Jaco Inspired shotgun build
This is pretty much a snip and clip from the build log I started at the guild but I thought I would post it here for the guys who are not members of the guild
I would also mention if you have not gotten a copy of Colin Stolzers book you need to get it! I will especially be using a lot of his methods making the hammer which I will cover as I get to that point of the build process.
the lock may evolve into a totally diffrent setup before I am finished
the Jaco Kentucky lock looks promising too so I will probably make that lock as well to see which lock will be best suited for this build.
so without further adue I will post something here to get this thread rolling.
here is what I have thus far in the way of materials the lock of course is a home built design and the barrel is an unchambered shotgun barrel with a .670 bore
the Jaco Hawken Instructions and drawings and Colin Stolzers book
the next step will to be to tap the barrel and make a breech plug and tang then I can get started on inletting the stock I just ordered
the stock had a couple of holes bored into it I wish was not there but I can still use the stock especially since it is walnut and only cost 27.00 shipped. so It will be used and I think I got the last one.
i can always plug the holes and cover with some fancy inlay or something functional like a sling base or something to that nature, I guess I will see about that sort of thing once I get to that point of the project.
what attracted me to this style of stock is it has a pistol grip, flat sides and plenty of meat so I can carve to a desired shape I just hope it has not been inletted very much for the barrel.
as I mentioned I am going to make a few diffrent styles of locks to see which will work best for the intended application.
As I start fabrication of the different locks I will cover the most important data and skip over everything else that may be similar procedures of building the diffrent parts.
I would recommend purchasing Colins book because there is a lot of very useful information about building percussion locks and hammers.
one little trick that I have discovered is download track of the wolf catalog http://www.trackofthewolf.com/pdfs/catalog/catalog18.pdf the locks and backing plates and other parts are actual size you can print off the page of the lock you want to build then use tracing paper to make the templates of the parts. once you have traced out the parts you can scan the templates or copy with a copy machine for multiple copys.
then you can cut out the templates, use spray adhesive and place the template directly to the raw materials that will make up the lock parts. this cut and paste work eleminates the need for laying out the part to the raw materials because the template has everything laid out on it already.
I will take some pictures and go a little more in depth with these procedures when I start building the next lock.
Just a Brief Overview:
I dont know who actually coined the phrase music wire but the phrase has kind of stuck with the RC airplane hobbyists. it is actually piano wire and is used for the percussion strings on a piano and it does produce a certain pitch or musical note when put under tension I suppose that is how the term music wire came about (that is just my theory), however being that it is a high tensile strength carbon steel wire or rod which is in fact a type of spring steel. it is very suitable for making landing gear for RC Aircraft's, compression and recoil springs as well as the springs I have made for this percussion lock and many other applications that require springy steel.
bending the 1/8" diamiter wire does not have to be annealed, it can be cold formed relatively easy and still maintain its rigidity and spring and does not require tempering after cold bending, although it is not required to temper the part after cold bending you can temper it which will make it even more rigid and more springy and nearly impossible to cold form without annealing however it can cause it to be a bit more brittle and can possibly break under a heavy load. I just don't see where it would be necessary to make this spring any stronger than it already is, YMMV. Anything bigger than 5/32" would require either annealing to hand form or hot bend then re tempered or cold formed with mechanical or hydraulic bender. as mentioned earlier Music/Piano wire can be purchased at any hobby shop from sizes 1/64" to 3/8" X 36" long.
one thing you do not ever want to do is hot bend piano wire or any other type of steel for that matter then quench it this will make it snap right past where it was heated and or make other types of steel more brittle.
when hot bending heat the part to the point it is soft in the area that is to be formed, hot enough to form to shape but not so hot to the point it is oxidizing and creating mill scale. Bend to shape then allow to slow cool. once the part is cooled you then can heat the whole part white orange to cherry red but not so hot that it is scaling once the whole part is red hot uniformly the same red coloration quench the part immediately in a high viscosity oil. (if you don't get the steel red hot and only heating to a straw or blue color then you stand a very big possibility of only making it brittle) 30 weight motor oil will work superbly for the tempering process some folks use cutting oil. try not to use anything that has a low flash point for obvious reasons. :o
Here is some pics of the bending procedure and a brief explaination of what I am doing and how I am doing it.
the bending process starts with making the first bend then I lay the wire on the scale drawing and
mark a line that will indicate the start of the next 180 degree bend
using the harry higley bending jigs I set the wire between the posts and pull it against the two posts
to hold it snug and in place I set the mark forward to the center of the post this will keep the wire in
the right orientation when starting the bend. back off tension to set the mark in the right location then
snug it back up when the wire is in the right location in the bending jig.
Note that the top of the jig is in line and flush with the bench top so I can keep the bends flat on the bench top.
I use sheetmetal bending pliers to aid in the bending process to keep from bowing the wire they are
useful tools to keep the wire straight Both hands are needed to form a good bend one to hold the
pliers tight on the bar and the other to pull the stock around the bending jig post.
once I make a bend I lay it on the drawing to check to make sure the bends are in the right location
then mark the next bend start line.
repeat the process by aligning the line just forward of the center of the two posts on the jig.
repeat the process of laying out the mark for the next bend
the last bend is made in the same manner as the previous then cut off and shaped with a
dremmel tool and a cut off wheel and sanding drum attachment
i fill a bowl of water and keep it near by, it is important to keep the wire cool during cutting
and grinding by frequently quenching the part in water while cutting and grinding if you get
the wire hot enough to turn it blue then you got the part hot enough to anneal it, you don't
want to anneal the wire if it does start to get hot during the cutting and grinding dipping the
part in water to quench it cancels out the annealing of the wire.
as for this spring It came out very good and I am overall pleased with the end result.http://i209.photobucket.com/albums/b...n/PICT1461.jpg
As mentioned at the start of the thread I am building two diffrent types of locks to see which design will work best for the configuration of the barrel and stock i will be using so I cut out patterns for both styles and drilled the holes. I will go a little more into detail with some pics I took.
here is the scale drawings of the locks I will cut out the different pieces to use as templates
Here I have cut out the templates and laid them out on the steel blanksl note that I have cut multiple templates just in case.
after gluing the templates I centerpunched the hole centers and around the templates in case the templates come off
diring cutting the parts out I have a mark to go by
some of the holes require a press fit for the pins in order to get a press fit hole requires using numbered bits and need to start out several sizes small and work up to the required size
I make it a habbit to step drill any holes regardless.
I have had to put this build off for a little while due to back problems but I did manage to get a start on building a couple more hammers and lock plates so I thought I might post my progress of those.
i am using 3/8" cold roll on this hammer to make it one piece I am doing the same with the kentucky hammer.
Note that I chain drilled the hammers due to all the compound curves and miter cuts I figured it would be a lot easier
to do it this way than to try to make a bunch of relief cuts and using up my cut off disks it was a bit more time consuming
but worth the extra effort .
chain drilling made cutting the hammer out a lot easier I still had to make a few relief cuts but not neaely as many if I would have cut the hammer all out by hand.
I got the hawken hammer cut out and roughed in and it is beginning to take shape pretty well if I say so my self.
while I was at it I went ahead and drilled the plates then chain drilled them also
Note the 1/4" hole that calls for a press fit I am going to drill and tap for a 1/4"24 shoulder bolt and use semi permanent thread locker . I will do the same thing on the 3/16" pins O will drill and tap that hole for a 3/16" fine thread shoulder bolt.
I gotta get one of those band saws and a belt sander
and a little bit closer.
well that is all for now.
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