Induction forges

[Chris Cramer]

I see. I’ll make a video of my build if it works fine, so every one can feel more confident purchasing the unit. I’ve looked at some commercial units online that look pretty similar to a welder and plasma cutter. I’m a bit curious about how it would work for someone to use an old welder as a power source with good control of the amperage, and voltage, as long as the other components within the driver are strong enough to make the unit operational. High alternating current runs back and forth through the coil and generates an alternating magnetic field which creates the heat by induction. as soon as anything magnetic or conductive passes through the magnetic field then the cells within the metal continuously move back and forth creating heat by friction or high current. With that, a graphite crucible that fits through the coil is used to melt metal like copper brass, platinum, silver, and gold. That would be very useful for casting metal.

 

[kevin.decelles]

Thx Chris, From the pictures, the coil loop looks to be in the 2-3 inch diameter, not a 5-10 inch diameter that I'd expect for a crucible. Were you envisioning a different coil?

 

[Chris Cramer]

I keep getting put off by the plumbing/water cooling requirements. The power consumption seems reasonable, and would actually be pretty good off my solar here in the fire season, when the neighbors are least happy with my solid fuel forges. But I keep imagining all sorts of "water everywhere" grief in my future with one of these.

I’ll have to find a good way to seal the mini water hose, but even if a small leak does happen, it is only a very small quantity of water moved by the mini water pump. Commercial induction heaters pump cooled water through the coil from a small reservoir, that is cooled continuously to get rid of the heat. I’ll have to add that to my design as well, probably with ice if that could last long enough.

 

[Chris Cramer]

According to the information on Amazon the coil is 50mm. I don’t know if that refers to the inner or outer diameter, but the crucibles I ordered are 50mm as well and different heights. If they don’t fit then I could either widen them or make another one with some copper tube.

 

[Chris Cramer]

I've been trying to convince my Boss to buy one for years. We harden a lot of O1 fixture gauge pins a year, and currently just use oxy/acetylene torch. An induction forge would be awesome for our process, and the ROI would be pretty quick.

I have one of the little 1000w ones from banggood, and it will actually bring stuff up to 1/4" to a dull red. I haven't played with it much, but I'm sure with some different coil shapes I could find some good uses for it. I just bought it as a toy to play with. Would love to get one of those big ones at home eventually, but have a much longer list of stuff I want first. I've been tempted to buy one of the 2500w ones but I'd rather just hold out for the big guy.

How much voltage have you tried using it with? The more voltage the more current and power is generated. Several people have used the 1000W modules with a 48V power supply and are able to heat items as thick as 1”.

 

[Dan Dubeau]

How much voltage have you tried using it with? The more voltage the more current and power is generated. Several people have used the 1000W modules with a 48V power supply and are able to heat items as thick as 1”.

ok, I got mixed up on which one I have. Turns out mine is only 120w
This one
I've only run it from bench power supply on 12v. I've only played around with it a few times, and not in a long time.

 

[Chris Cramer]

I tested the induction heater, and it does work, but I don't know if it performs as well as it should have. I used a 30v 10a power supply which heated a 3/16" steel rod pretty slowly. The water pump circulates water from a bowl of water through the copper tube and back to the bowl which works well. I think it is just because the power supply could not provide enough power, so I chose to return the power supply and the heater. After doing some more research I found a more popular unit on Amazon, and a 48v 50a power supply off a different site.

 

[Chris Cramer]

https://www.amazon.ca/gp/product/B07ZTMD65Y/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

I just received this induction heater which requires even more power than the other. It barely heated a 3/8" steel rod with my 30v 10a power supply, but I know it works, I just need more power input.

 

[Chris Cramer]

I just received a 48v 50 amp power supply for my 3000W induction heater, and tested it out for the first time. This power supply delivers enough current to allow the induction heater to heat thicker metal stock. You can tell that it is drawing more current as you run thicker stock through the coil because the fan for the power supply starts to run very fast; however that requires you to heat some pretty heavy metal, like a 1/4" 1" square tube.
This is only my very first assembly/ test of the unit through quick wiring, I still plan on designing a fully encased machine that is wired/soldered correctly, equipped with a voltage/amperage meter, and a fully sealed water cooling system.

 

[6.5 Fan]

Chris, looking forward to your full build. At a farm show a few years back there was a business selling several sizes of hand held induction heaters geared towards farmers and repair shops. The idea was to use them on severely rusted bolts heating them up and not requiring a open flame of a torch.

 

[Susquatch]

Chris, looking forward to your full build. At a farm show a few years back there was a business selling several sizes of hand held induction heaters geared towards farmers and repair shops. The idea was to use them on severely rusted bolts heating them up and not requiring a open flame of a torch.

Gotta wonder how well that works...... Not much beats an OA rose bud torch......

 

[Dan Dubeau]

Nuts can't be stuck if they're liquid

 

[Tom O]

I just came across this in a pawnshop for 40 bucks I think its worth a go.

 

[Chris Cramer]

The induction forge has gone fairly well. I finished wiring a fixed multimeter ment to keep track of a device's amperage, voltage, power, and energy. The heater still works as well as it did when I first tested it, but the potentiometer I installed that is normally used for dc motor control did not work with controlling the heat from the heater. I don't think reducing the voltage input is enough to reduce the heat generated by the inductor. I've read more that a change in frequency is also required to control the power output of the induction heater, since it is an ac unit.
It can heat steel rod fairly quickly to bright red, which is enough for shaping wrought iron. However, at 1400 - 2000 Watts most other heaters I've seen online will bring steel to a bright orange or even white forge welding temperature. I'm thinking that may have to do with the size of the coil. In comparison to those high powered heaters, they have much smaller sized coils, which are probably more effective to smaller sized rods with the copper tube coiled closer around the metal being heated.
I did shape a smaller coil with the same sized copper tube, but I need to find a way to exchange the coils without having to open the case and remove the water cooling tubes to replace the current coil. If there is some sort of small water sealed copper/metal fitting that I could slip the copper tubes into for quick connection to the water cooling system, and remain connected to the power output.

 

[Ggordon]

The unit @Canadium quotes would cost 2.5 kilowatts of power per hour of running at 100%. So if you dig out a power bill, see what you're paying per kilowatt and multiply that by 2.5 will give you the hourly cost to run the unit.

But you are only running it for like 30 seconds at a time maybe 10 times an hour so in an hour you would only use it for like 5 minutes or about .3 kWh.


Sorry, just reread the post yes 2500 watts per hour of running. So you would get about 3.5 hours of run time per 2.5 kWh of power usage or at $.2 per kWh about 50 cents. Cheap cheap if it does what you need it to do.

 

[Chris Cramer]

I've gone back to my induction heater project. The previous 2500W module stopped working, so I ordered a replacement module which is 3000W. The power supply is 3000W but I can tell that it's working far too hard byhow fast thefan is running even when the module is only drawing about 1Kw by using a bit more than 20 Amps at 54 volts which is 1080 Watts.
I want to increase the duty cycle of the machine when it's working fairly hard by heating thicker steel or maybe melting metal in a crucible.
So I ordered a second power supply from aliexpress, the same as the one already installed; and I'm planning to connect them in parallel to deliver more current. The single power supply already delivers 54v and the max input of the module is 65v, so what I need is more current. It will also double the duty cycle.

Those are the updates only on the power supply and module. I also made improvements by installing a radiator system to cool the water that circulates through the coil for cooling. I found an old cpu cooler master that has several copper tubes running through an aluminum heat sink with a 12v fan on top which is ideal for cooling the water as it runs through those copper tubes. The rearranging of the parts is adding time as the case was designed around a different system.

 

[Ironman]

I keep getting put off by the plumbing/water cooling requirements. The power consumption seems reasonable, and would actually be pretty good off my solar here in the fire season, when the neighbors are least happy with my solid fuel forges. But I keep imagining all sorts of "water everywhere" grief in my future with one of these.

I would not worry about the water cooling stuff. Why not use a fish tank pump and filter setup to circulate the water? Toss the filter, not needed.
Heat rejection is not a big deal, it is the heat picked up from the iron bar that can melt the copper tube. I have seen stationary engines run for hours with hoses attached to a 45 gallon drum of water, and the water was not hot, just warm.

 

[Dabbler]

There are a bunch of DIY induction units described on Youtube; Some are even by reputable people(!!).

I have been thinking about replacing my oxyset with an induction heater for brazing carbide and small heating requirements (for a while). That's all I use it for these days.

There are so many advantages over gas, if a reliable power supply can be found. - All my kitchen cooking converted to induction over 20 years ago.

 

[Bandit]

Yes, @Ironman, seen the water barrel used a few times, looks a bit funny tried to the front of a truck, going down the road!

 

[Ironman]

Adds a lot of weight to the front end too. I did say they were stationary.
I have a big old engine from National Oilwell, and it has a neat cooling system, sort of a modified 'boiling pot' system like the hit and miss engine had.
There is a radiator and a fan on top of the water jacket surrounding the cylinder, and it is a totally enclosed system with no pressure relief. As the water gets hot enough to steam, the steam rises up into the radiator core and cools, condenses and drips back down into the hot water around the cylinder.