This is a very small update of Krupp Howitzer production, but it may have some interest to those who are thinking of some day putting some stamped letters or numbers on their cannon. A bunch of pictures detail a type of easily built fixture to keep everything square and spaced correctly.
But first, a completely off topic suggestion of a new award that could be given out to deserving members who like to pinch their pennies until Lincoln squeals. Cat Whisperer, this is your chance to shine, just as Double D. has with his Kewpie Award. Some people, including me, have long resisted the pushes, shoves, and pleadings to get an artificial Christmas tree. I finally gave up the long fought battle to keep the sweet smell of a Balsam Fir in the house for 3 weeks a year. But, the way I did it deserves an award, let's call it the Ebineezer Scrooge Award! See pic below.
Stamping pics will come a little later, after I round them all up.
Tracy
The last tree Lowes had at 75% OFF, floor display model without a box purchased 3 days ago. A smaller than usual, for us, five footer. You can see all the roominess of the smart car! There's plenty of room for the tree and the driver too, who is holding his sales receipt with the $16 plus tax price on it.
Timothy, what do you think?
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Thanks for the nice compliments, Battleshipduke. We try really hard to do a good job on the details. Most of the time we succeed.
Eventually you will think of something more appropriate than 'Ebineezer', Tim. What does the KaBoom Award entail? What criteria must a photo satisfy? Just curious.
The details of this mini-update are in the cations to the pics. We are about 3 to 4 weeks from delivery right now, barring some last minute hold up.
Tracy and Mike
The Krupp tubes all lined up for marking of the trunnion faces, 1866 on the right trunnion and KRUPP on the left one. The eight tubes in the right row are .312 cal. and the rest are .354 cal. (9mm).
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With the tube held firmly in Baltic Birch, soft jaws, trunnion axis straight up and down, tube level, you can see the bottom of the little fixture we made to align the stamps. The bandsaw cut lets you clamp down on the trunnion via a cross-bolt, while the rimbase has a c'bore with clearance.
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The fixture's top with the back fence and left hand end stop where two feeler gages of .021" and .022" are located. This amount of initial offset lets the first stamp, that for the number 1 in 1866, be held firmly in the correct place when you put the first spacer block ( see 4 of them on the vice's anvil) between the feeler gage stack and the No. 1 stamp.
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All we had left was a short 1/4-28 socket head cap-screw, so Mike put it way down in a deep c'bore. You can see what a former gunsmith will do to overcome the fact that L-shaped Allen wrenches are not long enough and the seacoast guys don't have a complete set of T-handle Allen wrenches!
Oh, just a little Snug here, don't tighten completely!
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Aerospace industry accuracy can be had, if you know how to make a "Sight Gage". This one is simply a 12" steel scale taped to the stamp fixture, it's edge pressed tightly along the back fence. If you align the fixture by eye this way, you can expect each number can be plus or minus .0025" from a datum line which is parallel to the gun's bore axis. When I used to inspect Titan Rockets back in the 80s, we had some sight gages that would position holes within a few thousanths of an inch and they were 'Yards' apart! Believe it or not, that's the truth. And in 'clocking' a feature to say just seconds, you can do it over and over with a sight gage which has and indicator arm that may go out to 10 feet and point at a huge 20 foot graduated circle scale with degree grads, minutes and seconds on it. Extreme accuracy, and no computer in sight!!
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A little light tapping with a plastic mallet and you have the back fence accurately aligned and are ready for complete screw tightening now to lock the fixture onto the .750" dia. trunnion.
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With the tube tight in the vice and the fixture tightly on the right trunnion and the first number stamp in place held tightly against the back fence and the first spacer against the shims and left hand end-stop, I am ready to make the first impression. STOP!! Do you have a Heavy, ball peen, hammer?? If not, go out and buy one right now. Another old gunsmith trick is to always use a heavy hammer lightly or with moderate blows. There is MUCH more control this way. Much more than you will have by whaling away with a light or medium hammer to get similar results. Fewer, hard to remove errors means the job is done more quickly and looks better too! Try to keep the hammer face square to the stamp at the moment of impact for clean looking impressions.
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Done correctly the 1866 should look like this. Hope it's big enough to see.