Idea for getting HP pins up to temp initially

[MikeS]

Hi All.

I'm going to start by saying I currently don't have any HP moulds, nor any experience with them. I see lots of threads where folks have problems with the HP pins not being hot enough, causing stuck boolits. This got me thinking about something. Erik over at hollowpointmold.com has a system where the pins are mounted into a block, rather than being individual pins like in a cramer style setup. I was thinking, using this style setup, but extending the block below the level of the bottom of the mould, by say 3/16" or so, so the block is the lowest thing on the mould, so when the mould is placed on a hotplate to preheat it, all the heat would have to get to the mould thru the HP pin block. Would this work in getting the pins up to temp quicker, and/or keep the pins hotter than the surrounding mould blocks?

[Jailer]

Hot plate and turn the heat up a bit higher than normal.

At least that's what has worked for me.

[mroliver77]

Your complicating it Mike. I have an 1/2" thick 5" x 5" aluminum plate that sits on my hotplate. I preheat my molds on it and leave them there while taking a break. There are some holes drilled in it for a use in its former life that a hp pin can preheat in. It works great! Before the hotplate I dipped the corner of the mold in the melt and then the pin for a few seconds. This was satisfactory but I prefer the hotplate.
Jay

[MikeS]

Jay:

You're talking about a Lyman style single HP cavity, with removable pin, right? What I'm talking about the pins aren't as easily removable!

[HeavyMetal]

Mike:
I've got a couple Cramer style molds and I've seen Eric's "update" design with the connector plate.

I've also seen one with a complete plate under the mold holding the pins but the makers name eacapes me at this hour.

To use any and all of these molds I built / welded a special plate to sit on top of my hot plate to pre heat the mold and keep it hot during the casting cycle. The idea is to hold the mold on it side so the mold contacts both the sprue plate and side of the mold to give max contact for conducting heat into the mold.

Since I cast using two molds one will always be in "rotation" on the hot plate to keep the working temp stable.

This works well and is about as easy as it gets. Never had an issue with boolits sticking to the pins.

[Lloyd Smale]

propane torch

[btroj]

Once the blocks get good and hot the pins will too. May just take a bit longer than "normal".
Most of the guys having this trouble aren't getting the blocks nearly as hot as they need to be. The blocks need to be around 350 to 400 degrees and I bet most of the ones having trouble aren't getting them much past 200 to 250.
Making the blocks taller added weight and expense. Those are two things I don't need more of.
My suggestion is this- if you get a Cramer type mould then learn to use it. Find out what it takes to make it run.

[fredj338]

Idon't seem to have that much of aproblem w/ my HP molds. With the cramer style, heat the mold, pour a few throw aways to heat the pins & start casting. For the removable pins, I dip them in the alloy & then start casting. As long as i keep a steady pace, the pin doesn't cool down.

[Larry Gibson]

propane torch

+1, this works for me before and during casting. Simple to adjust the flame for the right temp.

Larry Gibson

[MikeS]

Once the blocks get good and hot the pins will too. May just take a bit longer than "normal".
Most of the guys having this trouble aren't getting the blocks nearly as hot as they need to be. The blocks need to be around 350 to 400 degrees and I bet most of the ones having trouble aren't getting them much past 200 to 250.
Making the blocks taller added weight and expense. Those are two things I don't need more of.
My suggestion is this- if you get a Cramer type mould then learn to use it. Find out what it takes to make it run.

Well, if it's a matter of some folks not preheating their moulds enough, then I should have no problem. I routinely preheat my moulds to about 325 or so. I will definitely learn more once I get my MiHec cramer style mould. I'm not planning on changing it either, I just saw Erik's 'Inset Bar' multi pin HP, and was thinking that if when preheating a mould like that, if all the heat was going thru the block that held the HP pins (by having it being the part that's in physical contact with the hot plate) that it might help get the pins up to casting temp quicker. I don't think having that block 3/16" thicker would really add anything much to the weight or cost of the modification, which is already a high priced mod.

I'm also kind of curious, with his mod, where all the pins are held together as a unit, rather than each pin being free floating (independent of other pins) like the Cramer, or RG pins are, if that could create a problem if one of the cavities should stick?

Has anyone here actually used one of Erik's 'Inset Bar' conversions? I'd love to hear thoughts from somebody that's actually used it, and even better yet, somebody that's used it, Cramer style HP, and RG2(4) style HP setups, Just kind of curious what folks think of the various systems for multi-HP moulds.

And just to clarify something, I'm going to be getting a Cramer style mould from MiHec within the next few months, and will no doubt learn a lot more about them once I have one, but as a machinery designer, when I see something, I always wonder if there's a better way to do it. Not because the way it's being done now is bad, just natural curiosity if it can be done differently that might be better.

[btroj]

The insert bar looks like it should work fine. I wonder if he went that route because it was an easier retro fit? Since Miha uses CNC from the start his method may just be easier for him to machine.
I wonder also if some of this is because they just thought up a way to do it and went down that one path.
Once you get that Mihec Cramer style you will wonder why you used anything else. I personally prefer it to my RG 4 NOE mould but that is just personal preference. Seems to be less "fiddly" when closing the mold.

Get you mould hot enough, keep the part that holds the pins to the block lubed, and you will get ALOT of bullets fast. I really like my 359640 HP mould. That is good because my Marlin does too.

[HARRYMPOPE]

The insert bar looks like it should work fine. I wonder if he went that route because it was an easier retro fit? Since Miha uses CNC from the start his method may just be easier for him to machine.
I wonder also if some of this is because they just thought up a way to do it and went down that one path.
Once you get that Mihec Cramer style you will wonder why you used anything else. I personally prefer it to my RG 4 NOE mould but that is just personal preference. Seems to be less "fiddly" when closing the mold.

Get you mould hot enough, keep the part that holds the pins to the block lubed, and you will get ALOT of bullets fast. I really like my 359640 HP mould. That is good because my Marlin does too.

MiHec stole Erick's reintroduction of the Cramer idea.The inset bar is a work of art superior to the Cramer in every way.

George