Induction brass annealer redux

[LR88]

Added a "Analyze" routine to my software.
It asks for 5 cases to insert and anneals them to melting point , drops the case 0.4 seconds after max current. (image 1)
From average melting-time the anneal time is calculated (image 2 + 3)

eg 8.1 sec gives me 4.0 sec

 

[SGK]

But what formula do you use to calculate the anneal time? That's the key. AMP constructed their formula based on brass analysis.

 

[LR88]

The 5 "analyze" cases look like image 1.
Cases of same make annealed with the calculated 4.0 seconds shown in image 2 + 3
works with different cases (6,5 CM, 270win, 30-06, 308, 300Winmag, 9,3x62)
.222 or .223 not tested yet.

 

[LR88]

But what formula do you use to calculate the anneal time? That's the key. AMP constructed their formula based on brass analysis.

P = tMaxAv * (F + K * (tMaxAv-90)*0.1);

F = 0.48;
K = -0.016;
P => proposal in 10/s;
tMaxAv => time max current average in 10/s;

tMaxAv should be in a range from 6 to 13 sec (choose V ZVS accordingly)

 

[SGK]

And the basis for the formula?

 

[Cadtek]

Here is a brochure of case brass with annealing time 2 minutes. Half the time and you need to add 10° C. Think this gives quite the right annealing time and temperature.

 

[hdmunger]

Here is a brochure of case brass with annealing time 2 minutes. Half the time and you need to add 10° C. Think this gives quite the right annealing time and temperature.

Umm...I think that brochure is talking about larger/heavier chunks of brass than we are dealing with. With a slower rise to final temperature and the intent to anneal the entire mass, it is probably fine. But with our need to get just the neck/shoulder area to temp without having that high temp migrate down the body towards the case head, it just doesn't seem very applicable.

 

[Cadtek]

I didn't think about using 2 min. Here we can halve the time and add 10°C. First time to 1 min. second half 30 sec. third half 15 sec. and so on. After 7 halves, we are at approx. 1 sec. which is approximately the time we have the case above 400°C (750°F). At 100HV. we see that we have approx. 460° + 70° = 530°C (986°F). This agrees well with the temperature curve of the AMP posted earlier here.

 

[hdmunger]

I didn't think about using 2 min. Here we can halve the time and add 10°C. First time to 1 min. second half 30 sec. third half 15 sec. and so on. After 7 halves, we are at approx. 1 sec. which is approximately the time we have the case above 400°C (750°F). At 100HV. we see that we have approx. 460° + 70° = 530°C (986°F). This agrees well with the temperature curve of the AMP posted earlier here.

Okay...you are so far over my head that you are leaving contrails. I kind of feel dense having made the comment that I did, but I'm going to leave it there in case that other, denser, guy shows up and reads this part of the thread...

 

[Cadtek]

My English is not very good so I use Google translation and it does not work very well in Norwegian.

 

[davexre]

P = tMaxAv * (F + K * (tMaxAv-90)*0.1);

F = 0.48;
K = -0.016;
P => proposal in 10/s;
tMaxAv => time max current average in 10/s;

tMaxAv should be in a range from 6 to 13 sec (choose V ZVS accordingly)

@LR88 - assume I'm an idiot (it wouldn't be far from the truth... ha ha). I get how you'd arrive at tMaxAv. Just curious where the constants come from? Given your guidance for a tMaxAv range, I'm trying to understand how that falls apart if tMaxAv is less than 6. I may just be dumb or caffeine deprived this morning, but ... would help to understand what F and K represent, I guess? And, maybe it's just stylistic choice, but why not leave off the *0.1 and make K = -0.0016?

 

[jrb95]

[QUOTE = "8mm, poste: 37257133, membre: 1308153"] Des essais avec .223? J'ai testé (15) FC 223 REM à partir d'un copain - le tout dans la même boîte. Tout tiré une fois. Il y a une énorme différence aux mêmes réglages - certains fondus peignent une trace à la bouche, certains le long du cou n'importe où, et quelques-uns sous l'épaule.
D'autres calibres semblent avoir une très bonne cohérence par estampille. [/ CITATION]

 

[Gina1]

You've come a long way from page one of this thread..scratching my head (Gina1)

 

[dulcimer]

Hey all, here's my version of the GinaErick Induction Annealer:
First off, a huge thank you to Gina1 and Hollywood for making the idea of this design public, and especially to Gina for being so accessible for consultation. Secondly, I owe the inspiration of my design heavily to dabeechman's design (which can be found here http://forum.accurateshooter.com/th...-annealer-redux.3908353/page-41#post-37147086 and http://forum.accurateshooter.com/th...-annealer-redux.3908353/page-42#post-37147479) which I found very appealing for its compactness. I was able to find an enclosure, the Hammond 1416o, that matched almost perfectly.
Somethings I did differently included utilizing compression fittings for the reducing union between the 1/8" coil and 1/4" tubing, and using 1/4" compression x 5/16" barb fittings to attach to the coolant loop; the coolant loop only utilizes 5/16 vinyl tubing. I haven't noticed any adverse effects from the large brass fittings, and coolant flow seems more than sufficient. The 1/8" compression fitting does theoretically allow me to swap coils and drain fluid with relative ease.
Though it works fine mechanically, I'm not happy with the elevator and ejector system I have at the moment; the aluminum base absorbs too much heat and subsequently heats up the solenoid over extended use. I'll try to find another solution utilizing corian squares I have on the way.
Otherwise, it was a fantastic experience building this device (over the last several months) considering I was a complete novice in things electrical and building. This was one heck of a first electronic project to say the least.. but now I've got new tools and knowledge for the future. Hopefully this inspires other inexperienced readers on the fence to go for it.
I'd be happy to answer questions to the best of my ability, and my parts list is on hand if you're interested.

Here's a demonstration of it in action by over-annealing a .223 case

 

[Gina1]

Hi Abe. Got your conversation/PM a few days ago. For some reason every time I tried to send my reply to you I got some kind of screwy software error.

Any way
Congratulations

You got it done !!!!!

Nice design...

Regina

 

[Brucey Boy]

Hey all, here's my version of the GinaErick Induction Annealer... it's nowhere as advanced as some of the other designs I've had the pleasure of reading about!!
First off, a huge thank you to Gina1 and Hollywood for making the idea of this design public, and especially to Gina for being so accessible for consultation. Secondly, I owe the inspiration of my design heavily to dabeechman's design (which can be found here http://forum.accurateshooter.com/th...-annealer-redux.3908353/page-41#post-37147086 and http://forum.accurateshooter.com/th...-annealer-redux.3908353/page-42#post-37147479) which I found very appealing for its compactness. I was able to find an enclosure, the Hammond 1416o, that matched almost perfectly.
Somethings I did differently included utilizing compression fittings for the reducing union between the 1/8" coil and 1/4" tubing, and using 1/4" compression x 5/16" barb fittings to attach to the coolant loop; the coolant loop only utilizes 5/16 vinyl tubing. I haven't noticed any adverse effects from the large brass fittings (yet!), and coolant flow seems more than sufficient. The 1/8" compression fitting does theoretically allow me to swap coils and drain fluid with relative ease.
However, though it works fine mechanically, I'm not happy with the elevator and ejector system I have at the moment; the aluminum base absorbs too much heat and subsequently heats up the solenoid over extended use. I'll try to find another solution utilizing corian squares I have on the way.
Otherwise, it was a fantastic experience building this device (over the last several months ) considering I was a complete novice in things electrical and building. This was one heck of a first electronic project to say the least.. but now I've got new tools and knowledge for the future Hopefully this inspires other inexperienced readers on the fence to go for it!
I'd be happy to answer questions to the best of my ability, and my parts list is on hand if you're interested.

Here's a demonstration of it in action by over-annealing a .223 case

Great effort Abe. Very professional look. Can you post a video of it in action for 2 or 3 cases??

 

[dulcimer]

Updated my post, Bruce. Like mentioned above, I'm not a fan of the platform I have now so I'm redesigning it to hopefully get something similar to the traditional trapdoor design. The current design was simpler to make, but ejection puts too much force on the bottom coil, creates a longer footprint needed for the device, and has no means for cartridge centering beyond using your hands.. all in addition to the aforementioned heat issues.

 

[Brucey Boy]

Updated my post, Bruce. Like mentioned above, I'm not a fan of the platform I have now so I'm redesigning it to hopefully get something similar to the traditional trapdoor design. The current design was simpler to make, but ejection puts too much force on the bottom coil, creates a longer footprint needed for the device, and has no means for cartridge centering beyond using your hands.. all in addition to the aforementioned heat issues.

 

[Brucey Boy]

That is great - it works well. All of my work is in timber, so is my solution for your alignment problem. Firstly, mine is auto feed, hence the funnel. My trapdoor hole is 13mm diameter. I have attached another piece of plywood on top of that hole with a 19mm hole. The trapdoor hole is bevelled so when the case drops through the coil it is caught in the 19mm hole and then guided by the bevel to position in the 13mm hole where it sits on the trapdoor. With the average large rifle case (6.5Creedmoor, 243, 22-250) being about 11.9mm at the base it ensures that the cases are almost perfectly aligned every time. It also works quite well with my 223.

 

[davexre]

That Tempilaq is fried in my view. I don't think it is meant to be burnt like that. You are looking for a change in colour - a relatively subtle one, from green to a grey/green.
...
I found a case to illustrate my point. Unfortunately some of the Tempilaq has rubbed off but you can still see how the Tempilaq on the case neck and shoulder is a different colour from that on the side wall which didn't come to temp. Happy to be proven wrong but I believe that colour change indicates the Tempilaq hit 750F.

Here's a couple vids that might help show what Tempilaq should be doing - I realized that I only thought I knew what it should look like, too, based on various shooting forums. The first vid is from Tempilaq. The second vid is a demo of 750 and 475 degree Tempilaq being heated on what looks like a sheet of brass via a torch. In the second vid, note the color change in the Tempilaq before it starts to turn dark. That's the 750 degree mark, there. Past that, it's gotten hotter - so, if it's black, it's somewhere beyond 750...

So, SGK, I think you're right that your example case got to 750, but not beyond. The big question we've really got is whether or not 750 is the right temp to achieve the annealing we want, and I think AMP is showing that really, it needs to be a bit beyond that.

Minus using a Vickers hardness tester, the best option we may have is using a pin gauge to confirm the point where the brass stops springing back after being resized. Really, besides case longevity, the whole point here is consistent neck tension, right? Finding the anneal point that's consistently at the same neck tension (after annealing and sizing) seems to be a reasonable way to confirm that we're getting the desired results - and the easiest way to confirm that is a pin gauge. For instance, I shoot 6.5 Creedmoor and want consist .002 neck tension. So, I'd get .2610, .2615, .2620, .2625, and maybe .2630 pin gauges. I'd anneal and size cases (and expand, if doing that step). Then I'd see which pins fit and which don't. Ideally, with .002 neck tension, the .2620 gauge wouldn't go, and the .2615 gauge would. The others could be useful for determining where the case is really at.

I haven't gone that route, yet - still doing the Tempilaq and "guess" route, which seems to be working ok-ish, but I can feel that I still don't have 100% consistent neck tension when I seat bullets.

I'm actually in the process of converting mine over to Arduino control so that I can get a little more data on what my cases are doing as I anneal - and I'm following this thread with great interest to see if the Aztec theory pans out. I'm using the GrocMax current limiting power supply, so I'm guess I really need to track total power draw (cause voltage will vary downward as I hit the current limiter) rather than current draw, but I need to be able to gather the data first, so...