How to create a heat sink to keep neck turning tools cool and precise

[P1ZombieKiller]

I use PMA lube. I also have a process that is very regimented and timed out. Here is a time lapse video of my process. I check my case thicknesses on each case and when they move .00005" I know to move it back on the ice. You can see in this video that some times I place the cutter on the ammo tray and sometimes I don't.

 

[SteveOak]

Tens of thousandths 0.010 or tenths of thousandths 0.0001?

 

[xr650rRider]

Looks like 50 millionths!

Hey, he's really trying to be accurate.

 

[P1ZombieKiller]

most of the brass I make is .010"
When the micrometer reads .00995" I leave it off the ice until it reads .01005"
When the micrometer reads .01005", I put it on the ice.

With my PMA cutters, it is easy to stay within .0001" of desired thickness.

So did I get that decimal right? I am playing golf today, so I am not totally focused on this.

 

[JMayo]

What ever you do @P1ZombieKiller , it works.
Really Nice brass.

 

[jackieschmidt]

This solution is not high tech, and certainly not Blue Tooth compatible.

Years ago, at one of Mickey Coleman’s Matches at Rachel’s Glen in Alabama, a very well known shooter had to turn some fresh necks. He had his little hand held tool and his T Handle. A drop of oil on the mandrel, and he turned a neck. He then held the turner in a bowel of water for about a half minute, put a drop of oil on the mandrel, and repeated the process until he had about 25 cases done.

I think he won at least one yardage that week end.

 

[jelenko]

I put plenty of oil on the mandrel when I turn and never felt the mandrel getting tight or warm???

A steel pin .243" in diameter increases 0.00006318" inches in diameter for a 20F temp increase.

View attachment 1612899

Why doesn't this fact say there's no need to worry about having a heat sink while turning necks?

 

[JFrank]

most of the brass I make is .010"
When the micrometer reads .00995" I leave it off the ice until it reads .01005"
When the micrometer reads .01005", I put it on the ice.

With my PMA cutters, it is easy to stay within .0001" of desired thickness.

So did I get that decimal right? I am playing golf today, so I am not totally focused on this.

Are you letting the clutch slip and click when adjusting the ball mic ? I’ve always wondered if guys use that function.

 

[P1ZombieKiller]

Are you letting the clutch slip and click when adjusting the ball mic ? I’ve always wondered if guys use that function.

Yes. That's exactly how I check. I feel that clutch will give about the same stopping point each time.

 

[6BRA]

Yes. That's exactly how I check. I feel that clutch will give about the same stopping point each time.

I find it get better readings by feel long before the clutch slips measuring in the .0002s.

 

[jelenko]

Since brass expands at .000011 times it's length per degree F, if the neck is .0125" and the temperature went up 50*, the neck wall would be different by 0.00000687" - that's a difference over 50* of about 7 millionths. Are we saying that could possibly make a difference?

 

[Webster]

Since brass expands at .000011 times it's length per degree F, if the neck is .0125" and the temperature went up 50*, the neck wall would be different by 0.00000687" - that's a difference over 50* of about 7 millionths. Are we saying that could possibly make a difference?

Nice to deal with real info. Bad quality lube equals more heat. Like I said I never had a mandrel get warm. Warm doesn't mean it's getting bigger to any measurable degree. You can put simple info on this website and the replies indicate people don't under stand it or they ignore it.

 

[6BRA]

Donuts are heat generators

 

[6ShotsOr5?]

I use an old aluminum ammo tray i no longer take to the range. I place ice cubes in there and place the cutter on there as needed.

I run 7 different cutters. Some take a turn in the ice ammo tray every turn (once at temp) since they heat up more. Other cutters only take once every other cut. I measure every cut I place and when the thickness starts to vary up a half a click, I know its time to ride the ice.

View attachment 1614398

Me too, cuz’ I asked him how to do it.

 

[6ShotsOr5?]

Since brass expands at .000011 times it's length per degree F, if the neck is .0125" and the temperature went up 50*, the neck wall would be different by 0.00000687" - that's a difference over 50* of about 7 millionths. Are we saying that could possibly make a difference?

I’m not arguing with the observation that some have said they didn’t need to worry about it; however, I noticed that some are measuring their outcomes at a different precision than others.

I also noticed the above calculation is focused on the brass; however, maybe it should be focused on a geometry change for the cutting tool?

 

[jelenko]

I’m not arguing with the observation that some have said they didn’t need to worry about it; however, I noticed that some are measuring their outcomes at a different precision than others.

I also noticed the above calculation is focused on the brass; however, maybe it should be focused on a geometry change for the cutting tool?

Webster did the calc for steel: "A steel pin .243" in diameter increases 0.00006318" inches in diameter for a 20F temp increase." That's also about 6 millionths.

 

[6ShotsOr5?]

Webster did the calc for steel: "A steel pin .243" in diameter increases 0.00006318" inches in diameter for a 20F temp increase." That's also about 6 millionths.

0.00006318 is 63 millionths, not 6 millionths. It’s also 0.6 ten thousandths. The case neck micrometers that a lot of bench rest shooters use can be read to 0.0001 in +/- 0.00005 in. Some try to hold their thicknesses within +/- 0.0001 in of our desired thickness. @P1ZombieKiller is way better than most of us at achieving this. But only when he regulates the temperature of the neck turning tool.

The PMA neck turning tool body that @P1ZombieKiller and I and a lot of others use is made out of aluminum, not steel. Aluminum has a high coefficient of thermal expansion. So high that aluminum wiring has largely been replaced by copper.

 

[JFrank]

I wonder if anyone can see .0001 difference in neck wall thickness on paper at a 1000 yards. I know I can’t but if anyone can then please post the target.

 

[P1ZombieKiller]

I wonder if anyone can see .0001 difference in neck wall thickness on paper at a 1000 yards. I know I can’t but if anyone can then please post the target.

I can't comment on 1000 yards, but IMO you can't at 100.

 

[JFrank]

I can't comment on 1000 yards, but IMO you can't at 100.

I can’t distinguish .001 difference in bushing size at 100 yards.