Applefritter - Hardware

Review: Hakko FX-901 Cordless Soldering Iron

Sat, 11 Feb 2006 22:31:15 -0800

After reviewing and ultimately disliking the ColdHeat, I found myself still looking for a cordless soldering iron that I felt I could do quality work with. I have an excellent desktop iron, a Weller WLC-100, but that's hardly portable and is a pain to dig out and set up just to do a few quick solder joints. I figured I'd end up having to buy a butane-fueled iron, but then I found something much better. Well, in the interest of full disclosure, that much better something actually found [i]me[/i]. A few weeks after the ColdHeat review went online, I was e-mailed by Hakko USA and asked if I'd be interested in reviewing its cordless iron, the FX-901. I agreed, and shortly thereafter I received the iron with the price voided out on the invoice. [i]The Hakko FX-901 in its retail packaging.[/i] The packaging the FX-901 comes in is pretty straightforward. The iron and its accompanying safety cap are packed in a cardboard-backed blister pack. There's no instruction manual, no guidelines on how you need to solder with the iron -- in fact, right on the front of the package it instructs to "use standard soldering techniques." There's another interesting bit of information on the front of the packaging: "Safe! No spark! No flame!" After my [url=http://www.applefritter.com/node/9642]last review[/url], I know exactly what that info is referring to; I'll leave it to you to figure it out. There's some other useful info on the back of the package, such as instructions on how to replace the batteries and tip. The iron uses four AA-size batteries, which aren't included with the iron (but when was the last time you saw AA batteries included with a product anyway?). The tip that's included with the iron is of the pencil variety, with a nice sharp tip for precision work. There's a chart on the packaging that shows how long two types of batteries, alkaline and NiMH rechargeable, last and how the operating temperature of the iron decreases with their use. [i]The battery life-iron temperature chart printed on the back of the FX-901 packaging. Image courtesy Hakko USA.[/i] I was surprised to see that NiMH rechargeables were reported to last longer than alkaline batteries. Alkalines offer a higher voltage output, which one would assume would yield a longer operating time -- they generally do in other devices. But strangely, even though they output less voltage, NiMH rechargeables are reported to last almost twice as long as alkalines, 120 minutes vs. 70. I can only guess that NiMH rechargeables are much more linear in how their voltage output decreases over time, and that's what can make them last longer. The safety cap serves two purposes. First, it protects the tip (or protects other tools in your toolbox from the tip, depending on how you want to see it), and second, it keeps the power switch from inadvertently being turned on. The cap snaps on solidly and fits well. It provides a nice space around the tip internally, and is vented at the end; I was able to put the safety cap on the FX-901 while the tip was still hot, but this isn't endorsed or recommended by Hakko. [i]The FX-901 with safety cap attached.[/i] The yellow part towards the back of the iron is the battery cartridge. It's removed by sliding a locking tab at the end of the iron, and then pulling the cartridge out of the body. It's easy to load the four AAs, and there's a diagram printed on the side of the cartridge (hidden from view when the cartridge is installed in the iron body) that shows the polarity in which the batteries need to be installed. With the batteries installed, the iron is decently weighted, not too light but not too heavy. The iron is heavier towards the rear, but the balance isn't enough to make the iron difficult to hold or otherwise affect the ability to solder. The top-mounted power switch slides solidly, and a red LED illuminates when the iron is turned on. The FX-901 uses pretty conventional technology to heat the tip, so I figured the iron would take several minutes, like my desktop iron does, to heat to operational temperature. Surprisingly, it only takes a minute or so, much faster than I was expecting. The operational temperature of the iron was good too -- it's not adjustable, and won't get as hot as my desktop iron running full blast, but it gets plenty hot to melt solder and heat wires and terminals quickly. [i]The FX-901 without safety cap. The iron has a comfortable weight to it and is easy to hold.[/i] My primary test for the iron was with wiring and connectors. I tinned several ends of Belden PY balanced microphone cable, and I couldn't really tell the difference between tinning the leads with the FX-901 and my desktop iron. I then soldered on some Switchcraft and Neutrik XLR connectors and, again, couldn't see or feel a discernable difference in solder joint quality between the FX-901 and the desktop iron. Both irons heated the connection quickly and evenly, which made for smooth, defined solder joints. All of the joints I made with the FX-901 were solid and passed a clean signal.I didn't have a printed circuit board to test the FX-901 on, but I suspect it would work just as well as a desktop iron there too. The sharp pencil tip should make it easy to work on smaller components, and since the iron heats up the tip like conventional irons do, there should be no worry about killing ESD-sensitive components. I'm not sure I would do marathon PCB soldering sessions with the FX-901, nor would I solder under a microscope with it (leave that to a desktop iron with variable temperature control), but for routine repairs and mods, the Hakko should work just fine. Overall, I'm very impressed with the iron. It heats up quickly -- quicker than many desktop irons, even -- and feels natural to use. Because of its size, it's probably not appropriate for use on heavy-gauge wire, but neither would a comparable desktop iron. The back end of the iron is perfectly flat, so it will stand stably on a flat surface, and it will also lay on its side without the tip touching the work surface, so no soldering iron stand is necessary. It's probably a good idea to turn the iron off when you're not actually soldering, in order to maximize battery life. The FX-901's two drawbacks, as I see them, are rather trivial. First, though 70 and 120 minutes of runtime using alkaline and NiMH batteries, respectively, is quite decent, it would be nice to see that extended. Second, the FX-901 isn't as easy to find in stores as some of its competition; neither Digi-Key nor Mouser carry Hakko products. However, it's readily available online; just Google for it and you'll find a number of vendors who carry it. Hakko USA's Web site can also point you in the direction of a local reseller at [url]http://www.hakkousa.com/map.asp[/url]. Considering the price, which is commonly about $30, the Hakko FX-901 is a great value in my opinion -- it combines competent, solid soldering ability with good portability. It won't replace my desktop iron, but it's definitely earned a place in my toolbox. Here are my pros, cons and overall rating of the FX-901: [b]Pros:[/b] Good weighted feel and ergonomics Tip heats quickly Decent battery life, uses standard AA batteries Comes with solid metal pencil tip for precision work Heats up joints about as fast as a desktop iron Attractive price [b]Cons:[/b] Battery life good, but could be better Iron could be hard to find in some areas [b]Overall rating:[/b] Four-and-a-half out of five stars. [b]Additional info:[/b] Hakko USA product page: [url]http://www.hakkousa.com/products.asp?PID=FX-901/P&Page=1[/url] Froogle search for FX-901: [url]http://froogle.google.com/froogle?q=fx-901&btnG=Search+Froogle&lmode=unknown[/url]

Review: ColdHeat Soldering Iron

Wed, 04 Jan 2006 09:28:00 -0800

The ColdHeat soldering iron has been touted in stores and advertisements as an end-all solution to one's soldering iron needs. And indeed, when one reads the features list, the ColdHeat is appealing: it only uses a few AA batteries, has a built-in white LED work light, and the tip heats up and cools down in only a few seconds. On paper, the ColdHeat beats not only other, portable soldering irons (most of which are butane-powered), but also traditional corded irons. However, that's just on paper. As they say, looks can be deceiving. And in the case of the ColdHeat, unfortunately, they are deceiving indeed. I picked up a ColdHeat at Radio Shack; I was looking for something that would heat up faster than the plain $8.19 25-Watt iron I'd been using. The ColdHeat, which was sold under the Radio Shack brand, cost $19.99 and included the iron, plastic carrying case, and chisel tip. Supply a few AA batteries, and you're good to go. I don't like working with chisel tips on soldering irons, as a lot of times they end up being too large when working with small components. So for $9.99, I picked up the conical tip for the ColdHeat. [i] Fig. 1. The ColdHeat in its carrying case. [/i] An immediate problem I saw with the ColdHeat is the placement of the white LED light, meant to illuminate what you're working on. The problem with it is that they put it [i]underneath[/i] the tip, instead of on top of it. This, therefore, pretty much makes the light useless, unless you use the iron upside-down. [i] Fig. 2. The ColdHeat's white LED light. [/i] When I first opened the case, something didn't look quite right to me. First, the ColdHeat comes with a cap for the tip -- I had never seen an iron come with one. Also, the yellow sticker on the inside top of the case offered a warning: "The soldering tip is fragile. Please do not press hard." The warning is very true. After I installed the batteries in the ColdHeat, I pulled out the chisel tip that it came with and swapped in the conical one. As a test, I tried soldering two wires together. With some work, I got them together. I then tried adding more solder to the joint, and in pressing down on it, part of the tip snapped off. It was no more pressure than I'd exert on a normal iron with a small pencil tip. Herein lies one of the fundamental flaws of the ColdHeat's "instant heat" technology -- the tips are not made of metal, but rather a soft ceramic. [i]Fig. 3. The ColdHeat tips are split down the middle and are made of a soft ceramic material. [/i] The second flaw with the tip, that exacerbates the first flaw and also poses another problem altogether, is that the tips are split down the middle. The way the ColdHeat works is by passing an electrical current through the tip. When you press both halves of the tip to a conductive surface -- the solder or wire or whatever you're soldering -- it completes the circuit and causes the tip to heat up rapidly. However, because the tip is split, it reduces its strength. You need to use a very gentle touch when soldering with the ColdHeat, or else you'll be out $9.99 as I now am. The other problem that the split tip causes is a nasty sparking when the circuit is completed. And it's not a single spark that's emitted when the circuit is completed; no, it's more of a continuous arcing. [i]Fig. 4. The ColdHeat's tip sparks and arcs when it completes the circuit to heat the tip. [/i] It's hard to take a picture of the sparking/arcing, but the little bright spot next to one of the prongs of the tip above is one of the sparks. I don't know how much voltage and amperage the ColdHeat uses to heat the tip, but I'm seriously concerned about using it with anything ESD-sensitive. In fact, I'd go so far as to recommend that anyone who uses a ColdHeat use it for use on wires and connectors only. Do not use the ColdHeat on any kind of PCB. Overall, the ColdHeat has a good concept -- a soldering iron that's completely portable, heats up and cools down fast, and uses standard batteries. Its execution is horrible, however. While the tip does heat up and cool down in about 5 seconds, the longer you use the ColdHeat the longer it takes for the tip to cool down. The tips wear quickly, and prone to breaking, are large (making detail work hard if not impossible), and expensive, and the overall technology behind how the ColdHeat works could potentially kill any ICs you work on. Here are my pros, cons and overall rating for the ColdHeat: [b]Pros:[/b] Iron is relatively inexpensive ($20) Uses standard AA batteries Compact Comes with carrying case [b] Cons:[/b] It solders, but not well (normal irons create joints smoothly) White LED light misplaced Tips are large, expensive ($10 each) and prone to breaking Iron is potentially dangerous to ICs [b] Overall rating:[/b] Two out of five stars. [b] Additional note:[/b] ColdHeat has struck a licensing deal with Weller, a well-known and respected soldering iron manufacturer. Weller will begin selling the ColdHeat under the Weller brand name. Keep in mind that Weller does not manufacture this version of the ColdHeat; as sold by Weller, it's just a normal ColdHeat that's been rebadged. So, don't buy the Weller version thinking it'll be better -- it's not. [i]The Weller iron is actually ColdHeat's new "Pro" model, not the model reviewed here. Please see Weller's post in the comments below. - Tom[/i]