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Pen Engineer

Interesting.

I think I may try something on one of my old Bock or Jowo nibs in my Twsbi or my Jinhaos. The expanded breather hole is not something I'd seen before. If it makes any difference.

It will. Promise!

with kindness...

 

Amadeus W.
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Pen Engineer

Very interesting and worth the time to read and watch, thanks!

 

I would propose that a fixture to hold the pen and apply a controlled pressure to paper on a digital scale would give the best quantitative measure of force to flex. One could digress into the complexity of finite element analysis would be the purest path for an engineer.

 

Force-to-flex, coefficient of drag for both nib and paper ...... geekdom extraordinaire awaits!!

At the same time the pen or paper needs to move to reduce friction and the tines can spread in a natural way

with kindness...

 

Amadeus W.
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Pen Engineer

 

Yes, I've been thinking about FEA and fountain pen nibs. Not long ago I ran across an online CFD, FEA, and thermo simulator suite that may have enough CPU time in the free account to model a nib. It's called SimScale:

 

https://www.simscale.com/

 

The limitation in SimScale might be the selection of, or specification of materials. But even with that limitation the exercise would still be helpful by allowing the forces in the nib to be visualized, especially with different breather hole shapes and sizes as well as trimming for added flex.

 

Regards, David

That's waht ingeneers ar four. Sey do it all in ser heds!

with kindness...

 

Amadeus W.
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Pen Engineer

>> ... speaking of metaphysics which involves philosophical and unproven matters. I am talking about pure physics, based on facts and hard data. A lot of people do not have a hard grasp of physics. <<<

... and every now and then, hard pure physics comes to an end where all gets mystical and the magic want CAN supply solutions... I have been there, a hard and pure ingeneer! :rolleyes:

with kindness...

 

Amadeus W.
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Pen Engineer

 

This the sixth and final test in this series of flex experiments on no. 6 flex and extra fine nibs from Fountain Pen Revolution. In the next few days, I'll get a chance to summarize my conclusions and recommendations from the overall process.

TEST NO. 6 -- FPR NO. 6 FLEX NIB (SIDE SCALLOPS AND THINNING OF MATERIAL UNDER SHOULDERS)

WRITING RESULTS AFTER MODIFYING NIBS WITH SIDE SCALLOPS, JUST BEHIND THE SHOULDERS, AS WELL AS THINNING OF NIB MATERIAL USING A DREMEL-TYPE GRINDING TOOL

Click pen with side scallops, no. 6 FPR extra fine nib, 6.3 mm standard ebonite feed

In this test, the no. 6 FPR flex nib was modified with angel wing scallops on the sides, just behind the shoulders. Additionally, a Dremel-type spherical grinding tool (Graphic 2, below) was used to thin the steel nib material from approximately the shoulders through the tines. In comparison to the no. 6 FPR flex nib used in Test 2 (side scallops only), this wing-modified and thinned nib provides additional line variation (approximately 3x, from a line width of about 0.6 mm to 2 mm), with more flexibility, and a smooth writing experience (Graphic 1). The nib never railroaded. However, the ink is more difficult to control.

CONCLUSIONS OF TEST NO. 6

Flexibility and line variation are increased, but at the expense of ink control. Additionally, without a micrometer, it's difficult for a layman to control the material-thinning process and to determine exactly how much material is being removed.

 

Graphic 1

fpn_1501437127__handwriting-sample-test-

 

 

Graphic 2

fpn_1500854988__wality-test-nib-thinned-

 

 

Wow, you have done a great job, Grinding away from the inside where the nib usually touches the feed would interfere with the ink flow. The same effect on flexibility could be achieve when grinding away from the top of the nib.

 

About micrometers... there are vernier calipers, which can measure to a hundredth of a millimetre, which should be accurate enough. I have seen them made of carbon fibre reinforced poly-carbonate and cheap as chips.

with kindness...

 

Amadeus W.
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Pen Engineer

First of all, you appear to be getting much better at modifying nibs.

The work you are doing now looks much cleaner.

 

So far as the thinning the underside, I have a couple of thoughts.

 

I'm curious as to how well a sand paper disk would do on a Dremel tool for that modification.

 

I'm also wondering how the orientation of the scratches effect ink flow.

Would scratches made lengthwise increase the speed of ink flow from the pen while ones made side to side increase flow from slits in the feed???

Yes, scratches made lengthwise increase the speed of ink flow from the pen... However, only when put together initially. Once all is well covered with ink this interface is not efficacious any longer.

with kindness...

 

Amadeus W.
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Pen Engineer

I really liked your article on plastic feeds and feed design.

https://fountainpendesign.wordpress.com/feed-supply-ink-function-foutain-pen/fountain-pen-feed-function/

I noticed this after "reinventing the wheel"

 

My most successful feed design is kind of pear shaped with the Zebra-G sitting on top (larger on the bottom)

Also, it starts out round where it goes into the section and then gets bigger from there from rear to front.

I'm not sure how easy it would be to make with a machine, I sanded it by hand.

It looks a little like a pregnant guppy wearing a Robin Hood hat (nib) :D

attachicon.gifuuuu.jpg

I'd be very interested to know what you think about the difference between vented and non-vented nibs and how capillary action is effected.

hole, no hole, makes no difference. The reason for the hole is manufacturing and reducing the stress at the end of the slit. See the finite element picture, The larger the hole diameter the lower the stress.

 

As has been shown in this forum, the diameter or oval shape increases the flexibility if the hole is near the effective cross section

with kindness...

 

Amadeus W.
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Pen Engineer

Hi PenIngeneer! I will definitely look into your writings. Please feel free to use the image (just quote my name Antonios Zavaliangos)

I am a mechanical engineer by training and I am a professor of materials science and engineering - mechanical behavior of materials is my "love" (ok, second to pens :))

 

Looking forward to your feedback. B)

with kindness...

 

Amadeus W.
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Pen Engineer

I love Fountain Pen Network. I don't know the backgrounds of everyone, but in just this one thread on flexible nibs, we have the following:

 

- the owner of a pen company

- a calligrapher who studied with Lloyd Reynolds

- a professor of materials science

- an expert on Chinese pens

- an engineer in writing instruments

- an expert in vintage flex pens

I would like you to mention your criteria for placing the participants in the above sequence!!!! :lticaptd: :rolleyes: :blush:

with kindness...

 

Amadeus W.
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ReadyFireAim

hole, no hole, makes no difference.

I drilled a hole in the back of my Noodler's Ahab and it killed it.

I pulled it & put aluminum tape over the hole. It worked fine again until the tape fell off.

 

I've tried blocking other holes in non-flex nibs and it turns them into instant gushers.

The tape was not placed far enough forward of the hole to make it a improvised over & under feed.

 

Something is going on.

 

I'm thinking that moving the hole forward is the same as sliding the nib/feed forward (out of the section)

Moving the hole all the way forward (in front of the tip :D AKA ...No hole) makes the pen as wet as it can be.

 

With one problem.

When the air goes into the hole and toward the tip, the pen will drip. (not to be confused with wet pen)

This happens when the nib's undersurface, in front of the feed, experiences "nib creep" or when the feed is too far from the nib.

If the feed is too close it can restrict nib flex, cause hard starts & possibly even starve the pen.

 

Wet pen and dysfunctional pen are 2 different things.

And there are other things that can cause "wet pen" but those are mostly feed slit/channel issues.

 

I guess what I'm trying to say is that behind the hole, the feed's job is to suck ink down.

Forward of the hole, the feed's job is to suck ink up.

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Pen Engineer

I drilled a hole in the back of my Noodler's Ahab and it killed it.

I pulled it & put aluminum tape over the hole. It worked fine again until the tape fell off.

 

I've tried blocking other holes in non-flex nibs and it turns them into instant gushers.

The tape was not placed far enough forward of the hole to make it a improvised over & under feed.

 

Something is going on.

 

I'm thinking that moving the hole forward is the same as sliding the nib/feed forward (out of the section)

Moving the hole all the way forward (in front of the tip :D AKA ...No hole) makes the pen as wet as it can be.

 

With one problem.

When the air goes into the hole and toward the tip, the pen will drip. (not to be confused with wet pen)

This happens when the nib's undersurface, in front of the feed, experiences "nib creep" or when the feed is too far from the nib.

If the feed is too close it can restrict nib flex, cause hard starts & possibly even starve the pen.

 

Wet pen and dysfunctional pen are 2 different things.

And there are other things that can cause "wet pen" but those are mostly feed slit/channel issues.

 

I guess what I'm trying to say is that behind the hole, the feed's job is to suck ink down.

Forward of the hole, the feed's job is to suck ink up.

Guess, I was a bit flippant with my snappy "hole, no hole" comment. My sincere apologies. :o :(

 

The other contributing component is the feed. The feed I designed has its air channel at the back (for many good reasons) and in that case my comment applies. B) I did check this for the manufacturing department, at the time (40 years ago, oh dear!) They wanted to see if they could get rid of the hole because the stamping pins where so small and snapped off frequently.

 

Since I am somewhat biased :rolleyes: I often forget that there are feeds with the air channel on top. Then it does matter and your observations are correct.

 

I wish you had fun performing your experiments. I know that's the way we learn best.

Edited by PenIngeneer

with kindness...

 

Amadeus W.
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Thank you for these insights, Peningeneer!

 

If we imagine looking at the tail end of the feed, are we concluding that a single ink channel at the 12 o'clock position, combined with a large vent hole, creates too much air/ink interchange? Would placing two smaller ink channels at something like 2 and 10 o'clock, avoiding the large vent hole at 12 o'clock, prevent the problem? And in the case of these ebonite feeds, is the single channel on top serving as both the air channel and the ink channel?

Reviews and articles on Fountain Pen Network

 

CHINA, JAPAN, AND INDIA

Hua Hong Blue Belter | Penbbs 456 | Stationery | ASA Nauka in Dartmoor and Ebonite | ASA Azaadi | ASA Bheeshma | ASA Halwa | Ranga Model 8 and 8b | Ranga Emperor

ITALY AND THE UK

FILCAO Roxi | FILCAO Atlantica | Italix Churchman's Prescriptor

USA, INK, AND EXPERIMENTS

Bexley Prometheus | Route 54 Motor Oil | Black Swan in Icelandic Minty Bathwater | Robert Oster Aqua | Diamine Emerald Green | Mr. Pen Radiant Blue | Three Oysters Giwa | Flex Nib Modifications | Rollstoppers

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ReadyFireAim

Thank you for these insights, Peningeneer!

 

If we imagine looking at the tail end of the feed, are we concluding that a single ink channel at the 12 o'clock position, combined with a large vent hole, creates too much air/ink interchange? Would placing two smaller ink channels at something like 2 and 10 o'clock, avoiding the large vent hole at 12 o'clock, prevent the problem? And in the case of these ebonite feeds, is the single channel on top serving as both the air channel and the ink channel?

 

Here is my take on that.

Flex pens and non-flex are completely different animals as are vented and non-vented nibs.

 

Flexing a non-vented nib moves the nonexistent hole, that for theoretical purposes is in front of the tip, to the rear thus slowing the ink down.

It does this because the tines move away from the ink channel and break the surface tension thereby creating a vent hole.

The vent hole slows down capillary action because it is not a tube anymore.

The narrow trough can still wick ink forward but at a much reduced speed.

 

This is why you can go fast and wide to start and then you have to slow down or reduce your flex.

The harder you flex the further to the rear the effective vent hole becomes.

It works against you.

Some people widen the channel to get more of an ink puddle reserve but refill speed suffers.

 

Flexing the pen quickly stretches the ink film and pulls it down the feed in a pumping sort of action.

People dry start pens using this method.

 

Vent hole nibs are very different.

Once the ink is gone from the channel in front of the hole it draws ink from the slits.

Once that is gone you have to wait for the pen to slowly refill around the hole.

There are creative ways around the "hole problem" that involve a bottom lengthwise slit in the feed and other more complicated things that would take a drawing to explain.

 

I just started messing around with bottom vents like Peningeneer mentioned earlier.

I'm thinking the idea has great potential, especially for very challenging nib designs like the Zebra-G.

Funny thing is I sort of discovered it by accident when I made a feed too small and a unintentional an air gap formed at the bottom lengthwise slit.

It worked really well but took a long time to adjust after pulling the nib every night (to avoid rusting a nib)

Edited by Bordeaux146
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One matter that I don't think I have seen discussed so far is the issue of capillary action and designs that better/best allow for consistent surface tension to be maintained between the feed and nib as it flexes. I have found that designs that allow for greater/easier nib flex don't necessarily allow for more consistent flex writing if the design interferes with capillary action/surface tension. I would guess this may be why the wing cut designs tend to perform more consistently than adjustments to the breather hole. So, the perfect recipe would be a combination of "flexiness", sufficient ink flow, and consistently maintained capillary action/surface tension. Thus, of course, different inks would have an impact on the equation due to variations in flow/wetness and properties that impact surface tension within the ink itself.

 

However, that said, I realized early on in this thread I was probably in way over my head in terms of IQ in light of the very intelligent and experienced replies I have seen from some very sharp folks. Bob, you have managed to bring together a pretty salty group on this topic. Great work!

 

Kevin

Fountain Pen Revolution

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Honeybadgers

Anyone who thinks that we simply can't replicate the materials of the past has never set foot on the practical machinist forums. There are people smart enough to figure it out. Trust me.

 

For pete's sakes we sent a piece of steel to the bottom of the ocean to pull up a sunk russian nuclear submarine and they knew EXACTLY what went wrong with the steel's metallurgy when one of the lift claws broke.

Selling a boatload of restored, fairly rare, vintage Japanese gold nib pens, click here to see (more added as I finish restoring them)

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Pen Engineer

 

-Stainless steel does rust. It rusts *less* than other alloys, but it does rust.

 

 

Ahm... B) Better (pure) stainless steels (iron Fe) have no steel in them. Nothing there to rust. :rolleyes:

 

Naming them stainless "steel" is rather unfortunate. Calling them stainless metal or chrome alloy would be better and would remove the confusion. -_- How does "chromalloy" sound to you? ;)

with kindness...

 

Amadeus W.
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Pen Engineer

Anyone who thinks that we simply can't replicate the materials of the past has never set foot on the practical machinist forums. There are people smart enough to figure it out. Trust me.

Bean ser ... don sat! :lticaptd:

with kindness...

 

Amadeus W.
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ReadyFireAim

I've been working on a Leonardt Principal / Jowo #6 / FPR 6.3 combination in a sac pen.

 

It's been working quite well after 3 days of testing and the Zebra-G feels hard now.

 

https://www.jetpens.com/Leonardt-EF-Principal-Nib/pd/15699

 

I think I'm getting great results because of the type & size of "vent hole" it has (not that dip pens have vent holes)

I'm setting the pen on full wet and the surface tension of the ink will not let it come out of the hole.

It's kind of an unsophisticated way of doing things but it has been working very well.

 

Hairlines to 3 mm with very little pressure is just unbelievable.

It's kind of like a brush pen where you have a lot more control.

 

If this nib has lasting ability, I'm pretty much done experimenting.

Edited by Bordeaux146
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Bordeaux, is the Leonardt Principal nib paired with an FPR 6.3 feed?

Reviews and articles on Fountain Pen Network

 

CHINA, JAPAN, AND INDIA

Hua Hong Blue Belter | Penbbs 456 | Stationery | ASA Nauka in Dartmoor and Ebonite | ASA Azaadi | ASA Bheeshma | ASA Halwa | Ranga Model 8 and 8b | Ranga Emperor

ITALY AND THE UK

FILCAO Roxi | FILCAO Atlantica | Italix Churchman's Prescriptor

USA, INK, AND EXPERIMENTS

Bexley Prometheus | Route 54 Motor Oil | Black Swan in Icelandic Minty Bathwater | Robert Oster Aqua | Diamine Emerald Green | Mr. Pen Radiant Blue | Three Oysters Giwa | Flex Nib Modifications | Rollstoppers

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ReadyFireAim

Bordeaux, is the Leonardt Principal nib paired with an FPR 6.3 feed?

 

Yes...It took me about an hour to carefully sand it down and heat set, but it was well worth the time.

As you can see, the back is cut off the Jowo holder on this one also. (the feed is sticking out)

post-135048-0-24443200-1502398416_thumb.jpg

This thing is very obviously more flexy than the Zebra-G and a lot less temperamental. (so far)

 

I'll be interested to see how long the plating will last exposed to ink.

If it lasts a week, I'm cleaning my other pens and putting them away. :D

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