Lesson Learned and Development of the TADT

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DrD

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I never did go into the full story of why I wanted to make a stylized slimline with a "section." Part of the reason stemmed for my work with putting a flared tip at the nib, as shown in the first photo, a pen I had previously posted here. I wanted to change the refill in this pen, and try as I might I couldn't get the nib-tube-tranny assembly out. The flare prevented getting enough purchase to remove that assembly - even though the tube at the cap/clip end had been shortened considerably so that it just contacted the tranny enough to keep that part of the pen in the body tube.

Today, as I was contemplating this perplexing issue, my attention was drawn to a rubber band on my work desk: I give you photos 2 and 3. I still like the section concept better. Guess I had best be prepared to include a rubber band, er a technologically advanced disassembly tool - TADT - with each pen sold.

Thanks for looking! Please comment.

DrD
 

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magpens

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@DrD

Thanks for your pictures.

If you go to a lab for a blood test, they probably use a rubber band (about 1" wide and 15" long) as a tourniquet on your arm.

That tourniquet gets discarded after the blood is taken. . I ask permission to take the rubber band home with me (and they will often give me an extra as well). . I find that these rubber bands work very well in the role you picture above.
 
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its_virgil

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Have you not read my article on one piece slimline improvements? I think it is in the library. If not, I can get a copy to you. Problem(s) solved.
Do a good turn daily!
Don
 

DrD

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Have you not read my article on one piece slimline improvements? I think it is in the library. If not, I can get a copy to you. Problem(s) solved.
Do a good turn daily!
Don
Finally got your article opened, and yes each of your modifications were incorporated into the pen design, as appropriate.

The glued upper brass tube makes contact with only 3/16" to 1/4" of the upper barrel of the tranny. Any less contact makes the nib-tranny assembly prone to just falling out of the pen body. I did a lot of experimentation in this particular area, and reached what showed to be the optimum contact length between the upper tube and the exposed portion of the tranny. Using something like a rubber band gives needed traction on the only part of the nib that is "graspable" and the assembly is easy to remove and easy to replace. The condition created by a flaired barrel mating to a conical nib prevents proper "purchase" on the nib to remove the nib, while not limiting the ability to rotate said nib, lowering or retracting ball point. In respect to optimizing the contact between the upper tube and the exposed tranny, your article was quite helpful, but I don't think it anticipated the steric hinderance created by the two two limiting geometries of the flair at the nib end of the pen body and the conical nib. Perhaps others may not experience the issue in removing the nib assembly; unfortunately my fat finger were unable to make enough purchase on the nib for removal, thus the need for a TADT.

There is no need to reinforce the nib area of this I piece pen body because of the flair which creates added thickness in the area of the nib. Typically this would be the thinnest part of the body of the pen, but not in this case. I did do this on the 1st 1 piece body I turned, but have since not had the need for this reinforcement.

And an easy to turn tranny was used.

The problem is that the flair prevents getting good purchase on the exposed nib to affect removal of the nib-tranny section. Doing the modifications did not solve the problem experienced with removing the nib for refill exchange with this design, thus the need for the TADT.

I do appreciate your input, and truly appreciate your articles in the IAP archives on turning 1 piece 7mm pens. You have been instrumental in helping me and untold others apply this interesting modification to a rather bland pen design. And I thank you for that.

DrD/Don
 
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its_virgil

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It sounds like you solved a few limitations. I like the idea of the flair on the nib end to add a little thickness especially if the blanks end is enlarged just a little.

Thanks for the nice compliments also.
Do a good turn daily!
Don
 
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