Author: Al Williams

4599 Articles

PCTG Filament Has Interesting Properties

March 24, 2021 by 37 Comments

Early 3D printers used ABS, but bad fumes and warping made most people go to PLA. However, PETG has a lot of the great properties of ABS along with some of the ease-of-use of PLA. According to a recent [VisionMiner] video, however, PCTG — Polyethylene Terephthalate-Glycol — could be the next filament of choice. The filament itself is from Essentium, but it appears that [VisionMiner] is a reseller of the filament (along with other engineering plastics). Thus the video below has a bit of marketing speak in it, but it also has good information and examples of using PCTG.

The plastic is relatively inexpensive, but still not as cheap as PLA or even PETG. A 750g roll is about $40 The benefits? According to the video, this plastic is stronger, tougher, and clearer than other common options.

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Coil Winding Machine Makes It Easy

March 24, 2021 by 19 Comments

[Mr Innovative] needed to wind some coils, and decided to make a machine to do the work. Making such machines has become a lot easier over the years. There was a time when we might probably have had to hack an old printer or scanner to get linear rods and stepper motors. Now, thanks to widespread 3D printing, we can order parts like that from lots of places. The 3D printing helps, too, to fabricate all the little custom widgets you need to put something like that together.

The machine looks great. It uses a number of parts that would look at home on a 3D printer or CNC build. We thought his Chinese mini table saw did a great job cutting the aluminum extrusions, but we did worry about the safety of his fingers. We’ll admit we are generally lazy and buy the extrusions precut.

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Hacking The Ortur Laser With Spoil Board, Z-Height, And Air Assist

March 23, 2021 by 14 Comments

Last month in my hands-on review of the Ortur Laser I hinted that I had done a few things to make it work a little better. I made three significant changes in particular: I anchored the machine to a spoil board with markings, I added a moving Z axis to adjust focus by moving the entire laser head, and I added an air assist.

Turns out, you can find designs for all of these things all over the Internet and I did, in fact, use other people’s designs. The problem is the designs often conflict with one another or don’t exactly work for your setup. So what I’ll tell you about is the combination that worked for me and what I had to do to get it all working together. The air assist is going to take a post all by itself, but some of the attempts at air assist led to some of the other changes I made, so we’ll talk about it some in this post, as well.

One of the modifications — the spoil board mount — I simply downloaded and the link for that is below. However, I modified the moving Z axis and air assist parts and you can find my very simple modifications on Thingiverse. You’ll also find links to the original designs and you’ll need them for extra parts and instructions, too.

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PCB Reflow With A PCB

March 21, 2021 by 17 Comments

We wonder if [Carl Bugeja] was looking at a 3D printer’s heated bed when he got the idea to create a PCB reflow heater using a PCB. He tried a quick test to heat up a standard PCB and made it self-reflow. That worked, though it obviously wouldn’t be practical for all boards. But it proved he could make it work.

To improve the heating performance, he laid out a metal core PCB, along with some custom control electronics. The board’s resistance didn’t quite perform to calculations, but luckily, it was too high so a shunt wire was able to reduce the overall resistance. One important thing to consider is that the heater board needs to use higher temperature solder so it doesn’t desolder its own components

We were glad to see [Carl] use a metal core board as standard PCB material can get cranky at high temperatures over 130C. Even so, it would be good to check the boards you plan to use this way to make sure they are rated for the kind of temperatures required.

We’ve seen lots of reflow heat sources. Halogen lights come to mind. Or, raid the toy closet and find an Easy Bake oven.

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Arduino And FPGA Done Differently

March 21, 2021 by 37 Comments

FPGA guru [Max Maxfield] recently took a look at the XLR8 (pronounced accelerate) board from a company called Alorium. On the surface, it looks like another Arduino UNO clone. But instead of a CPU, it contains an Intel MAX10 FPGA that runs a softcore AVR processor. Of course, that’s only part of the story. If the board was just a mock Arduino using an FPGA, that’s not very interesting for practical purposes. However, by incorporating accelerator blocks or XBs, you can add FPGA modules to the soft CPU. [Max] shows an example that you can see in the video below where an FPGA block controls servos more easily than a standard Arduino. There’s also a version that looks like an Arduino Nano, but can clock much faster as well as use the XBs.

In addition to prebuilt XBs, there is a workflow to build your own if you are familiar with working with FPGAs. The products aren’t exactly new, but we enjoyed [Max’s] take on the product. We also appreciated the simple code examples showing exactly how you would convert a program to use the accelerated functions. Continue reading “Arduino And FPGA Done Differently” →

Phasors In LTSpice

March 17, 2021 by 8 Comments

[Ted] recently demonstrated the analysis of an RL circuit using a piece of paper, Octave, and LTSpice. If you prefer, the Octave code should work fine in MATLAB, as well. If you are looking to get serious about electronic theory this is a reasonably simple case and is a good chance to get a workout with some of the tools.

We like the approach because too often it is easy to just use the computer and not pick up the understanding that you get when working through a problem by hand. You do need to understand complex numbers, but, overall, the math isn’t too hairy.

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Science Officer…Scan For Elephants!

March 17, 2021 by 29 Comments

If you watch many espionage or terrorism movies set in the present day, there’s usually a scene where some government employee enhances a satellite image to show a clear picture of the main villain’s face. Do modern spy satellites have that kind of resolution? We don’t know, and if we did we couldn’t tell you anyway. But we do know that even with unclassified resolution, scientists are using satellite imagery and machine learning to count things like elephant populations.

When you think about it, it is a hard problem to count wildlife populations in their habitat. First, if you go in person you disturb the target animals. Even a drone is probably going to upset timid wildlife. Then there is the problem with trying to cover a large area and figuring out if the elephant you see today is the same one as one you saw yesterday. If you guess wrong you will either undercount or overcount.

The Oxford scientists counting elephants used the Worldview-3 satellite. It collects up to 680,000 square kilometers every day. You aren’t disturbing any of the observed creatures, and since each shot covers a huge swath of territory, your problem of double counting all but vanishes.

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