Sunday, June 12, 2016

Building the Jim Chambers Lancaster Flintlock: Brass Patch Box Design

This is the fun part, however, after reviewing hundreds of pictures and needing to stay within the Lancaster genre, I needed to have a scale blank sheet of paper to sketch on.

1st I needed an "edge tracer" so that had to be made.
I went with a 20 degree angle for a standard round pencil.
It is best to use wood so with a grinder you can tune the block into dropping the line straight down.
Make sure to add a grid of known dimension to the paper.
I traced both sides, once with the trigger guard, and once without.

Building the Jim Chambers Lancaster Flintlock: Fit Ram Rod

The ram rod is 0.375" dia. and so is the RR tubes bore.

As annoying as this is it puts the maker into a similar predicament as the early makers.

I created a scraper for the purpose of reducing the dia. of the shaft by drilling into a piece of 0.060" mild steel and counter sinking it, the countersink creates a sharp edge.

0.125" hot rolled steel would be more robust.

It takes a while to get the whole piece scraped, I used one of the tubes as a "Go"gauge. The scraping process resuts in a slightly irregular final shape which I think will add to authenticity.
Ultimately the breech end had some sticking point that was difficult to work out but eventually I got it.
I am going to make a steel tube version for use and keep this one for show.

Friday, June 10, 2016

Building the Jim Chambers Lancaster Flintlock: Inlet Trigger guard and Ram rod tubes

The trigger guard is very time consuming; it has a 100 ways to be off. The casting has to be bent back into alignment which is fairly easy with soft brass.

First I undercut and curved the two areas to be inlet.
I chose to pin both ends.
Took a break from making to set up my chisel collection,I have never done a lot of small scale carving so I pulled a piece of scrap wood and set this up.
After inletting the RR loops I needed a drill fixture to get the height correct. I made some measurements and decided that the center of the tab (down from the top line) on the tubes was 0.55" for two of them and 0.62" for the rearmost. 
I took a piece of rect. alum. extrusion and put the two different heights on it.
I screwed up the 1st two holes by not compensating for the 0.125" wall thickness of the ext. so just re-drilled the holes further back. The single clamp holds both the tube and fixture in place.
Next time I will go with thicker wall alum. ext.
Everything pined in place.

I have been trying to get to this stage since leaving the Chambers workshop and have been reading the Recreating the American Longrifle studying up for the brass patch box test. 

Tuesday, June 7, 2016

Building the Jim Chambers Lancaster Flintlock: Making a steady Rest

Not far into it I needed a good steady rest. I decided to go for something with some substance and easy adjustability, together with no cost.

Finally after 35 years that old Mercedes Benz V belt pulley came in handy, I pulled it from a 1972 4.5ltr when I worked at Wood Motors on Gratiot back in the 70's.

That as a base I fashioned some perf-tube, dropped in a 5/8-11 threaded rod, and made a cradle lined with leather to top it off.

Building the Jim Chambers Lancaster Flintlock: Straighten the Top line

The top line on the stock was wavy in the rough milling and so I had to come up with a way of stabilizing the stock without the barrel in it. I decided that the ram rod groove was the only reliable feature and so made a unique steady rest for just this one operation.

This allowed me to have support along the entire length.
All it took was a 3/8" dowel pined to a scrap plank.
It was hard to photo the wavy top edge.
Using my machinist straight edge and a dry erace marker I went thru the process.
Using my old body sander and a rasp I kept the material reduction to a minimum.