Fountain Pen Design

Function, Development, Construction and Fabrication

Flex-Nibs – A – Outline

This article has been inspired by a forum in the Fountain Pen Network, namely Experiments With Flex.  My ingeneer’s mind was stimulated by the methodical way of experimentation and the valuable contributions by the visitors made this forum a lively experience.  This motivated me to write this paper.

After an initial discourse on the definition and classification of flex‑nibs, I introduce the mechanics of nibs with particular emphasis on flex‑nibs.  Then follow chapters on the practical application of such findings.  Finally, I respond to visitors’ comments of the forum’s contributors when consolidating their discoveries with ingeneering information.

Outline of Paper

Let’s start with an introduction to the structure of this paper.  It helps me to sort out where what belongs and it helps you to find what you are interested in.  The Headings are links to the main sections.  I added the links to the chapters underneath

B – Definitions of Flex – chapt. 1 – 4

When reading some of the forums Fountain Pen Network, I noticed that there is a multitude of most romantic descriptive expressions for the various styles of fountain pen nibs, such as “Wet Noodles” and the opposite “Nail”.  Experienced flex‑nib writers may sense the meaning, but I also noticed the confusion they caused, especially amongst novices.

Chapters: 1. All Nibs Flex (What is flex?) — 2. All Nibs are Preloaded — 3. What’s the Difference? (various write scenarios) — 4. Types of Flex Nibs (findings of the web)

C – Quantitative Classification – chapt. 5 – 7

I comment on two suggestions of classifying nibs according to their technical parameters and summarise with a proposal of my own.

Chapters: 5. Technical Approach (Investigation and analysis of a test method) — 6. Useful Line Width (How far can the tines be separated and the nib still produces a full line) — 7. Useful Writing Pressure (Comfortable writing pressures)

My Classification Proposal – chapt. 8

A synthesis of what I learned from the above measuring methods and my own thoughts.

D – The Technical Side – chapt. 9 – 12

This is an ingeneering approach to the function of flex‑nibs, an introduction to the mechanical physics of bending, the nib’s shape and material and the suggestions of expressions on nib characteristics.

Chapters: 9. When one applies Sufficient Force (… anything can be bent, Force vector diagrams on nibs) — 10. Spreading of Tines (Why do the tines open when force is applied to the tip of the nib?) — 11. Bending (Basics on bending) — 12. Bending of a Profile (about bending moments and the effect of shape)

E – More Specifically Technical – chapt. 13 – 16

In this section, I apply the basics from the above to the characteristics of a nib in dimensional details.  Comparisons are made between nibs after their dimensions have been calculated or graphically established.

Chapters: 13. Variation of the Theme (application of the basics on dimensionally detailed nibs) — 14. Permanent Damage (A refresher on Stresses and Strains) — 15. Nibs are not flat (discussion on the effect of curving a nib) — 16. Effective Dimensions (How to establish the dimensions, which influence a nib’s performance.)

G – Flex Nib Modifications – chapt. 17 – 19

As the word suggests, here I respond to some of the technical discussions of the forum Experiments With Flex.  They cover aspects of adding or increasing the breather hole or adding scallops to the side of nibs.  I also include here the function of flat tines. 

Chapters: 17. A – Increasing of the Breather Hole — 17.B – WIng Scallops — 17.C – Long Slit and Breather Hole —  17. D – Radius of Nib Curvature — 17. E – Thinning Nib — 17. F – Shape and Position of Scallops —  17. G – Mating Nibs and Feeds —  17. H – Underside of the Nib —

18. Hole versus Scallops (What’s more effective?) — 19. Flat Tines (Samples of flat nibs, how they work and how beautiful they are)

G – Finale (Thanks and acknowledgements)


Amadeus W.

27 September 2017

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