Cutting threads

[Paul Paukstelis]

Things are pretty quiet around here, so I thought I would show something that I have been playing with recently. Using my bolt-on CNC for the lathe I wrote a little script with a few parameters that spits out gcode that lets me cut internal or external threads for boxes, etc. Suffice it to say 0.7 mm pitch isn't going to be useful (but can be done!) and the 2 mm pitch either needs multiple passes or CA glue to prevent some of the chip out. The router with the collet adapter also has way more runout than I would like.

 

[robo hippy]

Hmm, well, for sure, some woods are far better for cutting threads than others. Soft maples are very difficult to cut threads in. Dogwood is okay, Osage is very difficult. Boxwood, of course, is ideal!

robo hippy

 

[Monte Richard]

How do you feed the cutter to determine the threads per inch?

 

[Paul Paukstelis]

How do you feed the cutter to determine the threads per inch?

I just tell the motor to move a certain distance (pitch) every time it rotates the piece 360 degrees. It is all computer controlled.

 

[colinsp]

Impressive use of technology but it may be quicker to use conventional thread cutting chasers

 

[Paul Paukstelis]

Impressive use of technology but it may be quicker to use conventional thread cutting chasers

It maybe slightly faster, but certainly not as versatile. With this you can easily cut threads in side grain bowls/boxes, something that you would very hard to do well with conventional thread chasers.

 

[Darryl Fective]

I keep wondering if stepper motors and arduino couldn't be used to create a master/slave function to cut threads and spriral flutes, etc. I don't know where to start with it though.

 

[Paul Paukstelis]

I keep wondering if stepper motors and arduino couldn't be used to create a master/slave function to cut threads and spriral flutes, etc. I don't know where to start with it though.

Certainly. The machine I've created does that and a whole lot more. It There are a lot more powerful microcontrollers than Arduinos these days and it is much cheaper to buy a motor control board for a 3D printer rather than trying to wire everything up to run steppers off of Arduino.