Spru plate unscrewing on older Lyman #358-91; 4-Cav; 148.5 gr. WC mould

[Land Owner]

On this older Lyman mould there is no set screw. Operating the spru plate unscrews the keeper screw, effectively loosening the spru plate immediately.

Any "fix" that doesn't mean machining a hole for a set screw?

[runfiverun]

look at the sprue plate.
quite often they get a burr on them that grabs the washer, which in turn grabs the screw head.
clean all that up.
you might also be able to use a wave washer and some lock-tite to get everything set.
you have to watch if the screw is setting down on the mold top but the washer is giving you enough tension on the plate.

[GaryN]

:goodpost:
I would add the wave washers can really be polished to a slick finish. Work it down with wet and dry sand paper until you have used 2000 grit. It will work almost as slick as a ball bearing.

[gunoil]

drill and tap with set screw.

[Horace]

I`d drill and tap.

Horace

[texassako]

I have an older 4 cavity 35891 that had the same problem, until I realized someone had swapped the sprue plate screw and the stud(?) because of some stripped thread. Fixed threads, switched them back, and it now has the set screw. Maybe yours has been switched and the set screw is on the wrong screw? I also put in the wave washer and ditched the split one likes to dig in.

[happy7]

Has to be what texassako said. I don't think lyman ever made a 4 cavity mold without a set screw, and I have also seen them swapped.


I have an older 4 cavity 35891 that had the same problem, until I realized someone had swapped the sprue plate screw and the stud(?) because of some stripped thread. Fixed threads, switched them back, and it now has the set screw. Maybe yours has been switched and the set screw is on the wrong screw? I also put in the wave washer and ditched the split one likes to dig in.

[leadman]

If you find the hole for the set screw you may want to run a tap thru it 'cuz most aren't tap with a bottoming tap, just a taper tap. The screw binds up in the threads about the time it starts to tighten against the pivot bolt.

[gimling]

http://www.harborfreight.com/hand-tools/tap-die/40-piece-sae-carbon-steel-tap-and-die-set-39391.html

[Land Owner]

I have an older 4 cavity 35891 that had the same problem, until I realized someone had swapped the sprue plate screw and the stud(?) because of some stripped thread. Fixed threads, switched them back, and it now has the set screw. Maybe yours has been switched and the set screw is on the wrong screw? I also put in the wave washer and ditched the split one likes to dig in.

You know, that set screw hole wasn't where I was looking for it. It was hiding in plain sight on the other end. Interesting how we "see" what we want to see and miss the obvious.

Now the mould's spru plate is properly positioned, handles rotated, set screw placed, and the mould is 'just right'.

I get the Homer Simpson "Doooph!" for that one...but I am a whole lot more familiar with my mould now than I was before.

Thanks.

[prs]

You know, that set screw hole wasn't where I was looking for it. It was hiding in plain sight on the other end. Interesting how we "see" what we want to see and miss the obvious.

Now the mould's spru plate is properly positioned, handles rotated, set screw placed, and the mould is 'just right'.

I get the Homer Simpson "Doooph!" for that one...but I am a whole lot more familiar with my mould now than I was before.

Thanks.

Now, they still tend to come loose. Last session every thing was going along ticky-boo with boolits dropping like hail stones and all of sudden the spru plate bound-up on my Lyman 4 holer. I had to stop, let it cool, and then I set the pivot screw tension just right and marked its head right where the set screw should mate with its shank. Then I tool a mill file and flattened the surface of the shank in that spot. Maybe that will teach the little sucker a lesson.

prs

[captaint]

Do what r5r said - then drill for the locking set screw. Mike