I Want To Build This Cartridge Case Annealer

brino said:
Thanks Jim!
What about copper? If I want to undo the "work hardening" that occurs?

-brino

PS: sorry if it's seen as a post hijack! No offense intended!
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The same with copper.
 
John_Dennis said:
I am wondering if anyone has experimented with these RPM meters. I really need one designed for precisely measuring low RPM in 5-9 rpm range. I could also measure duration instead, but I haven't found a way to do that.
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Those tachs won't measure in 5-9 RPM range accurately, but you know the gear ratio in the gear box so put the tach pickup on the motor shaft rather than the geared output and do a little math.

I would probably use a cheap stepper motor/drive and a cheap pulse speed controller. That way you can use the stepper drive PPR as the ''gear box'' and the rpm is a function of the number of pulses per rotation. You could hook the tach to the pulse input to the stepper drive to read RPM or duration.
 
This is not an rmp meter, but it does give you a simple and accurate method of setting and resetting flame time (when combined with some testing and the templaq). Add a 30-40 rpm motor and you should be good to go.
http://www.amazon.com/Unique-Goods-...=1452852521&sr=8-16&keywords=motor+controller

I have a similar unfinished build languishing on my bench. I used a bronze bushing, an aluminum cake pan, a couple of bolts for axles, and a motor with chain and sprockets to power it.
 
JimDawson said:
It really has nothing to do with ammo specifically. The way to harden brass (and aluminum) is to work it between rollers or other mechanical stressing. To anneal it, heat it and cool rapidly, The opposite of ferritic metals.
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Just a detail about cooling the brass, is the quench in water necessary? From what I have read about cartridge annealing air cooling in ambient air should be sufficient. Water cooling doesn't hurt but it adds a drying step to the whole process.
 
To more accurately measure low rpm you need to use more magnets. The more magnets mounted the better the accuracy for low rpm motors. If also place them on the fastest moving parts. Of course you need something doing the counting & math to give you the reading.
 
Very cool.

Also, this was linked on that same video, a person making one in their homeshop:
 
Re: Heat transfer on the shaft
If you want direct drive, you could create an aluminum coupler with heat sink fins to connect the motor to the rotating shaft. Phenolic or some other non-metal would work as well.

I researched a bunch of these when I was getting ready to start my build. One guy said he overheated the plastic gears in his motor; that and timing the release of the shell to the tray were the reasons I went with a chain drive.
 
Tozguy said:
Just a detail about cooling the brass, is the quench in water necessary? From what I have read about cartridge annealing air cooling in ambient air should be sufficient. Water cooling doesn't hurt but it adds a drying step to the whole process.
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There are two good reasons to quench.
You want to prevent the body of the case from annealing.
You want to stop the annealing.

Annealing the case body has issues, but more importantly, annealing the case head can cause major problems even on bolt rifles.
To anneal brass, the temp should be held at ~650 F for about 2 minutes. Since this would result in the heat spreading down the case, the more common practice is to heat to about 750 F for a few seconds. Since you do not want to fully anneal the case neck, the annealing must be stopped - so quenching is the common practice. If the case neck is over-annealed, it will not grip the bullet securely. Repeatability is fairly important in annealing, especially if the bullet is not crimped (a common practice in precision shooting).

I have always had some doubts that these annealers actually produce good repeatability when RPM and dwell time is blindly followed.
The roller will heat as the machine is being run, so it will be actively cooling the first cases, and actively heating the last cases. This will have an effect on the rate at which the case necks reach the proper temperature. One would really need to have a bunch of old cases that would be run through the machine to get it into equilibrium. It is easier to just watch it run and adjust it on the fly. The flame temp will also vary depending on the temp of the propane bottle and amount of propane remaining.
I think the platter style annealers answer most of the problems better than the vertical style.
One idea I had was to use a temp sensor and an Arduino to eject the case at the proper temp.
 
If the neck is over annealed the case is scrap anyway.
With many bottleneck rifle calibers, if the neck is properly annealed within a few seconds then removed from the heat source is it likely that residual heat will continue to anneal the neck and that enough heat will be conducted to the case head to anneal it? If as you say the case head is exposed to being heated during the heat treatment then it should be prevented by design features of the machine rather than be compensated for by water quench.
I have used water quench for handgun calibers but don't find it necessary for longer bottleneck cases.
 
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