Induction brass annealer redux

[303enfield]

Interestingly enough, I checked into the possibility of purchasing square copper tubing (more efficient?). K+S Engineering out of Chicago sells small 12" inch lengths (1/8" square) for model builders. I called them and they can provide longer lengths but there is a minimum buy for it. The total is to be around $100 worth as a minimum.
I quoted 4ft lengths of the square copper tube (composition I didn't check) would be 8 pieces minimum ($12.62 each) and another $18 to ship.
I live on the west coast near Los Angeles. Anyone willing to do a group buy over the next several months to try out square tube? I can already imagine the logistics problems. One guy buys it, gently coils each into a wide 1 ft coil or just mails it in a Priority poster box (37, 11/16 inch long) and each person will will pay around $20-$22 per 4 ft section of copper tube.
A builder needs around 36" inches minimum to get the 8 coils and straight leaders long enough to run to the induction board. If enough interested people want to try it I may be willing to make a group buy over the next couple months (I still need to complete my annealer build.). The only issue is how to ship a straight section cheaply? Or do we just bend the ends and keep a middle 36" section straight? If anyone has found an alternate supplier or a method of pressing the round tubing a little more square, I willing to read it.

 

[GrocMax]

I looked into square tubing as well as forming 'D' shaped. Fab becomes tricky with either, may need to fill with cerrosafe and anneal to form. Yes you need a minimum of about 4' to form an 8 turn coil with enough pigtail for connection.

For D shapes a roller form tool would probably be easiest. Not sure .032" wall 1/8" OD will work well here, the reshaping will restrict internal cross section even further and introduce pump head loss in the cooling system. .014" wall 101 is hard to find.

 

[normmatzen]

Don't know why you would even consider square tubing? If you evaluate the heat flow situation of heat dissipating from a square tube you will find it is nowhere as efficient as round tubing. In addition, keeping it square while winding it will be a real chore.

My Annie has both the water cooled and air cooled coils and when annealing a couple days re-loading the heat is not an issue as the anneal happens so fast.

 

[alverman]

Hello everyone. I' m Marc and I live in Belgium (Europe)
I stumbled upon this thread a few weeks ago and haven't stopped reading it since.
I'm very tempted to have a go at it myself this winter but i haven't decided yet what version i will make.

At this time I have one question though:
If you make the coil as described in the first post, by winding the copper tube around a 3/4" pvc pipe, how can you end up with a coil with an ID of 1 1/8 inches?

 

[Gina1]

Hi Marc

I'm not sure what the actual dimensions are for PVC pipe in Europe. For schedule 40 PVC pipe, in the US, a 3/4" pipe is the "inside diameter"of the pipe. The "outside diameter" of the pipe is around 1 1/8". Hence winding the copper tubing around the 3/4" pipe will give you the 1 1/8" ID coil. Schedule 40 PVC 3/4" pipe was selected because it comes closest to the ideal coil size, and its low cost..

Gina

 

[GrocMax]

Use whatever will get you a 28mm-29mm ID coil. 3mm OD coil tubing is nearly the same size as our 1/8", ~ .007" smaller OD. Should work fine.

Looks like PVC is sold by OD over there. For pipe we use nominal ID which isn't exact, '3/4" pipe' will be a little over 3/4" ID and the OD depends on what schedule or pressure rating (wall thickness) it is with sch 160 being the thickest commonly available. I love imperial measurements.

 

[alverman]

Use whatever will get you a 28mm-29mm ID coil. 3mm OD coil tubing is nearly the same size as our 1/8", ~ .007" smaller OD. Should work fine.

Looks like PVC is sold by OD over there. For pipe we use nominal ID which isn't exact, '3/4" pipe' will be a little over 3/4" ID and the OD depends on what schedule or pressure rating (wall thickness) it is with sch 160 being the thickest commonly available. I love imperial measurements.

 

[alverman]

Thanks
I can get 30mm OD PVC tube and 3mm OD copper tubing. That is the closest to the original design that i can find. As you said, that will be close enough.

Right now, locating a suitable supplier for some of the items takes some time. I want to be sure that I can get everything needed for a basic build, before I order anything.

 

[Gina1]

Marc...

Good luck on your build

Gina

 

[alverman]

Marc...

Good luck on your build

Gina

Thanks, It might actually take some time yet before I start building. It'll be a winter project. I do plan to make a very basic unit, maybe even with a manual trapdoor.

Just wondering why an amp meter of 50A is needed if the current does not exceed 20A (with a 600W PS). Wouldn't a 20A model be sufficient?

 

[Gina1]

Yes a 20A meter would make more sense. At the time of my build, Amazon only carried a 10 and 100. So I listed the 100 in the parts list.

As I have said, this is every one's build. As you know from reading this thread, there have been a number of mods that have been added to it. Using a 20A meter would just be (now available) one more.

Take care
Gina

 

[GrocMax]

Just make sure the shunt is matched to the meter, it is the voltage drop across the shunt that is used to calculate current. Smaller capacity ammeters will have an internal shunt.

 

[justinh]

Just ordered most of Fishindog's parts list off page 22. going to attempt to build something

 

[sharp.shooter.ser]

I tried (as said) the cheaper approach. Got me a cheap ZVS (not the 1000W one), and a friend of mine made me a power supply, 25V 15A. Now, I didnt use the volt/amper meter (although I got it). I used 3 mm copper wire, 9 turns, ID is 18 mm. It took 3 minutes 15 seconds to heat the 8x57 case to 400 C. I was concerned that I might get it too soft (I did some testing, shorter time, longer etc with contact meter, not temiplaq since its not available here). Then I took it and have it measured, and the 3 minute gave me good results. Necks were soft (from 100-120 vickers) and mid and bottom were in the extra and spring hard, as described in http://valmontfirearms.co.uk/BrassAnnealingService.html . Results were not the same for every cartridge, but I am not sure is that necessary. I ve used some of those with no issues, but I still didnt check for accuracy when using these annealed cases.
I believe its all good, but the turnaround time, its a killer when doing 200 cases, so I might go the faster route for next project

 

[Gina1]

Shaking one's head... I can understand trying to produce the GinaErick annealer at a lower cost. What you have there sounds like it's not working very well. Precision shooting is all about consistent repeatably. the basic annealer does that. I think you need to go back to the original design. Innovation is good, but don't lose sight of what you are trying to do.
Gina

 

[Jose_Luis_G]

I tried (as said) the cheaper approach. Got me a cheap ZVS (not the 1000W one), and a friend of mine made me a power supply, 25V 15A. Now, I didnt use the volt/amper meter (although I got it). I used 3 mm copper wire, 9 turns, ID is 18 mm. It took 3 minutes 15 seconds to heat the 8x57 case to 400 C. I was concerned that I might get it too soft (I did some testing, shorter time, longer etc with contact meter, not temiplaq since its not available here). Then I took it and have it measured, and the 3 minute gave me good results. Necks were soft (from 100-120 vickers) and mid and bottom were in the extra and spring hard, as described in http://valmontfirearms.co.uk/BrassAnnealingService.html . Results were not the same for every cartridge, but I am not sure is that necessary. I ve used some of those with no issues, but I still didnt check for accuracy when using these annealed cases.
I believe its all good, but the turnaround time, its a killer when doing 200 cases, so I might go the faster route for next project

Fully agree with Gina1. I'm quite sure that you are using the wrong coil design. I'd change into 8 turns and a bit larger diameter. That will, for sure, speed up the annealing time. Also to use a water cooled pipe instead of a wire will improve the efficiency of the ZVS, due to less power losses in the coil.

 

[303enfield]

Maybe a better way to say it is...
Your primary purpose is to get consistent "ballistic" and "shooting" results. The less time you spend on the reloading and tooling bench, the better.
Try to get from the start to finish (annealing and reloading tasks) the fastest and slow down for marksmanship practice more.
Use only the excess free time to fine tune the annealing and reloading bench details.
First priority is time behind rifles.

 

[Mike17]

Hi,

has anybody of the RSP-750-48 users connected 0V to one of your switch pins of the current limitation (as in #300, 305, 345)?
The manual tells me the voltage should be between approx. 2V (40%) an 5V (full power).
What happens if 0V is connected to 7(PS) of the RSP-750-48? Any experience ?

Mike

 

[GrocMax]

Hi,

has anybody of the RSP-750-48 users connected 0V to one of your switch pins of the current limitation (as in #300, 305, 345)?
The manual tells me the voltage should be between approx. 2V (40%) an 5V (full power).
What happens if 0V is connected to 7(PS) of the RSP-750-48? Any experience ?

Mike

Not sure what you are referring to when you say 'switch pins' but works best leaving the voltage limit control alone and using the current limit control. Limit control does not work if you use the 0v, just put your control voltage to the PS, no ground. See pg 19 of this thread for diagram.

 

[Mike17]

Maybe this was the wrong word ;-)

At pg 19/#373 (att 1.jpg) there is the schematic with the hint to connect only to 7 of the power supply (without 11) - that's fine with me.

At pg 18/#345 (att 2.jpg) there is the schematic of the sub board.
Switch position "1" is connected via the black line to 0V of the 5V-LVR.

If I switch to position "1" 0V is connected to 7 (power supply - current limit control).
In this case the voltage is less than 2V and I'm not sure if this is right and what happen.

In your first idea pg15/#300 there is a resistor between the pot and 0V that is preventing that the voltage goes below 2V - that's fine with me, too.

Maybe I'm wrong and I haven't see this resistor in your schematic.