Jeshua Lacock Presents Lost Shell Sand Casting for PLA 3D Printed Models

[3DTOPO]

It isn't really a matter of it being difficult, the problem is one of scale. 15kw is hard to obtain for a home user, but certainly possible.

Actually swashing around 700 amps in the primary coil and many thousands of amps in the secondary (work) coil at 30-85 thousand times a second at 230 V input without blowing up is quite technologically demanding.

There is a reason modern induction generators weren't invented until the late 60s early 70s.

Just 15KW needs a fairly massive DC transformer, a massive water-cooled capacitor bank (totally deadly if mis-touched), a massive toroid, water cooled work coil, big fat water cooled insulated-gate bipolar transistor (IGBT) and a well designed control card.

Unless you can show me a web page with schematics and proof of working induction generator over 5kW, I think I have made my point. The biggest I am aware of is ~5KW and was designed by my friend Tim Williams - who went on to design induction generators for Radyne.

Besides purchasing all the hardware, it will take weeks (if not months) of someones time to build the circuit boards, order and assemble all the parts and just hope that it all works. The project is easily on the same level as a thesis project.

I suspect I could build one with reasonable safety devices, liquid cooled coil, appropriate power (including professional installation of the sub panel) and have it running for maybe 3k USD.

Or - you can buy one brand new for around $1k. Sealed in an enclosure and working with instructions.

[Ama-fessional Molder]

Or - you can buy one brand new for around $1k. Sealed in an enclosure and working with instructions.

I have no idea where they are getting that 15kw rating from a device which runs on 110v single phase. That's simply not possible with any safe currents. You would need 140-150 amps to do so at that voltage.

http://www.mtixtl.com/15KWDualStatio...Q-SP-15AB.aspx


This one pulls 34a from the wall at 240v. That's 8kw, and they are calling it a 15kw unit also. Certainly a LOT more power than those 110v amazon units for around $1k are utilizing. Those ones don't even list an input current rating.

They would have to be using some massive capacitance to charge/discharge 15kw through that coil long enough to actually melt something, but these units claim they can run at 100% constantly... which means they aren't charging anything.

I was referring to building a *proper* 15kw furnace instead of one that is just "kind of" 15kw. The math just doesn't add up. If you have some insight as to how those things are magically taking at most 3500 watts of 110vac (you can run up to 30a on 110v if the wiring and outlets support it) and turning it into 15,000w (at any voltage) please fill me in. I am honestly curious.

[3DTOPO]

I have no idea where they are getting that 15kw rating from a device which runs on 110v single phase. That's simply not possible with any safe currents. You would need 140-150 amps to do so at that voltage.

http://www.mtixtl.com/15KWDualStatio...Q-SP-15AB.aspx


This one pulls 34a from the wall at 240v. That's 8kw, and they are calling it a 15kw unit also. Certainly a LOT more power than those 110v amazon units for around $1k are utilizing. Those ones don't even list an input current rating.

They would have to be using some massive capacitance to charge/discharge 15kw through that coil long enough to actually melt something, but these units claim they can run at 100% constantly... which means they aren't charging anything.

I was referring to building a *proper* 15kw furnace instead of one that is just "kind of" 15kw. The math just doesn't add up. If you have some insight as to how those things are magically taking at most 3500 watts of 110vac (you can run up to 30a on 110v if the wiring and outlets support it) and turning it into 15,000w (at any voltage) please fill me in. I am honestly curious.

I believe they call it 15KW because that is how much power is in the work coil at resonance.

That said, mine will even pull 45 amps running at 240V - that is over 10KW.

I have no idea about the 110vac one you are talking about.

I am actually going to buy a 65KW unit. Well its 65KW on 3-phase and 48KW on 2-phase. I currently only have 2-phase here. That one will require a 125-amp breaker on 240v. For the money, it just can't be beat trying to build one IMHO.

[Ama-fessional Molder]

I believe they call it 15KW because that is how much power is in the work coil at resonance.

That said, mine will even pull 45 amps running at 240V - that is over 10KW.

I have no idea about the 110vac one you are talking about.

I am actually going to buy a 65KW unit. Well its 65KW on 3-phase and 48KW on 2-phase. I currently only have 2-phase here. That one will require a 125-amp breaker on 240v. For the money, it just can't be beat trying to build one IMHO.

Now that's some serious hardware.