Houston- We have a Problem

Lunch Thursday, I stepped over to the forge to hammer out a chisel. Hammering is probably a lot like resawing. you can resaw for a long time if you do it slowly, but if you’re in rhythm, you’ll have enough of it in half an hour for an hour to do something else.

As I was starting to celebrate getting more efficient at making a chisel, my forge would only work at lower and lower current. Each time it would quit, it would click and spark through the bolts on the front of the forge. Before you get excited about the idea of holding a piece of metal in a coil that’s sparking, the voltage is low, and the current is high. Around 800 amps at 5 or 6 volts. I guess you could get a tingle, but I’ve never gotten anything off of the machine.

This progressed in a matter of minutes until 1/8th power was all the machine would run at.

So I did the thing that all smart people do with a machine that can pull 7 or 8kw continuously from the wall, I took the cover off to see what I could find. I couldn’t see anything initially but I pulled the foot pedal back to a safe distance and could see a flash of light each time the machine reset.

Definitely not a flash of light that’s supposed to occur.

These machines are simple in one sense, but fairly complicated by adding controls and safety trips. the hoses are all water lines. The coil has to be cooled, but so do other components inside the machine. Actually seeing how much stuff is cooled in the machine taking it apart is nice – I have less concern about it running continuously and being damaged.

However, what’s going on here is the magnet stack is arcing to the bracket that holds it in. As it did that, it burned more insulation off of the bracket quickly, and here we are. What do you do?

There’s a year warranty on the machine, but it’s not like amazon where you just return and exchange. You have to try to fix the machine and the warranty is parts only. So it’s kind of worthless aside from technical help. The technical help wasn’t really much help. This is an $1100 continuous duty machine, and versions of it can be found as cheaply as $475 from china. You would go broke if you tried to source the parts and even make it for $1100, so I don’t expect much and the warranty doesn’t bother me that much.

The more curious thing knowing little about induction forges, is that the bottom stack magnet where the spark occurs is cracked. It probably always has been, but a little piece has come loose. I know as much about magnets as I know about forges. Not much. But an irregular surface on a magnet is probably a problem, and I picked out the cracked bits on the bottom corner and that definitely exacerbated the issue. They were coming out, anyway.

What do you do? Well, first, the video is close up, but I’m not that close to it with the cover off. I think there’s no danger as long as you stay away from the high voltage stuff at the back of the machine – there is definitely danger there at the very least, in the form of an enormous high voltage capacitor. But I just used an old cell phone taped to the wall to get video and pictures of what was going on after this to see exactly where the arc was. And I covered it with electrical tape. Burned right through that. A couple of layers of paper, burned right through that. And then card stock , and that seems to be enough for now.

I’m waiting for mica sheet to show up from amazon, and I think that will be a permanent fix, as much as it can be. I use this machine for several hours a week sometimes – it’s not something I have an interest in going without, and this looks to be a one-off thing by how the bracket is against the stack. The other three legs of it do not touch the stack – just “quick work” by the person making the machine and then the magnet probably cracked when it was shipped.

But the $475 machine can be gotten to the US for $600 total, and I’ll have to think about maybe making a few things to sell or selling a few things (unrelated to tools) on ebay and getting a spare. it’s too good to go without and I use little of the functionality – Just the foot pedal and then how much power with one knob, so chinese writing on one of these for less than half the price is no big deal.

At some level, I was surprised how quickly customer service expected i’d get readings off of the rectifier to start diagnosing things. At another one, I kind of like the idea that we aren’t all just babies who can’t ever fix anything and demand to return something 7 months in just because we aren’t getting our way. I’d much rather learn more about the machine and fix it than just get another one and have no clue.