Our artist friend Bruce was given a 250 pound cast steel tube 15 years ago. He has beautifully cleaned up the rather ugly casting and has inspected the bore which is fortunately bright and without rust. At our urging, he purchased a complete set of No. 1 carriage drawings from AOP and is scaling them down to 66.67% to make an exact 2/3 scale, 6 pounder with authentic scale hardware, woodwork and wheels. Occasionally we will post new pics of his progress as he creates this impressive carriage. He has asked us to be his spokesmen on this project and we said, "Sure".
Mike and Tracy
P.S. The bore diameter is 2.452"
Bruce started this large project by cleaning up the tube with files, body grinders (3 diff. sizes) and lots of dirty, filthy work (6 days worth). We estimate he probably removed 4 pounds of cast steel dust and filings. Now you can actually tell what that blob near the muzzle swell is (astragal with two fillets).
You should have seen this area before Bruce got after it! The 1st reinforce to second reinforce transition was just a ski slope and the rimbase/tube intersection was a completely filled in slope with no vestige of any definition line such as you now see. A full day of grinding and filing was expended on these features alone.
The base ring was another mess to clean up. A one-half inch radius existed here where the Base Ring meets the tube and the cascable looked like some kid threw his half eaten pear at the breech and what resulted was sold as a cascable. Another full day was required to re-shape the cascable and the junction between it and the breech's rear.
Bruce used the bandsaw to first shape the 60 Lb. chunk of 1018 that he found at a surplus and cut off steel supplier. Then he used the milling machine to clean up the rough saw marks. Both trunnion plates were machined in unison to keep all dimensions the same and to save time. The trunnion cradle area has not been removed yet. The Douglas fir, wood structure is a special made fixture to hold the steel for welding and drilling holes for through bolts and other hardware.
Some of the smaller hardware Bruce turned down from 1045 steel rods. The tops of through Bolts, (bottoms to be threaded and welded to the 'tops') and some Eye Pins are shown here. The Eye Pins need about two hours of hand filing to complete internal and external round overs on the 'Eye' part.
Bruce checked the drawings frequently while laying out the steel trunnion plates for drilling and milling.
After drilling a clearance hole for the 5/8" through bolts, Bruce is milling the hole into a square shape with a 3/16" end mill. Next a 1/8" end mill was used to tickle the corners before a file finished this job. This shape receives the square projection on the bottom of the beveled bolt head preventing rotation of the through bolts during tightening of the cheek bottom nuts.
