General discussion > Gun Building
Brown Bess Lock Kit
smart dog:
Hi,
Generally, they will true up nicely. I do this job with a simple wood lathe, fliles and stones. A metal lathe would be better but I achieve all the precision I need for a good working lock. I place the large spindle in my lathe chuck first. Rest a file with safed edges on edge on a tool rest, I spin the tumbler and true up the side. Then I place the safed edge against the side of the tumbler to clean up the big spindle. Usually, it takes very little filing to true up the sides ad spindles. Use a medium or fine cut file and be careful the spinning toe of the tumbler does not catch the file. Next turn the tumbler around and do the same on the other side. The bridle spindles on Bess locks are large so don't take off much diameter. Next, I repeat the process using stones and oil. Keep in mind JMF, you are not building a jet engine with spindles that turn thousands of revolutions a minute. You want the best precision you can do but you don't really need a CNC milling machine to build a fine lock. I urge you to buy a copy of Goldstein and Mowbray's "Brown Bess", which is an invaluable asset for building the locks and the guns. The only thing better is an original in your hands. Another tip, if you can, heat soak the cast parts at about 800 degrees for 15-30 minutes and let air cool before working on them. Sometimes, TRS parts can be really tough on the surface after the molding process and they can ruin your files. The preliminary heat soak will remove any risk of encountering surface hardening. Finally, do not completely trust the witness marks on the lock plate. Usually the tumbler hole is marked accurately and you should establish that hole first before drilling any other holes. The position of the tumbler will determine all else internally including the position of the main spring.
dave
jmf:
I do have an old Fay & Egan wood lathe, and a 4 jaw chuck, but the chuck isnt geared, but rather independently adjustable. I only use it for offset turnings, so Im thinking I need to use my geared 3 jaw for this, chucking above the square on the larger journal, then truing the smaller journal. That smaller journal is at .200 as cast. Just by observing it spinning in a hand drill, it appears tome that I would be fortunate to get .125 diameter after truing. Is that sufficient, or should I build it up a bit before turning?
Ido have a copy of The Brown Bess by Goldstein and Mowbray. Its the next best thing to your advice.
45-110:
The tumbler shaft(s) need to be co-axial, along with concentric. Working with on a lathe with a collet set up offers the best machining solution.
smart dog:
Hi JMF,
The spindle on my Delta lathe is hollow and takes a Morse tapered chuck inside as well as 3 or 4-jawed chucks screwed on the outside. I simply have several Jacobs chucks that slip into the spindle and automatically center the work. On all of the TRS cast Bess tumblers I've trued, none needed much metal removed from the spindles and both sides were concentric when checked with a point inserted into the tail stock.
dave
jmf:
Yes, there is a #2 mt as well as the 1-1/4 threads on my lathe spindle. I can get that chucked up. This morning I decided to look at the hammer and cap. I did some rough filing to fit things up. That notch for the cap took an hour of filing andI still need to work it into the dead end some more. Is it normal for the hammer shelf to be at such an angle? Its off about .180 from one side to the other. I filed the slot straight with the hammer, not perpendicular to the shelf. The boss on the cap is not centered is why its slightly off center. Should I grind the shelf to be perpendicular to the hammer or is it cast correctly?
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