A few years ago I made animatronic singing pumpkins using an Arduino Uno, a Wave shield, a 16-channel servo/pwm controller, and some DC-DC power converters, all from Adafruit. I designed a single PCB that unified all of that and included a 15W amplifier. Today I completed assembling that board and began its commissioning. I used solder paste and a mylar stencil cut on our laser. Its the first time I have ever soldered a TSSOP package with no shorts.
Anyway, I managed to forget to bring a microSD card, but the program loaded into the AVR OK and is running. All the various power supplies are outputting the correct voltage. 6 volts for the servos, 5 volts for the AVR, and 3.3V for the microSD card and buffer chip. The amplifer gets the raw 12 volts. So, I’m hopeful that over the next week I’ll be able to bring the board completely online.
The Turndrawble is a drawing machine I designed, based loosely on an old vinyl turntable, but instead of playing records, it creates drawings.
The construction was done using stacked layers of wood and acrylic. I wanted to avoid using the typical laser-cut “box” enclosure I usually use. I’m pretty happy with how it turned out.
The Turndrawble is meant to be used to create 12″ circular drawings. One of the knobs controls the platter speed, and the other sweeps the arm in and out. Since it’s a new drawing device, it hasn’t been mastered yet, but we’re working on it!
Here’s a short video showing the turndrawble being operated. I’ll probably have it at some future art events for people to try out and see what they can create with it.
I recently acquired a new eyepiece to replace the damaged one that came with the Meade ETX-90 telescope I bought at a swap meet last year. I decided it needed to have a web-cam mount so I designed and printed one that is a variation of a previous design for a microscope. It took about 20 minutes to recreate the CAD file in DesignSpark Mechanical, and about 90 minutes to print on Son of MegaMax.
This thing has an odd shape to accommodate the odd shape of the camera. I designed the adapter in two pieces so it could be printed without any support material. After printing the two pieces were glued together with a little super glue.
Unassembled 3D printed WebCam adapter and eyepiece.
Assembled adapter on the eyepiece.
The adapter fits over the barrel of the 32mm fl eyepiece and stays put.
I shot a short video to test it and it works perfectly! The cars driving by are about 1/2 mile away.
If we ever get a clear night I’ll try shooting Jupiter or Saturn and then run Registax to enhance the images.
Files are here: https://www.youmagine.com/designs/web-cam-adapter-for-meade-telescope-eyepiece
I built a QWERTY keyboard that types the letters Q, W, E, R, T and Y, and nothing else. No space, no return, no escape.
It’s a fully-functional USB device, you know, as long as you just want to type words that can be composed with Q, W, E, R, T and Y. (WET, WRY, YET, TRY, there’s a bunch of them!)
I wrote plenty more about this project on my blog, and if you want to read about the history of the QWERTY layout, and its connection to Milwaukee, and why the way we interact with technology is interesting and sometime ridiculous, well… I got that too.
I found this nice vase on Thingiverse and printed it at 75% scale a couple weeks ago.
75% scale vase looks fine from this angle…
It came out pretty good except for the area near the bottom where it was overhanging. 3D printers don’t handle overhangs without support material very well. I tried reslicing with support material added, but didn’t like the way it looked in either Cura or Slic3r so I didn’t try to print it again.
Overhang caused poor print quality for the first 6-8mm of the vase.
Then I tried printing it upside down- the overhang is much smaller.
100% scale vase printing upside down.
About 12 hours later, here’s the result: perfect!
The two vases, bottoms up- the 100% scale vase is perfect!
I finally got around to using Python mode for Processing 2.x. I have used pyprocessing for 1.x in the past but the current version is supported by the official IDE. While I am not very good in either, I am more comfortable with Python over Java, Processing’s default language.
I create a few simple “sketches” to get used to the format. After comparison of a few animations in both languages, Python mode was noticeably slower – around 2-3 FPS versus > 15. I worked around this issue by saving each frame as an image and combining them with GIMP to make a .GIF animation. Here are a few sketch outputs – both static and dynamic.
Hopefully a few crafters out there will appreciate the measures we’ve taken to protect tools that have been loaned to the group. Deterring misuse is only one feature of this upcycled sheet metal enclosure. It’s also incredibly stylish! A padlock could easily be added in the future, but surely it won’t come to that.
In following the internet chatter about the FTDI bricked-chip dust up some months ago I came across mention of a Silicon Labs USB-Serial chip, the CP2110, that worked a bit different. The device enumerates as a regular HID device and uses a standard OS driver rather than a manufacturer specific one. Being a HID device, there is no COM port. Instead you link a library into your application that knows how to engage the standard HID driver to talk to the chip in a serial-like fashion. In effect, this moves the driver from the OS to your application.
So I grabbed some of the chips and made up an OSHPark board that implemented the minimum passives and broke out the pins. Tonight, during Builder’s Night Out, I finally got around to soldering it up. The worst part about the CP2110 is that it is a 4mm x 4mm QFN with a 0.5mm pin pitch. I used the space’s 50W laser to make a solder paste stencil out of some of the giant roll of 3 mil mylar we have. My first go at it with one pass of the solder paste squeegee didn’t put down enough paste on the QFN and my second go with 3 or 4 passes in orthogonal directions put down too much solder paste. There is probably a middle ground there.
Anyway, I used the space’s Zallus reflow toaster oven to reflow that second paste attempt and wound up with a number of the QFN pins shorted together. (I should have wiped the paste off and looked for that middle ground.) To fix the shorts I used the space’s hot air rework gun to pull the QFN chip off. That allowed me to solder wick the pads to a point free of shorts and then use the hot air gun once again to put the chip back. I over heated and burnt the tantalum caps and the LEDs in that rework process. So I used the hot air gun to remove those components and then hand soldered replacements back on to the board.
The moment of truth came when I plugged the freshly soldered board into my laptop’s USB port. I fully expected it to say “over current limit”, but to my delight it happily installed the HID driver! I’m looking forward to trying out the link library.
MegaMax was a great 3D printer, but it was time for some changes. He was difficult to transport because the electronics were in a separate housing with many cables to disconnect and reconnect, barely fit through doorways, and required a positively gargantuan enclosure to keep the temperature up to control ABS delamination. Though it hurt to do it, I tore him apart and did a complete redesign/build into a form that is more like what I would have done had I known anything at all about 3D printing when I started building MegaMax.
I reused what I could including a lot of the 8020 extrusions in the frame, the Z axis screw assemblies and drive belt, and the X and Z axis motors.
ball screw drive Y axis with high torque motor- precise but noisy
linear guides in X and Y axes instead of 1/2″ round guide rails and linear bearings
SmoothieBoard controller instead of Arduino/RAMPS
BullDog XL extruder and E3D v6 hot end
RepRapDiscount graphic LCD control panel
narrower frame design without giving up print volume- easier fit through doorways!
polycarbonate panels to enclose the print area yet provide a clear view of the print
electronics in a drawer for easy service and transport and neater appearance
DSP motor drivers and 32V power supplies for X and Y axes
Liberal use of screw terminals to make servicing easier
Modular X and Y axes that can be removed for service and replaced in minutes.
SoM will be making his public debut at the Milwaukee Makerspace very soon…
Son of MegaMax electronics drawer
Side view of Son of MegaMax
September 27-28 at Wisconsin State Fair Park, the same weekend as Harvest Fair. Admission is free. Maker Faire Milwaukee's Call for Makers is now open.
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