Locator / Alignment pin height for RCBS molds?

[ohland]

I bought a new RCBS 243-095-SP, and the finish and fit are good. Issue arises when you want to open the mold. If you use your hands to pull the halves apart, it's just so, no slop. Try with either RCBS or Lee handles, and it hangs on one pin every time. Tried turning the block end-for-end, but the same pin binds.



The pin that does not bind is .140" high.
The pin that binds is .153" high.

I ran through @ 50 bullets casting, and having to jerk the handles apart to open the mould causes some boolits to fly off and land on concrete.

Buffalo Arms said to contact RCBS. One RCBS tech brightly said he used all RCBS gear without a problem, but did not answer the pin height question.

Sent another note today to RCBS, titled alignment pin height, asking very specifically, what the height is.

An idea to make a precise seating jig: take a piece of flat stock, mill a pocket .140" deep. Take the block half with the pins, place the stock over the pin, stick er in a vise, and close it. When the stock goes flush to the mold face, the pin should pretty well be .140" high.

RCBS is doing this:

[462]

I'd call RCBS, again, re-express your dissatification and request they reimbuse your postage cost to return the mould for repair/replacement.

Aside from that, gently tapping the pin back toward the mould face, till the two halves close properly, is a quick and easy fix.

[RobS]

Just use a brass hammer to tap the alignment pin down a bit as 462 stated; quick easy fix. If you don't have a brass hammer then take a penny or nickel and tape it to your hammer (tape over the nickel and onto the hammer). It'll will hold up as you'll only need a few persuasive taps.

[peerlesscowboy]

Just use a brass hammer to tap the alignment pin down a bit as 462 stated; quick easy fix. .....

I've had to do that with the last two RCBS moulds I've gotten, seems to me that they should be able to fit 'em better at the factory but OTOH it's an easy fix.

[Doby45]

You can fix it faster than you typed your original post. (Rob Sneider from Water Boy) YOU CAN DO IT!

[MtGun44]

Use a brass drift to tap it very slightly down, checking the fit OFTEN and you will fix it very
quickly.

Bill

[ohland]

In the finest traditions of over engineering, I outdid myself.

Took the mould half off the handle.
Stuck the block in a smooth jawed vise.
Turned the handle a bit.
Measure, repeat as needed.

Results? the high pin is @ .127, mould opens MUCH easier. Still a slight hang, but slight. Whenever I get some pin height measurements on well adjusted RCBS moulds, I'll finish applying micron level fine tuning.

[RobS]

Are you using a mold lube? This may very well take care of the rest.

[gray wolf]

I'd call RCBS, again, re-express your dissatification and request they reimbuse your postage cost to return the mould for repair/replacement.

Aside from that, gently tapping the pin back toward the mould face, till the two halves close properly, is a quick and easy fix.

Yes and yes

I had a mold from RCBS that you could not open, the pins were set so bad.
One call and got a new mold. All the advise is spot on, but it looks like you are on your way.

[ohland]

Thanks for the commiseration, but could someone measure the pin height >on both pins< from an RCBS mold that is easy to open and that closes good?

I can set the blasted pin height in .001" increments if I wanted to. What height is good?



"What we have here... is failure... to communicate"

[ohland]

Well, they did reply with useful info. Glad this isn't brain surgery.

We do not have access to the dimensions for the pins. Set the pins so
they are tacky and pull apart easy. Let us know if you have any other
questions. Have a great day!

Thank you,

Technical Services/xx
ATK/RCBS Operation
(800) 533-5000

[cbrick]

Not un-common to need to adjust alignment pins on any brand of mold, not just RCBS. I have never given a thought to what the pin should measure in thousands. If the mold blocks are loose I use a brass punch to tap it out, if as in your case, it is too far out I tap it in with one or two light taps checking the block halves fit often. The whole thing takes about two minutes and should never need to be done again on that mold.

I doubt if RCBS has the measurement your looking for, there is probably more variance in the alignment hole diameter and chamfer that would preclude an exact measurement in thousands for the pins.

My last new mold from NOE needed a slight adjustmnet of one pin and NOE is one of the world's premiere mold makers. It happens but it is a quick, easy fix. If you don't have a small brass punch Lyman sells one with a small brass hammer for a few bucks, that's what I have been using for many years.

Rick

[smoked turkey]

I only have two RCBS molds. Both needed slight adjustment. As has been said I just tapped ever so easily using a brass punch, then tried the fit by just using the mold in my hands. When the halves come apart easily, its fixed! So easy a cave man can do it as they say. I doubt there is such a thing as a specific pin height. I recommend you just do it by feel. You'll know when its right.

[ohland]

Gave 'er a bit more squeezing love in the vise. Not quite fall open like some molds that I've used, but she locks up tight.

Pins are at .127 front and @ .114 rear, not nuklear rocket science.

Odd, does any mold maker tell folks that pin adjustment is normal?

[cbrick]

Odd, does any mold maker tell folks that pin adjustment is normal?

In a perfect world they wouldn't ever need adjustment but in the real world of mfg tolerances it does happen on occasion, I wouldn't go so far as to say it's normal but it does happen. Now that your aware of the cause and the fix it should no longer be a big deal for you.

As long as the cavities are good cast'em & shoot'em.

RCBS has been putting out a really nice, high quality mold the past few years. They had some problems for a couple of years and soved it with brand new computer controlled machines. The last few RCBS molds I bought were exceptional.

I recommend you get some Bullplate & lube the pins & sprue. The key to success with Bullplate is that a very little goes a very long way. You do not want it in the cavities, you will not be a happy camper. Follow directions that come with the bottle.

Rick

[justindad]

I’ve got a brand new RCBS mold that needs alignment pin adjustment, which is evident to me because I can see light pass through the mold halves . My adjustment method is to place washers around the pin and use an arbor press to drive the pin. The washer stack ensures both pins are at the same height, which I suspect is more important than the nominal pin height.
*
I had an NOE mold arrive with eccentric cavities, which was caused by a mismatch in pin height. When I got the pins to the same height, the cavities were concentric.
*
I’m here now because the backside of my pins appear staked. If that is correct, then pin adjustment would be impossible. Since other folks have adjusted RCBS pins, I must be wrong about the staking.

[jsizemore]

The pins are made to be moved. They should be a slight interference fit so when the handles are used to close the mold they are a snug but not tight and no light between the blocks. You check each pin independently. There used to be a sticky on the whole procedure when setting up a H&G mold.

There is a bit of wear to the mold block from the harder pin especially if they aren't lubricated.