6 hours ago
Just to learn how, I decided to try threading on my 3 axis CNC. VCarve Pro has a toolpath for doing that, so why not? First, however, you need to have a threading bit. I bought this one:
![[Image: AP1GczNfrJmlrnsInOQ4STxjDRwHlyu8YQfJsOpA...authuser=1]](https://lh3.googleusercontent.com/pw/AP1GczNfrJmlrnsInOQ4STxjDRwHlyu8YQfJsOpAXeAgz5UHbq7DnHejJ93vbwBwY1fVj7fU5pUnV_cEOLo5i9A01RIJ0HxoTneL6nRMNjjMxkabCwRB1eJKqfSWalUDsE15M7XciwNzDcfHDFXyuke69V6KaQ=w1445-h825-s-no?authuser=1)
It wasn't clear at first how to mill the threads so that the tip diameter of one thread would mesh with the root diameter of the other, allowing some slop factor. I think that would work had I milled the threads to give a land on them, like an acme thread, but I made V-shaped threads and for that to mesh I had to make the male thread one thread depth larger before cutting the thread. I'm going to cut some threads with lands on them to see if the logic is more straight forward. In any case, I was successful and the threads mate very smoothly.
![[Image: AP1GczMyk6-rR4QOdWSE2Vb27MZ823Rx08KunizR...authuser=1]](https://lh3.googleusercontent.com/pw/AP1GczMyk6-rR4QOdWSE2Vb27MZ823Rx08KunizRgdCUtEK-Cz_QNkE-PQTwhKWdAnSYAEcLh57tuMxDJkU8HQci1IRpSBECj8Oz4IgupRNlqDOyzv-jUaQ8eWpljuq1WMUeNFU0EgclIQ6QpN0mLh2XhwY82Q=w1565-h880-s-no?authuser=1)
The box is about 4" OD, with a UTS 1" thread I had to make the lid as two pieces, otherwise the threading bit won't cut deep enough. The thread wasn't cut quite completely on the threaded section, so it wouldn't fit down tight to the base, so I added the O-ring to take up the slack. Still learning.
![[Image: AP1GczOCo-rsxVrCKPIJeHkWzxFyZccNq5kwCRen...authuser=1]](https://lh3.googleusercontent.com/pw/AP1GczOCo-rsxVrCKPIJeHkWzxFyZccNq5kwCRenloCrx4-kOJs6aesS2UqKw3bKv2x4lmm1A1wppIBgPXOxmsZidol5rSGCpiE0gU_2Y0LKIeWGKzrDrGJ41IKKVtqnEfAg6Eg5zmLgE7E7d7Kthre6LF7XMA=w1565-h880-s-no?authuser=1)
![[Image: AP1GczNObmNnXmbi1YUiLLqxk5JarcSJRiacH3jf...authuser=1]](https://lh3.googleusercontent.com/pw/AP1GczNObmNnXmbi1YUiLLqxk5JarcSJRiacH3jfohUsIj6wkePQJKQeSlJNG4JoP7uIOLjClg3sXcXMY3fSf-n4KBQnFvFfAa782L2fdyl_5Y-jJOjEMfLwY067QHvQTIySUM9BYb5hKDAdaG8KL9Y93ynXIw=w1565-h880-s-no?authuser=1)
Normally, the lid has a female thread and fits over the male thread of the box. To do that, however, a back cut needs to be made below the thread for clearance, again because the shape of the tool doesn't allow it thread to the bottom of the recess. I managed to figure that out, too, but I need a narrow T-shaped bit before making more.
And that kept my brain engaged for a couple of days.
John
It wasn't clear at first how to mill the threads so that the tip diameter of one thread would mesh with the root diameter of the other, allowing some slop factor. I think that would work had I milled the threads to give a land on them, like an acme thread, but I made V-shaped threads and for that to mesh I had to make the male thread one thread depth larger before cutting the thread. I'm going to cut some threads with lands on them to see if the logic is more straight forward. In any case, I was successful and the threads mate very smoothly.
The box is about 4" OD, with a UTS 1" thread I had to make the lid as two pieces, otherwise the threading bit won't cut deep enough. The thread wasn't cut quite completely on the threaded section, so it wouldn't fit down tight to the base, so I added the O-ring to take up the slack. Still learning.
Normally, the lid has a female thread and fits over the male thread of the box. To do that, however, a back cut needs to be made below the thread for clearance, again because the shape of the tool doesn't allow it thread to the bottom of the recess. I managed to figure that out, too, but I need a narrow T-shaped bit before making more.
And that kept my brain engaged for a couple of days.
John