Posts about Technology

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The First Transistor Radio hit the market on this day (18 October) in 1954. (Read that in the voice of Garrison Keillor.)

Learning this today reminded me of one of my first pieces of electronics as a kid. It was a little blue, portable transistor AM radio that took 2 AA batteries. I got it as a prize from the school fundraiser, and I specifically remember it being listed as a transistor radio, like that was something special. I’m not sure how special that really was in around 1985, since we’d evidently had the technology readily available since 1954.

That radio was packed full of components on a board in its blue plastic shell. From the first time I had to open it to put batteries in it, I was intrigued by it — solder joints, variable capacitor, capacitors, resistors, transistors, antenna coil with ferrous core, bits of glue holding it together, etc. That thing came apart many times as I compared its contents to other devices and to those on my electronics kit later.

The kids got a little M3D Micro for Christmas, and so started our adventures into 3D printing.

I intended to let the kids learn the whole thing from scratch, but I knew I was throwing them a little bit of a curve ball by only having Linux netbooks to drive it, so I ended up getting a headstart setting up OctoPrint and the M3D-Fio driver.

At the end of December 2015 when I was starting, the M3D-Fio driver had some configurations in the repository that might not have been optimal, so I was fighting a bit with a few problems:

I thrashed around for quite some time changing settings I didn’t really understand, and Matthew spent a night helping me and showing me what his much larger printer could do — that helped immensely, since it gave me some hints as to what I should be expecting from my printer. I also learned what the different settings should be doing for me.

For an entire Sunday, about 18 hours, I printed 1cm test cubes and experimented with settings. I quickly decided I should have my settings and profiles tracked in my own local git repository, so I can always rollback to previous settings.

After a week or so, some updates from the M3D-Fio repository brought us more success with more default settings that matched the defaults found in the original software from Micro. The conservative settings also added rafts and slowed down the print a bit.

I was able to take those conservative settings and speed them up a bit and remove the rafts — the BuildTak holds a print pretty well even without the raft. I based my customizations on the stock profile that prints at 0.25mm layer thickness to get even more speed out of the printer.

I also found keeping a -0.4mm bed offset on my printer helped get just enough squish in the first layer to help get a more solid bottom layre and good adhesion to the bed.

Another notable configuration tip I had picked up was to set the wall thickness to a multiple of the nozzle size. In the case of the M3D, the nozzle thickness is 0.35mm, so I’m using a thickness of 0.70mm. Before I had learned that, a couple of my initial chachkies came out with thin gaps where the slicer should have decided to fill.

I’m at the point now that I have pretty reasonable expectations for what the printer can do, and I can start up the machine after a week or 2 of sitting, and run a print through reliably without needing to make adjustments. That’s great for letting the kids just make whatever they want. Both kids have been able to get into Tinkercad and produce some printable designs. Ben’s doing Nerf rail accessories, and Marie is designing a new cap for my growler.

Finally, I’ve pushed my configurations to a public git repository to serve as reference for anyone else who cares.

An update added a slicker settings dialog to allow more intuitive adjustments to a profile, so I’ve been testing relatively successfully with using the stock PLA profile and just flipping options. I did find that using a raft in "medium quality" mode fused my little 10mm test cube to the raft in a way that I can’t remove it. I usually avoid the raft anyway, though, since it sticks so well to the buildtak already.