My method of fitting cap rings

[javier75]

Excuse me for my lateness, I hoped I could upload this before, but lately I have been very busy.
The user Psychmike22 asked me about the way I use to put the center bands in the caps. I understand that this is the obvious method, and I´m sure there will be other better, so I would appreciate if some of you wants to share them too. As I said, this is the way I use to fit the center bands in the caps, but this method only gives a good finish with ebonite or any other completely opaque material.
To put them in acrylic caps is another story, because of the transparency you get when you drill the cap, and if you try to overlap an acrylic band to close the body of the cap, there will be spots of the glue and the paint of the inside of the band, so this way does not work fine.

These days I´ve been making one cap as an example, and as I have taken pictures of the whole process, I will use them to explain it better.

We start from a 5cmx18mm ebonite rod.

Then I turn it to get a 13,5mm diameter section in one of the two ends.

The next step is to fit an aluminium tube in this end, (this tube has 13,5mm of internal diameter and 15mm of external diameter) and glue it to the body.

When the glue is dry, I cut off the ring in the lathe (I do this because it is a very thin and fragile ring).

Then I fit over the ring an ebonite band, and glue it too, and I repeat the whole process with another aluminium ring and another ebonite band for closing everything. Finally, I turn the body down to 14,7mm which is the size of this cap, and I drill the cap and make the thread and only remains the polish.

 

[duncsuss]

This is excellent, thank you!

What is the largest drill size and threading you would use on this cap?

I normally make my larger pen caps with M13 x 0.75 threads -- would this be safe for this diameter cap ring? (Only 0.25mm thick ebonite under the aluminium ring?)

 

[Psychmike22]

Thank you for posting this. You answered all my questions.

 

[javier75]

Well, the largest diameter I drill in this cap (in every cap, really) is 13mm just in the beginning of the hole (about 4mm deep), because the thread I am using in all my models is M12x0,75. Think that in the model that I showed some days ago the maximun thickness is 12,75mm and in others that I make is 13,10mm. So, I think with the measurements you propose yes, should be very thin. Maybe using a wider ring, you could solve the problem

 

[duncsuss]

Well, the largest diameter I drill in this cap (in every cap, really) is 13mm just in the beginning of the hole (about 4mm deep), because the thread I am using in all my models is M12x0,75. Think that in the model that I showed some days ago the maximun thickness is 12,75mm and in others that I make is 13,10mm. So, I think with the measurements you propose yes, should be very thin. Maybe using a wider ring, you could solve the problem

!Vale, gracias!

I also use M12 x .75 a lot. When I try using your method for a larger cap, I'll make the rings larger also to leave extra wall thickness underneath them.

 

[jalbert]

To comment on the transparency issue of overlapping acrylic rings, I do not apply glue underneath the acrylic ring when assembling the barrel or cap. For example, in the pen below, I only applied epoxy the the ring on the front of the cap, then sandwiched the whole thing together to let it cure. After it cured, I applied thin CA glue over the rings while spinning slowly on the lathe. My theory is that the glue will penetrate between each ring, rather than underneath the acrylic ring. I can't say whether or not my theory holds or not, but I have never had a problem with the rings moving while turning the cap down to its final diameter. Hope this helps!

 

[haskoson]

Thank you so much for this post.
I was wondering some time how to do rings - now i get it!
Will try this on my woodlathe. Don`t know if i can cut off that precise by hand, i`ll see.
Thanks again.

best regards

Gerrit

 

[javier75]

Thank you very much for your advice, jalbert. I know that it´s not necessary to glue every single ring I fit in the caps, I thought about it, because the bands are snapped in the cap, so, closing with the last piece should be enought. But the problem comes when the last piece is an acryilic one to make the lip of the cap (if you know what I mean) and there are spots between both walls (the external of the cap and the internal of the band, think that I make mostly black pens), so I left that method in the making of acrylic caps. What you propose about applying a thin CA glue over the rings when turning slow, is something I find very interesting, and I´ll make the prove to see how it works. By the way, I have visited your facebook, and I´m really astonished for the beautiful work you do. Congratulations!
About what you say, hakonson, I´m sure you will be able to cut the ring in your woodlathe if you can´t find them already cut, only remember to do that in the lower speed and use a sharp tool and, of course, being patient enought

 

[jalbert]

Thank you very much for your advice, jalbert. I know that it´s not necessary to glue every single ring I fit in the caps, I thought about it, because the bands are snapped in the cap, so, closing with the last piece should be enought. But the problem comes when the last piece is an acryilic one to make the lip of the cap (if you know what I mean) and there are spots between both walls (the external of the cap and the internal of the band, think that I make mostly black pens), so I left that method in the making of acrylic caps. What you propose about applying a thin CA glue over the rings when turning slow, is something I find very interesting, and I´ll make the prove to see how it works. By the way, I have visited your facebook, and I´m really astonished for the beautiful work you do. Congratulations!
About what you say, hakonson, I´m sure you will be able to cut the ring in your woodlathe if you can´t find them already cut, only remember to do that in the lower speed and use a sharp tool and, of course, being patient enought

Thanks for the kind words!
I absolutely agree that you run into problems when using an acrylic band as the "end" band. I usually try to use metal or something opaque like an ebonite. It's just one of those things that's difficult to get around, and something I honestly don't have a solution for. I usually just try and engineer my pens to avoid running into that problem