Induction brass annealer redux

[Apex360]

Can someone tell me the approximate ambient temperature above the coil and offset about .5"-1" during annealing?

 

[Gina1]

Can someone tell me the approximate ambient temperature above the coil and offset about .5"-1" during annealing?

Not really sure what you are asking for.. The coil does not get hot during annealing. The coolant does get a little warm (after 50 cases) but the radiator drops the temp of the coolant back down.
Somewhere in this thread, one of our members shot an IR video of the coil during annealing, showing the heating/cooling cycle.
Gina

 

[Apex360]

Not really sure what you are asking for.. The coil does not get hot during annealing. The coolant does get a little warm (after 50 cases) but the radiator drops the temp of the coolant back down.
Somewhere in this thread, one of our members shot an IR video of the coil during annealing, showing the heating/cooling cycle.
Gina

Thanks. Found the IR video and got what i needed. Place a fixture above the coil amd offset a bit. Needed to make sure the shielding was adequate.

 

[303enfield]

Nice contributions from everyone.
I am about to start making parts purchases and still debating on the parameters for the power supply.
It seems some have proposed using a lower voltage and higher wattage PS but didn't expect them to work. Your original design draws around 8-12 amps at 43 volts depending upon the case in the coil. Depending upon the power supply internal loads and resistance relative to the annealer electronics and coil, you likely need the 43 volts as a minimum, correct? The voltage setting determines the amperage draw so a lower voltage setting won't have enough to cause the system to draw enough current, correct? Some spoke about needing a little more power in the event you may need a little more for a larger sized cases in the future. Jameco also sells a 750W, 48V power supply at significantly higher price ($169). I was considering this in order to not to risk not having enough power in the future. I plan to anneal mostly 308Win cases and possibly 338LapuaMag later on. Do I need to upgrade the induction heating circuit as well?

 

[Jose_Luis_G]

Nice contributions from everyone.
I am about to start making parts purchases and still debating on the parameters for the power supply.
It seems some have proposed using a lower voltage and higher wattage PS but didn't expect them to work. Your original design draws around 8-12 amps at 43 volts depending upon the case in the coil. Depending upon the power supply internal loads and resistance relative to the annealer electronics and coil, you likely need the 43 volts as a minimum, correct? The voltage setting determines the amperage draw so a lower voltage setting won't have enough to cause the system to draw enough current, correct? Some spoke about needing a little more power in the event you may need a little more for a larger sized cases in the future. Jameco also sells a 750W, 48V power supply at significantly higher price ($169). I was considering this in order to not to risk not having enough power in the future. I plan to anneal mostly 308Win cases and possibly 338LapuaMag later on. Do I need to upgrade the induction heating circuit as well?

If I should start now, I'd choose a 1000 W/48 V power supply. That works with everything.
Time of annealing is based on two parameters: the coil diameter and the number of turns.
These two control all the rest, amperage included.
Read all about coils in the thread.

 

[Gina1]

Jose is correct. It's like spending BIG $ for the very best scope you can buy. Cry once and then you have the very best, that you can always move to another rifle.
The coil that is spec'ed here was deigned for .308 .454 diameter. How much of the case you put into the coil will control the amount of current that is pulled from the power supply, and that in turn will set that amount of time you are annealing. In my case 6mm Dasher, with enough of the case in the coil (neck even with the top of the coil) I had to set my PS voltage to 43 volts to keep from pulling more than 12 amps. My annealing time is about 4.6 seconds. Now with a 1000 watt PS @ 48 volts current limit would be about 21 amps. In this case annealing time would be very short, As the case would get super hot very quickly.
If your going to anneal 338 Lapua. .554 diameter, your case will be closer to the spec'd coil sides, and this will pull more current. With out winding a larger coil for the .338, it would be good to have the extra current capability for the .338.
I'm not saying to go out and buy $$ a 1000 watt PS. Your choice of 750 watts is most like likely OK (about 15 1/2 amps). Again your controlling factor is how much of your case is in the coil.

Good luck on all of this. Oh and BTW I don't think you need to upgrade the inductor PCB. Just be sure to keep it cool with a fan or/and heat sink.

Gina

 

[303enfield]

Thanks again, for the tips. I finally finished reading through all the threads from start to finish. I finally ordered an RSP-1000-48 having the current limit feature. The only major change I have is possibly using the 50 amp induction board for the reason that it has a powered fan already on the unit. I am hoping using it will eliminate needing to epoxy heatsinks to bottom of the board. Targetshooter2 had experience with both 20A and 50A and can maybe comment.
I wanted to make the unit with a lower part count. I appreciate all the contributors and so happy I didn't try to fabricate my original stepper motor driven torch annealer.
Lastly, this project is fun to put together and I will be happy to report results, but...
my primary goal is to go out rifle shooting more and reloading and processing brass less. Anything that helps speed up reloading bench time and let us have more practice range time is best.
(Is evolving to progressive presses, wet tumblers and this annealer the likely result of where we all end up?)

 

[Gina1]

Thanks again, for the tips. I finally finished reading through all the threads from start to finish. I finally ordered an RSP-1000-48 having the current limit feature. The only major change I have is possibly using the 50 amp induction board for the reason that it has a powered fan already on the unit. I am hoping using it will eliminate needing to epoxy heatsinks to bottom of the board. Targetshooter2 had experience with both 20A and 50A and can maybe comment.
I wanted to make the unit with a lower part count. I appreciate all the contributors and so happy I didn't try to fabricate my original stepper motor driven torch annealer.
Lastly, this project is fun to put together and I will be happy to report results, but...
my primary goal is to go out rifle shooting more and reloading and processing brass less. Anything that helps speed up reloading bench time and let us have more practice range time is best.
(Is evolving to progressive presses, wet tumblers and this annealer the likely result of where we all end up?)

Really good idea, building the current limiting design. I really like it. The original "basic" design was the first one. The idea was to KISS (keep it simple stupid) So it was relativity easy to build.
Stay in touch and be sure to post a picture of your finished "build"

Good luck Gina

 

[bigfish28]

Thanks again, for the tips. I finally finished reading through all the threads from start to finish. I finally ordered an RSP-1000-48 having the current limit feature. The only major change I have is possibly using the 50 amp induction board for the reason that it has a powered fan already on the unit. I am hoping using it will eliminate needing to epoxy heatsinks to bottom of the board. Targetshooter2 had experience with both 20A and 50A and can maybe comment.
I wanted to make the unit with a lower part count. I appreciate all the contributors and so happy I didn't try to fabricate my original stepper motor driven torch annealer.
Lastly, this project is fun to put together and I will be happy to report results, but...
my primary goal is to go out rifle shooting more and reloading and processing brass less. Anything that helps speed up reloading bench time and let us have more practice range time is best.
(Is evolving to progressive presses, wet tumblers and this annealer the likely result of where we all end up?)

Check the fan voltage. Mine was 24v. Putting 48v to provided the old adage - It's the smoke that makes electronics (and automatic transmissions) work.

 

[Joergen Sivertsen]

Hello and thanks for this great thread. I read through the whole thread last year and ordered most of the parts during the winter. A couple of weeks ago i finished the build and the annealer works great. But i use a 600w 48V PS and i really would like a bit more power. Yesterday i received a RPS-1000-48. I used the original coil design from Gina and Hollywood with 8 turns and 1 and 1/8" ID. My question is, the induction driver board beeing max 20A and the PS able to deliver 21A. I guess i need some way to regulate the current. The RPS-1000 does not have the current limit feature as the RPS-750. But it has a remote voltage control feature. The only thing i need according to the manual is a 4k7 potmeter. Is this the way to go or do i need something else to controll the current? Thanks.

 

[Gina1]

Hello and thanks for this great thread. I read through the whole thread last year and ordered most of the parts during the winter. A couple of weeks ago i finished the build and the annealer works great. But i use a 600w 48V PS and i really would like a bit more power. Yesterday i received a RPS-1000-48. I used the original coil design from Gina and Hollywood with 8 turns and 1 and 1/8" ID. My question is, the induction driver board beeing max 20A and the PS able to deliver 21A. I guess i need some way to regulate the current. The RPS-1000 does not have the current limit feature as the RPS-750. But it has a remote voltage control feature. The only thing i need according to the manual is a 4k7 potmeter. Is this the way to go or do i need something else to controll the current? Thanks.

Two ways to regulate the current (1) you can reduce the voltage some what. On My unit I took it down to 43 volts. (2) How much of the case you put into the coil will effect the current draw.

Gina

 

[Frog]

I ordered my zvs board, pump and radiator today
Now all I need is a power supply and I can start my own GinaErick annealer

 

[Gina1]

I ordered my zvs board, pump and radiator today
Now all I need is a power supply and I can start my own GinaErick annealer

Fantastic !!! Good luck. If you need any help, PM me.

Gina

 

[BlindBat]

Afternoon all. I have been hugely impressed with all the input to the projects being built here, with so much help available I have been persuaded to give it a go. I am good with mechanical stuff....airframes and engines......but no avionics or electronics so please bear with what may be stupid questions......I am trying to learn some new stuff at the same time

I am hoping that I can get some advice on parts to use for a UK based build......240v AC @ 50hz

I believe I have found a contactor that would do the job similar to the original Gina parts list......a '3100 2 Pole Contactor, 30 A, 208 -> 240 V ac Coil'. Would this puppy do the trick?

If the answer to the above is 'yes that will do' then my next question is 'what varistor do I use'? I have looked at a couple of tutorials but I am struggling with what to order. Can someone help me out with an order from this link at RS components please?

I haven't figure out if I am going to use 12v or 240v fans yet but I believe the remainder of the components are pretty much voltage independent. Am I correct in that?

Thanks

Paul

 

[Gina1]

Hi Paul

Yes, that contactor will work very well. As far a the varistor the following RS number 769-1515 should do you. Only problem it only comes in a package of 10, and you only need one.

What the varistor is doing is shorting out the (induced voltage) voltage across the contactor coil, once the energizing volt is removed. Normal contactor energizing voltage is 240 volts AC.
Once the timer removes this voltage, the collapsing magnetic field of the contactor coil will produce an inverse high voltage spark. This will tend to shorten the life of the timer contacts.
Think spark plug coil when the points open. The varistor will not conduct at 240 volts, but will at the higher voltage, hence removing that high voltage spark.

12v or 240v fans the choice is yours. Cost being the big factor. 12VDC volt fans are nice as they are easy to find. Ask anyone who has taken apart a PC. And yes it is voltage independent.

Good luck on your build Paul

Any questions, feel free to PM me.

Gina

 

[BlindBat]

Hi Paul

Once the timer removes this voltage, the collapsing magnetic field of the contactor coil will produce an inverse high voltage spark. This will tend to shorten the life of the timer contacts.
Gina

Ahah, I hadn't thought about how often this contactor will operate......makes more sense now.

Thanks for the help.

PC

 

[303enfield]

Exciting build even though not all my parts have come past my doorstep. The copper tubing came in Friday.

Have we determined anything new about coil configuration other than the 1+1/8 inch outer diameter with 8 turns (using .125" width copper tube).?
There was some talk about a truncated hourglass shape for bottleneck cases but no definite details yet. It would be nice to see the data and justifications to improve on the coil shape.
I am intending on annealing 308 Winchester cases most of the time (possible 338 Lapua Magnum later). Would the modification to the coil be a slight reduction in diameter at the "belt" of the coil stack or a slight widening of the stack diameter at the bottom and slightly at the top?

 

[GrocMax]

Exciting build even though not all my parts have come past my doorstep. The copper tubing came in Friday.

Have we determined anything new about coil configuration other than the 1+1/8 inch outer diameter with 8 turns (using .125" width copper tube).?
There was some talk about a truncated hourglass shape for bottleneck cases but no definite details yet. It would be nice to see the data and justifications to improve on the coil shape.
I am intending on annealing 308 Winchester cases most of the time (possible 338 Lapua Magnum later). Would the modification to the coil be a slight reduction in diameter at the "belt" of the coil stack or a slight widening of the stack diameter at the bottom and slightly at the top?

I wouldn't recommend straying too far from the 1.125" 8 turn coil unless you have a current limiting function in the PS, then you can go crazy experimenting because nothing bad can happen. Start with what is known to work first.

The coil design in induction heating is very application specific, the shape of the workpiece influences the optimal coil design. Shaping the coil 'bends' the magnetic flux lines produced to a shape closer to the workpiece shape. In my case I used the very top turn to sharply bend the flux lines away from the top (larger diameter), the 2nd turn is much narrower than 1", 3rd turn a little bigger to catch the shoulder angle area, 4th 5th 6th turn full diameter, bottom turn is near parallel to keep heat out of the middle of the case. A smaller coil to coil spacing also results in higher heating. As long as you have the same turns and same avg. diameter the inductance is close to the same as a straight wound coil. Keep in mind when the tubes are very close together and the juice is flowing in opposite directions, a cancelling effect takes place and no induction is produced between the wires. This can increase efficiency if you have stray inductance going on between the board and your working coil. Be careful with conductive items inside your case, such as trying to pass the tubes thru individual holes in a metallic case. See diagrams in link.

There are many papers out there covering inductive heating coil design to guide you. Here is a sample-

http://www.stanleyzinn.com/induction-heating/coil-design-1.html

 

[BlindBat]

Evening all

Running into some issues trying to locate a power supply that would be suitable in the UK........

I have a search set up with mouser.co.uk that shows the supplies that I have found available as an example.

Is something like the Cosel PJA600F-48 going to do the job? Or do I need to go for something like the Meanwell HRP-600-48?

Thanks

Paul C

 

[Gina1]

Hi Paul...

I think the Cosel will do you just fine. 48 volts @12.5 amps (600 watts) Average annealing time for .308, 30-06, is in the range of 4.8 to 5.4 seconds If you read some of the earlier posts, it talks about how to set up your current set point, and then the annealing time. With my 6 mm dasher cases I have to slightly reduce the volt to 43 volts to keep from pulling full current (12.5 amps).
Also the Cosel, I noticed was less expensive than the Meanwell.

hope this helps

Gina