 3D printed PLA gears. That reduces the risk of damage to other parts of the gear train.I called PM and they didnt know and suggested asking in this forum. Also I don't have a reference for 2.25mm either? Any idea how to get a 23 tooth gear to fit my lathe? I don't have that gear.
I guess I'm too new to this hobby to fully understand how to do what you have described. Thank you though.I suppose that you would have to make one.
Here is my text that I wrote up for cutting threads not listed on the quick change box.
Special threads may be cut by substituting a gear with the same number of teeth as the TPI desired on the QC box input, the tumbler gear and lever on the QC box are set for the for the number of threads as there are numbers of teeth on the stud gear. The levers may be set to cut multiples or halves of the QC box drive gear, and also the QC box range gear may be used to arrive at the correct pitch.
If you have a rotary table for the mill you can use it vertically to cut any # of teeth on a gear, even w/o the indexing plates. It may not be perfect but at the slow speed change gears run it will work. You can use the formulas in the Machinery Handbook to calculate the required diameter.
The indexing marks on my Vertex RT allow me to come really close to any # of degrees/parts of a degree of rotation. I've made a gear cutting tool for the mill from square HSS stock and an arbor that holds it much like a fly cutter. I just eyeballed the shape of the tool teeth against an existing gear of about the same size. I used aluminum for the gear and it ran fine. The hardest part was broaching the keyway on the lathe, slow but it works.
The indexing marks on my Vertex RT allow me to come really close to any # of degrees/parts of a degree of rotation. I've made a gear cutting tool for the mill from square HSS stock and an arbor that holds it much like a fly cutter. I just eyeballed the shape of the tool teeth against an existing gear of about the same size. I used aluminum for the gear and it ran fine. The hardest part was broaching the keyway on the lathe, slow but it works.