M11x0.8 triple start cheat sheet?

[spindlecraft]

Up to this point, I have been using an M13x0.8 tap & die for the body & cap of my kitless pens. With these choices, it translated to using an M10x1 tap and die for the threads on the section, which also required an M7 tap for the threads of the nib casing unit.

Does anybody have a cheat sheet of taps and dies to use for the rest if I am using an M11x0.8 tap & die for the body & cap, along with what nibs I could use with the thinner allowances?

 

[Valleyboy]

I've never used M11 myself but, just thinking aloud, you may find that it's gonna get tight and I don't think you'll be able to use a standard international cartridge/converter. Perhaps you're thinking of eyedropping it or using something else?
My thinking is you'll have a minor diameter of a little over 10mm on the barrel threads. Personally I like a minimum wall thickness of 1mm which means an 8mm maximum major diameter for your section threads (obviously that's just my preference and you can go thinner wall thickness on the barrel to have a wider section tenon). But if you go with that assumption and assume you can use m8x0.5 for the section threads you've basically got 7.5mm minor diameter left, and it's pretty tight to drill out for a standard cartridge/converter whilst also keeping a decent wall thickness.
Just something to think about (and apologies if I got any of the numbers wrong but I'm in a car writing this so there is every chance I made a mistake in my calculations).
Cheers
Ash

 

[duncsuss]

Not a cheat sheet, but it isn't too complex to work out.

M11x0.8 has a major diameter of 11mm and minor diameter of 10.2mm.

If you make the section threads M9x0.75 you'll have a wall thickness at the open end of the barrel of (10.2 - 9) / 2 = 0.6mm.

That's kind of thin, so you might be tempted to use a smaller section thread - but beware! Any smaller than this and you will run into problems fitting an ink cartridge/converter into the section. If you plan to use a different ink reservoir system (say vacuum fill or simply an open barrel filled by eyedropper) you remove that inner constraint.

 

[RobS]

Side comment when wall thickness is getting tight, that is when alternate thread pitches should be considered as @duncsuss is noting

Here is some quick calcs:

M10X1.0 = Minor diameter of 10-1=9.0
M10X.75 = Minor diameter of 10-.75=9.25
m10x.5 = Minor diameter of 10-.5 =9.5

m9x1.0 = Minor diameter of 9-1=8.0
m9x.75 = Minor diameter of 9-.75=8.25
m9x.50 = Minor diameter of 9-.50=8.50

 

[Jarod888]

I've heard a lot of folks use the m11 triple for the nib section in a m14 or m15 triple start body.

 

[duncsuss]

I've heard a lot of folks use the m11 triple for the nib section in a m14 or m15 triple start body.

I don't use triples in places where it serves no function.

To me there's no point using triple start for simple things like cap finials or blind caps covering pistons/plungers.

 

[Brooks803]

One major aspect to ask yourself is what type of ink system are you wanting to use. If it's a standard international converter you'll need at minimum a 8mm through hole. That'd mean the smallest thread pitch available for the section is 9mm.

If you're making an eyedropper, piston, or sac based ink system you can drop the section threads to whatever you want.

 

[spindlecraft]

Thank you to all those who chimed in.

The unfortunate conclusion that I am starting to arrive at is – the M11x.8 tap & die may have been a bit too hasty of a purchase.

In order for me to have the clearances necessary for even a kitless rollerball, I'm about 1mm off. Every time I try to turn threads on both the inside and outside of a tenon with less than 2mm of clearance (1mm per "side"), it ends up splitting – if not on the lathe, then later just assembling the pieces together.

So - doing the math, I just don't think the M11 is going to work. Hopefully I can exchange it for a different size without too much hassle.

 

[Jarod888]

Thank you to all those who chimed in.

The unfortunate conclusion that I am starting to arrive at is – the M11x.8 tap & die may have been a bit too hasty of a purchase.

In order for me to have the clearances necessary for even a kitless rollerball, I'm about 1mm off. Every time I try to turn threads on both the inside and outside of a tenon with less than 2mm of clearance (1mm per "side"), it ends up splitting – if not on the lathe, then later just assembling the pieces together.

So - doing the math, I just don't think the M11 is going to work. Hopefully I can exchange it for a different size without too much hassle.

Did you pay a lot for it? It's unlikely that a company will take it back. I may have an m10x1 USA made tap and die. I might be willing to swap you, if you are interested.

 

[PatrickR]

Up to this point, I have been using an M13x0.8 tap & die for the body & cap of my kitless pens. With these choices, it translated to using an M10x1 tap and die for the threads on the section, which also required an M7 tap for the threads of the nib casing unit.

Does anybody have a cheat sheet of taps and dies to use for the rest if I am using an M11x0.8 tap & die for the body & cap, along with what nibs I could use with the thinner allowances?

After seeing this i decided to make a sheet that shows major and minor diameters for the taps and dies i have for a quick visual aid. You may find it usefu.