Category Archives: Electronics

Posts about electronics. Usually meaning electrical gadgets smaller than a proper computer.

Thrunite T10 Repair

T10Bodymd

The Thrunite T10 light I’ve been carrying failed to come on when I reached for it the other day. It wasn’t a dead battery, and, yesterday, I determined that the 24mo warranty offers free repair contingent on you paying for shipping to and from Shenzhen, China, which comes out similar to the purchase price. I like my little T10, so this evening, I decided to fix it myself.

tl;dr: If you have a T10 die on you, it is likely to be the negative contact spring in the bottom of the body corroding/moving. Try cleaning and/or re-seating it.
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Shapeoko: Part 6

SH7-8

I’ve been working on my Shapeoko in little fits and spurts that individually haven’t been terribly documentation worthy, but in aggregate are pretty interesting. Continuing from where I left off in Shapeoko: Part 5, I’ve iterated a bit on belt tensioners, switched to a commercial breakout board, put the spindle under computer control, attached the spindle to the machine, made some tentative test cuts, and added hall-effect endstop/homing switches to the X and Y axes.
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Adventures in 3D Printing

The MakerGear M2 3D printer the KAOS lab ordered arrived last week. I am thoroughly impressed with the machine and how little fussing has been required to get decent prints out of it.

I’ve been pushing annotated pictures of our adventures with the M2 to a G+ album, because the auto-upload from my phone is too good to give up, even if the G+ album manager sucks. Take a look to get a taste of our massive new distraction.

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Shapeoko: Part 5

SH6-1
This was originally posted as Shapeoko: Part 6, because I apparently can’t count.

A while ago I ordered a 300W ER-11 DC spindle kit from China to install in my Shapeoko. I finally got to the post office yesterday (stupid recipient-must-be-present shipping) to pick it up, am impressed with the whole process. Most of this post is about the spindle, there is some more belt tensioner tinkering down at the bottom.

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Shapeoko: Part 4

I got some more time to work on my Shapeoko over the last few days, and now have mostly correct 3-axis motion. As before, details under the fold.

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Shapeoko: Part 3

Naturally, this post is a follow-on to Shapeoko: Part 1 and Shapeoko: Part 2. I’ve basically put the machine together now, and can move the X and Z axis around from the host computer, but still have to figure out belt attachments for the Y axis, and run the wiring in a sane way. I was holding up a microswitch to the various relevant spots for end-stops as I went, and everything but detecting the upper extreme of the Z axis should be easy. As in the last two posts, there is an assembly gallery under the fold.

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Shapeoko: Part 2

This continues from where I left off in my previous post Shapeoko: Part 1.

I alternated my Sunday afternoon/evening between tackling my grading backlog and building pieces of the Shapeoko. This pattern works well for tapping since they are both exceptionally tedious tasks, but in different ways. Gallery with captions below the fold:
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Shapeoko: Part 1

My Shapeoko kit arrived from Inventables while I was away at SC.

I’ve been trying to build myself a small CNC milling machine since 2009, and contemplating it for longer than that. It became clear that my original design, however educational, was a dead end sometime last year. I’d been idly watching the Shapeoko project for some time as it had similar aspirations to my design, and a couple months ago I was in a particularly mechanical mood when I saw that a batch had reached enough buyers to be produced, so I bought in for a mechanical kit to mount my existing electronics on.

The Shapeoko community is really excellent, and the kit was designed to be flexible, so I’m starting off with some suggested modifications – I’m using NEMA23 motors instead of the usual NEMA17 on the X and Y axis, because I already had some nice Lin Engineering 130 oz-in NEMA23 motors and the frame can fit them. I’m configuring for dual Y motors, which give more even force across the Y axis, and routing my belts on the outside of the frame, since I needed to buy different hardware for the NEMA23 motors anyway and this particular modification is widely recommended.

There is a gallery to document my first round of assembly below the fold (captions don’t display properly in the RSS feed).
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Raspberry Pi

I finally got my Raspberry Pi yesterday, and wanted to ramble about it for a bit under the fold.
My Raspberry Pi
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The WiFi Common Ancestor

WaveLAN PCMCIA Card

We’ve been doing some parts closet cleaning along with the sysadmin types in our building on campus, and I spotted an original AT&T branded WaveLAN PCMICA card (Model 3399-K2624) in one of the bins. These are the precursor to all modern wireless networking devices – they don’t just predate the 802.11 standards, but were actually the contributed technology that eventually became the basis for the standard – I love computer history artifacts, so I had to play with it.

Sadly, the wavelan and wavelan_cs Linux drivers were demoted to staging in 2.6.33 in 2009 (commit) and removed in 2.6.35 in 2010 (commit… gods I love well documented F/OSS projects).

This is eminently reasonable, since it is non-standard in every way, and I may be handling one of the only remaining functional examples – assuming it is fully functional. I tried to verify with some LiveCDs of suitable vintage, but inserting the card either errored the module on load or crashed the machine… which is probably why it was removed from the kernel. It’s still a neat artifact and will be getting tucked away with my odd vintage machines.

Internals of the EAM

While I had it out I opened it up (Imagine! Opening a consumer device without having to pry the fucker apart with spudgers while praying to whatever gods you believe in that none of the tabs break.) The picture above is the “EAM” (External Antenna Module) pulled apart. There isn’t too much to see among the RF cages, but the fact it is assembled with the wire harness apparently hand soldered into a row of machine pins is amazingly quaint, and the fulls-scale R/F parts are awesome.

I’m pretty enamored of the industrial design on this thing – it looks like an important transitional device. It is the dull gray that was common on (especially AT&T) computer equipment in the 80s, which has grown even uglier with UV yellowing, so the color, logos, and sharp edges look like it crawled out of the 70s, while the rounded accents, domed round indicator LEDs, and darker molded stress relief look surprisingly modern.

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