Differences In Feed Shapes (And Materials?)

[lightless]

I was thinking about my pens and I got to wondering about feeds and how different they all look, and how their shapes might influence performance. My Lamy Safari has a very streamlined feed, sloping up parabolically against the nib. The Vanishing Point has a tiny feed fitted to its tiny nib, Pelikans and Auroras have stout feeds that I find attractive, the Pilot Custom 823 has a kind of combination, with a very Lamy Safari looking portion with a hole near the nib's tip broadening into a flat section with fins near the section. Sailor feeds have an area which seems to be under the breather hole where a tiny cube would fit. Some feeds fill the whole underside of the nib, and others leave plenty of space in every direction.

 

Is there a functional difference that leads manufacturers to design their feeds with so many shapes, or is it mostly aesthetic? They all do their job despite coming in so many different shapes and sizes. Are there flow differences between shapes; is it a matter of designing a feed that goes along with the nib's geometry; a feed that goes along with the design of the pen? Is there a particular design that's well suited to tolerating differences in pressure, temperature, and humidity? Ebonite seems to be very respected as a feed material - would a feed made of ebonite be preferred over a plastic feed of the same shape?

 

 

[jar]

Is there a functional difference that leads manufacturers to design their feeds with so many shapes, or is it mostly aesthetic?

 

Usually a good bit of both as well as a pinch of buying what is available.

 

Are there flow differences between shapes; is it a matter of designing a feed that goes along with the nib's geometry; a feed that goes along with the design of the pen?

 

Usually a good bit of both as well as a pinch of buying what is available within the selling price point margin.

 

Is there a particular design that's well suited to tolerating differences in pressure, temperature, and humidity?

 

There are thousands of designs that meet those requirements. Again, the choices are a compromise.

 

Ebonite seems to be very respected as a feed material - would a feed made of ebonite be preferred over a plastic feed of the same shape?

 

Maybe by some collectors. BUT, you can't just change materials and expect a design to perform the same. You may be able to engineer a plastic to replicate Ebonite but why? Unless the plastic fully replicated Ebonite the feed would perform differently. Note only differently; it might perform better or worse.

[akustyk]

I am sure there are differences, and even in my modest experience, I've seen bad flow from generic plastic feeds, and amazing, consistent flow from my OMAS, Aurora, and Waterman ebonite feeds. At the same time, the plastic feeds in my Japanese pens have been very good, providing very, very consistent flow. My Pelikan M205 also has a very generous feed with consistent flow. I would say that it's both the material and design/manufacturing that contribute to good flow. Of course, the fit is crucial for proper capillary action.

[lightless]

Is there a functional difference that leads manufacturers to design their feeds with so many shapes, or is it mostly aesthetic?

 

Usually a good bit of both as well as a pinch of buying what is available.

 

Are there flow differences between shapes; is it a matter of designing a feed that goes along with the nib's geometry; a feed that goes along with the design of the pen?

 

Usually a good bit of both as well as a pinch of buying what is available within the selling price point margin.

 

Is there a particular design that's well suited to tolerating differences in pressure, temperature, and humidity?

 

There are thousands of designs that meet those requirements. Again, the choices are a compromise.

 

Ebonite seems to be very respected as a feed material - would a feed made of ebonite be preferred over a plastic feed of the same shape?

 

Maybe by some collectors. BUT, you can't just change materials and expect a design to perform the same. You may be able to engineer a plastic to replicate Ebonite but why? Unless the plastic fully replicated Ebonite the feed would perform differently. Note only differently; it might perform better or worse.

Ah, meeting points between all the factors involved. No One True Feed, which adds another dimension of excitement to fountain pens. Thank for the breakdown, jar.

 

I am sure there are differences, and even in my modest experience, I've seen bad flow from generic plastic feeds, and amazing, consistent flow from my OMAS, Aurora, and Waterman ebonite feeds. At the same time, the plastic feeds in my Japanese pens have been very good, providing very, very consistent flow. My Pelikan M205 also has a very generous feed with consistent flow. I would say that it's both the material and design/manufacturing that contribute to good flow. Of course, the fit is crucial for proper capillary action.

Thanks. My Japanese pens have treated me the same way. I've been wanting to buy my first Italian pen, and my curiosity and want for an ebonite feed (just for the sake of having one) is pointing me towards Aurora.

Edited August 30, 2013 by lightless

[Pen Engineer]

Hi to all of you!

 

Having designed a feed for a fountain pen I liked reading your comments and what you say is correct. At the end compromises need to be made. Somewhere I read: "If you find the perfect feed, drive over it." I have almost finished writing about feeds in my website. Link in the signature.

 

There are certain scientific parameters, which are given, to every fountain pen. They are influenced by dominating, uncircumnavigatable technical circumstances such as, the volume of the ink reservoir, the distance between the tip of the nib and the top liquid level inside the reservoir and its elasticity.

 

Only after that things like feed material and design starts counting... implying that it the design of the feed is ok. If not, then put your pen on a plinth or cast it in perspex and leave it there.