Spur Plate Magmet

mrbill2 · 11-06-2009, 08:08 AM

Some time ago I made myself some thicker spur for my bullet molds for better base fillout. I like to keep them loose so they lay flat on the mold. In order to keep them in place when closed I installed a small magnet in the plate. Works great.

theperfessor · 11-06-2009, 09:45 AM

Neat idea. Is it glued in place?

BABore · 11-06-2009, 09:59 AM

Heat usually destroys a magnet in time.

theperfessor · 11-06-2009, 10:13 AM

I think the ceramic magnets are a lot more resistant to demagnetization than the all metal ones.

mrbill2 · 11-06-2009, 04:24 PM

No they are not glued in. So far so good, if they do come loose I'll center punch the edge. They are rare earth magnets bought from MSC. There is a small hole on the top of the plate not shown in the picture so they can be pushed out if the hole depth was to shallow, otherwise they would be hard to remove. I was surprised at there holding power.

Shiloh · 11-06-2009, 05:22 PM

I've often thought that thicker sprue plates would be a benefit. I'd also like to see a V or U shaped channel connecting all the holes.

Is Your thicker plate beneficial??

Shiloh

Cadillo · 11-06-2009, 06:47 PM

Quote:

Originally Posted by Shiloh

I've often thought that thicker sprue plates would be a benefit. I'd also like to see a V or U shaped channel connecting all the holes.
Is Your thicker plate beneficial??

Shiloh

I recently cast some bullets with an a friend's old H&G 68 mould which had the channel you describe. It is a nice feature that aids with controlling the sprue thickness. Why do the other mould makers not do this simple machine step?

Lazy & Cheap!

paul edward · 11-06-2009, 10:58 PM

I had access to a machine shop back in 1980 and made a few sprue plates from a thicker material for my 2 cavity RCBS and Lyman molds. As an experiment I milled a trough connecting two of the sprues. It has been working well ever since.

Not sure why the manufacturers do not offer this feature.

PED

oneokie · 11-06-2009, 11:15 PM

Quote:

Originally Posted by paul edward

Not sure why the manufacturers do not offer this feature.

PED

Thicker material=more cost for material.

Trough to connect the holes=more machine time-more cost.

trk · 11-07-2009, 05:26 AM

Rare earth magnets are formulated for the temperature range desired.
As they get hotter, they get weaker.
The strength of the magnet depends on both the formulation and the intensity of the fields when the magnets are 'shot'.

One can bore a hole and press the magnet into it, leaving a flush surface that will clamp another piece of steel directly to it.

Easy to remove - magnets tend to shatter when struck.

mrbill2 · 11-07-2009, 08:05 AM

Is Your thicker plate beneficial??

Yes. It does take a little longer to heat, but my bases ar nice and flat. The screw for the spur plate is kept loose so there is no gap between the plate and the mold. The magnet just helps to keep it in place because the screw is loose. It is not meant to draw the plate to the mold.

Quote:

Originally Posted by Shiloh

I've often thought that thicker sprue plates would be a benefit. I'd also like to see a V or U shaped channel connecting all the holes.

Is Your thicker plate beneficial??

Shiloh

XWrench3 · 11-08-2009, 06:08 AM

Quote:

I'd also like to see a V or U shaped channel connecting all the holes.

+1 on that, especially with my lee 6 holers! it would be awesome to just hold the mold under the spout, and have all of them fill one after the other without dragging it along.

Le Loup Solitaire · 11-08-2009, 07:56 PM

Thicker or heavier sprue cutters/plates do better. Firstly they are less likely to warp or get bent; they can tolerate a healthier whack if necessary from a mold mallet, plastic or lead hammer. They sit on the blocks with more weight and that helps with sharper and flatter bases. They need more heat to bring them up to temp, but they hold more heat and that helps in keeping the sprue liquid somewhat longer which in turn helps in feeding the shrinkage; and that minimizes voids and or incomplete fillout. A trough helps with the consistency of the pour as it moves from hole to hole as you move the blocks. If there is no trough or sprue channel then the caster has to tilt the mold and pour "uphill" to better control the uniformity of the melt stream from hole to hole... from the dipper or ladle or from the nozzle of a bottom pour pot and the sprues can become pretty grotesque i.e a lot more melt than necessary is used and the pot empties out quicker. LLS

11-06-2009, 08:08 AM	#1
mrbill2 Boolit Man Join Date: Oct 2008 Location: Lebanon County Pa. Posts: 121	Spur Plate Magmet Some time ago I made myself some thicker spur for my bullet molds for better base fillout. I like to keep them loose so they lay flat on the mold. In order to keep them in place when closed I installed a small magnet in the plate. Works great. Attached Thumbnails __________________ Mr. Bill2 CB Tip: John spilled his ammo coming up the celler steps getting ready to go to a rifle match. He won the match. Now he spills all his ammo down the celler steps after reloading.

11-06-2009, 09:45 AM	#2
theperfessor Boolit Master Join Date: Dec 2007 Location: southern indiana Posts: 551	Neat idea. Is it glued in place? __________________ ******************** Technology is an applied science, i.e., it translates the discoveries of theoretical science into practical application to man’s life. As such, technology is not the first step in the development of a given body of knowledge, but the last; it is not the most difficult step, but it is the ultimate step, the implicit purpose, of man's quest for knowledge. [Ayn Rand, 1969]

11-06-2009, 09:59 AM	#3
BABore Vendor Sponsor Join Date: Apr 2005 Location: West Michigan Posts: 1,087	Heat usually destroys a magnet in time. __________________ BRP Products, LLC Stock Group Buy and Custom Boolit Molds http://www.brp.castpics.net

11-06-2009, 10:13 AM	#4
theperfessor Boolit Master Join Date: Dec 2007 Location: southern indiana Posts: 551	I think the ceramic magnets are a lot more resistant to demagnetization than the all metal ones. __________________ ******************** Technology is an applied science, i.e., it translates the discoveries of theoretical science into practical application to man’s life. As such, technology is not the first step in the development of a given body of knowledge, but the last; it is not the most difficult step, but it is the ultimate step, the implicit purpose, of man's quest for knowledge. [Ayn Rand, 1969]

11-06-2009, 04:24 PM	#5
mrbill2 Boolit Man Join Date: Oct 2008 Location: Lebanon County Pa. Posts: 121	No they are not glued in. So far so good, if they do come loose I'll center punch the edge. They are rare earth magnets bought from MSC. There is a small hole on the top of the plate not shown in the picture so they can be pushed out if the hole depth was to shallow, otherwise they would be hard to remove. I was surprised at there holding power. __________________ Mr. Bill2 CB Tip: John spilled his ammo coming up the celler steps getting ready to go to a rifle match. He won the match. Now he spills all his ammo down the celler steps after reloading.

11-06-2009, 05:22 PM	#6
Shiloh Boolit Master Join Date: May 2006 Location: Upper Midwest Posts: 2,570	I've often thought that thicker sprue plates would be a benefit. I'd also like to see a V or U shaped channel connecting all the holes. Is Your thicker plate beneficial?? Shiloh __________________ Democracy is two wolves and a lamb discussing what’s for dinner. Liberty is a well armed lamb willing to contest the majority decision”. Benjamin Franklin, 1755 Utopia Is The Opiate of Liberals.

11-06-2009, 10:58 PM	#8
paul edward Boolit Bub Join Date: Nov 2007 Location: Denver CO Posts: 39	I had access to a machine shop back in 1980 and made a few sprue plates from a thicker material for my 2 cavity RCBS and Lyman molds. As an experiment I milled a trough connecting two of the sprues. It has been working well ever since. Not sure why the manufacturers do not offer this feature. PED

11-07-2009, 05:26 AM	#10
trk Boolit Master Join Date: Mar 2005 Location: Mountains of Virginia Posts: 458	Rare earth magnets are formulated for the temperature range desired. As they get hotter, they get weaker. The strength of the magnet depends on both the formulation and the intensity of the fields when the magnets are 'shot'. One can bore a hole and press the magnet into it, leaving a flush surface that will clamp another piece of steel directly to it. Easy to remove - magnets tend to shatter when struck. __________________ trk aka Cat Whisperer Chief of Smoke, Pulaski Coehorn Works and Winery N 37.05224 W 80.78133 (front door +/- 15 feet)

11-08-2009, 07:56 PM	#13
Le Loup Solitaire Boolit Master Join Date: Aug 2007 Posts: 549	Thicker Sprue plates/cutters Thicker or heavier sprue cutters/plates do better. Firstly they are less likely to warp or get bent; they can tolerate a healthier whack if necessary from a mold mallet, plastic or lead hammer. They sit on the blocks with more weight and that helps with sharper and flatter bases. They need more heat to bring them up to temp, but they hold more heat and that helps in keeping the sprue liquid somewhat longer which in turn helps in feeding the shrinkage; and that minimizes voids and or incomplete fillout. A trough helps with the consistency of the pour as it moves from hole to hole as you move the blocks. If there is no trough or sprue channel then the caster has to tilt the mold and pour "uphill" to better control the uniformity of the melt stream from hole to hole... from the dipper or ladle or from the nozzle of a bottom pour pot and the sprues can become pretty grotesque i.e a lot more melt than necessary is used and the pot empties out quicker. LLS