Making Lock Waxes — Tinker or Leave it Alone!?

[Hudnut]

From the original part used to make the die to the steel casting, there is shrinkage.  It might be an idea to produce waxes that incorporate extra material allowing for fitting.  If no provision is made for fitting, the castings will not go together as well as they did in the original.  Any sins in the original will be carried over into the copies, only worse.
Here are a couple of trade gun locks I set up many years ago.  The lower lock was assembled using castings from my dies.  The upper lock uses a lockplate from the Upper Missouri Trading Company completed with my castings.  I believe they used the same original lock as I did, borrowed from the Museum of the Fur Trade. The other photo shows one of my locks in a gun; markings were die stamped.  The markings in the Upper Missouri lockplate were cast in.  My dies were cast epoxy.  The springs and frizzens are 6150.  Those springs were made over 50 years ago, and are as good as when they were new.
If you have ever seen a John Clark Toronto flintlock, his dies were machined aluminum, with fitted aluminum slides.  Beautiful dies, beautiful castings.  But the dies were very costly.

[PhDBrewer]

Parts that you might want to build up are the bearing surfaces on the tumbler. Then one can turn the tumbler to the correct size.  Hard to add material later. Usually a couple wraps of masking tape on the original seems to work well to build up the surface.
Or possibly the frizzen & pan where you want to "file to fit".
Hope that helps.

William

[Hudnut]

Parts that you might want to build up are the bearing surfaces on the tumbler. Then one can turn the tumbler to the correct size.  Hard to add material later. Usually a couple wraps of masking tape on the original seems to work well to build up the surface.
Or possibly the frizzen & pan where you want to "file to fit".
Hope that helps.

William

Exactly! 

[Jim Kibler]

Another is the top of the pan and underside of the frizzen.  There are a good number of other places as well.  Basically anywhere you want to fit one part to another.

[Bob Roller]

I have seen locks that seem to have the tumbler made from wax.Dead soft steel was the real problem.
I once was asked if I could use aluminum in a lock and I told this man I was aware it existed but no idea about  how to use it in a lock and still don't.One of the L&R guys told me years ago that foundries were the big bug in the soup was the indifference of foundries who thought quality control was was and obscene idea.
   The idea of high quality parts apparently came from Europe and England certainly brought it to the top of the line with their lock filers.I have had a "blast"copying some of their work.
Bob Roller

[Hudnut]

Finding a foundry that is prepared to deal with low numbers of castings and is prepared to work to achieve the desired quality at a reasonable price is a challenge.  There are different methods of removing the investment which can affect the surface.
When the castings were made for those trade gun locks, batches of 100 pieces were requested.  The foundry had a standing order for 30,000 pieces a month of one part for a single industrial customer.  There is a limit to how much time and effort they can put into a project that is insignificant compared with other orders.

[Jim Kibler]

Finding a foundry to make just a handful of pieces is difficult, but if you have any kind of production it's not a problem.  I've used three different foundries over time and they've done decent.  You really just have to understand the technology and what you are dealing with.  We could make fantastic locks just with castings and no CNC.  People like to throw around the word CNC and think it's the reason for better locks.  In some ways yes as it allows us to make quality locks faster, but it's not necessary.  As and example look at the great locks Bob Roller made. 

[Bob Roller]

Jim Kibler,
Thank YOU for the comment on my lock making skills.It gave proof to my comment about what I think of myself as the maker and my opinion of the buyer.Your own work stands out like a goose egg in a bucket of coal and keep it up.
Bob Roller

[silky]

Awesome. Thanks for the replies, guys.

I'll wrap the tumbler post with some tape, add material to the pan and frizzen (had to anyway to rebuild the original's worn out one).  I'm thinking the hook of the mainspring wear it engages the tumbler nose, and the back of the top jaw wear it fits into the post to slide up and down, too.

The foundry I have talked with has been good to work with so far. I have been very clear since the start that this is a small project and they haven't balked at it. Speaking of, and based on your experiences, are there any specific points I should ask them regarding the process they use to ensure these come out the best they can? An example is the investment removal process that Hudnut mentioned.

Thanks!

- Tom

[Hudnut]

Ask them how they remove the casting from the investment.  What options are there?

[Jim Kibler]

Don't be too picky if your just doing a few pieces.  They are really just doing you a favor.  There really isn't much you should have to specify.  Most foundries are pretty good.  Who are you using?  I might know them.

Jim

[Bob Roller]

I forgot about the locks made by Chet Shoults in Lapeer,Michigan in the 1950's.We thought they were the work of a master machinist but later and by chance,a man who knew about gun locks saw castings ready to ship in a foundry and they were all that was needed to make flintlocks.The cat was out of the bag but who cared.It was a quality lock and I used a lot of the external parts and made locks with them.
The parts became  available to anyone who wanted them and Mr.Shoults lost control of the dies that cost $5000 in the early 1950's.
Later a man similar lock was offered by a man with the name Cochran and I bought external parts from him as well.Another assembler of
flint locks was Theodore (Ted)Cole from Wilkinsburg,Pa.He used to come to Friendship but I don't think he ever sold a lock there.He had his springs made by W.G.Sutter from Ruffsdale,Pa who also made Bedford County locks and used torsion bars from Chrysler and Packard cars to make tumblers from.I told him about the easy machining of 1144 for tumblers but he wasn't interested in the idea.Every so often I recall these people and they were part of the story of the revival of long obsolete guns that could have perished as time passed.
Bob Roller

[wvcruffler]

After reading this thread I wondered - how much would it cost to get a small vacuum/inert gas foundry? If one were interested in doing small scale carbon or stainless-steel casting. The answer is about 30K. That's actually less than I expected. The biggest challenge would be the amperage required. I'm going to eyeball a unit like this over the summer (there is one being installed at U of Akron and I'm out that way fishing in the summer). Won't hurt to go look at one. There are smaller less expensive high temp casting furnaces but they do like 100g and are more for gold, silver, platinum instead of steel. The ones I was looking at were at 1kg and 3-5kg. The 1Kg was the one I was pricing.

dr Phil

[silky]

I finished a few more molds tonight and shot some test waxes. Overall, pretty good, but I do have a question….

The sear nose and tumbler notches fit well, in both the original and the waxes. However, the notches and nose, while fitted nicely, are not square and true (I hope the pictures explain it).

Simply put: is there anything wrong with this?

Do I add material and reshape both to be true, or leave them as is? I feel like the former could be opening Pandora’s Box, but also wonder if leaving them will cause undo stress in the internal mechanisms. Of course, this lock is almost 300 years old and still going strong so maybe that’s the answer!?

[Hudnut]

Referring to the trade gun lock photos I posted above...  The dies were made using casting epoxy with original parts as patterns.  Dies were hard and rigid.  Most dies were two piece.  The lockplate die had a slide to allow for the cut between the plate and pan arm.  Wax was used on parts to create draft, etc. so waxes could be extracted easily from the dies.  The dies had provisions for keeping the halves aligned, and were clamped closed with wing nuts.  Channels for injection of wax were machined into the dies as appropriate.  Warts in the original parts were carried on into the waxes and steel castings.  An insignificant example were the marks on top and bottom edges of the lockplate where a vice had left marks at some time.  These appeared in the steel castings.  Fit and function don't get better in the transition from original to wax to casting. 
I would suggest that the steel castings should be at least as good and ideally better than the original parts.  Original parts were hand fitted and as you noted, aren't square.  Perhaps the dies could be adjusted so that parts could be used more or less as cast, or material could be left to allow for final fitting.  If the castings are unaltered reproductions of original parts, there likely won't be enough material to touch up to get the best possible fit.

[Jim Kibler]

This is the conundrum with using original parts as patterns or masters.  You're basically following the process used by people like the Rifle Shoppe. 

[silky]

Yeah, I’m definitely experiencing the pros and cons of these processes. That’s not a negative statement; very positive, actually.

Hudnut, I like your approach and agree that the new product is ideally better than the original. There’s certainly a balance in picking one’s battles, but good lock function is non-negotiable! I may try the casting epoxy on a future project. It sounds interesting.

I have a box of reproduction musket internal components and after some fitting, it seems some Brown Bess components will work very well. So I’m going to play around with that idea today and will report back… probably with more questions!

Thanks guys.

[Hudnut]

Here's a photo lifted from an auction of a rifle with one of John Clark's locks.  The dies for the waxes were machined aluminum.  I had the opportunity to examine them, and they were beautiful.  The castings reflected the quality of the dies.  They were also removed from the investment with minimal damage to the cast surfaces.  My castings, using waxes from epoxy dies made using the originals as masters were certainly usable, but John's were in a different league.  Incidentally, John didn't make that rifle; his lock was used by the builder.

[Clint]

Most lock experts will sat that parts cast from originals are too small because of shrinkage. As gunsmiths were born into the late flintlock period things like trigger guards and butts got smaller and thinner . That was from using old pieces for patterns and then using the new pieces for patterns. I have used old pieces for patterns, but prep the patterns by dipping them in poly U to build them up a few layers. That build-up gives you room to file and polish each piece and still arrive at the original dimension.  CSW