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I finally got a Metcal
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RandyT:

I picked up a Metcal tower and about a dozen tips (STTC type) for $35 at a flea market several years ago.  They are great and the difference between it and other systems is pretty amazing.  I still use it today for the SMD stuff.

My only complaint is that the tips seem to wear quicker than a Weller, or other more conventional soldering system.  I've seen those used and abused tips still being usable after a little TLC is applied to clean them up, while the thinner metal of the Metcal tip will wear through and then it's pretty much toast.   This won't be a huge issue for someone giving it occasional use, and others who are really wearing them out can justify the $25 retail cost of the replacements (cheaper if you look around some.)

It really does have the best feeling handpiece of any I have used, and as was already stated, ready to go in just seconds.

RandyT
MaximRecoil:

--- Quote from: RandyT on March 13, 2008, 12:21:28 am ---My only complaint is that the tips seem to wear quicker than a Weller, or other more conventional soldering system.  I've seen those used and abused tips still being usable after a little TLC is applied to clean them up, while the thinner metal of the Metcal tip will wear through and then it's pretty much toast.   This won't be a huge issue for someone giving it occasional use, and others who are really wearing them out can justify the $25 retail cost of the replacements (cheaper if you look around some.)
--- End quote ---

I've never actually worn through a tip, but when I used them at work I was very picky about how well the tip worked, so I'd throw it out as soon as I noticed the slightest decrease in performance (about 2 weeks/80 hours). So I was probably throwing them out long before the tip itself had a chance to wear through.

I did production + inspection on PCBs. The boards were big, maybe a foot and a half square, and they were essentially complete (all surface-mount stuff soldered in the Panasonic SMT machine), except they needed about 100 terminal blocks through-hole soldered to them (why they didn't do that in the Wave, I'll never know). 100 terminal blocks may sound odd for a single board, but it was actually like 50 small boards all together as a single board with perforations for breaking them apart later; each one needing two 4-position terminal blocks soldered in. 

So you had to set all the terminal blocks in position on the board which was mounted in a big orange foam-backed board holder, and then you flipped it over and the foam kept the blocks in place so you could just solder all of them non-stop. So when you are soldering that fast (less than a second on each fillet) you need an iron that can keep up; and Metcals with a new tip (less than 80 hours of use) are the only irons I know of that could do it (because of their near-instant recovery times). But also, when you are soldering that fast, you'll notice the slightest drop in performance immediately, whereas for home use, you are probably not soldering 100 joints in 90 seconds, so you probably wouldn't notice an increase in recovery time as the tip starts wearing out. So if you were to continue to use it, I can see the tip actually wearing through I suppose.


--- Quote ---It really does have the best feeling handpiece of any I have used, and as was already stated, ready to go in just seconds.
--- End quote ---

Agreed.
RandyT:

--- Quote from: MaximRecoil on March 13, 2008, 12:48:29 am ---I did production + inspection on PCBs. The boards were big, maybe a foot and a half square, and they were essentially complete (all surface-mount stuff soldered in the Panasonic SMT machine), except they needed about 100 terminal blocks through-hole soldered to them (why they didn't do that in the Wave, I'll never know).

--- End quote ---

Don't they use a solder paste screening and conveyor oven process for the SMD components?  I don't think I've ever heard of a wave machine for SMD.  But even so, terminal blocks require a lot of heat to avoid cold solder joints, more than what is necessary or even safe for some smaller components.

The other thing to keep in mind is that there are no heat controls on the Metcals.  The heat is a function of the cartridge, so the one you used for fast soldering of the terminal blocks was likely a pretty beefy one designed to handle the high heat output required by the work you were doing.  We used to use a 1/16" rounded tip (IIRC) and it performed at a pretty steady level throughout it's life span.  It was usually only a few hours between the time when a performance dropoff was noticed and pinhole formed on the tip. 

The tip I use for the SMD's is showing some wear as well, but it is much beefier.

RandyT
MaximRecoil:

--- Quote from: RandyT on March 13, 2008, 01:08:36 am ---
--- Quote from: MaximRecoil on March 13, 2008, 12:48:29 am ---I did production + inspection on PCBs. The boards were big, maybe a foot and a half square, and they were essentially complete (all surface-mount stuff soldered in the Panasonic SMT machine), except they needed about 100 terminal blocks through-hole soldered to them (why they didn't do that in the Wave, I'll never know).

--- End quote ---

Don't they use a solder paste screening and conveyor oven process for the SMD components?  I don't think I've ever heard of a wave machine for SMD.  But even so, terminal blocks require a lot of heat to avoid cold solder joints, more than what is necessary or even safe for some smaller components.
--- End quote ---

We had a huge multi-million dollar Panasonic SMT machine for the SMD components (about the length of a football field), which plucks the parts from a reel and places them onto the solder-paste covered pads automatically, and then heat would do the actual soldering.

However, the terminal blocks were through-hole, and that's where I (and the others on my line) came in. The Wave was for through-hole components and would have worked fine on the terminal blocks. I never really got a straight answer from anyone why they didn't do the terminal blocks in the Wave. I guess it was something like; they had to be manually placed in the boards, and the boards were also given a final inspection at that point (final human inspection that is; they still needed to go through the Hewlett-Packard HP 3070 PCB tester); so I guess they figured we might as well solder them ourselves while we were at it.


--- Quote ---The other thing to keep in mind is that there are no heat controls on the Metcals.  The heat is a function of the cartridge, so the one you used for fast soldering of the terminal blocks was likely a pretty beefy one designed to handle the high heat output required by the work you were doing.  We used to use a 1/16" rounded tip (IIRC) and it performed at a pretty steady level throughout it's life span.  It was usually only a few hours between the time when a performance dropoff was noticed and pinhole formed on the tip.
--- End quote ---

Yeah, the STTC-1XX tips are 700 degrees, and the STTC-0XX tips are 600 degrees. We used the 1XX tips on everything. Since we also inspected, we often had to fix/replace SMD componets (up to and including square surface-mount IC's with dozens of tiny legs). We didn't change tips, and neither did the techs, whose full-time job was rework. We built PCB's for commercial fire alarm systems like would be found in schools, hospitals, etc. In fact, Disney World in Florida used/uses fire alarm systems built there. The boards were categorized as "life saving equipment", and were subject to more red-tape than if we were building say, alarm clocks. They've been in the business a long time, so they knew what was and what was not acceptable when it came to building PCB's.

And I'm not sure what you mean by "beefy", but the STTC-126 tips we used for most everything are quite small (you can see a picture of it in one of my earlier posts). Metcal irons can do relatively big jobs with relatively small tips, due to their fast recovery time. With a conventional iron, the bigger joints pull the heat out of a small tip faster than the iron can recover.

The reason the Metcal irons are so good for fast soldering is their near instant recovery time; meaning you don't have to have big tips and excessive temperatures (risking trace/pad damage) just so the iron can keep up. They are essentially a constant heat source, and remarkably well-regulated at their specified temperature. 
RandyT:

--- Quote from: MaximRecoil on March 13, 2008, 01:40:58 am ---And I'm not sure what you mean by "beefy", but the STTC-126 tips we used for most everything are quite small (you can see a picture of it in one of my earlier posts). Metcal irons can do relatively big jobs with relatively small tips, due to their fast recovery time. With a conventional iron, the bigger joints pull the heat out of a small tip faster than the iron can recover.

--- End quote ---

Take a look at the attached image.  Your tip on the top and mine below.  The tip on the 002 is much larger and farther from the heater, so the metal is probably thinner and the shaft hollow to keep response times high.  The tip you are using is shorter and narrower, so it's probably a solid tip.  And because it's so close to the large conical base, it looks like you could use it directly to heat larger pins, whereas one couldn't really do that on the 002.

But I''m just guessing at this point :)

RandyT
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