M800 Back Heavy

[gyrosan]

Dear FPN colleagues,

 

I have the great luck of acquiring a well preserved M800 from 90's with a PF medium nib. I must say that it is quite more flexile than the modern Pelikan nibs (and I have tried M400, two M600 nibs). It reminds me of 400NN medium nib as far as the springiness is concerned, though not so flexible (I'd say it's about 60 % flexible as 400 NN).

 

So there's a problem that reoccurs quite often on FPN, namely that M800 is the right girth, right size nib, the pen is long enough to use unposted, the only problem seems to be the back heavy brass piston. The balance point when the M800 is empty is very far off (I measured it in Photoshop after balancing it), the point is at 43 % of the barrel length measuered from the last thread at the grip section till the golden rings at piston end. When M800 is filled with water, the balance point rests at 51 %.

 

http://www.shrani.si/f/3L/125/4hnoFydQ/m800-comparison.jpg

 

Is there a way to make the M800 lighter at the end?

 

Thank you for your thoughts and ideas,

gyrosan

[hari317]

Is there a way to make the M800 lighter at the end?

 

 

I am sure there is a way, I have been thinking about this for a while now since i am not too fond of the weight in my M1000. The weight is due to to the brass connector used in the M800's filler. This component can be manufactured in a lighter but strong material, possibly Delrin or some such engineering plastic? you need to find a talented machinist who can make this component for you, I suggest you get in touch with FPNer Fountainbel, he might have some ideas.

 

Best,

hari

[Bo Bo Olson]

Go over to the forefinger up method of gripping a pen instead of the pinch method.

 

I post all my pens. I have a MB 234 1/2 Deluxe (52-55) that is a tad back heavy posted. It is wonderful there, the better balanced for writing for me, than even my perfectly balanced P-75.

 

A Tad back heavy is not bad, Pinched it sits in the web of the thumb.

Forefinger up, is a much lighter grip than the than the quickly tiring pinch grip, and forefinger up automatically places all my pens in the web of my thumb.

 

It took me @ 2 minutes to learn forefinger up. Put your forefinger on the section top or a tad to the right if right handed, the pen body rests on the bottom of the first joint of the middle finger rather than the middle like when you pinch.

Your thumb slides up the pen barrel until where the thumb nail separates from the meat of your thumb, is at the first joint of your forefinger.

Try that for some 20 minutes.

 

If it is still to back balanced, then you will have had some practice with the close version, you can then move the pen further back on the pen. I have to do that when I post my Cross Townsend and Lamy Persona.

 

I used the pinch system since picking up my first pencil, some 55 years ago. About a year ago I learned forefinger up, and 95% of the time use forefinger up...with out a thought, it has become natural. At first after you have learned the forefinger up system, you must take a long time, three or four seconds to decide, pinch or not, and it don't take but a second to change grips.

 

I still pinch my P-75; it has perfect balance and the built in pinch triangle section.

Edited July 18, 2010 by Bo Bo Olson

[gyrosan]

Go over to the forefinger up method of gripping a pen instead of the pinch method.

 

Dear Bo Bo Olson,

 

I think that the nib would write more like a bold one instead of medium one in this way (correct me if I'm wrong).

 

Regards,

gyrosan

[FPFan]

I like my 800 & 1000 just the way they are. If you want a lighter pen use something else or go back to your 600.

[gyrosan]

I like my 800 & 1000 just the way they are. If you want a lighter pen use something else or go back to your 600.

 

I did own a M600 but the pen is too small for my hand, girth could be wider and the nib longer. I don't miss M600 even though it's a great pen.

M1000 feels a bit clumsy in my hand, but I tested it only at the shop, holding it empty. Having a pen full of ink makes a difference in pens that hold about 1,6 mL.

 

[Garageboy]

I find back heavy annoying and the pens feel like they want to "pull" away from the page

[PAKMAN]

With my grip the 800 fits so that the filler knob is resting on the web between my thumb and first finger and as such can be back heavy since it doesn't extend above my hand.

[gyrosan]

I am sure there is a way, I have been thinking about this for a while now since i am not too fond of the weight in my M1000. The weight is due to to the brass connector used in the M800's filler. This component can be manufactured in a lighter but strong material, possibly Delrin or some such engineering plastic? you need to find a talented machinist who can make this component for you, I suggest you get in touch with FPNer Fountainbel, he might have some ideas.

 

Best,

hari

 

I have contacted "fountainbel" and he had an idea of modifying the brass piston to cut the brass part that wasn't threaded and use the wrench flats as they are more resistant to allen wrench. The material would be "peek" or Polyetheretherketone and he would make a bushing, reducing the weight by more than 50 %. With his permisson i'm posting his picture and description.

 

I asked him why would Pelikan use brass component of the brass piston part and here were his thoughts:

 

"The static brass piston housing does not add anything to the sturdyness of the piston filler system.The only benefit I see is the excellent wear resistance of the wrench flats.

I think Pelikan opted for brass housing because Montblanc also uses a brass housing.

Although MB started with a brass housing, they went for plastic in a later stage, and then – triggered by customer complaints- they went back to brass.

This experience might have triggered Pelikan to opt for a brass housing.

The 59 % weight reduction is nice, and brings the gravity point of the pen considerably more towards the nib."

 

4,5 grams of is more than triple the amount of ink when the barrel is filled with ink. Reducing the weight by 59 % seems like a good, cost effective solution.

http://www.shrani.si/f/2f/w3/26ouBYAX/pel-800-1000-lighter-pis.jpg

 

I wonder what the weight of the brass piston part modified completely in PEEK material would be. My concerns are that the plastic wrench flats wouldn't hold quite well (particularly if a user would use the allen wrench in the wrong direction and damage the wrench flats. That's harder to do when fiddling with brass than with hard plastics).

 

Has anyone a better idea than this one?

 

Kind regards,

gyrosan

Edited July 19, 2010 by gyrosan

[hari317]

I personally think that Francis's idea of retaining the brass threads and the brass wrench flats is excellent. A recently released piston pen design(It is excellent, BTW) uses an all plastic filler with a similar scheme to Pelikan and I read that at least in one pen the flats got "rounded" but the filler did not budge, so that is a real danger. However if a user monkeys enough with their brass filler and over torques it in the wrong direction, there is a danger of splitting the barrel itself!

 

Francis, as usual is very generous in sharing his ideas and it is a pleasure to see this sketch.

 

Gyrosan, do you have to send in your filler's brass connector for this modification?

 

Best,

Hari

[Silvermink]

I'm not wild about this either - I have an M1050 which has the same top-heavy balance. I eventually got used to it, but not before I almost sold it off.

[Viseguy]

I would love to have this sort of modification done to my M800. It has a sublime B nib from John Mottishaw but is sadly underused because it's just too heavy for me.

 

[AltecGreen]

 

 

I wonder what the weight of the brass piston part modified completely in PEEK material would be. My concerns are that the plastic wrench flats wouldn't hold quite well (particularly if a user would use the allen wrench in the wrong direction and damage the wrench flats. That's harder to do when fiddling with brass than with hard plastics).

 

 

I would try the all PEEK piston. PEEK is an engineering plastic and quite durable compared to your typical consumer grade plastics. PEEK should be able to hold up to the stress. It might be worth trying carbon loaded PEEK or another engineering plastic like Torlon. I'm a big fan of Torlon. Brian Gray made a pen for me out of the stuff and it is a wonderful pen. Ford made a car engine out of Torlon so the stuff is pretty tough. I think the material to try is Primospire SRP. It almost has the same tensile strength of brass and is lighter than PEEK or Torlon. It is also 1/2 the price of Torlon.

 

 

If you want to try the Torlon, I have an excess piece leftover from the pen Brian made for me.

[fountainbel]

Hi all,

 

Thank you gyrosan showing my sketch & picture !

 

I thought I should chime in showing the leatest status of the project.

 

Attached a completed picture, now also showing a complete housing made from Peek.

 

Just as Gyrosan I was curious how a complete Peek piston housing would behave in view of the gravity point.

 

Given the special (non standardised) screw threads Pelikan used - hence both the left & right hand threads needed to be cut on the lathe - it took me a while to make the part.

 

I've installed both the full Peek housing & the altered housing in my Pel 1000 & both make it like another pen, very light weight & balanced!

 

The weight of this Peek piston housing is only 1 gram, gravity ( or pivot ) point remains however practically identical compared the brass part equipped with 2twoPeek bushings.

 

Given this fact ,and also taken in consideration the wall thickness under the wrench flats being only 0.3mm -, I'm affraid the Peek wrench flats would wear off over time , resulting in the fact one can not further dissasemble the filler unit easily.

 

Therefore my personal preference goes to the approach Gyrosan posted earlier : using the existing brass housing & make it lighter installing the 2 Peek bushings.

 

I personally don't think using Torlon would drastically reduce the risks of wearing the wrench flats, but I'm always willing to give it a try

 

Peek being a rather expensive material ,I do know Torlon is extremely expensive.

 

 

As always your comments & thoughts are very welcome!

 

Francis

 

 

 

 

http://i62.photobucket.com/albums/h89/fountainbel/Pel800-1000lighterpistonhousing003.jpg

[hari317]

http://i62.photobucket.com/albums/h89/fountainbel/Pel800-1000lighterpistonhousing003.jpg

 

Francis, how much clearance is there between the ID of the filler housing and the "lead nut cylinder" which attaches to the piston knob? If there is more clearance, then maybe the ID of the filler housing can be reduced so that the wall thickness under the wrench flats becomes thicker?

 

Thanks!

Hari

[shyrlock]

I had pretty much the same problem with the balance, plus I didn't like the feel of the threads on my finger.

I made up a nice soft little leather sleeve that I place over the lower barrel when I write.

It seems to have corrected the balance, and the finger on the threads problem.

Cheers,

Mike

[gyrosan]

I had pretty much the same problem with the balance, plus I didn't like the feel of the threads on my finger.

I made up a nice soft little leather sleeve that I place over the lower barrel when I write.

It seems to have corrected the balance, and the finger on the threads problem.

Cheers,

Mike

 

A nice solution that covers the threads, too. But the aesthetics seems to suffer.

 

Regards,

gyrosan

[gyrosan]

I would try the all PEEK piston. PEEK is an engineering plastic and quite durable compared to your typical consumer grade plastics. PEEK should be able to hold up to the stress. It might be worth trying carbon loaded PEEK or another engineering plastic like Torlon. I'm a big fan of Torlon. Brian Gray made a pen for me out of the stuff and it is a wonderful pen. Ford made a car engine out of Torlon so the stuff is pretty tough. I think the material to try is Primospire SRP. It almost has the same tensile strength of brass and is lighter than PEEK or Torlon. It is also 1/2 the price of Torlon.

If you want to try the Torlon, I have an excess piece leftover from the pen Brian made for me.

 

Thanks for your idea, AltecGreen.

 

Here's a picture of comparisons taken from a site http://www.solvayadv...8808-2-0,00.htm

 

http://www.solvayadvancedpolymers.com/static/wma/gif/2/4/8/4/3/PS_Tensile.gif

 

http://www.solvayadvancedpolymers.com/static/wma/gif/2/4/8/4/1/PS_Ductility.gif

 

Looks impressive.

And Torlon (Torlon^® polyamide-imide (PAI)) is used in aircraft industry for hardware, fasteners and bushings.

 

Regards,

gyrosan

Edited July 20, 2010 by gyrosan

[fountainbel]

http://i62.photobucket.com/albums/h89/fountainbel/Pel800-1000lighterpistonhousing003.jpg

 

Francis, how much clearance is there between the ID of the filler housing and the "lead nut cylinder" which attaches to the piston knob? If there is more clearance, then maybe the ID of the filler housing can be reduced so that the wall thickness under the wrench flats becomes thicker?

 

Thanks!

Hari

 

Hi Hari,

The lead nut bushing just slides in the brass housing, clearance is only 0.1mm.

Consequently one can't provide a thicker wall.

Given the risks of wearing and deforming the keyflats, I would stick to the brass central part & press fit the 2 Peek bushings.

Regards, Francis

[lapis]

My M1000 and M800 are two of my very most favourite pens. They are different, and watever the balance differences may be, I still love them both. Maybe my hand "corresponds" automatically to the weight and shape of each, and I never post any pens.

I'd say that if you don't like the balance of any pen, forget about getting anything adjusted; just buy any other pen.

 

Mike