..............I couldn't stand it so decided to be selfish and self centered. To the exclusion of all else, I decided to make a set.
This core mould is the first mould I've ever made. It turned out well and I learned some valuable lessons for the next one. I'd bought a 6' stick of common 6061 alloy aluminum that was 3/4" thick by 1.5" high. I also got a piece 1/4" thick by 1.5" wide (and 6' long). I'd made a few sprueplates out of it and it's worked very well for that.
To make the blocks I setup and bolted a webbed angle on a faceplate, and laid one piece on it. In previous checking, this extruded aluminum bar is amazingly accurate over it's length, varying no more then a couple tenths anywhere. So I didn't worry about it but found center and clamped 2 of'em together .
Valuable Lesson #1. Draw a plan with at least some rudimentary measurements so your envisioned 4 cavity blocks don't turn into 2-1/2 cavity blocks. Sheesh. Been here and done this before, but it's beginning to sink in ............ finally.
First up was to drill and ream for 3 alignment pins. That was pretty much done except for the 2nd. I forgot the reamer and wondered why THIS particular pin was so dad blamed hard to drive into it's hole. Once I realized what the issue was, I looked around to see if anyone had been watching. Luckily I was alone. I got them done, finally.
So then I got the blocks back on the faceplate and cinched down, and had actually marked the centers for each of the 3 cavities. It was SUPPOSED to have been a 4 cavity set but I'd used 1/4" holes for the alignment pin bodies and the opposing steel sleeves. Seems it's a pretty good idea to have material all around the holes, not to mention the pins. This meant I had to move them in. In was in the direction of the cavities. It wouldn't do to have the alignment pin holes intersect the cavities.
So I deleted a cavity and used the resulting extra room to make sure there was block material around the pins and their holes. As mentioned, so it's a 3 cavity now. I drilled and reamed each cavity. Then bored to size, and didn't bother to polish as they came out so nice. This proved out in actual use too! All you have to do it swing the sprueplate and turn the blocks upside down and the cores will slide right on out.
So here tis. It's used with Lee 6 cavity handles.
Yes, the right cavity adjusting stem is smaller (10-32) then the other 2 which are 1/4-28. The reason?:
Valuable Lesson #2. Have the base plate attached and use the correct tap drill size to drill through the blocks and base plate. You'll be assured the hole is truly centered to the cavity. What I had sone actually worked for 2 of the cavities. What I did was to turn a short centerpunch a thousandth undersized and inserted it into each cavity in turn, then giving it a good whack to produce a mark. I guess for that one, the ole MkI Mod I eyeball detector just wasn't up to the task of centering the bit in the punch mark in the drill press..
To rectify the situation I countersunk each side of the bad hole in the baseplate, screw in a piece of aluminum and then rivited it in place and re-drilled the hole. I had to go to the smaller size as the minimal offset in re-drilling probably would have just knocked out the upset piece of aluminum.
Left Photo shows the baseplate with the cavity adjuster screws. Top & bottom on the right are the flathead sockethead screws holding it on. On either side in the middle are the mould handle screws. Their heads are recessed down below the plate.
Right PhotoThe cylinders on the right are for setting the adjusment stems in each cavity. Each one to the right are 1/8" shorter, which was arbitrary. You place a cylinder into a cavity and close the sprueplate. Then screw the adjuster up to touch. Remove the cylinder and place it into the next cavity and repeat, and ditto a 3rd time.
There is no rhyme or reason for the lengths. The longest one was merely the longest length that could be cast and the 1/8" step down was just a number I pulled out of my............... ear. Since my Hi-Wall has a 18" twist the 2 longer ones will probably be useless as they produce a 320 and 338 gr core. Of course you will lose a bit in the core bleed die, but not really enough to satisfy the twist limitations. Maybe.
Just for fun, sitting here on the baseplate is an aluminum setting cylinder and on the right is the cast lead core. Believe it or not, that's a BORED finish in the cavities!
......................Buckshot