Great job, Bruce! Can you post a picture of this rig with the results? I've been wanting to mess around with this too.
Ok, let's see if this works, if you REALLY need to see exactly what I ended up with, let me know and I'll shoot it tomorrow.
Here, courtesy of Snap On, is what a tap looks like. (Not so coincidentally, the same size I used today.
I got my set from Harbor Frieght for $8.99 for about a 21 piece tap and die set. These aren't real high quality tools but will suffice for what is essentially cutting threads into plastic, not even metal.
They are used to cut female threads. The 3/8 is the diameter of the thread being cut, the 16 is 16 threads per inch and the NC is National Course, the Type of thread being cut. The squared off end usually goes into a T handle that comes in the tap and die set. (Taps cut female threads, dies cut male threads.) I guess you could use the T handle that comes in the set for the pen use too, visegrips were just recommended to me. (I got the about 6" long mini-visegrips for another non-pen reason. In a pinch, they can be used as a motorcycle gear shift lever if the stock one breaks or falls off and I'd misplaced the small set that was once in my bike toolroll so this pair is going there when not being used for pens.)
First, I soaked the 2 caps I was working on, the real one and a practice one in ammonia water for a few days to get all the ink out from between the inner and outer cap. (You have no idea how much can get up in there) I didn't want anything to impede the inner cap sliding out and sometimes I hear they can be really stubborn. The easier they come out the less likely you are to damage the inner or outer cap or rip through the threads you cut in the inner cap. I left the inner cap wet from water to use the water as a ultra-light lubricant. When you are cutting threads in metal, you usually use a light oil to keep the tap or die saturated in while you are doing the cutting.
I clamped the squared off end of the tap into the locked down jaws of the mini-visegrips.
Whether or not this is the proper usage or not, here's how *I* did it, I was kind of flying blind with no real instructions to go by.
I inserted the tap into the cap and down into the inner cap. The inner cap is about 2" long and necks down a bit towards the end closest to the cap jewel. You can feel the tap getting tight against this narrower than the rest of the inner cap area. Being right handed, I used my right hand to slowly turn the cap around in circles on the tap which would be cutting small grooves into the inside of the inner cap that would provide a grip to pull against to remove the inner cap. You can feel as it tightens up that you are tapping into the inner cap. Once it felt nice a secure and tight, I held the cap in a rubber gripper and gave the visegrips a pretty good yank outwards. The tap came out with the inner cap screwed onto it and could be seperated easily by hand. You really can't see the threads down in the inner cap unless you have a really bright light and no one looks down in there usually and the grooves aren't thru the inner cap or anything that drastic.
I reinserted one of the practice inner caps and it held fine. If necessary you could run a couple stripes of section sealent down the sides of the inner cap before reinserting.
According to Herr Estie Doktor Farmnboy, a real inner cap puller can deform both or one of the inner cap and outer cap and he feels the tap method can actually be safer to the pen's materials.
So far as the Trans jewel retainer goes, it looks like a thick plastic washer with a threaded whole in the middle. The threaded hole is where the jewel screws into. According to Farmboy (and it sure looks like this to me) this "washer" retainer slides in between the top of the inner cap and the inside ridge of the outer cap. It is just pressed into the necked down area of the outer cap until it is snug. Unfortunately, in my case, it's not snug, it's zeefloppin so I had to get the inner cap out to press the retainer washer back into the end of the outer cap.
Bruce in Ocala, FL