Scratch Building a Henry Nock Screwless Lock

[Gunnermike]

WHY?
I think he was having a pint down at the pub one night with some other builders, when a challenge was issued.....
Yeah, I'm sure alcohol was involved
A clever guy like Nock feared of nothing!

All great endeavors were fueled by alcohol.  Mind your P's & Q's gentlemen, mind your P's & Q's.  (that's pints & quarts to you teetotalers, zzzzzzzzzzzz.......  )

I have nothing new to report.  On an English forum one member was kind enough to post photos of a musket version of the screwless lock.  An inside view of that lock showed the bolster was a lot thinner than mine.  So I thinned the bolster, frizzen and shortened the 2 pins.  Nothing worth showing though.

Any of you gents have any secrets to forming the curved portion of a mainspring that bears on the tumbler foot?  I don't have a forge, but have a oxy-acetylene torch.

[Acer Saccharum]

Mike, you have done a fantastic job. Hats off to you, especially for such a wild pattern, with little known information to go by.

On the original photo, the sear and hammer screws have what appears to be a 'key' which shows on the outside of the plate. Do you know what those are? Your lock has fixed pivots, maybe the original lock pivots unscrew?

Now on to building the gun! Can't wait.

[Gunnermike]

Tom, if you drag the picture to your desktop and zoom in you can see the end of the wires.  The wires look like they are coming through the lock plate.  I originally thought it was so sort of staking but I don't have any idea what it is.  Those wires don't show on the musket lock. 

I'll be working on the mainspring again this weekend.  The original has a stirrup on the mainspring.  Here's another photo from an English forum that a member (Adrian - the 95th Rifles re-enactor) posted of the interior of the musket lock:



On my lock the sear pivot is about 3/32" too close to the hammer pivot to shape the rear of the hammer correctly.  I thinned the outside of the sear pivot area & there still isn't enough clearance to re-shape (& enlarge) the back of the hammer.  Maybe the Mark II version will get the bugs out.

[Rasch Chronicles]

It just keeps getting better! Thanks for the time and for sharing!

Best Regards,
Albert “Afghanus” Rasch
In Afghanistan: It's Been a Long Road

[doug]

Any of you gents have any secrets to forming the curved portion of a mainspring that bears on the tumbler foot?  I don't have a forge, but have a oxy-acetylene torch.

      When I make the curved portion from a flat end on the spring, I heat it up with an oxy propane torch then have my wife hold it (with pliers ) over a piece of 3/4 " steel plate with a round notch filed in it.  I hammer down using a round ended cold chisel.  Usually takes about 3 heats to get the full curve.
     More recently I tend to leave a bump on the end of the spring and file that into a hook or curve; it is a little easier to get the length correct.
     Spectacular work, by the way; I am totally impressed.

cheers Doug

[doug]

     I seem to find a new way of screwing up every time I post :>(  How do I change the font size when posting a reply with a quote.  My previous reply comes out in tiny print at least to my aging eyes

cheers Doug

[Rasch Chronicles]

Mr Doug,

Highlight the text you want to resize, and click on the button that is second from the right on top. It's the black A with the arrow pointing up and down. When I do that, it only gives me one option 10pt. I just went and changed it to 12 and 14 on the message.

Gosh, I hope that was clear...

Best Regards,
Albert “Afghanus” Rasch
Albert A Rasch In Afghanistan

[Gunnermike]

     When I make the curved portion from a flat end on the spring, I heat it up with an oxy propane torch then have my wife hold it (with pliers ) over a piece of 3/4 " steel plate with a round notch filed in it.  I hammer down using a round ended cold chisel.  Usually takes about 3 heats to get the full curve.
     More recently I tend to leave a bump on the end of the spring and file that into a hook or curve; it is a little easier to get the length correct.
     Spectacular work, by the way; I am totally impressed.

cheers Doug

Thanks much Doug for the mainspring forming explanation.  I was kind of thinking along those lines, thanks for confirming it.  

I have been buying 1/8" spring stock from Dixie GW and smaller sizes for the sear spring.  

I think I'm going to re-do the lock cover with 1/16" stock again.  Brother, the prototype pile of reject work keeps growing!

I just remembered, I found a Nock's carbine on the John Slough of London website:
http://www.johnsloughoflondon.co.uk/Antique-Arms/
There's a commercial Baker listed just below it!

[doug]

     Perhaps worth mentioning that I forge my springs out of drill rod; usually 3/8" for a mainspring.  That allows me to leave a lump at the end of the thin part.  Also worth mentioning, I think, that before filing to final thickness, I grind the scale off of the surface.  For thickness, most mainsprings run around .070 at the tip and around .1" at the bend.

     If you are starting with flat stock, it might be worth trying adding a blob of weld to the very end of the spring to be, to build up the thickness.  Case harden the very tip after shaping to reduce wear.

cheers Doug

[T*O*F]

Perhaps worth mentioning that I forge my springs out of drill rod;

Drill rod comes in air, water, and oil hardening. I'm assuming you are using oil hardening rod.  I tried forging a spring from water hardening rod and it exploded when I hit it with the hammer....much like spitting in a lead pot.

[doug]

     I am not sure what kind it is; just go into the local small order metal shop here and ask for drill rod in whatever size I want.  I have been buying it that way from 2 or 3 different shops over 20 years or so.  I used to harden by quenching straight into water but more recently and for no good reason, I have about 1/4 - 3/8" of oil floating on top of the water in my quench container.  The material is high carbon and does through off a shower of bursting sparks on the grinding wheel
     What you are describing sounds like the air hardening steel used in planer blades.  I tried making a knife out of one and if you heat it beyond red, it becomes very brittle and will break in half if you lift it out of the forge flat ways.

cheers Doug

[Acer Saccharum]

You can quote someone by using the quote button, and then select from the top row of the 'Add BBC Tags' Captital letter 'A' with the arrow pointing up and down. That gives you a default 10 pt type size. But you can change the number to any type size you want. I made this size=14pt

[Robby]

Turn your hearing aid down Doc!
Robby