Problems with Lyman 4 cavity 429421

[Don1357]

The joys of buying stuff from ebay... A few months back I picked a 4 cavity 42941. First problem; the top plate screw is stripped... I'll need to tap an oversize one and hopefully find a small pipe to correctly align the top plate. For now I managed to press it in and hold it with the set screw. Then the second problem; the molds are misaligned; looking it from the bottom a .429 sizing die leaves an untouched spot on next to but on opposite sides of the cast line.

Is there fixing this?

[Don1357]

just to add a bit more info, I was casting WW + 2% tin. This is my first time casting with a 4 cavity steel mold and had to keep the temperature way higher than with 2 cavity aluminum and steel molds, else I had fill problems.

[Kevins750]

Not familiar with that mold, what aligns the mold?

[Winger Ed.]

Call Lyman, tell 'em what ya got, and make your best deal if you can't straighten it out.

[Don1357]

Is there an oversize top plate bolt available somewhere? The problem is that the bolt has a fat area towards the top to snugly fit the hole on the top plate.

[Charliemac]

Before going oversized, I'd would think about installing an insert like a Helicoil or a Keensert. $.02

[Don1357]

Before going oversized, I'd would think about installing an insert like a Helicoil or a Keensert. $.02

You are 100% correct and I do have a kit of those, but on second inspection it is the screw that is stripped. A replacement screw should fix that.

That leaves the issue of the misalignment... Measuring on one side of the cast line the boolit is .4285, on the other side .4232~4.That seems to be fairly consistent across boolits from different cavities.

I'll call Lyman, if nothing else to order the rebuild kit and while at it to ask them about the mold misalignment. Do you guys think that there may be a chance they would do something about an old mold? If not, is there anything else I could do? Not being able to size to even .429 seems like a really bad thing.

[Conditor22]

there was a time that the newer Lyman molds had multiple problems.

Pictures would help,

I'm not sure how a round cherry could create an oblong hole

[Don1357]

there was a time that the newer Lyman molds had multiple problems.

Pictures would help,

I'm not sure how a round cherry could create an oblong hole

Oh, I'm certain the hole was nice and round when it started, it is the misalignment that makes it do that. If you slice a circle in two and move the halves up and down, when you measure across the cast line one side will be as much bigger as the other side is that much smaller.

[Wayne Smith]

Before you do anything else take the mold off the handles and see if it is still missaligned.

[Oyeboten]

Oh, I'm certain the hole was nice and round when it started, it is the misalignment that makes it do that. If you slice a circle in two and move the halves up and down, when you measure across the cast line one side will be as much bigger as the other side is that much smaller.

Post us some images so we can see the details of the Mold, and of this problem..?

Hard to tell otherwise, what exactly is wrong...images, can tell the tale well..!

[Don1357]

There isn't much to see when the problem is about .002 of an inch...

Here's an illustration as to why I can tell it is misaligned. The one on the left, round. Measuring A to D and B to C are the same. The one on the right, measurement of A to D is significantly smaller than B to C. When you run a misaligned boolit through a sizer you may see it sizing the areas B and C but not A and D. for a .004 difference the misalignment is .002 of an inch.



Furthermore the problem is across all four cavities. The mold is not aligning as it should.

[Mal Paso]

The 429421 I have uses 3 ball end alignment pins. Take the mold off the handles and see how the pins fit. Sometimes the handles create the misalignment, sometimes that creates a wear pattern. The female alignment part is a hole in the mold block and I've seen molds with the edge of the hole rounded causing slop. Pushing the male alignment pins out a little may help.

[Don1357]

The 429421 I have uses 3 ball end alignment pins. Take the mold off the handles and see how the pins fit. Sometimes the handles create the misalignment, sometimes that creates a wear pattern. The female alignment part is a hole in the mold block and I've seen molds with the edge of the hole rounded causing slop. Pushing the male alignment pins out a little may help.

I took the mold out of the handle and it indeed has play. The problem then is that the ball-pins are pressed in; there is no hole on the back I could push them out through. Do I grab them with vice grips and wiggle? That would certainly mar the pins.

[fast ronnie]

I took the mold out of the handle and it indeed has play. The problem then is that the ball-pins are pressed in; there is no hole on the back I could push them out through. Do I grab them with vice grips and wiggle? That would certainly mar the pins.

If you have a milling machine, it could possibly be set up and drill a small hole from the back side, then tap them out with a small punch.

[Mal Paso]

I took the mold out of the handle and it indeed has play. The problem then is that the ball-pins are pressed in; there is no hole on the back I could push them out through. Do I grab them with vice grips and wiggle? That would certainly mar the pins.

Vise grips will just chew up the metal and you'd never get a grip. fast ronnie has the answer and a drill press would do it.

Mine has the male pin holes all the way through the block.