If I was going to do the Flux concentrator again I would not have bought the one sold by Fluxeon and just bought some Ferrite bar stock and cut and shaped it to how I wanted it. There is nothing wrong with the part from Fluxeon however.
All you need to do is use some glue to join the two halves together. I used a metal glue like liquid weld. You may want to shape the ends from square or round to form a smaller concentration. You may also want to change the gap in between the two halves depending on size cases you are annealing. When I purchased the parts from Fluxeon I got 4 halves to make 2 concentrators with different gaps.
You will need to coil the Litz wire around the Ferrite as shown. The Litz wire works by having lots of smaller stands of copper wire by doing this it increases the effective current if you like due to skin effect so 500 small wires is like having 500 turns of one larger wire. For that reason you cant put it in a copper tube as that would negate all the small wire skin effects.
The duty cycle is not that bad as it runs at a lower overall current than a 7 or 8 turn coil made of copper tube. The main area of limitation due to heat are the components on the board mainly the Inductors and the capacitors and the connections to the Litz wire. Heat sinks that can be stuck on the underside of the board help.
Your unit is looking good so far the box is the hardest thing. On the copper tube coil you need to make sure that each wind is insulated from each other. You can buy some fiberglass tubing on ebay for $1 per piece and it works great. Makes winding the coil easier too.
Thanks mate, re the flux coil, not run Litz wire inside the tube but around it, kind of plait two 500 strand cores together or no tube maybe ? Depends on how strong it is at staying in one place. And how cool it stays.
Good tip on the glueing the halves together
My first induction board was a bit low on the Feq range and I ended up putting copper plate strips along the capacitor banks on the under side, as it heated up to the point where the board started to delaminate!
While I certainly admire the skill-set you blokes have in building these units, I don’t think @Oldbloke is about to go to that much trouble for 20 odd rounds.
For small batches, a drill, a socket just big enough for the case head and a gas torch held in a vice is all that is required to do the job. Also, I’ve found that in dim lighting I could read the heat change better. Tempilaq, as has been suggested makes it even easier. Clean, tumbled brass gives best results, drop a case into the socket, get the drill spinning, ( on low speed ), and for me, about 6 seconds is what works for the cases I’ve used this method on. I do have a machine but save that for doing large batches.
Sooo, last week I annealed 30, 30.06 cases.
Gas torch in vice.
3/4" wooden dowel with hole drilled in one end to hold the case.
Rotate in flame by hand, about 5 - 6 seconds.
Flame placement seems important. I aim for the shoulder.
Low light can see the change to blue easily.
Dump on a damp piece of damp cotton cloth.
Will make a massive leap in technology one day and use a drill as above.
No perfect but does a reasonable job.
Been doing it this way for a few years
The drill just gives more consistency, turning by hand is a bit erratic but does work.
I use the drill method when I’m just playing with some load testing in small batches. For bulk batches of brass, I have one of the Kase Annealers shown way above that I bought a few years ago.
@sungazer been looking at the induction annealer links… Yes, boredom and thought, screw it, I want to build one (with coolant/pump) .
Had a look at the schematic and your setup, a few differences. Can you share where you bought the induction coil? Also, regarding the induction board, where did you buy it from and what’s the model (link)?
Do you mind sharing some detailed photos of the guts of the machine?
And any other lessons you learnt, for example where did you shop for parts? What power supply would you suggest (link to shop?), any other components that work better than those listed on the Accurateshooter?
The Induction board is of this type. I ended up purchasing 4 over the journey and I cant find the best one quality wise available now. Whatever you need to reheat the major joints as they are most likely cold solder joints and will have cracked in transit. Mostly the coils on the board but also heatsink and transistors.
The best one I bought was only about $5 the cheapest now is $17
The size of the copper tube coil in the origanal build on Accurate Shooter is 1/8 This is a bit thin and very hard to pump water through.
I used 4mm tube and also dropped a coil off using only 7 turns this works well both heating wise concentrating wise (not so tall) and liquid flows much better.
The power supplies from Ali are suitable. Also on ebay a little more expensive. You need a 12V source and a 36 or 48V source. I have used a 48V as have most other people I have turned the voltage down as much as possible though so now 45 V. I think a 36 V may give better results slightly longer anneal times it might heat up the board more? but probably more adjustable in the anneal temps as it will heat slower. The rate of temperature increase is incredible.
The timer and there are two that both look the same so be careful both will work but with the two relay you can program the trap door to activate after a set time or program a wait time between anneals to slow you down and give the board some cool down time.
To cool the induction coil I used this pump and this computer water cooling radiator.
Power supply from Ali or ebay
It needs to be at least 600W
Make sure you use a relay for the switching of the power supply to the induction board. I wanted to use a Solid State Relay but they kept burning up it may have been under rated Chinese parts or it might have been flyback voltage spikes taking them out. I tried using diodes to protect them but in the end old reliable contact points work. There is quite a ark across the contacts when they switch so limited life ?
Some of this may be out of order it was a bit hard to track down parts from a few years back. So ask away to put it straight or fill in details.
To operate a trap door I used this little solenoide
I had to make the trap door a L shape to get some leverage to get a bigger opening rather than just use it as a straight pull. Try at description so the door is a L shape with the piviot at the point if you looked at it like a pointer the long end of the L is over the hole and the solenoid pull at the tip of the short end.
Also, can you share the details on the coil? did you buy after-market one somewhere or ‘coiled’ your own; and if you did, what’s the internal diameter?
I rolled my own coil out of the 4mm copper tube the internal diameter is 2.8cm I think the mandrel I wound on was 2.5cm.
I placed the tube in this fiberglass covering before winding the coil and the soldered this 4mm tube into some of the larger pipe that comes with the unit as it fits in the clamps better and also the water tube which is held on by just hose clamps.
The ones in the Automotive section are not really upto the job despite what they may say their current or wattage ratings are Large is your friend here lots of gap between the contacts.
