M800 ink capacity

[vladek]

Hi all,

 

Recently I acquired M800 and when tried to fill it up it surprised me how small capacity this pen has. The piston moves only for about 1/5 of the body and the filling screw turns only small number of times compared with my old pelikan (M140) that actually used the body space quite well in comparison with M800.

 

Could anyone tel me their experience about this? I.e. what is the piston path in mm from full to empty and how many turns you actually get with the filling screw.

 

Considering that everyone is praising the capacity of oversized Pelikans, my expectations were much higher.

 

Thanks,

Vladek

[KCat]

this topic comes up often. the 800 has no more capacity than the 200/400/600 pens. All of them run about 1.3 mls give or take.

[JRG]

  vladek said:

Hi all,

 

Recently I acquired M800 and when tried to fill it up it surprised me how small capacity this pen has. The piston moves only for about 1/5 of the body and the filling screw turns only small number of times compared with my old pelikan (M140) that actually used the body space quite well in comparison with M800.

 

Could anyone tel me their experience about this? I.e. what is the piston path in mm from full to empty and how many turns you actually get with the filling screw.

 

Considering that everyone is praising the capacity of oversized Pelikans, my expectations were much higher.

 

Thanks,

Vladek

Well, fully retracted, the piston in my 140 leaves about 2.2cm of clear space in the barrel. For my M800, the corresponding number is about 2.4cm. The bore of the M800 appears to be greater than that of the 140, so I'd conjecture that the M800 holds more ink. But, I've not actually measured the maximum ink load of these two pens -- have you?

 

And 1/5 of the body doesn't sound quite right. The binde on the M800 barrel is roughly 6.5cm; the piston travel must be well under that, to allow room for the necessary mechanism. 2.4/6.5 = 37% which isn't too bad. 1/5??

 

My 140's knob rotates 3.5 turns; my M800's knob rotates just over 4.0 turns.

[JRG]

  KCat said:

this topic comes up often.  the 800 has no more capacity than the 200/400/600 pens.  All of them run about 1.3 mls give or take.

Just for the amusement, I did a couple of quick checks using a graduate with 0.1mL marks. I got just bout 1.3mL for both the M800 and an old-style M250.

 

But, I also got 1.3mL for a vintage 100N and for my 140.

 

The only Pelikan close at hand with a larger capacity is a vintage 400, at 2.0mL.

[vladek]

Thanks!

 

OK, the body is 6.5 cm long. When fully retracted my piston is in the position of 1.5 cm from the bottom (of the visible part of tank) i.e. 23% - quite close to my initial estimation of 1/5. There are certainly no 4 turns of the knob and there is quite long mechanism above the piston.

 

I would test number of turns again, but I live in New Zealand where a bottle of Parker's Quink costs $13.99 so I may wait till I use all ink (which will be fast due to capacity of the pen and "Pelikan medium" nib).

 

Quite disappointing ..

[vladek]

  KCat said:

this topic comes up often. the 800 has no more capacity than the 200/400/600 pens. All of them run about 1.3 mls give or take.

Isn't that a bit weird? Larger pens should naturally have more space for ink. Surely 1.3 ml is not some sort of Pelikan standard.

 

From the design perspective it is much harder to replicate 1.3 ml over all pens than proporcional tank increase with the size of the pen.

[JRG]

  vladek said:

Thanks!

 

OK, the body is 6.5 cm long. When fully retracted my piston is in the position of 1.5 cm from the bottom (of the visible part of tank) i.e. 23% - quite close to my initial estimation of 1/5. There are certainly no 4 turns of the knob and there is quite long mechanism above the piston.

Hmmm.

 

there is quite long mechanism above the piston Well, there has to be! It's the mechanism that makes the piston move up and down, and it has to be somewhere. And it can't be inside the knob that you're turning. All Pelikan piston fillers are going to have a similar amount of space devoted to that mechanism. (And I don't see a lot of difference between modern and vintage Pelikans in the amount of such overhead.)

 

That's why your 1/5 is misleading --- not all of that binde length of 6.5cm is available for piston travel. So, a travel of 1.5cm is a lot more than 1/5 of what is possible.

 

But your 1.5cm for a M800 sounds a little low. And I've checked several Pelikans here --- most have about 4 full turns, except for that vintage 400 which has almost 5 full turns.

[HDoug]

Here's a link to nibs.com pen measurement page which lists the capacity of an M800 as 2ml, and the M250 at 1.8ml. Just though it might be helpful.

 

Doug

 

Nibs.com pen measurement page

[JRG]

  HDoug said:

Here's a link to nibs.com pen measurement page which lists the capacity of an M800 as 2ml, and the M250 at 1.8ml.  Just though it might be helpful.

 

Doug

 

Nibs.com pen measurement page

Call me deeply skeptical.

 

I just measured the M800 capacity again: 1.3mL, just as many others have reported. That's with the fullest load I can manage, in which case there's only a very small air bubble between the top of the liquid and the bottom of the piston (when the pen is held nib down).

 

Now, if you could manage to eliminate that little bubble (i.e., achieve a 100% fill), which is impractical, you might raise the load to 1.4mL.

 

To 2.0mL? No way. Not with this M800 nor, apparently, with the M800s that other folks have.

[vladek]

  HDoug said:

Here's a link to nibs.com pen measurement page which lists the capacity of an M800 as 2ml, and the M250 at 1.8ml. Just though it might be helpful.

 

Doug

 

Nibs.com pen measurement page

Thanks Doug,

 

Excellent source of relevant information. My soul can now rest in peace.

 

The table shows that, quite naturally, larger pens have larger capacity, but also that my measurements and the table information come to exact same values.

 

How come? Well here is some basic calculus:

 

- the section diameter of M800 is 0.53 in = 12.985 mm (from the table)

 

- this means that the piston area is about 132.42 sq mm i.e. 1.3242 sq cm

 

- 2 ml capacity (from the table) = 2 cubic cm

 

- 2 cubic cm / 1.3242 sq cm = 1.51 cm of piston movement -> precisely the piston movement as I measured it before.

 

Again, thanks Doug.

[JRG]

  vladek said:

  HDoug said:

Here's a link to nibs.com pen measurement page which lists the capacity of an M800 as 2ml, and the M250 at 1.8ml.  Just though it might be helpful.

 

Doug

 

Nibs.com pen measurement page

Thanks Doug,

 

Excellent source of relevant information. My soul can now rest in peace.

 

The table shows that, quite naturally, larger pens have larger capacity, but also that my measurements and the table information come to exact same values.

 

How come? Well here is some basic calculus:

 

- the section diameter of M800 is 0.53 in = 12.985 mm (from the table)

 

- this means that the piston area is about 132.42 sq mm i.e. 1.3242 sq cm

 

- 2 ml capacity (from the table) = 2 cubic cm

 

- 2 cubic cm / 1.3242 sq cm = 1.51 cm of piston movement -> precisely the piston movement as I measured it before.

 

Again, thanks Doug.

So, load your M800 with water, as full as you can get it, and then discharge it into a graduated cylinder. And then tell me that you squirted out 2mL.

 

I also gotta dispute your numbers. The maximum barrrel diameter (that's outside diameter) of the M800 is 0.53in. 0.53in = 13.46mm (not 12.985), which leads to 142.3 mm^2. But that would be the cross-sectional area of the entire barrel including its walls, not the inner chanber in which the piston is operating.

 

Here are a few other measurements:

 

Pen Measurements Collection

[vladek]

  JRG said:

  vladek said:

  HDoug said:

Here's a link to nibs.com pen measurement page which lists the capacity of an M800 as 2ml, and the M250 at 1.8ml.  Just though it might be helpful.

 

Doug

 

Nibs.com pen measurement page

Thanks Doug,

 

Excellent source of relevant information. My soul can now rest in peace.

 

The table shows that, quite naturally, larger pens have larger capacity, but also that my measurements and the table information come to exact same values.

 

How come? Well here is some basic calculus:

 

- the section diameter of M800 is 0.53 in = 12.985 mm (from the table)

 

- this means that the piston area is about 132.42 sq mm i.e. 1.3242 sq cm

 

- 2 ml capacity (from the table) = 2 cubic cm

 

- 2 cubic cm / 1.3242 sq cm = 1.51 cm of piston movement -> precisely the piston movement as I measured it before.

 

Again, thanks Doug.

So, load your M800 with water, as full as you can get it, and then discharge it into a graduated cylinder. And then tell me that you squirted out 2mL.

 

I also gotta dispute your numbers. The maximum barrrel diameter (that's outside diameter) of the M800 is 0.53in. 0.53in = 13.46mm (not 12.985), which leads to 142.3 mm^2. But that would be the cross-sectional area of the entire barrel including its walls, not the inner chanber in which the piston is operating.

 

Here are a few other measurements:

 

Pen Measurements Collection

Interestingly, according to Pelikan site Sov. Pens Dimensions the diameter is 13.1 mm.

 

Regardless of that, I find it pathetic that the piston movement is about 1.5 cm and even more pathetic that all Pelikans regardless to the size have 'standard' 1.3 ml. I can't accept it as completely irrational. I consider the barrel utilisation of my M800 as completely inadequate to its size.

 

I'll take your challenge to test the volume myself, although measuring small volumes is not often easy and/or accurate.

[fjf]

Apparently, if you fill the whole barrel with ink, you'll also have a big bubble of air sooner or later, when you start emptying it. And air dilates with your hands heat, leading to a pen that leaks drops of ink when warm. One way to avoid this is to limit the volume of the ink chamber. Other would be using a heat-isolating material in the barrel. The big japanese eyedroppers are hard rubber (isolating) and use a shutoff valve. Pelikan uses small chambers in their pistons.

[KCat]

I can only guess that the 2 ml claim may include feed capacity. Otherwise, it's hooey. Doesn't matter how many calculations you throw at it, it's very simple to measure the volume with a 1-3 ml syringe. The only thing you can't determine from that is just how much ink goes into the feed/nib. The larger feed and nib on the 800 might allow for more overall capacity. Would it be .7mls worth? I don't know. I don't own one. I know the Rotring Core can hold almost an entire converter's worth (about .7 mls) of ink so it wouldn't surprise me if the 800 nib holds about .5 mls while a 200/400 nib may be only abut .2 - .3 mls.

[Stylo]

I find the ink capacity of pelikans above average. And in any case, those who put down converters because filling a piston is so much more of a soul stirring and exquisite experience, why deprive yourselves from the pleasure of filling more often by asking for gigantic ink capacitites?

[KCat]

  Stylo said:

I find the ink capacity of pelikans above average. And in any case, those who put down converters because filling a piston is so much more of a soul stirring and exquisite experience, why deprive yourselves from the pleasure of filling more often by asking for gigantic ink capacitites?

There's something to that. I rarely actually empty a Pelikan before I get impatient and want to refill it. even with the same ink - something about seeing through that ink view bothers me. I want a bird with a full tank. But I do find that my VPs seem to run out too quick. That dinky little converter. And I'm not liking how they behave with the cartridges. I know that seems contradictory to general knowledge. So I guess I'm very picky. I want my VPs to have more capacity along with the good behavior. But I wouldn't want them to hold much more than my Pels. I've often considered an ED but then I wonder...why? It makes sense for someone who carries one or two pens and no ink with them and does a ton of writing every day. But that isn't me.

[Blorgy]

I measured the ink capacity by weighing the pen before and after filling with water. The weight gain was 1.62 grams.

[chemgeek]

Blorgy has the right idea. The only way to accurately measure ink fill volume is to weigh a clean, dry pen before and after filling with water. The difference in grams is the effective practical fill volume in mL. Pelikans have about twice the typical fill volume of typical converters.

 

Cheers.

[maryannemoll]

i'd say more than twice. with my sheaffer imperial's full converter, i can write only up to twelve letter-sized pages of handwriting. with my pelikan M205 medium nib, i have written 20 pages starting from a full reservoir, and noticed that there was still half a reservoir of ink left. and then i lost count of the pages.

 

but i admit, after having used a piston-filling pen, it would be difficult for me now to revert to a converter filling pen as a main pen.

Edited January 24, 2007 by maryannemoll

[southpaw]

Might I suggest an alternative method to measuring the capacity and comment on another.

 

First, Blorgy's weight gain is an excellent idea provided you know the density of the ink. Knowing that ink is mostly water gives us a rough approximation, but only rough. If the density is 1, then it's 1.6 ml capacity; if 0.9, then 1.8 ml, and if 1.1, then 1.5. There's a little bit of variability there.

 

A better method - and the one which IIRC some of the pen companies themselves used - is to put water in a graduated cylinder, measure it, fill the pen, and measure what's left. The difference is the capacity of the pen.

 

Just my $0.01.