Half way done!
You guessed it... test fitting
Getting setup so I can part off the adapter
Here's the adapter, after parting it off from the main brass bar
Checking to see how it torques down
Not looking too shabby there!
Here I am using the drill to align the part and install it back in the chuck (on its original axis)
Getting ready to drill the hole on the other end, so that I can tap the adapter to 1/8-27 NPT
Almost ready to tap the hole that has been drilled
Added a slight chamfer on the hole, in order to help the tap start a little better
Using the tail stock to hold the 1/8 NPT tap
The initial threads for the gauge
Test fitting the gauge. As you can see, it sticks out way too far. This is because NPT threads are tapered, not parallel. The solution is to use a second pipe tap and grind it down (turning it into sort of a bottoming tap). Luckily, I just happen to already have one in 1/8 NPT, which I used to use when building motors.
Here you can see the normal 1/8-27 NPT (bottom) and also the "bottoming" 1/8-27 NPT tap (top). The tap on top allows you to widen the hole, which will allow the gauge to thread further down into the adapter (for a nicer fit).
Back to work threading - this time with the bottoming in pipe tap
That's much better.
Here you can see that I have put a shoulder around the inside of the top thread (to allow the gauge to seat down a bit better). I've also turned down the neck a bit, in order to give a bit of a separation between the hex area and the top part of the adapter, which accepts the gauge.
Here is a side view, albeit a bit dirty
Here's the finished adapter, after a little cleaning and polishing
Here it is with the stainless steel pressure gauge installed (I used Teflon tape on the threads of course).
The copper sealing washer had to be filed down, in order to correctly position the adapter and align the gauge in the forward facing position. The initial size of the washer was .050" thick; I had to take it down to about .045"
Here's the finished copper washer on the adapter
Here's a shot of the gauge, now that I have the La Pavoni back up stairs.
Here's a side view
A close up, showing the final positioning of everything.
Bringing the machine up to temperature, in order to pressure test the connections.
No leaks whatsoever; it's nice to have the adapter finished and have the gauge back on the machine.
So, aside from a couple of very minor things that I still need to do to the machine (such as gluing back on one of the rubber feet, etc.), I think this basically concludes the La Pavoni PID project. It's been quite a project, that's for sure. Thanks to everyone who commented and provided input/suggestions on this thread... I really appreciate it.
When I have a second, I'll make a video of the machine in action (pulling a shot and making a latte).
The PID controller has made a huge difference. I know some people have commented that adding a PID controller to a lever machine isn't needed and/or that it's a waste of time. However, based on my experience(s) with this project - as well as using the machine before and after installing the PID controller - I can stay definitively that adding a PID controller makes a huge, huge (i.e. night and day) difference in not only the ease of use, but also in the consistency and quality of the shots. It's like having a whole new espresso machine.