Power Progress – 240 Volt Quick Disconnect

240V Quick Disconnect

In the photo below is my power test setup at home. Unfortunately, where my other shop is right now, I am unable to make changes like this. Here I explain what I did to get around that and make power progress!

DIY Induction Heater Power

Now that the ReactorForge is back on the bench it’s time to get it powered up!

This setup isn’t necessarily something that an inspector would like to see.  So don’t think this is my recommendation for a permanent solution. I’m just sharing what I did to make my current setup work. Keep in mind the breaker should always be OFF before connecting or disconnecting wires on the quick disconnect assembly.

To hook up 240 to the ReactorForge in this shop I have to run a temporary line. I don’t want to have to remove the breaker each time I do this, so I made an enclosure that mounts in a breaker slot. The assembly houses 3 Burndy splicers (PN: AMS2BAG2R). It does a few important things, it isolates them from each other, from the breaker box, and it snaps closed to prevent the lugs from sliding out (and attacking passer buys). On the side where the wires enter the assembly from the breaker, it is closed off except for holes just big enough for them, so it’s impossible for the splicers to slide out from that side. There are also ears on the front to keep the entire assembly from sliding all the way in the breaker box.

I printed a quick test in PLA, made a few changes and am ready to 3D print the final version in nylon after Thanksgiving. I’m sharing all the files here in case anyone else finds it useful. Be smart, be safe.

Power progress photos:

New Shop Power Panel

My problem is that I do not want to open up the panel and remove the breaker and wires every time I need to remove the temp line.

Power progress

Fusion 360 power splice quick connect

So I drew a simple small enclosure to house some common splice blocks made by Burndy.

The prototype:

 

The slide lock action:

Technical Drawing:

240V Quick Disconnect Drawing v10.pdf

*Tip: I usualy try to make a technical drawing before I 3D print a part. It’s quick and easy in Fusion 360 and saves me wasted prints and time redrawing later. I always catch a lot more looking at the drawing with multiple views and mesurements than just looking at the drawing in the viewport.

You can view and download the CAD files over at Thingiverse – 204 Volt Quick Disconnect Splice Housing 

ReactorForge History – A brief history lesson 01010010

ReactorForge History

There were many before it, after it and in-betweens, but these are the milestones! This is a brief ReactorForge History lesson.

ReactorForge History

From left to right.

  • The first MOSFET version on a PCB. It worked great but didn’t couldn’t handle the power level I wanted. I ended up pushing it to failure and moving to brick IGBTs.
  • The first IGBT version on a PCB. This design is based on a CD4046 PLL and uses gate drive transformer to drive the large brick IGBTs (the ReactorForge now uses hybrid drivers). If you are into electronics and you’ve never worked with a PLL, even if just on a breadboard you should. PLL’s are very well documented, fascinating little devices. This circuit works great but its frequency operation range was limited by the external passives for the VCO (voltage controlled oscillator). Due to its reliance on these passive components, it is also affected by temperature.
  • For mainly that and a few other reasons I decided to explore a software PLL solution. After going around the usual suspects and understanding how a PLL worked I thought there must be some way to do it with a low-cost MCU, not a freaking FPGA or high power processor. Maybe some type of PWM/comparator combination I thought. I found my solution in a motor controller, or power stage controller chip made by Atmel, the PSC216,316 microcontroller. That’s what this breadboard is, the early testing for what is now a rock-solid way to find the resonant frequency (Fr) and adjust power levels by offsetting that frequency from the current Fr all while soft switching (i.e. not making heat in the wrong places and exploding electronics). This was the result of those early tests…

ReactorForge History - Current

The Future:

One more board redesign may be in order but we’ll see. I may look into reducing the size of the board down the standard Eurocard PCB size of 100mm x 160mm. Although the current size is still within the free size limit of 160mm^2 for Autodesk Eagle.

That was the ReactorForge History, now let’s forge ahead to the future!

Cooling is a GO

Cooling - connected and flushed

I got the new fittings and hoses hooked up then flushed the water chiller and the induction heater. No leaks, cooling is a go!

Cooling - connected and flushed

Cooling - New metal base for cart

Before putting it back on the cart I replaced the top plastic liner with 16 gauge sheet metal that I cleaned and lightly wiped down with oil. I think I’ll go back and add a lip around 3 sides with the box break to catch any falling sparks and molten beads of metal that try to escape.

Back on the cart!

Cooling setup on cart

And here it is with cooling set up on the new cart.

Cooling setup on cart

Now to move on to power. I am making a quick disconnect near the breaker box. I will need to draw and 3D print a small enclosure for the 3/8″ dual splicers. More on that progress here.

Hooking up cooling water and power

Hooking up cooling water - parts laid out

Hooking up cooling water, but first, fittings!

Hooking up cooling water - fittings

One trip the hardware store later and I’m ready to hook utilities up to the induction heater. 

Hooking up cooling water - parts laid out

Hooking up cooling water isn’t the only step… Power!

I also ordered a larger variac, a 5000VA 220V model to aid in testing and firmware optimization. I have a small 2000VA 120V variac but running it on such low voltage skewed a lot of the readings. The variac is nice because running full power while testing new features can a bit nerve-racking and wasteful.

Reactor Forge on the Bench

Reactor Forge on the Bench

The Reactor Forge on the Bench and ready to hook up!

Reactor Forge on the Bench

This new rolling stand from SAMs club was perfect for holding the Reactor Forge, Bernard Weldcraft 3 gallon water cooler, extra bricks, and coils. I just need to replace the top plastic insert/mat with a piece of sheet metal. 

High-level action plan:

  • Publish existing mechanical specs, unit wiring schematic, core control board schematic, to Atmel C code to Github.
  • Add my current issues and changes that need to happen to each of the above topics in Github for proper tracking.
  • Work on those issues, changes, and improvements.
  • Make the next version, test, refine, and repeat as needed.
  • Work on BOM supply chain.
  • Kit logistics: work on which parts will be preassembled and which will require user assembly.
  • Create and publish a kit manual.
  • First test kits for users, feedback, etc. etc…

What’s next after getting the Reactor Forge on the Bench?

Hooking up cooling water and power.

Induction Heater Price what is your target range?

Induction Heater Price

I want to get a better idea of what a machine like this is really worth to you. I’m doing this in an effort to ensure that the additional work I’m about to put into this project to transform isn’t in vain. Because an induction heater price can vary wildly and to go from DIY induction heater to a kit or production unit is a big leap.

I will be completing this project and making it open source regardless of whether or not making a kit is viable. But before I do go down that path, to kit or not to kit, I’d like to know what it’s true value is.

To give you something more concrete to evaluate use the two videos below to get a rough idea of the capabilities of the machine as it relates your needs and use these technical specs.

Reactor Forge Induction Heater Specs:

  • Simple interface and usability
  • Operating Voltage: ~220V
  • Maximum Current Draw: ~40A
  • Typical Current Draw: 10-30A
  • Power Factor of near .99% (You won’t find that in a cheap overseas model!)
  • 100% duty cycle
  • Water cooled (cooler not included but it can be as simple as a garden hose attachment)
  • Mid-range frequency operation best for small to medium size workpieces. (Lower frequency is possible for larger items above 5-6″ cross section at lower power levels.)
  • Remote foot switch operation
  • Simple to complex programmable cycles
  • Many safety features
  • All digital operation (so performance is not affected by the environment)
  • A fully sealed case for protection against debris and dirty shop air.
  • Hackable! Many future improvements possible such as workpiece temperature feedback for reaching very precise temperatures.

Videos of the current Reactor Forge, Critical Mass in use:

https://youtu.be/C8s0zIcqVfk

https://youtu.be/4vICz4akL6k

So what is your target induction heater price?

Please check out the full post and Poll on Patreon to cast your vote: https://www.patreon.com/posts/15375592

Induction Heater Price

Also, check out The ReactorForge Origin Story to learn more about how this project got started.

Why a Patreon page

Patreon

This project is moving forward regardless of Patreon backing. However, any support will be a great motivator as well as help with the time, money and effort required for this project.

The ReactorForge open source induction heater is my way of giving back to the maker community so Patreon or not I hope you find use in this work! For anyone who has ever wanted to make a homemade induction heater that goes beyond being just a novelty, the DIY kit and plans will be your ticket!

Support ReactorForge on Patreon

Patreon

The ReactorForge Origin Story

induction heater origin

ReactorForge Induction Heater

A couple of years ago I had considered doing a Kickstarter campaign to fund making a small/medium batch of induction heater kits, but I have seen and studied the downfall of many similar projects attempting to use crowdfunding to accomplish the same goal. I won’t underestimate it, this is a complicated machine with lots of parts, and although I believe I could be successful on Kickstarter, I am choosing to go a different route. One which I think will yield a higher quality product and allow me to better support it. I’ll be making small batches and selling them based on a waiting list similar to how a well known, successful maker of an excellent gas forge operates.

For some years my brother had a small blacksmith shop where he mainly made tools for other blacksmiths. He is currently taking a break from it but, like many, he first worked with coal then moved up to using a gas forge. He used a dual burner propane forge exclusively for a while but starting talking to me about the limits in production he hit as a result of waiting on stock to heat in between working it, sweltering summer heat, ventilation issues in the winter, and high propane costs. None of which were preventing him from working or making a great product, but he was feeling the heat. (That’s the only pun I’ll use, promise!) He mentioned how great it would be to have an induction heater. However, the domestic models were too expensive, and the cheap overseas models didn’t have an exceptional track record living up to their 1.21 JiggaWatt claims. Also, any issues with the unit left you high and dry with little to no support or ridiculous shipping and repair costs. Being a typical maker who loves a challenging project with an atypical way of creating multi-disciplined solutions I told him I’d look into it. After combing the internet for examples and inspiration as well as using what I already knew, I threw together a proof of concept that worked for a few minutes then went up in smoke. I saw the potential and knew I could do better, so I redesigned a couple of times, used better components and about six months later had a unit cobbled together in an old computer case that was good enough to run 100% duty cycle with water cooling from a garden hose. He used it for a week and never fired up his propane forge again. Each heating method certainly has its strengths and weaknesses but the induction heater better fits his needs, and it opened up a lot of possibilities. He significantly increased his production output and earning and was able to build a bigger shop, all centered around that one machine. Over the next couple years, I redesigned and refined a few more times, making the unit more powerful and more reliable. The induction heater I have today is a beast and is much more than I ever expected. Aside from its power, I’m excited about its reliability. The original unit was in an open computer case exposed to all the shop elements including that black sticky metallic dust that gets everywhere. You know what I’m talking about if you’ve worked with metal on any level. My brother pushed his induction heater is ways that made me cringe while watching. I resisted the urge to tell him to ease up because I wanted him to drive it to failure and that he did many times. Every time I repaired it, modified the design and improved the components. Back and forth we did this until now, the unit sits there and just works regardless what he does to it, for years now. That level of reliability is perfect for me because I don’t want only to be a customer support specialist. Downtime and trying to fix problems remotely is just no fun, so I don’t want to make something that is going to put me in a nightmare job position! I’m using quality components, a sturdy sealed enclosure, code to detect and prevent failures and I believe I will still be able to sell this around the cost of the inferior overseas models.

I wish the kit form of the ReactorForge were ready now, not because I need to or want to make money off it but because I’m excited at what it will do for all the hobbyists and makers who can use a machine like this. Think blacksmiths, bladesmiths, metalsmiths of all kinds, glass melting, scientific uses, etc. the applications are vast. Thank you all so much for your support, and I can’t wait to be working together soon!