Manu Propria Pens - Screwed it up?

[MartinPauli]

Some time ago I posted a report where I presented the idea of replacing the common ebonite or plastic feeds with a metal feed. In the past months I have continuously changed and adapted the profile of the feed. I have been using this fountain pen for a few months now. The ink volume under the nib is quite large and therefore the ink flow is excellent, no drying of the ink and thanks to the weight the nib writes almost by itself. The brass feed I first coated with palladium, then with 24K gold. Palladium forms a barrier so that the gold coating is not absorbed by the brass and thus prevents corrosion. The feed is made from a brass, fit with a M:6 tread, similsr to a srew

 

Your opinion?

[PAKMAN]

Very interesting! I wonder why pen manufacturers didn't ever go this route of metal feeds?

[MartinPauli]

I don't know but this is the case in many areas. Even in school or university, don't ask question, do what we tell you or you'll get bad grades. The same in many industries. Ebonite for making feeds is an excellent material, indeed ut the same time it is a weak material. Brass is stronger I guess and the longevity is better. If I have to clean or repair a eonite feed I have to be very careful. A brass fed with its gold or steeel nib I can heat up to 150 degree celsius without damaging any component

[Karmachanic]

1 hour ago, PAKMAN said:

Very interesting! I wonder why pen manufacturers didn't ever go this route of metal feeds?

 

Increases the cost of a £400 pen by 50%?

[Ron Z]

1 hour ago, MartinPauli said:

Ebonite for making feeds is an excellent material, indeed ut the same time it is a weak material. Brass is stronger I guess and the longevity is better.

 

Longevity....   I have a Sheaffer flat top from 1924 in my pocket.  Same nib, same feed, same section.  I can't knock nearly 100 years of longevity.

 

I think that there are other principles in play, besides the cost of production and materials.  Plating with the materials you used is not practical time wise and cost wise for mass production.  I'm sure that our pen engineer would have some thoughts.   There is a link to his web page pinned at the top of the repair forum.

[arcfide]

I think this is a really neat exploration. My major thoughts about whether such a feed would be an improvement would be:

• How easy is it to mate the feed with the nib to ensure proper flow and engagement? Plastic (such as Platinum) and ebonite feeds can be heat set to fit them to the nib, but that wouldn't work for the brass
• It's easy to get ready flow *or* good leak resistance, but does the brass feed enable you to get both with high reliability? 
• More malleable feeds can fit into a section reliably and without damaging the section while still achieving a tight seal, how well does the brass work? 
• How much weight does the brass feed add to a pen?

Fascinating stuff!

[Paul-in-SF]

Regarding the design of the feed: I don't see a straight channel like most feeds have, so does the ink flow along the screw threads, i.e. around the feed over and over as it works its way to the front? Are there any drawbacks to that design that you have come across?

[es9]

10 hours ago, MartinPauli said:

Your opinion?

I’ll answer your question with a question: Why? 

[txomsy]

What I would be concerned is about nib swaps. If the nib and feed are removed for cleaning or if the user wants to try different nibs, wouldn't the friction affect the coating and ultimately lead to corrosion?

 

This could be fixed using nib units so users swap the unit and not the nib, but probably then cost would largely increase.

 

Finally as to whys, a plastic feed (or unit) that can break will require replacement (typically of the whole pen by unknowing users) and that means larger turnover and more sales (programmed obsolescence being an extreme). Something that never breaks will need substitution only when lost. That implies you only have an interest in investing in unbreakable items if you expect that breakable items will last as much (e.g. because they are so expensive that users will take so good care of them that whether the item is breakable or not will not make a dent on your bottom income line), or if you want to make room for yourself in the market.

 

I know, it is a cynic view, but one I've witnessed so often I do not tend to discard lightly.

[MartinPauli]

Thank you for the many comments and I will try to answer them if possible

First, I am not a mass producer. I make 130 to 150 fountain pens a year, of course all built from Japanese Ebonite from NIkko Tokyo and concentrating on Urushi lacquer So I don't do nonsensical unit cost calculation as in mass production.

Small anecdote on the side regarding ebonite feeds.

Namiki uses ebonite made in Germany by Schöneberger for their feeds.

This ebonite is made with rubber and sulfur, with the addition of lampblack to make the material properly black. This material is also used by Namiki for tobacco pipes. There was an attempt by Namiki to use the cheaper ebonite from Nikko for feeds. The attempt was abandoned because the Japanese ebonite tired the tools too quickly. The German ebonite cannot be used for pens with Urushi lacquer, because Urushi does not adhere well to the oily material.

Ebonite is an excellent material for feeds and pen bodies that have stood the test of time for decades

Since I do all the work myself in my studio, I always try to think outside the box and find the simplest and most efficient solution.

I have spent years studying feeds and feed patents, and I have found that most of them are extremely complicated and elaborately constructed. On the other hand, there are concepts that are extremely simple and work just as well. See, for example, the great feeds from Toma Pens, feeds made of ebonite, which does not need a comb at all. I have discussed feed and nib making with Toma on many occation

Well, to make a regular ebonite feed you need a lot of fine tools and machines to cut the shape and especially the fine fins. So the question for me was: how can I make a feed as simple as possible and with as few tools and tool settings as possible, reproducible.

Hence the idea of cutting a thread on a 6 mm brass rod to replace the fins/comb, turning the feed tube directly and milling the main ink channel. I can do all this work on the Schäublin 102 lathe and my Hauser 2BA precision Jig boring machine. Of course, this could also be done with stainless steel or ebonite.

Anyway, the feed is cleaned and palladium coated before 10 microns gold plating.

The palladium acts as a barrier that prevents the gold plating from being absorbed by the brass

The feed and spring are pressed into an ebonite sleeve, and the ebonite sleeve is heated to 130 degrees Celsius beforehand.

I find the added weight of the brass feed very attractive, the nib writes almost by itself with very little pressure.

Finally, my point is not to badmouth the classic ebonite feed, but just to introduce a new idea.

 

[txomsy]

Thanks for the detailed explanation. My previous answer was as to how potentially appealing designs and solutions (like yours) may become less attractive to current producers, but I confess, from my personal point of view, you idea looks great (if only I could afford it).

 

Keep the great work and innovation. It is well worth and most illustrative.

[MartinPauli]

Thank you,

I think the manufacturers will stick to their proven ebonite or plastic feeds. No need to complicate things

[como]

@MartinPauli Very interesting and informative read. Thank you very much for sharing! Does brass feed interact with ink? What does it look like after some time of use, may I ask?

[MartinPauli]

Thank you Gomo, the pictures at the geginning of the post show you the feed after 6 months of use.

In 2019 I have made #8 feeds cast in Bronze and also cast 18 Kt gold nibs, the feed plated in red gold.

One set was sold in a buffalo horn pen to a customer in Hong Kong. He uses it dayly and is very happy

[txomsy]

Those look great (so far)!

[LordCactus]

I think this is a really cool idea, great job! 

[como]

@MartinPauli Very interesting indeed. Thank you for showing. I guess for someone who enjoys generous ink flow, this may be a suitable candidate?