Lyman 429421 DC issue

[M Hicks]

I have a 429421 DC that I used a couple of days ago and cast about 120 boolits during the session. About half way through I started to get fins on the nose and sides of some so I inspected the inside of the mold. I didn't see anything that was out of the ordinary. Nothing that would keep the mold from closing all the way. After trying to cast more and getting frustrated with the mold I set it to the side and let it cool. After it cooled I looked at it closer. The alignment pins seem like they are not allowing the mold to close all the way. It essentially rocks with the pins being the fulcrum. Any ideas what could have caused this and how I can fix it? The mold is pretty much new. I got it around Thanksgiving and used it one other time with no issues. Can I every so gently tap the pins in a little more to give the necessary clearance it needs.

Thanks.

[MT Gianni]

Yes that is the accepted way to close up a mold. Make sure that you don't go any further than necessary which you would know when the halves started to rock when closed.

[cbrick]

Yep, I use a brass punch with the mold on a flat surface. If you do go to far just tap them back the other way.

Do it a few times and you'll have a feel for what is just right.

Rick

[M Hicks]

Thanks MT Gianni and cbrick. I appreciate the help. I was tempted to take a punch and hammer to them but didn't want to do something that would mess it up to the point it was a $65 paperweight.

[runfiverun]

tap is an understatement.
i'd look real good at them before i started moving them.
quite often a burr on the female side will make you think it's the pins.
and it could be just one of the pins, the one closest to the handles usually.

[M Hicks]

I looked at them and ran a small flat tip screwdriver around the opening of the female side and looked for any deposits around the pins. When I put them back together they didn't close fully. The gap was enough to see light through it when held the right way. I could push them together really hard by hand and get it to close up but opening it required a few taps from a rubber mallet.

[johnnybar]

I looked at them and ran a small flat tip screwdriver around the opening of the female side and looked for any deposits around the pins. When I put them back together they didn't close fully. The gap was enough to see light through it when held the right way. I could push them together really hard by hand and get it to close up but opening it required a few taps from a rubber mallet.

Lube the pins regularily?

[GP100man]

Lube the pins regularily?

This was my thoughts also ???

Are ya removing em from the handles when inspecting ???



Could it be the handles or some alloy that got into the handle slot ???

Does the sprue surfaces of the mold close flush ??? (maybe the mold has been hot enuff to warp ??)

1 last thought , look very close at the pins to see if any alloy is around em ,it does`nt take much . If ya smoke the molds a peice of carbon could be camoflauged ??

I have to have some magnification these days to see all there is to see !!

GP

[GaryN]

Before I tap on the pins I pull out the dial caliper and see what the pin measures. Then I can tell how far I moved it.

[M Hicks]

I lubed the pins and sprue cutter and had them off the handles when looking at them. I don't smoke my molds. I looked around the pins and didn't see anything. I will look again before I try to tap them back a little.

[rintinglen]

Don't sweat this one. It's easy and virtually a no brainer. Dismount the handle from the mold. Place the mold on a firm flat surface--I use a piece of scrap aluminum plate. Measure the protrusion using a caliper or micrometer. Using a brass punch and a light hammer (12-16 oz), tap the pins once each,smartly. Remeasure. If all is well, the pin should have moved .002 -.005." If not, try again. Once you get movement, try the mold halfs together. You should just be able to press them closed with firm finger pressure. If you get too energetic and drive the pins in too far, you can tap the base of the pin from the other side to increase the length of protrusion. 10 minutes should see you through.

[M Hicks]

Tapped them into place a little to far but sent them the other way and all is good now. Thanks for the help. I was just a little leary about taking a hammer and punch to it.

[geargnasher]

Tap IS usually quite an understatement, but I'm glad you got it worked out easily. As the holes in the block wear gradually over many thousands of cycles, the blocks will become loose again and can tend to build up burrs around the holes from displaced metal, so part of regular checking and adjusting is to apply a straightedge and backlight to the female block to check for raised areas around the holes, either peen or block-sand the block flat, chamfer the holes, and adjust pin depth. Some moulds tend to work the pins farther out in the first couple of casting cycles, not sure why but I've seen it a lot, so your experience isn't unusual and now you know how to fix it.

The main thing as has been mentioned is use brass or aluminum to drift the pins INward, a steel punch will damage the rounded heads and rivet them somewhat.

Gear

[M Hicks]

It was a little bit of an aggressive tap. I was unaware that they tend to move around over the life of the mold. It makes sense given that it is heated and cooled often.