Author Topic: LBT Mould construction  (Read 936 times)

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Offline krems

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LBT Mould construction
« on: October 29, 2007, 07:07:24 PM »
Veral,
I have a number of moulds from LBT and the only negative comment I have are the tight fitting spring pins you use. The blocks are hard to open sometimes.  Do these wear out the aluminum sockets over time to where there is play in closing the blocks???......................Any reason you use the spring pins over the more traditional pins for alligning the blocks.  I'm sure you have a good reason or you would have made the moulds different.  No complaints ...just curious!!

Thanks in advance!..........................Krems

Offline Veral

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Re: LBT Mould construction
« Reply #1 on: October 30, 2007, 05:13:04 PM »
Thanks for asking!
I use spring pins for alignment because they will never loosen, nor do they deform the mold when pressed in, whereas solid pins have both problems.   Springs pins are not precision IN THEMSELF,  like ground pins would be, and for this reason, I handscrape the sockets to insure absolute precise alignment, more precise than any other method of alignment.
  The deep engagement which I insist on is what causes you problem in closing the mold tightly.  I do this so the mold alignment will never change or wear out for most customers,    IF A DAB OF MOLD LUBE IS APPLIED REGULARLY TO EACH ALIGNMENT PIN!  (Same for under the sprue plate out at the end where the spring finger holds it down, and on the pivot screw area.  The best mold life I have had reported to date was 400,000 bullets from a four cavity, which was returned to me out of customers pride in it's performance,  It was still casting round within .0002 inch.  Half the thickness of saran wrap!

  Being a bit pig headed about quality I set myself this standard way back when I started making molds, 27 years ago, and use it with all my products.  -- If there is any problem with what I make it gets reengineered  and the change incorporated in all future products, immediately!  A couple of bullet designs were yanked instantly,  when I got bad reports, back there in the beginning.  Though I still had them in the catalog till my stock of catalogs was used up, I refused to make them.

  So, you'll see no blush when I claim LBT molds are the best made in the world.!
Veral Smith

Offline krems

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Re: LBT Mould construction
« Reply #2 on: November 02, 2007, 04:35:06 AM »
Veral,
Thanks for the response.  I understand why they are made this way.  Keep up the great work!.  All the LBT moulds I have are still tight as when new!

Krems

Offline krems

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Re: LBT Mould construction
« Reply #3 on: November 02, 2007, 06:35:55 AM »
Now you got me thinking about some of the moulds I have besides yours.  W/ Aluminum moulds wouldn't the spring pin wear out the sockets because they have a greater hardness than the 2024 aluminum....???......The physics background tells me it has to. Also some makers have been using stainless steel pins w/ stainless steel bushings for their alignment system.  They must have thought that the stainless steel pins would wear out the sockets over time.  Does the heat factor play a part in any of this.??  I'm curious because I need to buy a couple of moulds for a winchester 38-55 rifle and a 45 colt handgun.  And I prefer round bullets year  after year. Talk me into odering some more of your moulds again Veral...

PS....I don't think I'll be shooting 400,000 bullets like the above mentioned LBT mould user.

Thanks..........Krems

Offline Veral

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Re: LBT Mould construction
« Reply #4 on: November 03, 2007, 04:07:54 PM »
Many small engines run aluminum cylinders, and soft aluminum at that, with cast iron rings and aluminum piston.  They stand up extremely well running 3600 rpm, which is a bit faster than most people open and close their bullet molds.  They last because they are lubricated.  Higher quality engines run cast iron sleeves and run considerably longer, but if either is run without lube life is measured in minutes and seconds and about the same for both.  No one runs close fit aluminum against aluminum though.

Run an LBT mold without lubricant on the pins and it will go out of round faster than a cast iron one without lubrication on the pins, but not a whole lot faster.    If the pins are always lubricated the mold will still cast round for your great grandchildren.

  However, to answer your question a bit more accurately, regarding hard steel pins wearing aluminum fast.  The steel being hardest will wear least, the aluminum socket fastest, but wear will only occur while the pin fit is real tight, until the pin engagement is broke in, then wear stops, same as the aluminum piston causes no wear against the aluminum cylinder because it has a bit of clearance with lube preventing contact.
Veral Smith