BSW

I was having some issues with threads in one of my prototypes. I was using what I had on-hand, and was putting a 6-32 thread on a stainless rod into a hole tapped into 6061 aluminum. Predictably - it did not work very well as stainless is actually very abrasive. So I consulted a long-time friend - AC1L. Richard has forgotten more about machining, radio and nozzle design than I will ever know. He holds more than a few patents and has been encouraging me all along.

He took one look at my project and said "You should try British Standard Whitworth threads."

I have run into these beasties in my 1968 MGB-GT - and they are usually more of an annoyance than a help ! However - they have several nice properties. They have rounded rather than sharp angles and for the size I need, they allow me to use a 1/8" rod without compromising thread engagement (6-32 done properly would require .164" rod) - it also has 40 threads-per-inch - so I think this will allow me to use easy to machine brass instead of stainless. This is a picture of the BSW taps, die, and the test block I made.

Touch Probe

It has been a busy few weeks despite the lack of posts. I made major headway with the Smith & Wesson M&P tool. Unfortunately I am going to keep the photos off the net for a while so it does not interfere with any potential patent decisions. It is going to be a very interesting tool...

Curiosity got the better of me and I finally ordered the Wildhorse Touch Probe. This probe sells for $140 - far less than the $1150 probe sold by Tormach. I have been playing with it and am still on the fence. I think it will be very useful for certain operations - like finding the center of a hole. It requires a bit of fiddling to get it centered - you can see the centering setup using the Starrett 650 back-plunger indicator. I do not think it will be better than the trusty Starrett edge finder for locating edges and setting the machine DRO. I played with the digitizing functions a little - it uses a "bed o nails" approach and drives straight down on the object. This will work for metal, but it will make marks on anything wooden.