Making a lock template?

[Scota4570]

Hi,

I have a TRS casting set to assemble.  I have no template.  The hole indications on the plate casting are not clear.  The bridle has a cast in stud the prevents accurate placemen based on the tumbler. 

I have a second completed lock done by TRS from identical castings.  After some tuning it functions fine.  All the holes are in reasonable positions.

I was thinking of making a template from the working lock with a piece of metal glued to the lock plate.  The template would be made to fit the pan bolster precisely.  The existing holes would be transferred and tap drilled in the template through the existing plate.  I would then remove the template.

I would first locate, drill and ream the tumbler hole to match the previously finished tumbler in the new plate.  The tumbler hole appears  accurately indicated in the casting. 

The template would be indexed, on the plate casting,  based primarily on the tumbler using a guide pin, then align the frizzen spring hole and pan bolster.  Glue it in place.  Then the remaining holes would be transferred and tap drilled based on the template, though the template.

Did I forget anything?

Sound like a reasonable plan?

Scot

[Rt5403]

Would love to see how this turns out. Always wondered about the casting sets.

[Bob Roller]

I used 2 sets of their Manton parts for two double barreled guns and made the internal works for all of them.I recommend you make the innards for this project.Using old and flimsy designs for mould masters is a bad idea.I don't think the originals were very durable either.
I notice a number of these flintlock guns with such marvelous workmanship have little or no wear on the frizzens and that makes me wonder
how long they would last if put to the uses we do now.
   Several years after in a moment of temporary insanity I made two tiny Fenton locks for 2 16 bore rifles.One of them was never used and circulated thru this part of the country as a medium of exchange in different swaps and trades.
You might consider making the internal parts for this lock insstead of the aggravation of these cast parts.
Bob Roller

[Scota4570]

I do not like cast parts either.  I will replace any parts that are not usable.  I bought the necessary and recommended steel a while back at Bob's suggestion.

I figured the tumbler was a good place to start.  I was able to true it up on the lathe using collets.  The cock screw hole drilled just fine.  Tapping it is another thing.  It it cooling right now.  Hopefully annealing it will do the trick.  If it is a problem I'll make new one.  I see no reason for a fly, which is part of the cast tumbler design.   Besides I hate broken taps in precision parts. 

[Clint]

Tapping tumblers is one of the first things i do when putting a lock together. I generally drill slightly oversize for the screw and that makes the threading go a little easier. Annealing after drilling usually takes care of any work hardening left by drilling. After starting the tap, I try to hold the tumbler with my fingers (fifty years of blacksmithing) or a small pair of pliers. It may be a while before you fit the flint cock but if you file the slightest taper on the square shaft and slowly press the tumbler into the flintcock you will see where the hard contact is and and you can file the hard spots off. I press the two together in a vise and use a 1/4" nut to protect the bridle pin, and drive the tumbler out with a long screw that fits to the bottom of the tumbler hole. WHAT'S THIS? the screw wont fit into the tapped hole! The tumbler shaft is being swaged down in size and needs to be re-threaded as you fit the tumbler into the square hole. you may need to re thread two or three times, so much for the initial loose thread fit. I seldom make the same lock twice, so drilling jigs don't do me much good.

[Rolf]

I made a template like you suggest when I made the 1772 pistol locks. Worked fine.
https://americanlongrifles.org/forum/index.php?topic=49769.msg493990#msg493990

I have several cast locksets from Blackley which include all the "guts". Tumbler shafts are all slightly crooked and there are other minor problems with most of guts, mostly due to shrinkage and flaws in the wax patterns. I plan to use the cast parts as rough patterns and make new parts.

Best regards
Rolf

[smart dog]

Hi Scot,
Yes, that sounds like a good approach as long as you are confident the built lock is correct.  I usually ignore most of the witness marks on TRS lock plates although usually the tumbler hole is accurate (but not always).  I urge you to drill and tap for one part at a time and test it before drilling the holes for the next component. The cast innards depend a lot on how big the lock is.  On large locks, I've found the cast parts to be fine because there is always excess metal to work.  That is not true on pistol sized locks. I also urge you to make and install the fly.  Even if you do not use any set triggers, the fly will allow you to create a light trigger pull with a simple trigger.  Without the fly, you may have trouble keeping the lock catching in half cock when firing if you lighten the trigger pull too much.

dave

[Bob Roller]

I do not like cast parts either.  I will replace any parts that are not usable.  I bought the necessary and recommended steel a while back at Bob's suggestion.

I figured the tumbler was a good place to start.  I was able to true it up on the lathe using collets.  The cock screw hole drilled just fine.  Tapping it is another thing.  It it cooling right now.  Hopefully annealing it will do the trick.  If it is a problem I'll make new one.  I see no reason for a fly, which is part of the cast tumbler design.   Besides I hate broken taps in precision parts.

Countersink the holes to be tapped the depth of one thread so the tap will start easier and any threading fluid is OK.
Bob Roller

[flatsguide]

Hello Scot,
I’m following along and would like to ask if it is possible for you to post pictures of this project.
Thanks Richard

[Scota4570]

OK, I'll take pictures as I go.

[Scota4570]

You get a bag of rough castings.  All have excess metal.  I see no problems that require welding.  All parts need to be filed.  The plate was pretty straight.  The blemish bear the tail was from the original as the other lock has the same mark.  The tumbler was a little wonkie but cleaned up.  The diameters were non-standard.  I reamed the plate and sized the bridle with a number bit.  Several screws were 8-32 instead of the required 6-32.  Making screws is faster than complaining.  They all need to be trimmed anyway.  I really like that TRS uses modern standard sized screws instead of obscure sizes. 

I worked on the plate and bridle before taking the picture





TRS assembled lock



Old/new plate



Making a template then using super glue to hold it in place.  The holes were marked with a transfer punch.  I used a smaller bit for the pilot hole so the tap drill would drill to size. 








pic upload


Improvised line boring the plate and bridle for the tumbler.  The holes were later sized to the fit the tumbler as turned to size  up on the lathe



The tumbler was to thick for the bridle



So far so good, the tumbler turns freely with no bind or wiggle. 

[Jim Kibler]

I highly doubt there is “excess” metal on these parts.  I’m pretty certain they pull molds directly from the originals without adding stock in the mold making process.

I’ve pulled molds from originals, but when doing so, I’ve built up all critical surfaces with cardboar, sheet wax etc. before pouring the molds.  This is the best way to do things.

[Scota4570]

I did not communicate that well.  The parts have little buggers here and there that are "excess".  There are also gates that need to be removed.  The tumbler was to thick to use with the bridle.  I have not found myself needing to add metal yet. 

I fitted the cock.  The shoulder on the cock with not touching the plate.  IT was stopped by the bridle.  That seems prone to break.  I fitted it so the shoulder on the cock was stopping on the plate.  The square on the tumbler and cock were already there so I did not clock it wrong or have any choice in that. 

So the mainspring??  Should I heat threat it before I install it for fitting the first time?

[flatsguide]

There was a website that had a very good article with good photos about a guy that assembled a flintlock from TRS castings. I just tried to find it with no luck. The website is worth finding, I suggest calling TRS I’m sure they know. He mentioned using some type of shellac to hold two parts together from drilling instead of solder....good luck and thanks for posting the photos
Cheers Richard

[flatsguide]

Found it! Hope this is some help. Richard

http://www.ctmuzzleloaders.com/ctml_experiments/mantonlock/mantonlock.html