My most reliable pen

[tzoram]

Hi everyone,

 

I'm curious whether my experience with my TWSBI Eco is common or not.  Out of all the pens I own, some expensive, some not, some really not, my Eco is by far the most reliable.  That's not to say I prefer how it writes.  It has more feedback than I like, nor is it quite as wet as I prefer.  HOWEVER, when I go to write with it, it lays ink down immediately, with no need to prime it, no matter how long it's been since I last used it.  The ink doesn't dry out inside it at all, even if it's been months.  It writes the same every.  single. time.  I suppose this is related, but it never leaks, and it never skips.  It also cleans out more easily if I want to change inks.  It's not the fanciest, but it just works.  So, is this typical?

 

Thanks!

 

[Paul-in-SF]

I wish it were typical for all fountain pens, but it isn't (at least not in my experience). I don't own an Eco, but I get the same reliability from my Vac700R. I can see the top of the section being forced against the inner cap to seal it, and I can feel it too. There are other modern pens that provide a comparable level of seal for the nib, such as the Slip and Seal closure on some Platinum pens such as the 3776 Century. I've had the same startup reliability on my Pilot Kakuno, although I don't know the mechanism responsible for it. And all my vintage Parker 51's, it's amazing to me how well that slip/clutch closure works. There are lots more I'm forgetting.

 

And there are lots that don't, both modern and vintage. Trying out a new-to-me pen model is usually chancy, and if it doesn't work well in this respect there doesn't seem to be much I can do about it. 

[jchch1950]

I have the same positive feeling with the Twsbi Swipe. It write without any problem even after weeks of no use,

[Mark from Yorkshire]

On 4/18/2023 at 7:07 AM, jchch1950 said:

I have the same positive feeling with the Twsbi Swipe. It write without any problem even after weeks of no use,

+1 even with Diamine Dragon 🐉 blood 🩸 which is a lovely red an’ gold Shimmer ink.

[tzoram]

On 4/17/2023 at 11:07 PM, jchch1950 said:

I have the same positive feeling with the Twsbi Swipe.

 

6 hours ago, Mark from Yorkshire said:

+1 even with Diamine Dragon 🐉 blood 🩸 which is a lovely red an’ gold Shimmer ink.

I've never used the Swipe.  Considering how I like my Eco, I was thinking of adding another.  Maybe the Swipe is the way to go.  What size nib did you guys get?

[jchch1950]

3 hours ago, tzoram said:

 

I've never used the Swipe.  Considering how I like my Eco, I was thinking of adding another.  Maybe the Swipe is the way to go.  What size nib did you guys get?

Mine has 1.1  nib.

[Mark from Yorkshire]

@tzoram my swipe is a broad nib

[tzoram]

You guys are awesome.  Thank you!

[Aethertigris]

This has also been my experience with a TWSBI Eco Medium.

[Merrick]

My TWSBI 580 is similarly reliable, and a very smooth writer. It’s not my favorite to write with in any aspect but I appreciate its steadfastness. I keep it in a pen cup on my desk so if I have to grab a pen fast, it’s ready to go. 

[Skydiver]

Take the following with a huge grain of salt. I just started with fountain pens a month ago. My EF 580 and Swipe are super reliable, and I've not had to do anything with them.

 

My EF Eco was great when I first inked it with Platinum Carbon Black, but started having trouble starting, as well as skipping the next day. I cleaned it out and put in Noodler's Air Corp Blue-Black. It was great that evening, but again had problems the next day. Looking with a loupe, I saw good alignment, but that tines were very tight at the tip. I ran a .00015 feeler gauge between the tines, but didn't see any change. I next pressed down on the shoulders and saw a little bit of change. Ran the feeler gauge again and it looked better. Now the Eco is just as reliable as the 580 and Swipe.

 

Just got a EF Go, but my daughter wanted to see and use a stub nib, so I swapped nibs and let her play. She and my wife seem to be enjoying it, specially with the Murasaki-Shikibu (?) ink sample my daughter wanted to try out. I was surprised that she likes it more than her F Kakuno given Pilot's reputation for their nibs.

 

My Vac700R is still waiting to be inked. I feel like I have too many pens inked currently. Based on various people's comments I've read here and elsewhere, I am expecting it to also be a workhorse that just keeps on working all the time.

[Mark from Yorkshire]

Sad to say that swipe succumbed to TWSBI cracking and the cap failed so is at the recycler coated me in ink in process 

[Skydiver]

Yikes!

[inkstainedruth]

Hmmm.  I have few TWSBIs (a 580-AL a 580-ALR, and a Vac700).  I haven't used the last one all that much (it's a bit of PITA to flush out) -- but I've had problems with both of the 580s in that if I get an air bubble in the ink chamber, it's really hard to get the ink to flow.  That is compounded by the fact that the pistons do not extend all the way to the back of the feed (which I consider a design flaw)  -- and I've heard the same about the smaller Ecos.

Ruth Morrisson aka inkstainedruth

 

edited for typos

[AceNinja]

15 minutes ago, inkstainedruth said:

the pistons do not extend all the way to the back of the feed

I've noticed this design as well.  My thinking is that they did this kind of design partly because they can claim/quote to have a slightly larger ink capacity than other piston filler.

ie, if given the same overall barrel length and internal diameter, if the piston stroke is shorter, then the overall piston mechanism is shorter, which means more space for ink.  And this looks better on marketing material as you can quote a large ink capacity.  The trade-off is that each piston stroke is drawing up a smaller amount of ink, you've to nib up, push out the air, nib down, and stroke the piston again.

 

It's not necessarily a bad thing, sometimes one prefer a larger ink volume at the cost of just slightly more filling time/effort.  Just that I wonder if normal pen user will notice this nuance in design choice by manufacturer.

 

Maybe in addition to total ink chamber volume, we need to have measurement of piston displacement volume also, just like car engines. 😆

[A Smug Dill]

5 hours ago, AceNinja said:

My thinking is that they did this kind of design partly because they can claim/quote to have a slightly larger ink capacity than other piston filler.

 

I don't understand (the implied, underlying logic of) what you said there, sorry.

 

The sheer interior volume of a pen's ink reservoir is its theoretical ink capacity, tempered by the officially published (or supplied-with-the-retail-product-package) instructions on how to fill a pen or converter; the latter simply cannot achieve more than the former, discounting the unaccountable (by numbers, sheer) volume of ink trapped in the feed and/or grip section.

[AceNinja]

On 9/7/2023 at 4:44 PM, A Smug Dill said:

 

I don't understand (the implied, underlying logic of) what you said there, sorry.

 

The sheer interior volume of a pen's ink reservoir is its theoretical ink capacity, tempered by the officially published (or supplied-with-the-retail-product-package) instructions on how to fill a pen or converter; the latter simply cannot achieve more than the former, discounting the unaccountable (by numbers, sheer) volume of ink trapped in the feed and/or grip section.

Okay I try to structure my words again to see if it makes sense.

1.  Normally for piston filler FP, roughly half of the pen's barrel length is occupied by the piston mechanism.  This is the balance between piston stroke volume and ink chamber volume.  This is same for a normal converter aka piston converter.  When the piston is fully extended, it reaches the feed/section.

2. You can increase the ink chamber volume by moving/designing the piston towards the end of barrel, thereby increasing the space to the front of barrel (ie the ink chamber).  However this requires reducing the length of the piston rod.

4. When the piston rod is reduced, this means when the piston is fully extended, it now wouldn't reach the feed/section, because the rod is shorter. This reduces the piston's displacement aka how much volume of ink it can draw in one stroke/pump.

5. Such as a TWSBI Eco.  If it didn't have the ridges just after the feed/section, its piston could stroke all the way to the feed/section.  But that would mean slightly less ink chamber capacity due to its piston rod just need to be a tad longer.

 

    

TWSBI ECO - Piston fully extended  (image from Andersonpens)

 

Pelikan (should be a M205 demo) - Piston fully extended  (image from pelikan passion's website)

 

So sometimes I wondered if there's a practical reason to design such that the piston couldn't extend all the way to the feed/section?

 

 

One can have a smaller/shorter overall piston mechanism while still retaining long piston stroke by using 2 technique (at least 2 that I've observed so far):

1. MB's telescopic piston mechanism

2. Conid's bulk filler type piston

 

[Skydiver]

What about that pen that had a magnetic plunger? Doesn't that have an even bigger capacity that is only limited by the barrel length and the thickness of the plunger/magnet assembly?

 

[A Smug Dill]

On 9/7/2023 at 12:50 PM, AceNinja said:

My thinking is that they did this kind of design partly because they can claim/quote to have a slightly larger ink capacity than other piston filler.

 

17 hours ago, AceNinja said:

Okay I try to structure my words again to see if it makes sense. …‹snip›… stroke all the way to the feed/section.  But that would mean slightly less ink chamber capacity due to its piston rod just need to be a tad longer.

 

I guess I didn't quite understand you the first time, because your assertion was missing the critical caveat of: for the same barrel length and internal diameter.

 

To factually claim one's pen design has a slightly larger maximum ink capacity, i.e. ink chamber volume when the piston has been fully retracted until it can physically move no further, one does not need — as in having no other option than — to have a shorter piston stem. One could simply increase the girth of the barrel, and/or thin its wall (presumably without compromising its robustness, by using material with sufficient strength and physical resilience, which may or may not add to manufacturing cost). It's easy for a larger pen to have a larger ink capacity “than other piston filler”.

 

If the true motivation for having a shorter piston that stops ~5mm shy of the back of the feed, then why not have an even shorter piston, such that it may take three or more strokes of the piston, including inversion of the pen body between strokes to allow the liquid to fall to the piston end of the ink chamber while air is being driven out?

 

17 hours ago, AceNinja said:

So sometimes I wondered if there's a practical reason to design such that the piston couldn't extend all the way to the feed/section?

 

I think it's simply the idea of having an ink window — a see-through part of the ink chamber where (outside of holding ink, of course) the sole design reason is to allow the level of ink to be observable — that is never blocked by the piston. Thus, there is no confusion even if the colour of ink used is indistinguishable visually from that of the piston plug.

[AceNinja]

On 9/11/2023 at 4:09 PM, A Smug Dill said:

If the true motivation for having a shorter piston that stops ~5mm shy of the back of the feed, then why not have an even shorter piston, such that it may take three or more strokes of the piston, including inversion of the pen body between strokes to allow the liquid to fall to the piston end of the ink chamber while air is being driven out?

I guess for average pen user, the notion of a piston filler unable to fill full/mostly full in one piston stroke is probably bizarre, before they consider the benefit of having a larger ink capacity. "why I can't fully fill the piston filler pen?  Bad piston mechanism design!"  Whereas for TWSBI, they just reduce the piston rod length by a tiny amount, small enough that people didn't really notice that it didn't fully fill the barrel in one stroke, but still enough increase in quoted ink capacity.

 

On 9/11/2023 at 4:09 PM, A Smug Dill said:

One could simply increase the girth of the barrel, and/or thin its wall (presumably without compromising its robustness, by using material with sufficient strength and physical resilience, which may or may not add to manufacturing cost). It's easy for a larger pen to have a larger ink capacity “than other piston filler”.

Maybe it goes down like this in TWSBI's product design meeting:

 

Product Director: Okay, show me the specification of this new pen called ECO.

Design Team: Ok sir, here it is.  It's a piston filler. The ink capacity of this pen is 1.5ml.

Director: hmmm.. but I want a larger ink capacity, people loves large ink capacity.  Maybe we can make the barrel wall slightly thinner?

Team: We can't sir, the barrel wall already at its thinnest possible.  Any more thin will cause the barrel to spontaneously crack itself.

Director:  Nevermind, if it cracks then we'll just ship replacement barrel to users FOC, we'll have user covers the shipment cost only.

Team: Another reason we can't change the barrel wall thickness is because you yourself have placed an order of 1 million units barrel to the manufacturer last week, remember?  The manufacturing is 80% completed and we've actually received the 1st batch in our warehouse.

Director:  How about we increase the barrel length?

Team: We can't sir, like I said, the barrel's manufacturing is almost done..

Director: But I wanted a larger ink capacity, people LOVES large ink capacity.  What else can we change?

Team: well... if we cut the piston rod shorter, then the piston will rest further away from the feed, increasing the ink chamber volume..

Director: Ok, good, how much increase we're talking about?

Team: maybe.. around 0.25ml.  but sir, that is at the cost of shorter...

Director: ok DONE!  We cut the piston rod shorter!  end of discussion.