ZVS Induction Heater Testing Coils for Forging and Heat Treating a Striker
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- เผยแพร่เมื่อ 14 ต.ค. 2024
- My goal here is to be able to forge and heat treat a "Flint and Steel" striker. I will need special coils, so I start by making a few out of solid wire, just to get an idea of inductance and utility of a few different designs. Then, once I have an idea about what might work, I switch to insulated 3/16 inch OD copper tubing for the rest of the testing. I finally end up demonstrating the forging and hardening process for a small tool steel "Striker".
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Sir , you so alive. You do proper experimental science. I will share few equations with you in the near future I hope you know them as well. My heart goes to you and I am watching now your lecture. It helps a lot. Thank you sir and God bless you
59 minute. thank you for advice
The following isn't statement of fact, I'm muddling through my own experimentation in a similar area but with different materials, so these are more like questions. I have limited experience in the field of electronics...
Question:- Having two coils in series significantly lowers LC resonant frequency, so once you reach Curie temperature, you can't drive much more energy into the workpiece. You need to reach higher frequencies and that requires a smaller coil (or smaller tank cap/s with much higher power rating?)
You should be aiming for higher frequency (skin effect) so should use smaller single coils and keep the work moving to compensate for smaller coil area?
Or.. you could get a 10+ KW system and just thrash the energy into the workpiece?
On a budget, two smaller, separate systems running in parallel with different coil shapes might be a better setup?
Ironically, my brother has a masters in electronics so I should ask him.... but we haven't spoken for years. :/
I'm experimenting with inductively heating non-ferrous metals and it was very interesting following you through this video. I learned a lot, thank you! 🤗
IMNSHO,Higher frequences seem to be more appropriate for nonferrous metals. You have to look carefully at the info out there to acurately see how this works.
Re:
"Or.. you could get a 10+ KW system and just thrash the energy into the workpiece?"
Answer: Yup!
Re:
"On a budget, two smaller, separate systems running in parallel with different coil shapes might be a better setup? "
Answer: Maybe.
But those "15KW" (really about 7.5KW) units that are all over the internet do a pretty good job.
Example:
www.ebay.com/itm/335031067466?
I hope this helps.
56 minute. scientific truth
I bought a 1kW unit similar to your "banggood" one last week -my plan is just to harden small tools (for a rotary broach), the coil it came with is maybe 2 1/2" diameter 5 turns, 6mm tube. I made a similar coil using 4mm tube, with an ID of 1" which better matches my workpieces, but was surprised that the idle current jumps from around 2 amps to 7 amps (rather like when you flatten your coil), Is this because of lower inductance, or some other phenomenon? I wonder if you've looked at work coil geometry versus idle current (I've watched a few, but not all, of your excellent videos today, but haven't seen you explore this)
Yes, the higher idle current is a result of lower inductance.
See:
spaco.org/Blacksmithing/ZVSInductionHeater/WorkCoilsForZVSInductionHeater.htm
and look at the "Work Coil Data" spreadsheet that is linked on that page.
@@frenchcreekvalley thank very much, looks like a great resource 👍👍
Summary: Flat coils with cheater hot plates for max forging temps. A little taper on wooden forms for easier coil removal. DC solid state relay needs to be massively over rated. My take only and sure I missed some other valuable nuggets - thanks again!
Good summary! MORE THAN a LITTLE taper!!! For the smaller "flattened" coil I did have some taper, but not enough. I prepared for that situation by weakening the form ahead of time, so I could splinter it to get it out
It finally hit me that maybe a simple fast acting fuse in series with the DC supply would keep me from blowing SSR's. I will be trying a cheap route, using a 12 volt (automotive) 50 amp "fast acting" fuse and holder in the near future. (Higher volt-rated DC fuses and holders cost big $$$!) I still have 3 of the cheaper TWTADE 60 amp DC-DC SSR's on the shelf. We will see how that goes. I will be prepared to see a big arc in case the 50 amp fuse can't quench it when, and IF it blows. Maybe I'll even try the fuse thing without the SSR first. Hmm.
@@frenchcreekvalley Not sure how good it would be, but I have wondered how these smaller ten dollar Push Button Resettable Thermal Circuit Breaker rated @ 50 amps would work.
-For the 2.5kW ZVS heater do you think there would be any significant power output difference between 3/16, 1/4 and 3/8" coils?
www.amazon.com/Manual-Circuit-Breaker-125-250V-Thermal/dp/B07FF5HN6Y
@@mevk1 Quenching a DC arc is a very big deal. I am certainly not the expert here, but I doubt that the breaker you linked to would actually survive even if it did trip where it was supposed to. There are many specs for breaker design. Often they are designed to trip at about 125% of rated load. There are "fast action" and "slo-blo" and other tripping profiles to consider. We (I) need the thing to open the circuit within milliseconds of a current rise above whatever my "setpoint" is or, the solid state device in the SSR WILL fail, usually in the "On" state.
Re: tubing size:
I have never tried 3/8" OD tubing. But I have used both 1/4" and 3/16" and even (once) 1/8" OD tubing. In general, for a given length of tubing in a coil, the idle current seems to go UP as the tubing size decreases. So, assuming that you only have so much current available, the higher the idle current, the less you have available for the work. I use the word "seems" because, when I use smaller diameter tubing, I am usually making smaller coils, so it's probably not that simple.
Lastly, the diameter of the tubing does have an effect on the spacing between turns, which in turn affects inductance and power transfer, so that's another variable to add to the mix.