Feeds-Simple And Complex

[praxim]

@Tinjapan, fins solved the ink blobbing problem which arises from variations in temperature and pressure, not from inky inertia. I see this from experience with my own finned and finless pens.

 

Flow smoothing is important but in this case I think the issue under discussion is not acceleration/deceleration of flow but rather external energisation of flow and managing that by buffering. Required flow volume may affect required buffering capacity although Penmacher/Peningeneer's comments on the utility of additional buffering (in one of the links I gave) was also interesting.

Edited September 18, 2016 by praxim

[Tinjapan]

My oldest non eyedropper is a 1906 Conklin Self-filling pen. I have several eyedroppers that may date earlier. Most of my vintage pens are from the early 1900s to the mid twenties. The blobbing is not constant but not unusual. In fact, isn't that the myth of the founding of the Waterman pen company, he sought a new feed and pen to house it to prevent ink blobs. Myth, yes but it would not have taken if ink blobbing and leakages were not an issue at the time. My vintage pens do not blob a lot, but they do on occasion and as Mr. Murphy dictates, they do so at the time of the greatest inconvience.

[Tinjapan]

  On 9/18/2016 at 11:41 AM, praxim said:

@Tinjapan, fins solved the ink blobbing problem which arises from variations in temperature and pressure, not from inky inertia. I see this from experience with my own finned and finless pens.

 

Flow smoothing is important but in this case I think the issue under discussion is not acceleration/deceleration of flow but rather external energisation of flow and managing that by buffering. Required flow volume may affect required buffering capacity although Penmacher/Peningeneer's comments on the utility of additional buffering (in one of the links I gave) was also interesting.

Wouldn't the temp and press variations cause a cap filled with ink rather than blobbing after an extended spell at writing? Wouldn't these differences be greatest during transport, say from warm house to cold outside or cool indoors to hot and humid outside or when first using the pen after transport than while writing?

 

The only time I have had caps filled with ink are in transport and I find that my new pens with fins on the feeds are no better at preventing this than my vintage pens with finless feeds.

 

My experience, limited to be sure, is that there are two main differences between vintage pens and modern pens. Vintage pens seems to have better nibs but modern pens do not blob nearly as much. From what I have read, new feed design which would include fins, go a long way to prevent blobbing while writing.

 

But back to your point, if not the fins, what feature solved the problems associated with flow deceleration? The ink that is flowing has to go somewhere.

[praxim]

The temperature variation from inside to outside a house should not be great unless you are waving pens around in snowy air then rushing into a hot room. On the other hand (literally) body temperature is usually significantly greater than ambient. Picking up a pen and writing with it will heat the pen and do it quite quickly. Pressure requires variations in altitude and also enters the area of tensions which I will not.

 

I do not regard ink deceleration as 'a thing' for practical purposes. Using the proverbial back of the envelope, one can work out that the flow speed and volume of ink is as nothing compared with capacity in the nib-feed interface even without fins. Otherwise, would not your finless pen blob every time you lifted it? Mine characteristically blob during writing or when just filled or running out of ink. Never does it happen simply when I lift the pen. This is not good data for an ink inertia theory.

[Pen Engineer]

  On 9/18/2016 at 6:39 AM, praxim said:

@tinjapan

 

Seeking to interpret what you are saying, the following is your model of how finned and finless feeds work:

1. Ink initially flows down the feed channel to the paper.

2. You lift the pen so the "entrained" ink (inertial flow?) needs to go somewhere so it goes into the fins while the flow slows to a halt.

3. You write again. Starting is immediate because there is a reservoir of ink in the fins to allow writing while the ink flow from the cartridge resumes and accelerates to the necessary speed.

4. By this time the reservoir is depleted and the cycle is ready to go again from 2. next time you stop writing.

 

If the feed is finless then the inertially careering ink flow will blob on the paper (sometimes).

 

I do not agree with your model. I am merely trying to get a clear and fair understanding of it given an alternative has been put forward by an engineer formerly professionally engaged with fountain pens.

 

If I have misunderstood details, please clarify so I know what is being proposed.

I use the word reservoir as a general term for anything storing ink, tank, cartridge, converter, bladder or what not.

 

 

1.) the initial flow of ink is caused by the capillary forces of the central capillary of the feed as soon as the ink in the reservoir gets in contact with the feed. Once this capillary is filled, ink moves into the slit of the nib. Once this is filled, ink flow stops. That's it.

 

 

2. When the nib touches the paper and ink is drawn from the slit / feed capillary / reservoir, and the ink flow starts again and stops when the nib is lifted off the paper.

 

3. The fins are not involved in this, unless they had been filled by ink pushed out of the reservoir through other conditions than writing. If the fins had been filled then they would be emptied before ink would be drawn out of the reservoir.

 

Finless feeds have no capacity to compensate when ink is pushed out of the reservoir through other conditions than writing.

 

Hope this makes sense. Behind the green words are links to my site and the appropriate chapters

[Tinjapan]

Temp variation for me means from my home, at my comfort level, to outside which is hot and humid in the summer and cool in the winter, the ten min. walk to to the station and then an hour on a summer heated train, either summer heated due to under cooling for the mass of bodies in a metal train under a blazing sun or the heat turned up too high in the winter then outside again for 10 to 20 minutes in the weather and then into an office that is way too hot.

 

The situation you mention would be the greatest when the writer takes pen in hand a begins to write, not later which is when I have the blobbing problem. Yes, heating the pen, in our case by use, decreases viscosity, expands all fluids and the pen itself, possibly the feed channels and would thus effect flow, but this problem would be greatest when the writer stops writing.

 

No, it would not always blob each time you lifted it. The system has some capacity to handle flucuations in flow, but under certain circumstances this capicity is not enough and the ink vent ps to the atmosphere having nowhere else to go. You gave a few examples of these circumstances yourself. As these occur almost exclusively with vintage pens, what design feature fixed this problem? I can say I have never had a pen with a feed with fins blob, period. Not when just filled. Not when writing. Not when nearly empty. So, what feature corrected this? Something did. May not of been the fins on the feed, but what if not them?

 

By the way, my 1900ish eyedroppers DO blob when I lift them up. That is why I no longer use them and probaby why they are in next to new condition despite being 100 years old or more.

Edited September 18, 2016 by Tinjapan

[Pen Engineer]

  On 9/18/2016 at 11:21 AM, Tinjapan said:

That would be part of it, a portion of the reservior function.

 

The design features and their purposes facinate me as they are so similar to larger fluid systems. Overflow/reservior tanks are necessary on any fluid supply system if a constant flow is desired despite varying demand.

 

Again, if the fins on feeds are not what solved the ink blob problem, what did?

The function of the fins is to capture overflow caused by conditions other than writing.

 

I use the word reservoir as a general term for tank, bladder, cartridge or converter or whatever holds ink.

 

Ink blobs... the question is what causes them. One cause could be hydrostatic pressure, another: wrong central capillary / nib combination or another: the above mention conditions other than writing. There are several solutions for each problem. You appear to be a technical minded person. Have a read of my chapter on feeds. Your understanding will lead you to those solutions.

[Pen Engineer]

  On 9/18/2016 at 4:14 AM, Tinjapan said:

 

"Once you put the pen down, ink flow should stop... and generally does."

 

Ink is still entrained in the feed channel and will go somewhere if the path used when writting is blocked.

 

"Ink in the fins dries out first and often clogs up the capillaries..."

 

Sure does but usuallly not so quickly that you don't have time to grab a sip of coffee or turn the page.

 

At present, I have a dozon or so vintage pens with finless feeds inked. While they are a pleasure to use, I do not use them for important documents especially those that require long writing spells. It is not an everytime time event, but I have had a lot of experience of ink droping from the nib or from around the feed after writing with my vintage pens and have never experienced this problem with modern pens.

 

As I have read that the reasons I gave are the reasons behind the development of feeds with fins and as they seemed to fix the ink flow problems associated with the earlier feeds and from my own expeirence with vintage pens without this innovation and modern pens with it, I remain convinced this is the case.

 

 

 

"How do you make sure that the ink goes first onto the paper and then into the fins?"

 

Path of least resistance. so true. The design of the feed is based on this principle of Japanese philosophy

 

I believe that things are not made more complex unless there is a reason for them to become more complex.... me too.

 

Fins solved the problem as you described it

[Tinjapan]

  On 9/18/2016 at 1:33 PM, PenIngeneer said:

I use the word reservoir as a general term for anything storing ink, tank, cartridge, converter, bladder or what not.

 

 

1.) the initial flow of ink is caused by the capillary forces of the central capillary of the feed as soon as the ink in the reservoir gets in contact with the feed. Once this capillary is filled, ink moves into the slit of the nib. Once this is filled, ink flow stops. That's it.

 

 

2. When the nib touches the paper and ink is drawn from the slit / feed capillary / reservoir, and the ink flow starts again and stops when the nib is lifted off the paper.

 

3. The fins are not involved in this, unless they had been filled by ink pushed out of the reservoir through other conditions than writing. If the fins had been filled then they would be emptied before ink would be drawn out of the reservoir.

 

Finless feeds have no capacity to compensate when ink is pushed out of the reservoir through other conditions than writing.

 

Hope this makes sense. Behind the green words are links to my site and the appropriate chapters

Thank, that I understand.

 

But, things in motion tend to stay in motion. Is it only capilary action that gets ink to paper or is it also the air that feeds from say 1880 on allowed to get into the "storage reservior" to "force" ink out?

 

My thinking is this, please correct as needed. Mankind has tried for thousands of years to find away to write with out the need

to dip the writing point into ink. The major breakthough was a feed that allowed outside air into the pen to counteract the forces of surface tension etc, in such a way as to allow a controlled out flow of ink.

 

There were many break throughs in this area near the end of the 19th cntury and early 20th century. Break throughs but not a perfect solution, but the important one was a way to allow outside air in to break the happy equilibrium inside the pen body and coax the ink out and on to the paper and not all at once.

 

The major remaining problems included a cap full of ink after carrying the pen and blobbing while writing. For writing, capilary action gets the ink in the the feed where it is at rest until pressure is placed upon the nib for writing. When this pressure is placed upon the nib, air flows into the pen body via the newly designed feeds, expelling ink into the feed and on to the paper via the nib. This is my understanding of the difference between unsucessful, ancient attempts at making a fountain pen and the more sucessful creations of a century ago.

 

IF this is the case, then, when we stop writing, ink flow is stopped but the internal pressure of the pen "storage reservior" is still at the higher writing pressure and is thus still exerting pressure at the head of the ink column. Under most conditions, there is enough capacity withing the system to handle this momentary imbalance of forces. However, under certain conditions the system does not have the capacity to deal with this imbalance and ink vents to the atmoshere and blobs.

 

Whatever the mechanism, this most certainly happens with my vintage pens but not my modern pens. If not the fins, which seem, to my limited knowledge of fluid dynamics from operating and maintaining steam propulsion plants and O2N2 generating plants, to answer nicely, what fixed this problem?

[Tinjapan]

sorry. double post again.

Edited September 18, 2016 by Tinjapan

[Pen Engineer]

  On 9/18/2016 at 11:36 AM, Bo Bo Olson said:

 

 

 

Peningeneer, yes I'm an American living in Germany. My wife poked her temple with two fingers (as Germans do) "Go to America where they only have 10 days of vacation, am I foolish?

(The so-called two weeks of vacation) The Germans have 30 full days of vacation plus a couple more when one gets old. (6 weeks) Of course normally you can only take three weeks at a time. It takes one full week to get rid of all thoughts of work....the second week is 'work free' then the third week starts getting ruined with thoughts of work interfering with mellow.

Working for the US government then, had the same.

 

The great think about the German health system is not having to save sick hours. I lost 300 hours twice when changing jobs.....In the Stars and Stripes later saw US Government workers begging sick hours Europe wide to die in the job...Saw teachers when I worked in the School system being gifted with sick hours....and I took that as 'normal'.

A man here on the com, got very ill and had to sell the worlds largest collection of Wearever pens for next to nothing...in Germany no one has to sell their house, car or even a cheap pen for health problems.

Health insurance costs between 13-15%. Just go to the Doctor...no pay in advance and hope your insurance is good for it. I saw a woman working at a motel where I stayed when in the States on business. She'd been bitten in the face by her dog, in she had to break up a dog fight in the neighbor's yard....or she could have been sued. After three days of watching her face look worse and worse I ordered her to the doctor....and she complained the generic medicine she got cost more than the $70 Doctor visit. No health care and worked 39 hours a week....well that was before Obama care...which was so gutted.

I can remember America before Reagan when everyone who worked had good insurance. There wasn't a single bag Lady in the US before Reagan.

When you live far away....you see the changes when you return for a visit.

 

xxxxxxxxxxx

My wife, as pen and box was new....now being semi-vintage to vintage, has a fine patina that good classics should have.

 

I worked in Ikea for 20 years, so was 'shocked' that the Lamy warehouse was so small and only two bins high. Just in time delivery, just in time pallets out the door. You have some good hard working organized men there.

xxxxxxxxx

 

The oldest pen I use is a slick feed Waterman 52....may be from the '20's. I have 'finless' pens from the '30's and some early '50's MB pens, one with shallow side combs (many others have shallow side combs too) the other with just two channels on the bottom, I don't have trouble with dripping ink.....perhaps you have a problem with your rubber sac has gotten old.

 

Perhaps it's your ink that is the problem. What inks do you use?

 

I normally use the basic MB, Pelikan (4001&Edelstein), R&G, Herbin, in my older pens.

With out rhyme or reason I tend to shy away from supersaturated inks in my old pens.

 

And I find the Diamine inks to feather, so don't use them much.....got to find a school kid to give them too....they still use fountain pens in German schools.

 

Lamy turquoise will shade on 90g paper....in I do like shading. It don't on 80g....(don't have Rhoda but expect it to shade there.)

 

Peningeneer's ink talk was as interesting as his modern feed talk. I do know both Pelikan and MB advise using their own inks.....and can see 'now' that Lamy ink, should be used in a Lamy. Well, I now see much more why each pen company recommends their own ink...in it has been fitted for their nib and feed................not just a way to sell more ink.

I'm still going to be using other folks inks in different pens....for the fun of it.

 

 

 

IMO....fins/combs came in with stiffer nibs, to hold back ink that flowed faster in superflex nibs. You needed faster flow because of the width a superflex tines can spread to.... the chicken or the egg?

 

The ink ate other pen's feeds, so was discontinued quickly. I believe that the P-51 may have had one of the very first plastic feeds.I'm a one-P-51 expert, you know. Rubber / ebonite is more resilient than plastics suitable for feeds.

 

I live in Australia now, Brisbane. And I remember the good old days very well.

 

xxxxx

 

would like to meet your wife...

 

xxxx

 

during my time, we had a huge central store, first in first out. Then, the variate of components was huge. It seems, later designs were strongly influenced by reapplying of components. Only the visual changed, what I would call no real innovation.

 

xxxxx

 

Peningeneer, I don't know when the Lamy ink bottle with the built in wipe came in.....how much different is the 'unopened' older 'gooseneck' bottles ink from that ink? Not sure, but I know that ink to my recipe was introduce in 1979.

 

Nice talking with you

[Tinjapan]

"Fins solved the problem as you described it B)"

 

Sir, please forgive me. I took a break from grading tests and had a few drinks, but...well, I'm confused. I made a simple comment on the purpose for the fins on modern feeds. You made a comment that such was not the case. I give an explanation why I thought such to be the case and the above is your reply. Which problem was solved by the fins as I described?

 

Truly, I am just a student. I am facinated by the thousands of years of human innovation that were needed to create these truly wonderful writing instruments. But I must also reconcile new information with what I already know, or correct what I already "know" to fit knew information.

 

So, again, which problem was solved as I described by fins?

[Pen Engineer]

  On 9/18/2016 at 11:41 AM, praxim said:

@Tinjapan, fins solved the ink blobbing problem which arises from variations in temperature and pressure, not from inky inertia. I see this from experience with my own finned and finless pens.

 

Flow smoothing is important but in this case I think the issue under discussion is not acceleration/deceleration of flow but rather external energisation of flow and managing that by buffering. Required flow volume may affect required buffering capacity although Penmacher/Peningeneer's comments on the utility of additional buffering (in one of the links I gave) was also interesting.

if all things are equal, ink flow smoothening depends on the size of the air inlet. Air comes in due to pressure variation in the reservoir. Have a look here. The size of the hole determines the fluctuation of pressure thus the smoothness of flow.

 

Thanks for your thoughts

[Tinjapan]

"Path of least resistance. so true. The design of the feed is based on this principle of Japanese philosophy -_-"

 

Hmm, true. It is a principle of Japanese philosophy but it is also true of flow.

[Pen Engineer]

  On 9/18/2016 at 2:08 PM, Tinjapan said:

Thank, that I understand.

 

 

 

 

There were many break throughs in this area near the end of the 19th cntury and early 20th century. Break throughs but not a perfect solution, but the important one was a way to allow outside air in to break the happy equilibrium inside the pen body and coax the ink out and on to the paper and not all at once.

 

The major remaining problems included a cap full of ink after carrying the pen and blobbing while writing. For writing, capilary action gets the ink in the the feed where it is at rest until pressure is placed upon the nib for writing. When this pressure is placed upon the nib, air flows into the pen body via the newly designed feeds, expelling ink into the feed and on to the paper via the nib. This is my understanding of the difference between unsucessful, ancient attempts at making a fountain pen and the more sucessful creations of a century ago.

 

IF this is the case, then, when we stop writing, ink flow is stopped but the internal pressure of the pen "storage reservior" is still at the higher writing pressure and is thus still exerting pressure at the head of the ink column. Under most conditions, there is enough capacity withing the system to handle this momentary imbalance of forces. However, under certain conditions the system does not have the capacity to deal with this imbalance and ink vents to the atmoshere and blobs.

 

Whatever the mechanism, this most certainly happens with my vintage pens but not my modern pens. If not the fins, which seem, to my limited knowledge of fluid dynamics from operating and maintaining steam propulsion plants and O2N2 generating plants, to answer nicely, what fixed this problem?

But, things in motion tend to stay in motion. So true, the law of inertia. however, the balance of forces in the ink system is finely tuned and in much harmony. The forces, weights, volumes are minute and are counteracted continuously by capillary forces.

 

Is it only capilary action that gets ink to paper or is it also the air that feeds from say 1880 on allowed to get into the "storage reservior" to "force" ink out? In order to keep this harmony it is mainly the capillary force that carries the ink to paper, a small amount is added by the hydrostatic pressure of the ink column.

 

The major breakthough was a feed that allowed outside air into the pen to counteract the forces of surface tension etc, in such a way as to allow a controlled out flow of ink. may I refer to my site the chapter on the principle of the feed? as well as application to the feed.

 

About getting the ink onto the paper, read about the function of the nib.

 

Air flows only into the reservoir when the pressure is low enough to rapture the meniscus in the air inlet into the reservoir. See here.

 

IF this is the case, then.... That's when tuning comes into the play. The variation of pressure during normal writing is compensated for by the capillary forces. As ink is drawn out the pressure drops, never increases .... just read above.

 

The pen blobs because of increase pressure due to increase of temperature of the air pocket above the ink or the hydrostatic pressure of the ink column from nib to top of the ink level in the reservoir.

 

In steam propulsion we talk about REAL pressures and inertias and movement. Fountain pens work at the opposite end of the scale.

[Tinjapan]

Thanks. Will do more reading.

 

What, became somewhat random thoughts are found below.

 

Steam propusion indeed is at the opposite extreme of fountain pens. But there is a universe of support and auxillary systems. Some, like the condenser, operate under vacuum. The oil supply system for the main reduction gear and bearings require orifices to keep any one or group of bearings from starving the others of oil, for all fluids follow the path of least resistance.

 

Ventalation systems also require some kind of flow restrictor to prevent one vent from hogging all the air from the other vents. All fluids follow the path of the least resistance.

 

Production, storage and delivery of liquid oxygen and liquid nitrogen brings with it cares of temp and pressure relationship and sudden changes in either that differ somewhat from main propulsion.

 

If capallary action is all that is required to get ink to flow through the feed and to the paper, what prevented this from happening in the millenia of pen design?

 

The only reason for my pens blobbing is heat? I can see how, after a time in the hand, a critical point would be reached that would cause expansion and lessening of viscosity to cause the ink to run out in a blob, but wouldn't this happen sooner rather than later as the greatest temp change would occur closer to the time when the pen is taken in hand than after it has been in hand for a while?

 

Hmm. I see the fins as a structure to counter overflow conditions regardles of the cause of the overflow. I have no doubt that heat plays a role, but I have not had any blobbing problem except when I stop momentarily from writing after a long term of putting ink on paper. It seems that my simple of simple feeds is capable of handling the problems caused by heat as long as I continue writing. It is only when writing is paused that the ink has nowhere to go and blobs onto the paper.

 

No fluid delivery system operates staticly. The longer a system in is in operation, the higher the heat from the motive force and friction. From my point of view, heat is always present and must always be delt with. In complex systems, we have complex heat removing systems.

 

The fact that heat cause increase flow is a constant on all fluids. Not being able to cool the pen, the solution is dampening the flow when needed and allowing a method of increase when needed. The fins do that. I am begining to think we may be describing the same situation but from slightly different points of view but arriving at the same solution?

[Tinjapan]

I think I found a different way to express what Imtried to above. Heat problems are solved by removing or adding heat. Flow problems are solved by increasing or decreasing flow. That is from the view point of my training.

 

It seems that we may be using different thinking to solve the same problem in the same manner.

Edited September 18, 2016 by Tinjapan

[praxim]

@Peningeneer, thanks for your extensive post however I already knew that. My post you reference was to ensure that I had a fair model of what Tinjapan was saying at the time.

 

I found in my own former work that investing first in clarifying other people's [assumed] models made for faster resolution of problems, because it became both clearer and more readily agreed which models failed or were inadequate so less time was eventually wasted on pursuing pet ideas.

[Tinjapan]

For me, the hang up was not the model. When the cause can not be treated, you treat the symptom. As we can not treat the disease, body heat, we can only treat the symptom, in this case, flow. As the disease can not be treated, it does not matter what it is and it is a waste of time to discuss it. It does not matter if the sudden increase in flow is caused by heat, the tides or martians, if we are not able to treat the cause all efforts should be focused at what can be treated, the symptom.

[praxim]

It does not appear to me that you were following what I said or why. It really does not matter.

 

cheers

P