Calling all electrical experts induction help

[JeepHammer]

HD, you are more or less correct...
Don't underestimate the home built units, with a market this small...
Start with the small portion of the world's population that are regular shooters, a small portion of those reload, a much smaller portion of those consider annealing, and an even smaller portion of those actually try annealing, and even smaller portion educate themselves on the process to do it correctly, no matter what process they choose (induction, resistance, gas, thermal mass, etc).

And then there is that very tiny fraction that try electrical induction annealing.

And keep in mind with a small fraction actually annealing and NOT accepting the results from common use/practice (usually wrong),
Then the even smaller portion that will educate themselves enough to build their own machine...

Then, and ONLY then, they build machines for sale.
Figuring they have invested a ton of time & money in the education, they introduce a product to a tiny fractional market...

Doesn't matter if it's electrical, gas, load (hot load/heat transfer, lead pots, heated dies, etc).
Keep in mind not even the big reloading equipment manufacturers offer an annealing machine (RCBS, Hornady, Lee etc), you are dealing with VERY small market, not even they are interested...

Every currently available machine is a really small company making them, a version they cooked up at home. Again doesn't matter how it's powered.

So taking offense at home built machines falls apart pretty quickly when you break it down.
No matter what you buy it's just a slicked up version of a home built machine since General Dynamics (or like company) isn't going to look at a market that isn't a billion dollars in sales a year...

I don't discount anything unless I've personally beat it with a stick in the shop and rolled the rock round instead of just turning every rock over.
It's not discounted until I've picked it apart...

Just like your favorite machine,
All magnetic induction machines use the same principle (electro-magnetic induction).
All magnetic induction machines are adjustable, simply by timing exposure to the magnetic field, or by initial power supply input (Volts/Amps).

All machines have some sort of movement limiting/spacing.
Either by holding the brass & coil/Ferrite fairly precisely.
Depending on power output, absloute precise spacing often won't matter as much,and as can be easily proven, lower power provides a more desirable anneal.

You either want a machine that is 'Plug & Play' and you don't want to mess with building or experimenting, which is entirely a personal choice.
Or you want more precise results which require experimentation and fiddling with vairables.

 

[RC20]

Unclenick:

The thing about theory is well and good, but I will remind you that the electrical theory was in fact derived from experiment and not someone who discovered the deep truths ala Einstein and E+MC2 by thought.

Having lived with a mathematics major for a while, my conclusion is that upper math is more philosophical in a twisted way than science.

Real world on the ground is that any engineer be it electrical or otherwise, runs the data (computer these days) does a prototype and then adjusts the circuits as needed because if they are new, they don't comes out as intended.

Sure the reason is in there, but as I often have told management, do you want me to try to find out why this worked in the first place or do you want me to fix it so it not only works now, but anyone following behind me can understand how it works?

Maybe the best one was a current sensing circuit. As you take inputs and have to reduce the current down to something an electronic circuit can work with, there is a significantly complex conversion process and then an output to react to a high current level and machine shutdown.

Said circuit would shut down the machine on over current and there was no occur current there.

The short answer was once their lab saw it (and these folks made the BEST UPS in the world at the time) was to adjust the circuit tolerances so it did not occur.

5 resistors of 1% and a transistor replacement (different ops values) and no more issue.

This same circuit was not even running at 10% load, so it was a huge bust.

As good as those people were, they missed that.

So much for absolute theory, reality reared its ugly head and fortunately they were sharp cookies who knew the ins and outs and that theory falls to reality often, they could test it and see where their theory was going off track and compensate the circuit for it. Theory makes no provisions for variations, programs can but they to can fail to get it all captures. It happened in 1 out of 100 machines.

 

[RC20]

Unclenick: I am going to have to concede (I was wrong) on the current vs voltage end.

Having worked with 3 phase power and motors, we double the voltage and half the current but that is a function of motor windings and how they are wired in. Higher voltage is a series start (usually) and lower voltage is a parallels Star.

Too long since I worked DC circuits and the combination.

 

[hounddawg]

Jeephammer you forgot one thing - frequency. From what little I have read on induction heating frequency is also a factor. Although that would be a minor factor affecting the efficiency from what little I know. I have a minimal knoledge of this theory but I do know as couple of things and those are :

If a Annie or DIY kit arrived on my doorstep tomorrow the first thing I would do is install a flux concentration coil on it to focus the heat into a small as region as possible.

Secondly I would do some experiments to determine where that energy is being focused that might include heating a bolt in a darkened room to see which area begins to glow, or perhaps painting a stripe of Templaq vertically on the case and observe where it melts first. Every smart phone is capable of doing a video and there are tons of freeware video editing programs out there to be able to go through a video second by second

Next I would build a jig to position the case exactly where I wanted it into the coil to focus the energyon the correct spot on the case in a every time.

The next step would be to determine the time to heat the case to the proper temp. From the threads here that might be able to be accomplished with powdered templaq and alcohol. Way I see that is if the 750F liquid has metals in it to prevent proper temp indications in a magnetic field what metals are in the stick version. No one I know has access to a $30K thermal camera to verify that it works or does not

then and only then would I trust it to do the job intended in a safe manner, just my two cents worth

 

[Unclenick]

RC20,

You and Jeephammer both seem to have got the idea I am a theoretician. I've been in the trenches, climbed radio towers, done repair work on circuitry at all power levels, worked with high and low voltages, and designed instrumentation and power circuitry, including ferrite toroids, C-cores and E-cores for switching regulator coils, and even good old silicone steel E-core laminations to wind my own special-purpose power transformers. I started electronics as a hobby in high school, teaching myself basic transistor circuit design from books and working in a TV repair shop and repairing musical instrument amplifiers in the cellar of a music store. I was a licensed radio station engineer halfway through College and left school to work as a technician in a well-known instrumentation manufacturing company where I worked up to designing the instrumentation that QC'd the instrumentation products, and then went back to school and finished. That's where I got the rest of the story. Closure, if you will, to any remaining questions I had. That's why it means something to me. It explained all I saw and made prediction of what circuits will do much more certain. Once you've seen a lot of practical application, the value of the theory that explains it means a lot more to you.

Theories always follow observation to explain what was observed. The observation may be of experimental results or of natural phenomenon when an experiment cannot be performed (astronomical events, volcanoes erupting, etc.). When a theory is first put forward additional observers propose alternate theories and everyone continues to observe and theorize until, one by one, observational details eliminate all but the one remaining theory that everyone agrees consistently describes what may be observed to happen and predicts experimental outcomes correctly.

That process is how consensus is arrived at in science: it is when alternate theories cease to be argued by anybody. That is not to say nobody will ever, ever have new ideas, but as time passes without that happening, it becomes increasingly unlikely.

Among those basics that remain unchallenged in the world of E&M are Ohm's Law, Kirchhoff's Law and Maxwell's equations. Making up new theories like making up new definitions for terms is not going to go be unchallenged because all that arguing has already been done. Especially not when you can turn to the textbooks or the dictionary and just look them up.

If you have a thing that doesn't do a job or that you want to scale to a different size or that you want to improve in some manner, a prediction of what is needed based on theory is very useful. It saves immense amounts of time and expense from selecting inappropriate parts or inappropriate equipment. But of course, you still have to prototype the results to allow for the fact there are tolerances and manufacturing variables and sometimes, as I've experienced, just flat out bad documentation published about a component. That doesn't mean the theory is wrong, just that human beings fail to achieve perfection. No surprise there.

 

[JohnKSa]

Why does a 'Non-Magnetic' brass case MOVE in the electrical field?
Seems brass isn't non-magnetic after all... Neither is aluminum by the way, they are just VERY LOW on the magnetic scale...

Since any conductor can be moved by a magnetic or electrical field under the proper circumstances, by that logic, anything that can conduct electricity is magnetic. That's not true.

However, it is true that any conductor can be temporarily made into an electromagnet via the proper application of current flow--and that current flow doesn't have to be from a connected voltage source, it can also be induced by a changing magnetic or electrical field.

When you put a conductor (such as brass) into a changing magnetic/electrical field, current flow is induced in the conductor--you know that already because that's what this thread is about--that's what makes induction heating possible. You also know that any current flow through a conductor creates a electrical field and that any electrical field has an associated magnetic field because that's how motors work. The magnetic field generated by the induced current flow interacts with the original magnetic field and can cause movement of the conductor.

I started out as a technician. Making things work and repairing them was interesting, but I always wanted to know the explanations that went with the rules of thumb and the things I learned by experience.

 

[BBarn]

Quotes like the one above concerning magnetic materials and this one about electrical conductors

ANY electrical conductor MUST be slightly ferrous, even if it's 'Common' to call it 'Non-Magnetic'

are completely false. Unfortunately such blatantly false statements can ruin the credibility of the individual even if other things they say are true.

 

[jmorris]

If a Annie or DIY kit arrived on my doorstep tomorrow the first thing I would do is install a flux concentration coil on it to focus the heat into a small as region as possible.

One like this would do what you want, the bottom looks like the top and they join at a point in the center.

Wouldn’t be my choice for annealing a bottle neck case though.

 

[Unclenick]

…And I notice those pancake coils seem to be a popular induction heating configuration for limiting spread of the field along the coil axis. They were originally one of Nikola Tesla's ideas and feature in both some Tesla and Oudin coil variants. There is a calculator and formula at this site. The form or the formula is similar to the other single-layer cylindrical coil approximating formula I gave, and like that one is good for about 1%-2% accuracy up to about 30 Mhz.

 

[hounddawg]

One like this would do what you want, the bottom looks like the top and they join at a point in the center.

Wouldn’t be my choice for annealing a bottle neck case though.

Fluxeon sells a optional accesory

http://fluxeon.com/flux/products.php?

seriously though, every demonstration of generic and home made induction heater coils I can find on youtube looks like they are very unfocused.

When I was modifying my rig I tried a couple of different torches. One was a swirl type torch, and the heat was unfocused and overheated the case. Then I tried a small butane torch, it was too small and concentrated the heat into too narrow an area. It resulted in a small band of the case getting overheated before the neck and shoulder got up to proper temperature. For a torch powered unit I found the generic plumbers torch worked the best. When I focus the inner pencil point of the flame just ahead of junction of the neck and shoulder I get a nice anneal without overheating the neck but still heats the shoulder up to temp. My cases come out looking like they are fresh out of the Lapua box

Again just my opinion but if one really wants to use induction unit for annealing they should drop the money for a AMP but if they just want a easy and consistent anneal a Giraud or Annealeez torch unit will do the job nicely

 

[RC20]

HD:

I was disappointed that you seemed not to have read what I wrote.

The steps I took with the Annie were the ones you listed.

I don't claim knowledge but by feel the concentrator coil look the most usable for me (and I got to use my brothers and confirm it)

As I found the Templiaq is not to be trusted, I did a full test approach.

I have repeatedly streesed my annealing is not to the max but somewhere below that.

I did find the upper limits with glowing cases (sacrificial ones) in the dark to get an idea what too far was.

On each test I also noted positioning and its affects. As long as the vertical was consistent and I can keep that to 1/16 or better, the horizontal does not seem to be a changing factor but that is kept close as well, for sure under 1/8.

As discussed by JH, the concentrating bars make a difference and I opened those up to do two things (and contrary to Fluxion)

1. Slow the process down which gives more latitude
2. Make it less position critical (keeping in mind the jig setup keeps it within 1/8, maybe closer but at least that.

I ran tests with the 750 and 800 and noted that despite the discrepancy, neither one pushed into a glow.

I took the Crayon and applied it and confirmed that upper limit.

I then backed off a few more tenths of a second from what already was below the critical point.,

I continue to keep an eye on the process looking for flaws to show up, not success but looking for a failure indication.

I don't claim I can prove it, but all evidence I put into the quality control I could says its under annealing. Closer to 700 at a guess.

While its a work in progress I have had no split cases so there is another indicator the process is working.

As brass is a considerable investment for me (and you don't get range pickup of 7.5 Swiss) that also looks to be ROI on the equipment and time invested I in the process.

If a Annie or DIY kit arrived on my doorstep tomorrow the first thing I would do is install a flux concentration coil on it to focus the heat into a small as region as possible.

Secondly I would do some experiments to determine where that energy is being focused that might include heating a bolt in a darkened room to see which area begins to glow, or perhaps painting a stripe of Templaq vertically on the case and observe where it melts first. Every smart phone is capable of doing a video and there are tons of freeware video editing programs out there to be able to go through a video second by second

Next I would build a jig to position the case exactly where I wanted it into the coil to focus the energyon the correct spot on the case in a every time.

The next step would be to determine the time to heat the case to the proper temp. From the threads here that might be able to be accomplished with powdered templaq and alcohol. Way I see that is if the 750F liquid has metals in it to prevent proper temp indications in a magnetic field what metals are in the stick version. No one I know has access to a $30K thermal camera to verify that it works or does not

then and only then would I trust it to do the job intended in a safe manner, just my two cents worth
__________________

 

[hounddawg]

Apologies RC, I guess I just skim read your previous posts. As long you are comfortable with your cases that is all that matters.

 

[RC20]

Apologies accepted, I try to read the in depth responses.

And no, as long as I am satisfied is meaningless, if I am satisfied and the process passes a rigorous scrub be it mine, others and more often a combo of input from others, to me that is what is important.

Also important is to pass on what you have found assuming it is valid (the paint on Templiaq issue)

The good news it the consequence of a poor anneal are not dire for being wrong.

Worst case the mouths are too soft, it would be interesting to be able to shoot well enough to see just how much that affects accuracy. I don't see that happening for me.

I am sorry that there is not more testing done in all areas.

Do all the steps to the max and vary just a single factor (neck thickness, neck tensions, anneal etc) and find out just how much it affects the end result.

Obliviously then you could start with the easiest done and work your way down.

If you don't anneal well enough (and or often enough) then you wind up with split necks. You loose brass but that's not fatal, just annoying (and you can up the anneal and maybe salvage the rest.

I may not be right (I clearly was wrong on the volts/amps issue) but its not because I don't work at it.

And always to work to passing on best tested information as opposed to opinions.

ps: I really dislike the inability of many not to sort out opinions.

Seatbelts usage is one. I know of a case or two that seat belts killed a person. Held in and could not release.

In the vast majority of incidents seat belts save lives.

So one person opinion that they don't is simply wrong.

Is a 270 better than a 30-06? That's truly an opinion. I have my preference but its only that, both are fine capable cartridges a sis 308 etc.

Sometimes I do get surprised, until I started reading about 6.5 mm it was not high on my list, acutely pretty poor opinion.

The more I read about it and its documented capability of taking large animals like Moose, its, hmm, boy did I miss that boat.

 

[hounddawg]

Well Bryan Litz tested annealing in his book Modern Advancements in Long Range Shooting Vol 2 and has declared it meaningless as far as accuracy. I have yet to purchase the book so I have no idea exactly how he tested it. However I am sure that Litz being who he is did a pretty detailed test. I have $300 bucks invested in the Anealeeze and it is really convenient to use so I don't plan on stopping annealing after each firing. My primer pockets get sloppy before the necks ever get brittle and that includes all those years when I was using the old socket and drill routine every fifth loading so I must be doing something right. Also a couple of years back PRB did a survey on how the top 100 precision rifler shooters reload and 65% anneal so I am in good company I guess.

 

[RC20]

If its working then that is good as well.

The big deal these days is neck tension and supposedly annealing will be better,

Flip to that is that while it gets harder to insert a bullet the longer outside being annealed, its also pretty consistent.

Bart B take for his shooting was that factory loads (granted good ones) worked better than reloading.

I suspect I will never get to the point I can see the difference, some days I can't shoot worth a hoot.

 

[Unclenick]

Litz does go through annealing in his chapter on Neck Tension, though what he actually measures for this is the change in neck OD from as-resized to that with a bullet seated. The actual tensile stress in the case neck is mainly the hoop stress placed on it as the bullet goes in and expands its diameter. That would be measured in lb/in² of stress on the neck wall cross-sectional area. The problem with that number is any difference in friction inside the neck due to carbon deposits, dry lube, surface roughness, bullet coatings, etc., will change how much bullet pull results from that tensile stress. Thus, the stress on the neck grip alone does not tell the tale. You need bullet pull to indicate that.

Litz used bullet seating force as a surrogate for bullet pull force. However, in the end, he had little confidence in his instrumentation method, which was hydraulic with analog gauge, and which changed value with the speed of the press stroke due, I expect, to expansion of the hydraulic line and delay in settling due to orifice flow constriction, and he couldn't get a correlation between its seating force results in either MV or SD, and so abandoned it. I've seen different results reported, so it's an area that deserves further exploration.

Litz used the AMP annealer. He used 10X fired cases, some not annealed and some annealed after every firing and some only annealed after the 10th firing. He got no clear difference in muzzle velocity SD among them except for a very small improvement in SD for those annealed after every firing. Despite his lack of confidence in his bullet seating force instrumentation, this is in line with his test of bullet seating force, above.

But there are a number of things he did not do that would have given us a more rounded perspective, and he promises more data for the future. One would be to be to compare cases fired in a chamber with a loose neck to the results from a tight match chamber. Another would be bullets with different amounts of jump to the lands. Another would be to compare results for fast and slow powders to see if the latter types aren't affected more. Another would be to see if mixed brass was made more uniform by this method. Another would be to see if crimped rounds are affected by it. Another that would be whether or not gas gun bullet tilt and seating depth observed on rounds ejected after feeding are made more uniform by annealing.

The inference from Litz's work is bullet hold by the case is too small a factor compared to other forces to make much of a difference in MV and SD by itself. Probably nothing most shooters could see on target. Yet, Litz did get lower SD's for smaller calibers when using 0.003" of "neck tension" verses lesser amounts (much more, he points out, can damage some bullets). Some folks using the Lee Factory Crimp die under other circumstances have found they did get lower MV SD, Many years ago, pistol match shooters found military match ball ammunition seemed to be more accurate than commercial, and it was finally figured out it was due to added bullet hold by the pitch sealant.

So, is what Litz found really true only his set of circumstances (his chamber and component choice)? Litz himself suggests there are just too many variables to isolate them all to a certainty. The bottom line, then, is to test what works for you and not to get too hung up on someone else's test results. What you can take away, though, is that any effect of annealing is likely on the smaller end of the scale as compared to getting ignition and cartridge runout in line. This may explain why less precise methods also make out OK. And, of course, annealing will make your cases last longer, saving you a lot of future case prep time and work.

 

[jmorris]

The bottom line, then, is to test what works for you and not to get too hung up on someone else's test results.

That’s it but with that attitude you can’t get over 4 pages of posts...that mostly don’t have anything to do with the OP.

 

[Unclenick]

Sure you can. You just have to take a glass half-full attitude. One of the truisms Litz brought up is that handloading is an enjoyable hobby, and so time and efficiency waste aren't considered as costs by the participants.

 

[JeepHammer]

I will consider anything I haven't directly done. Just about anything at all...
If I've beat it to death I've generally learned quite a bit about the subject and can call BS on some of the stuff.

As for annealing having ZERO benefits, I call BS.
It *MIGHT* not have improved accuracy for ONE person (book or not), it's increases brass life for RELODERS, and that alone is worth the pice of simple annealing considering how expensive the top end brass is.

I've been able to MAINTAIN accuracy from my brass annealing.
Now, you have seen the guys that keep track of how many times the brass was loaded...
I don't know if it's for failure tracking, or newer brass was more accurate for them since tracking is a personal choice for different reasons.

I anneal so I don't track, I don't see accuracy loss since the brass stay consistent,
AND,
The brass lives much longer, it's primer pockets or damage to rim that usually disqualifies brass, not neck splits.

----

I've been hearing "You Can't Do That" & "That's Impossible" since I was about 8 years old.
I wish I had a $5 bill for everytime I've heard it, I'd buy an island and retire!

When someone stands in front of something doing the "Impossible" while the gadget is working, you can't put much credit in the 'Expert' opinion...
When the 10 year old is tuning the mechanical voltage regulator, tuning breaker point ignitions & rebuilding/remagnitizing magnetos, swapping out breaker points for electronic ignitions when the 'Experts' are dumbfounded, bet on the 10 year old...

When the 'Expert' says the wind generator won't work, while it's actively producing in front of him, bet on the guy that made it work...

When the guy that says there is a noticable increase in power application to the brass using Litz wire, but the 'Expert' says it won't, consider testing Litz wire yourself.
The Litz wire didn't read the book that said it couldn't work, the experimenter didn't read the book saying it didn't work, so it might just work in spite of what was printed somewhere...

Nikola Tesla was an amateur, invented the AC electrical grid we still use today, virtually unchanged,
Ben Franklin was a printer, amateur that invented lighting rods & closed heating stoves, discovered the thermal conveyor currents in the Atlantic.
Amateurs built the laying over plow, the disk, the harrow, the hay bailer, virtually all farming tools used for centuries that feed the world today.
Amateurs built the pyramids.
The list goes on...

'Experts' & 'Professionals' built the Titanic, Hindenburg, Chernobyl and every other disaster you have ever heard of...

Keep Experimenting and keep creating! Someone has to come up with this stuff that ISN'T limited to what's in print somewhere!
Let the 'Engineers' figure out how to package it so it can be made in China once someone creative figures it out...

 

[Unclenick]

Actually, Tesla got some formal education at Graz University of Technology (Austrian Polytechnic) on a military scholarship, but if I recall correctly, he got bored and developed a gambling problem when he was out-thinking his teachers (or, one in particular; see, Man Out of Time, by Margaret Cheney, or even just the Wikipedia entry on Tesla). But he could do integral calculus in his head (he compulsively calculated the volume of his food at every meal before tucking in) and was able to work as a professional engineer.

Otherwise, uniquely, for this thread, I am in agreement with your last post. The huge number of variables Litz referred to means that no matter what we find for one setup, enough of those variables may differ in another to make what had no effect in the first setup do something observable in the second. Litz has not fully succeeded in isolating annealing as a variable, IMO, but that needs further testing to prove out one way or the other.


On reconsideration of Mr. Morris's comment and rereading the OP, it seems all he wanted to know was why he could heat a drill bit more readily than a brass case and what he could do to get the brass hotter.

Taking the last first, we all agree he needed a higher voltage power supply.

The reasons the drill heated better are three-fold: Steel has higher electrical resistance to be heated by current than brass does. Being an iron-based material it has greater magnetic permeability (will form a greater internal magnetic field in response to an outside magnetic field) than brass has. Because the drill's geometery has higher volume-to-surface-area ratio than case mouth and neck geometry means it doesn't lose heat to air as rapidly as the case (doesn't cool as quickly in opposition to how fast it is being heated).

So the OP's questions are answered.

I doubt all possible questions about annealing and its methods will be answered for a long time. RC20 may be right that this kind of thing deserves its own forum somewhere, but that won't be here. It is too specialized. It really is better just put into its own thread, and this one should come to a close to let that happen.

It occurred to me an induction heater with careful timing control would be a way to heat treating cast bullets. Maybe we should try for something in the cast bullet forum along those lines.