Your leaking thatched hut during the restoration of a pre-Enlightenment state.


Hello, my name is Judas Gutenberg and this is my blaag (pronounced as you would the vomit noise "hyroop-bleuach").


decay & ruin
Biosphere II
dead malls
Irving housing

got that wrong

appropriate tech
Arduino μcontrollers
Backwoods Home
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   consumer control
Thursday, August 27 2015
As I wrote a week or so ago, my old GreenWorks saw (model 20092) eventually ground to a halt in a way that suggested the wire in its armature had been overheated a few too many times. My solution was to buy a "bare tool" replacement on eBay so that I could continue using my existing battery and charger (which add substantially to the price of such tools). Before making the purchase, I thoroughly read the fine print of the listing and confirmed that my battery would work in this tool (a model 20272). One of the obnoxious things about the GreenWorks brand, it turns out, is that not all of their batteries of a specific voltage work with all of their tools of that voltage.
Today my replacement saw arrived, and I immediately went to test it out. You can imagine my surprise when I inserted my battery and found that it didn't go all the way in. Evidently the pains I had taken to ensure my battery would be compatible had been unsuccessful. I looked into the battery compartment and compared what I could see in the new saw to what I could see in my old one. It was immediately apparent that in the newer saw there were a couple plastic fins hanging from the upper part of its internal connector that were not present in the old saw. Otherwise, though, the two connectors were more or less the same. Using some wires and clips, I confirmed that new saw could actually be powered by the old battery. Once I'd established that, I decided to break those damn fins off. At this point I was pretty sure that they'd only been placed there to force people such as myself to buy entirely new batteries and chargers when their saws no longer worked (and they could no longer find an exact bare-tool replacement because it had been discontinued). Perhaps the "green" in GreenWorks is a reference to money. Certainly, filling landfills with perfectly-good batteries and chargers is not "green" in the Al Gore sense.
I've seen similar shenanigans with other combinations of batteries and what should be compatible tools. For example, DeWalt and Black & Decker tools are manufactured by the same corporation, but the former is the premiere brand and the latter is aimed at the "budget" consumer. The batteries from certain DeWalt tools look like they should fit into Black & Decker tools, but they can't because of little plastic fins that have to match up with corresponding slots. It is possible to shave away the fins (and I've done this on my 12v Black & Decker Firestorm drill so it can use my 12v DeWalt batteries). But most people would be thwarted by such techniques.
With the fins removed, my old battery snapped into my new saw without difficulty. But it still didn't work. There was some other issue of incompatibility at play, one of an electrical or electronic nature. I soon determined that the problem was one of the four metal fins that make an electrical connection between the battery and the saw. On my old saw, only two of those fins were connected to anything. One was positive and the other was negative, and they powered a motor when a switch was closed. Basic 19th-Century technology. Evidently this wasn't the case with the new saw. So I decided to break off one of the metal connection fins that hadn't been used in the old saw. I chose the right one, since it was the only one that appeared to be making a connection in the battery.
Once that was gone, the saw worked, but only for about five seconds at a time. I thought perhaps there was a safety measure in the saw that turned it off if it wasn't running under load, but when I went to cut something out near the woodshed, that weird five-second limit continued. I couldn't use the saw like that!
Some testing confirmed that problem was happening upstream from the motor, suggesting there were some electronics in the saw somewhere. (The old saw had contained no electronics outside of the battery.) Clearly I was going to have to open my new saw up. I'd already voided its warranty, so why not?
The old saw had been held together by a dozen or so phillips-headed screws, but the new one required two different sizes of torx wrench to remove all the fasteners. This seemed like a pretty obvious step towards thwarting user maintenance (assuming the new saw is actually a newer model, which, based on the transition to torx, is a good guess).
Inside the new saw, as expected, there was a circuitboard that hadn't been present in the old saw. It appeared to get some second voltage from the battery at that metal fin I'd removed to do something that ultimately controlled the connection to ground. I couldn't tell what that something was; most of the board was covered with a rubbery white material that obscured the semiconductors. There were, however, two larger semiconductors that I could see; one was an FR1300A dual rectifier and another was a IRFB3306 rectifier. I removed the entire thing and wired up the saw's internals as they had been in the old saw. It seemed to work great like this. So perhaps those plastic tabs were necessary to keep batteries requiring that board from being attached to saws without it and vice versa. But the idea that one has to do careful research before buying a GreenWorks battery for a saw or saw for a battery is ridiculous, especially since there don't appear to be any compatibility grids published on the GreenWorks website.
I took my saw out on a firewood gathering foray about 1000 feet from the woodshed west of the Farm Road and cut up a couple pieces of skeletonized Red Oak. The saw worked great and its motor barely seemed to get warm during the job, suggesting that my old saw had been unhealthy for a very long time. It had been running hot for months. Today's firewood load, for those such as myself who are keeping track, weighed in at 97.5 pounds.

Another project I've been working on is swapping out the 1.8 inch hard drive in Hyrax (my main laptop, that EliteBook 2740p) with an SSD I got for cheap on eBay. The problem with these drives is that their connectors are an unusual variant of the SATA standard with a reduced power connector, so I have no way to connect to them except for in the laptop itself. So my hope was that I could temporarily transfer my entire Windows 7 installation to a bootable USB drive, install the new drive, boot from the bootable USB drive, and then transfer the installation to the new drive. It used to be impossible to get a Windows installation working in a USB drive, but I thought times had changed and advances had been made. That's why I had hopes it was possible to transfer an existing Windows installation to a USB drive as well. But I couldn't figure out how to do it. The only way appeared to require a commercial version of a program called WinToUSB, but none of the versions I obtained seemed capable of doing it. They all died, claiming not to be able to use my particular SD card (I think; the error message was very specific but not human-readable).
I don't know why this stuff has to be so hard. In the Linux world, there's never been a problem installing an OS to a USB drive, and it's always been possible to just copy OSes from one drive to another. I suspect there is some engineered incompatibility going on with Microsoft installations so as to thwart pirates, but it's really just another type of consumer control, much like those fins and grooves in DeWalt batteries.

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