Screw It! Screw It?

[Anderglan]

Actually, no.

 

I mean: Yes: Converter/Cartridge pens, there's always something to screw with.

 

But, apparently the Barrel always has the Female thread, and the Nib Section is Male.

 

Is there any rule, or even better a ... physicistic or other non-esoteric ... explanation, WHY?

 

Or, do counterexamples exist?

Thank you

[Ink Stained Wretch]

Actually, no.

 

I mean: Yes: Converter/Cartridge pens, there's always something to screw with.

 

But, apparently the Barrel always has the Female thread, and the Nib Section is Male.

 

Is there any rule, or even better a ... physicistic or other non-esoteric ... explanation, WHY?

 

Or, do counterexamples exist?

 

Thank you

 

Maybe the threads are less intrusive to the fingers that way, idk. I haven't thought about it much, and I don't have an immediate counter example off the top of my head, but I wouldn't be surprised if there were one.

[greencobra]

in 67 years of life, i don't think i've yet met someone who was curious enough to inquire, much less waste breath, asking about this mystery of life. but for certain every time i bring out my garden hose and screw it into the faucet on the side of the house i will think of you...like that insidious tune that resides in my head from time to time.

[Cyclohexene]

If we're talking about plastic (or resin, or whatever fancy name you wanna call it) barrel, having a female thread means that your mould core (the part shaping the internal cavity structure) has a bigger diameter closer to the opening than the opposite, so it can be removed from the moulded part. Basically it makes it easier to manufacture than otherwise.

 

If we're talking about barrels machined from solid rod of material, drilling out a bore and tapping the insides is easier as well.

[Astronymus]

Also barrels are often quite cylindrical. The sections are often konical. So the barrel usualy fits a bigger thread.

[Driften]

I'm guessing because it was done that way since the time of the level fillers if not before. It makes a lot more sense for the section to go inside the barrel than the other way around when looking at the smaller bodied pens from the 1900s. In those slim bodies making the body with the male threads wouldn't leave enough room for a useful feed size to buffer the ink. When it works, why give up on 100 years of tradition? What advantage material wise is there to do it the other way?

[Parker51]

In thinking about it, if one did have a pen with a barrel that a section screwed onto, then one could have a number of such bodies with screw on caps that you could fill as eye drop fillers and keep as full spares in a case.

When one barrel of ink ran out you would just unscrew the section, uncap another body and screw the section onto the new full body, then cap the old body and put it into the case for future refill.

Given how plain many early pens and pen holders were, this could have been a different direction to fountain pen development. If someone figured out how to adress burping by placing a little ball permanently into the bodies we might never have seen the development of self filling pens and cartridge pens or at least they would have been delayed in development as a spare body would have easily held more ink than a cartridge and this sort of system would have been easier to manufacture than a self filling pen with simple pen bodies likely being cheaper with one or two spare bodies than one with a self filling mechanism. But it would have required a case and the use of an eye dropper still, so costs might not be in this type of pen systems favor.

Edited April 11, 2020 by Parker51

[Anderglan]

In thinking about it, if one did have a pen with a barrel that a section screwed onto, then one could have a number of such bodies with screw on caps that you could fill as eye drop fillers and keep as full spares in a case.

When one barrel of ink ran out you would just unscrew the section, uncap another body and screw the section onto the new full body, then cap the old body and put it into the case for future refill.

Given how plain many early pens and pen holders were, this could have been a different direction to fountain pen development. If someone figured out how to adress burping by placing a little ball permanently into the bodies we might never have seen the development of self filling pens and cartridge pens or at least they would have been delayed in development as a spare body would have easily held more ink than a cartridge and this sort of system would have been easier to manufacture than a self filling pen with simple pen bodies likely being cheaper with one or two spare bodies than one with a self filling mechanism. But it would have required a case and the use of an eye dropper still, so costs might not be in this type of pen systems favor.

Excellent! I was thinking quite similarly: if the barrel is the part having the male thread and has a tight grip around the cartridge or converter, one can probably avoid many cases of ink mess that not so seldom do happen when, in our traditional wide barrels, the cartridge or converter are wiggling around.

[JosephKing]

I'm not sure if I understand the question exactly, but I wonder if the Tactile Turn Gist is a counter example.

[JosephKing]

And as to why, my experience with the Gist has left me feeling that the section walls are too thin while trying to fit a converter in the barrel and at the same time keep the overall pen diameter a reasonable thickness.

Edited April 12, 2020 by JosephKing

[sansenri]

In my opinion it's logical.

The section needs to take the converter inside of it, and the barrel then has to screw over it.

If the female thread were in the section it would be much more difficult to hold a converter in its place, as the barrel would have to screw into the section. The converter would just hold itself on the feed nipple. Very unstable.

It's rather illogical to do it this way, while if the section is male threaded outside, it can then allocate the converter inside even with an additional female threading inside, or at least a sufficiently long recess to hold the converter in place.

If I understand what you mean...

Edited April 12, 2020 by sansenri

[txomsy]

And for a similar reason any pen with a feeder.

 

Think of it this way: the section is a cylinder that, on one side must connect with a cap, which must necessarily be external.

 

So, that gives us a cylinder that on one side must be thin and accept an external (possibly threaded) cap. then it gets wider to provide a stop for the cap. Then what?

 

If you get thinner again, and put the threads outwards, then the inner part of the section can be a continuous cylinder where the feed fits.

 

If, instead you keep the external side thicker and put the threads inwards, then the inner part is no longer a cylinder, it is a thinner cylinder for where the section friction fits, then it must become wider in the area of the threads so that the barrel with outwards threads has to come in.

 

Now let is consider tolerances: if I do fit the feeder and nib into the section and do not introduce them deep enough, there is little difference. But if I push them somewhat more inside, then in the first case, there is no problem either, it just goes deeper in the same, longer cylinder. But in the second case, it will get into the wider area of the inwards threads where the barrel must screw in. So either the barrel is very well machined to a strict tolerance or there will be a clash between feed and barrel.

 

The first design is less problematic and gives you more allowance during assembly, it is also easier to produce: the inner part of the section is just a continuous, homogeneous cylinder, and you only need to machine the outer part which is a lot easier. Plus, you can easily protect a delicate section by inserting a feed or dummy before working the outward threads. The barrel an cap are larger and simpler, yes, the thread will be inner on those two, but the overall design is simpler. Plus in most cases both barrel and cap will be the same diameter, so the same machine will work for both. Same for the section.

 

In the second design, barrel and cap have opposite threads, you need a system to machine the innards of the wide cylinder of the cap, two systems for the section (one for the thinner cap side, and one for the thicker barrel side) and one for the outwards threads of the barrel. Protecting the barrel while machining outwards requires a larger dummy to fit inside. And tolerance would have to be strict.

 

Not to say you can't do it. But it seems -to me at least- simpler and safer from an engineering point of view.

Edited April 12, 2020 by txomsy

[Anderglan]

I'm not sure if I understand the question exactly, but I wonder if the Tactile Turn Gist is a counter example.

 

Very interesting! Meanwhile I read and watched some reviews, e.g. --

-- any idea what was Will Hodges's rationale behind the decision to make it so?

 

In my opinion it's logical.

The section needs to take the converter inside of it, and the barrel then has to screw over it.

If the female thread were in the section it would be much more difficult to hold a converter in its place, as the barrel would have to screw into the section. The converter would just hold itself on the feed nipple. Very unstable.

It's rather illogical to do it this way, while if the section is male threaded outside, it can then allocate the converter inside even with an additional female threading inside, or at least a sufficiently long recess to hold the converter in place.

If I understand what you mean...

OTOH: there are some quite prestigious manufacturers that ask the user explicitly that one may firstly put the cartridge into the barrel, and then screw the nib section into the barrel. E.g., SHEAFFER, LAMY, ...

 

And for a similar reason any pen with a feeder.

 

Think of it this way: the section is a cylinder that, on one side must connect with a cap, which must necessarily be external.

 

So, that gives us a cylinder that on one side must be thin and accept an external (possibly threaded) cap. then it gets wider to provide a stop for the cap. Then what?

 

If you get thinner again, and put the threads outwards, then the inner part of the section can be a continuous cylinder where the feed fits.

 

If, instead you keep the external side thicker and put the threads inwards, then the inner part is no longer a cylinder, it is a thinner cylinder for where the section friction fits, then it must become wider in the area of the threads so that the barrel with outwards threads has to come in.

 

Now let is consider tolerances: if I do fit the feeder and nib into the section and do not introduce them deep enough, there is little difference. But if I push them somewhat more inside, then in the first case, there is no problem either, it just goes deeper in the same, longer cylinder. But in the second case, it will get into the wider area of the inwards threads where the barrel must screw in. So either the barrel is very well machined to a strict tolerance or there will be a clash between feed and barrel.

 

The first design is less problematic and gives you more allowance during assembly, it is also easier to produce: the inner part of the section is just a continuous, homogeneous cylinder, and you only need to machine the outer part which is a lot easier. Plus, you can easily protect a delicate section by inserting a feed or dummy before working the outward threads. The barrel an cap are larger and simpler, yes, the thread will be inner on those two, but the overall design is simpler. Plus in most cases both barrel and cap will be the same diameter, so the same machine will work for both. Same for the section.

 

In the second design, barrel and cap have opposite threads, you need a system to machine the innards of the wide cylinder of the cap, two systems for the section (one for the thinner cap side, and one for the thicker barrel side) and one for the outwards threads of the barrel. Protecting the barrel while machining outwards requires a larger dummy to fit inside. And tolerance would have to be strict.

 

Not to say you can't do it. But it seems -to me at least- simpler and safer from an engineering point of view.

Vide supra: the "Tactile Turn Gist" is a counter example

 

"simpler and safer from an engineering point of view" -- I guess that's basically always: "cheaper from the bean counters' POV"

[sansenri]

obviously not impossible, nice to see there is one clever exception. Any others? I still think it's easier the other way round, from an engineering point of view... In general the easier way to do something is the one adopted industrially, in a crowded market however exceptions have their space.

 

PS, in particular it works in this case because the pen is steel, try doing that with a plastic section... very fragile (unless you make the section very large).

Edited April 12, 2020 by sansenri

[JosephKing]

 

PS, in particular it works in this case because the pen is steel, try doing that with a plastic section... very fragile (unless you make the section very large).

Said pen comes in plastic (Delrin to be exact)

[sansenri]

seriously? looked steel to me, the wonders of technology

https://youtu.be/cLsGCv-Skj8

my fault, I never listen to videos...

 

still looks the odd one out though

[vicpen123]

in 67 years of life, i don't think i've yet met someone who was curious enough to inquire, much less waste breath, asking about this mystery of life.

In more than 67 years of life I had also not been curious enough to ask about this either. Even in the madness that is engulfing the world at the moment.

 

But, there is another mystery that needs to be solved. Testing on a limited selection of pens reveals that the number of turns to seal the barrel to the section varies quite a lot.

 

"51" 1.5 turns; P75 3,75 turns; Sonnet 4.75 turns; P45 4.5 turns; P UK Duofold 2.75 turns. Other pens tested are Sailor 1911 M 8 turns; Pilot Metrop 3 turns; Italix Parsons Essential 3+ turns; Sheaffer PFM 2.75 turns; Sheaffer Targa 2.75 turns;.

 

Why? And is there any hidden message based on date of design and manufacture?

 

Help. Add your own pens to the list.

[Anderglan]

In more than 67 years of life I had also not been curious enough to ask about this either. Even in the madness that is engulfing the world at the moment.

 

But, there is another mystery that needs to be solved. Testing on a limited selection of pens reveals that the number of turns to seal the barrel to the section varies quite a lot.

 

"51" 1.5 turns; P75 3,75 turns; Sonnet 4.75 turns; P45 4.5 turns; P UK Duofold 2.75 turns. Other pens tested are Sailor 1911 M 8 turns; Pilot Metrop 3 turns; Italix Parsons Essential 3+ turns; Sheaffer PFM 2.75 turns; Sheaffer Targa 2.75 turns;.

 

Why? And is there any hidden message based on date of design and manufacture?

 

Help. Add your own pens to the list.

 

My Parker 45 Classic (black plastics, fitted with a "Student" version steel nib) has 5.5 turns...

 

In deed, these questions do belong together: me thinks the basic rule is, the fewer the turns, the coarser the thread.

 

OTOH, if one wants a really coarse thread, one needs more flesh. And thus, the "Tactile Turn Gist" having an "ACME thread" for the cap, needed to re-think the entire question; I guess that was and is the reason that they decided that the barrel got a male thread.

 

edit:tpyo

Edited April 16, 2020 by Anderglan

[TorPelikan]

The first Pelikano(1960) and Pelikan P15/P25 have male barrel thread, I think.

 

Their "sections" are very long and "barrels" are short.

They Pelikan people, didn't want to make the sections any longer by putting male threads to them.

Too long sections will make it difficult to set ink cartridges.

Especially, the Pelikano pens are made for schoolboys and schoolgirls.

 

Their thread is fine and metal part is used.

 

 

regards,

 

 

Tor

[Anderglan]

The first Pelikano(1960) and Pelikan P15/P25 have male barrel thread, I think.

 

Their "sections" are very long and "barrels" are short.

They Pelikan people, didn't want to make the sections any longer by putting male threads to them.

Too long sections will make it difficult to set ink cartridges.

Especially, the Pelikano pens are made for schoolboys and schoolgirls.

 

Their thread is fine and metal part is used.

Tor, excellent information. Thank you

 

 

from: https://www.pelikan-collectibles.de/de/Pelikan/Modelle/Patronenfueller/Pelikano/index.html