Taper in nib slits

[antoniosz]

Kurt has expressed the desire to "see" the taper in nib slits after my remark that the nib on the logo should have a taper towards the tip.

I did not want to highjack the logo thread so I post it as a new subject.

OK Thomas (I mean Kurt ) here is (1) a Sheaffer from the 50s and (2) a modern Visconti Kaleido. The taper is discussed in this primer by R. Binder (scroll down a bit - you will see the schematic). Obviously this taper does not exist in all nibs as it requires an extra operation. I think Richard's discussion is clear. But let's discuss it more here if you prefer.

 

http://i22.photobucket.com/albums/b325/azavalia/taper1.jpg

http://i22.photobucket.com/albums/b325/azavalia/taper2.jpg

Edited March 21, 2007 by antoniosz

[Titivillus]

Kurt has expressed the desire to "see" the taper in nib slits after my remark that the nib on the logo should have a taper towards the tip.

Thank you for the pictures. Yep If I have something that I can see and someone says it's different I will ask for further information.

 

As I stated in my prior post I was looking for a continious taper from the breather hole to the tip when really the taper is only in the last 5% or so of the nib. I saw and fully agree.

 

 

Kurt H

[antoniosz]

I think you are misled by the shadow in the Sheaffer picture.

The Kaleido picture is very clear. I counted pixels and this is what I have.

 

http://i22.photobucket.com/albums/b325/azavalia/slit-data-kaleido.jpg

 

The taper is about 0.57 degrees. It is fair to say that there is not guarantee that the taper will be linear, since it is created by pushing the tines together. The deformation along the slit depends on the shape of the tines, and it is possible that in some cases the tiles will only approach each other close to the tip.

Edited March 21, 2007 by antoniosz

[Leslie J.]

Excellent demonstration Antonios.

[wimg]

Hi Antonios,

 

Thanks for the pics and explanation!

 

Warm regards, Wim

[antoniosz]

A new addition to the collection of interesting photographs showing the effect of slit channel variation. This is an Omas Tokyo with a diveging channel slit (bought on ebay from a good Pentracer fellow). The pen basically writes well when inked and storred horizontally. If the pen is stored vertically then the ink retracts back into the feed due to gravity since the capillary pressure is not strong to keep it up. The result is seeing a slow starting nib after being stored vertically.

 

So observe the slit as it widens towards the nib and also look at the small "defect" on the upper side of the slit. This is usually a sign that the user tried to open up the slit using an X-acto knife. So most probably he overdid it here.

Now I have to think how to close it just a bit. The pen works OK but it would work better if the slits were more paraller or even converging.

 

http://i22.photobucket.com/albums/b325/azavalia/slit-omas.jpg

Edited March 21, 2007 by antoniosz

[toothy]

Yes . . . Actually the features discussed in the article are more prominent on calligraphy fountain pens because the points are so wide, they need a higher flow rate of ink.

[Dillo]

Hi,

 

The expressions nib also needs a wide slit. Even some pens like the Sheaffer Reacktor have the taper.

 

Dillon