- Joined
- Jun 28, 2021
- Messages
- 142
One thing I have that could be useful to the V13 owners here is a spreadsheet I created almost ten years ago to calculate the thread pitch for any of the change gear combinations that are possible (or even impossible) on that machine. I had need to cut a triple-start thread having a 3.3333" pitch (10 threads/inch with three starts). The handy plate on the machine fails to identify this thread pitch which is why I thought to find the odd-ball pitches using a spreadsheet. Turns out you can get close to 3.3333 a number of different ways but you can also nail that pitch with the right set of gears installed.
As I recall, I had to remove the cover and defeat the safety switch to run the change gears I needed because they would have interfered with the cover. I got the three starts by using the three jaw chuck as the index (not my idea but I shamelessly stole it) to position the part on centers. The center in the chuck was cut in place and not moved until the threads were done. The photo of the threads and the nut installed are of the proof part made with PVC. The actual parts were aluminum. This was for an electronic connector that needed to be put through a vibration test, the threaded parts I made were part of the test fixture.
I attached the XLS file to this post so anyone curious or bored can play with it. You'll see the gears shown in the photo already in the spreadsheet and the 3.3333 pitch in the D-K position on the chart. Below that are a few other results I copied and pasted to save them including one for 3.3750. There no telling whether or not the odd pitch you need will be possible but at least you can give it a good look.
I used this method to cut a 'tap' with a pitch matching a Bowden cable housing so I could tap the little aluminum clamps I made to prevent slippage. Seems like the pitch was just under 17.5 and I found a gear combination giving me 17.45. Close enough for a short thread, worked perfectly......Bill
As I recall, I had to remove the cover and defeat the safety switch to run the change gears I needed because they would have interfered with the cover. I got the three starts by using the three jaw chuck as the index (not my idea but I shamelessly stole it) to position the part on centers. The center in the chuck was cut in place and not moved until the threads were done. The photo of the threads and the nut installed are of the proof part made with PVC. The actual parts were aluminum. This was for an electronic connector that needed to be put through a vibration test, the threaded parts I made were part of the test fixture.
I attached the XLS file to this post so anyone curious or bored can play with it. You'll see the gears shown in the photo already in the spreadsheet and the 3.3333 pitch in the D-K position on the chart. Below that are a few other results I copied and pasted to save them including one for 3.3750. There no telling whether or not the odd pitch you need will be possible but at least you can give it a good look.
I used this method to cut a 'tap' with a pitch matching a Bowden cable housing so I could tap the little aluminum clamps I made to prevent slippage. Seems like the pitch was just under 17.5 and I found a gear combination giving me 17.45. Close enough for a short thread, worked perfectly......Bill
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