Comment by fragmede | Hacker News Reader

Comment by fragmede | Hacker News Reader

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That's a weird flex, given that Metcals are a high-tech device, using a patented technology and were exorbitantly expensive before patent ran out. They still are, compared to the bargain basement soldering iron pricing. When the patent ran out, the original engineers ran off to start Thermaltronics.

We've all accidentally left the soldering iron on, sometime in our decades. The sensors in the iron lets it shut off and not burn your house down. Having an firmware (like the TS100 or TS80) means you can fully customize its behavior unlike most consumer devices. (I wish there was a microwave oven whos firmware I could tweak in order for, eg the popcorn button to make popcorn how I like my popcorn.)

Soldering irons are at this fairly unique intersection of consumer device and hardware hacker that I'm really surprised by the some of the luddite attitudes around here. I bet there's some cool firmware mods you could do if you have to solder something that looks like a heat sink. (Eg maybe it could do 18650 cells, if you don't have a welder.)

The other innovation of the TS100 is that battery-power capably powers a soldering iron. The TS100 is a bit older than the TS80, and can use 12V rechargable battery packs (eg for RC cars/planes); the TS80P can use recent USB-battery pack powering standards. It doesn't do much at the workbench, but if you're one of those people that leaves the house (modulo Covid), it turns out to be really useful! In decades prior, butane (cigarette lighter fluid) powered soldering irons existed, but could be persnickety and were a special version to buy. Now, just bring the iron along with USB battery pack you were probably gonna bring anyway.

The metcal PS900 is actually cheaper now than the equivalent bottom end Weller TCP units and much much cheaper than the Hakko FX951 irons.

The TS type irons and the T12's are however 100% not safe devices. The tip mount/socket shorts out which will blow the guts out of the MOSFET and there are various brown-out conditions which cause the thing to crash and dump the entire supply into the tip until it glows orange. And also the thermal sensor fails unsafe. That risk is especially high when you have high capacity supplies.

An image to back up my claim:

https://imgur.com/uE1CPn0

Buying a decent, simple iron will probably cost you less than your house does if it goes up.

As for leaving irons on I have never done it. Metcal PS900 also has an optional stand which puts the iron in safe standby mode. They heat up within 2 seconds when you pick the iron up as they do not use normal heating elements. They use RF heating. There is no condition that can cause a complete thermal overload cycle.

On the T12 irons which are sometimes mentioned they are borderline illegal when it comes to the power supply design earthing and will quite happily kill you dead if you don't rework them first.

Is economy worth it? Probably not.

> The metcal PS900 is actually cheaper now than the equivalent bottom end Weller TCP units and much much cheaper than the Hakko FX951 irons.

- Hakko FX951 is listed for $269.77, less tips

https://www.hakkousa.com/products/soldering/hakko-fx-951-sol...

- Metcal PS-900 is listed for $275.93

https://www.mouser.com/ProductDetail/Metcal/PS-900

The statement that the PS-900 is much much cheaper does not appear to be accurate now.

Check prices in Europe as well.

This is why discrete MOSFETs need to go away in low frequency applications.

There's not really any time I think "Hey, I want a transistor that doesn't make any attempt to handle short circuits, so I can save literally $2 it something".

Things that need power tend to be things that can short.

I actually have scars on my arm from blowing up MOSFETs so I agree :)

> I bet there's some cool firmware mods you could do if you have to solder something that looks like a heat sink.

At least one of the TS100 custom firmwares [1] has a feature which helps with that sort of thing. Pressing one of the buttons while soldering will force the heater into always-on mode, making it deliver heat faster than normal.

[1]: https://github.com/Ralim/ts100

>We've all accidentally left the soldering iron on, sometime in our decades. The sensors in the iron lets it shut off and not burn your house down.

Specifically for the Metacal irons, all of the ones I have used have a magnet in the stand that causes the tip to idle at a reduced temperature using some sort of feromagnetic magic. The great thing about those irons is they have such fast thermal control that it heats up in the time it takes you to lift the iron from its stand to your work. They also have a deep sleep they go into if they detect the tip is idle for more than a few minutes which can be disabled in a production environment. And for some absurd reason, it is all implemented in hardware...

The older Metcals don't have a sensor. They auto-off after a timeout.

They do not need a sensor--that is the magic of it! It is a fundamental property of the induction heating process that a magnetic field reduces the operating temperature of the tip.

I have a T100 with auto-off firmware. I don't have to put it on a stand, literally anywhere on my desk will do. Once I pick it up it'll be at temp before the tip touches the PCB in almost all cases.

The great thing about doing it in software is that I can change the timeouts and the idle temperature if I wanted. For most soldering my idle is 130°C so it can go quickly to target but when I'm experimenting I leave it at 80°C to reduce burn risks.

> I wish there was a microwave oven whos firmware I could tweak in order for, eg the popcorn button to make popcorn how I like my popcorn.

I wish for this every day.

I had another cheap microwave that would nag ever minute after the food finished so you wouldn't forget it.

I once had a microwave with steps -- I so wish I could save as "favorites"

I wish I could monitor a sensor to boil water accurately.

I wish there was a sensor, maybe a camera, that you could teach to watch for boil-over.

>The sensors in the iron lets it shut off and not burn your house down.

The old Wellers did that 30 years ago.

> The sensors in the iron lets it shut off and not burn your house down.

Isn't leaving it in the stand the best way to not burn your house down? I can't say I've ever left an iron heated up and also touching something flammable.

Yeah, in practice the advantage of the auto-shut off is longer tip life.

I had one melt through a plastic table after falling off the stand. It was a super cheap model and the weight and balance were all wrong, made dangerous by the stiffness of the power cord.

Ok, I get that this soldering iron may be useful if you leave the house. But otherwise, is it still the best soldering iron you could buy?

(personally I use my hot air station much more than my soldering iron)

And by the way, nowadays you could implement auto-shutdown using an accelerometer and a timer, I suppose.

The best cheap iron is a Metcal PS900. You can look for Metcal MX units on ebay which tend to go for not much. They can switch from soldering 0402 parts to nuts onto bolts without changing the tips or damaging anything:

https://www.youtube.com/watch?v=x10hW9qvT8E

Hell, for a basement prices, you can still scrounge up the older pre-mx variants such as the RFG-30 and PS2e (which is an RFG-30 and hand piece IIRC).

I picked up an older RFG-30 with handle for $80 USD off ebay about 2-3 yrs ago. An old friend of mine still has his original metcal PS2e from something like the 80s or 90s and it runs like a tank.

User programmable household applies seem like an interesting idea. I'd like to have a smart stove top that didn't have an app or require internet access (for example).

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