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CES 2016

I went to CES 2016 in Las Vegas. This is my second time visiting CES, last year I made this post (CES 2015) about it too.

This year is a little underwhelming than last year, perhaps its because last year was my first time, and this year is my second time. There are many things that simply remained unchanged, or just slightly improved. Here’s a list of what I found interesting: (continue reading)

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3D Printed Dust Skirt for Nomad 883 Pro

I got a new Nomad 883 Pro and it generates a lot of dust. This is going to be a big problem as I need to cut material that have hazardous fibers. I decided to make a dust skirt (aka vacuum skirt or vacuum shoe or vacuum head) so that a vacuum can suck up dust as the machine cuts. I 3D printed this thing, which is partly PLA plastic, and the skirt is 3D printed TPU (polyurethane) filament. The skirt is two layered and the cuts are made in a interleaved pattern so there’s a better seal. 3D printing makes this project really easy, just clean up the print, superglue, and tap the hole for the screw. The vacuum hose is 1.25 inch diameter and it just shoves right in with a perfect fit.

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The CAD files can be downloaded here

3D Printed Micro Match Connector Crimp Tool

I have a project that involves Micro Match connectors. They are similar to IDC connectors, but with a lower profile and a zig-zag pattern.

8_way_Micro_match_IDC_male_on_wire_connector_assembly[1]

I had to crimp one connector onto a ribbon cable, my first attempt using a vice failed miserably, instead of the conductors being forced into the teeth properly, the forces instead crushed the connector. Unlike a IDC connector, which is mostly solid plastic, the Micro Match connectors are pretty hollow, thus weaker.

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Continue reading to see how I solved this problem.

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3D Printed Battery Recharge Dock for Parrot Rolling Spider

20150902_222523 (Large)

I got a Parrot Rolling Spider for fun. The batteries are 570mAH and the life is under 10 minutes, plus the reviews often mention that the batteries will lose their capacity quickly. Further research into this problem indicated that charging them slowly will alleviate this problem.

I wanted a few spare batteries and a way to recharge them. I decided to DIY a dock for them. I had a handful of spare parts, such as the MCP73831 and plenty of small perfboards. All I needed to do was 3D print something to hold the batteries in place, and this is what I came up with.

More pictures if you continue reading.
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SD Card Bootloader by Backdoor Code Injection

For various reasons, I decided to try writing a SD card bootloader for my Ultimaker2.

The project is open source and on my GitHub here.

My goal was to install this new bootloader without having physical access to the circuitry. Thus I cannot use a ISP tool and must be done through the bootloader that is already present on the Ultimaker2. The only way to do this is to partition off a portion of application memory region for a secondary bootloader that executes after the original bootloader. But the ATmega2560 has a restriction that prevents anything in the application memory region from modifying the flash memory at all. Overcoming this restriction is what this hack is all about, continue reading if you are interested in learning more.

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Ultimaker2 Bearing Spool and Bearing Guide Upgrade

This is an upgrade to the Ultimaker2 3D printer for people who have spools that do not fit the original spool holder, and spools that are too tight and thus do not feed smoothly, causing under-extrusion.

It is composed of two assemblies: a replacement for the filament guide and a replacement for the spool holder. Both utilizes ordinary skateboard bearings to achieve smooth rotation. The conical shape of the spool holder allows for any sized spool to be used, easily swapped because it uses a wing nut.

um2 spool holder upgrade angleum2 spool holder upgrade sideum2 spool holder upgrade cross section

um2 filament guide upgrade angleum2 filament guide upgrade sideum2 filament guide upgrade cross section

Files are available on YouMagine. I want to emphasize that I am sharing the STEP files, not just STL, because STL are harder for people to import and modify than STEP files. SolidWorks files are also provided.

The cross section images shows you how to assemble the upgrade parts. The screw diameters are #6 for the filament guide and 5/16″ for the spool holder. Please figure everything else out from the cross section images.

3D Printed Raspberry Pi Case + Camera Case + Server

There is a law of the universe which states that if you own a Raspberry Pi and a 3D printer, you must print a case for it.

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There are plenty of case designs for the original R-Pi Model B, and some for the R-Pi Model B+, but there are a few minor annoyances I noticed about them. Plus I really like DIY my own designs, so I designed my own case to suit my own needs.

  • Designed specifically for 3D printing, meaning careful attention to how plastic is extruded, no weak spots, and no overhangs. Plenty of fillets and chamfers.
  • No screws required. The case is held together using latches that take advantage of the plastic’s natural flexibility. It is designed for just sitting on a desk, or attached via velcro/double-sided-tape.
  • I also designed a small case for the camera, which follows the same principles.

These parts are because I am going to set up a web server for my 3D printer, running OctoPrint and also serving live video through the camera. I also setup a cron job to take a picture periodically and upload it to this server. I can also stream video to my Ustream channel. (neither of these servers are 24/7)

I am sharing all of the source files for the models, not just STL files. It is very annoying when people only share STL files, because STL are not import or editing friendly. With my SLDPRT file, you can change one height dimension inside and it will re-adjust the entire case, maybe if you need more clearance on the bottom for screws.

files for R-Pi case

files for camera case

Ultimaker2 Improved Filament Feeder

The Ultimaker2 3D printer has a problematic filament feeder mechanism assembly. When the filament is stuck and the feeder motor turns, it can grind away the filament, causing a gouge in the filament. The gouge makes the problem worse since the tensioner bearing will force the gouge into the feeder’s knurled wheel more, causing even more grinding. This jam happens frequently because sometimes even if the temperature sensor reports that the print head hot end has heated up, the plastic hasn’t melted yet and can’t move yet.

The Ultimaker2’s feeder design is both beautiful and disappointing. It is beautiful in the sense that is is symmetrical and compact. If you had a dual extruder, you can use the same feeder mechanism for both feeders, cutting down on manufacturing costs. But it is impossible to disassemble without removing the stepper motor because the same 4 screws that holds the feeder together also holds the stepper motor in place. If you attempt to open the feeder mechanism to clear a jam, the motor will fall off. The motor is also covered by a metal casing so you need to remove the casing as well. This is very annoying.

There is no other way to move the tensioner bearing because the design is so compact and the spring is tight. There is no other way to remove the feed tube either.

What I needed was a feeder mechanism that can be opened up without removing the stepper motor, and also allow the tensioner bearing to be moved out of the way easily. I came up with the following design:


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3D Printed Tripod Adapter for Smartphones

I got a new 3D printer, a Ultimaker 2. After testing it out with some small test prints, I printed my first own custom design on this printer. (I’ve only designed for SLT printing previously and not extrusion printing before, this is my first design for extrusion printing).

It’s an adapter that holds my smartphone (Samsung Galaxy Note 3 with a wireless charging S-View flip cover case) and has threads (a 1/4″-20 threaded nut) so it can be mounted to a standard camera tripod. This phone has 4K video recording so why not?

The design is very custom because I need to consider the fact that I have a S-View flip cover case.

(I know I could also use threaded metal inserts, but nuts are easier to buy at the local Home Depot)

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Weekly Report August 16 2014

Nothing geeky to talk about. I managed to rent a 1 BR apartment in San Mateo for about $1725/month in a pretty good spot (but whoever built the place did not seem to own a ruler and whoever painted it didn’t own masking tape). Here’s me planning the layout using SolidWorks and Ikea’s catalog.
ikea floor plan

Trip to China

I went on a short trip to China, seeing some family and some sightseeing.

No trip is complete without seeing some Chinglish

Chinglish

Some wiring near WuXi (please ignore the camera flash being reflected in the glass window, I was on a moving bus, I didn’t have time to disable my flash)

Some BBQ Pupa


Reverse Engineering and Cloning a S-View Flip Cover

I got a Samsung Galaxy Note 3 as soon as it was released. I wanted a S-View flip cover for it. S-View basically means the screen will automatically turn on and off when you open and close the cover. It is also able to reformat the display to show important notifications through the square viewing window of the cover, etc. The phone knows if the flip cover is opened or closed because there’s a tiny magnet inside the cover.

But all of the official S-View flip covers available are very expensive at about $60 each. The cheap covers might look like S-View covers, but they do not support the actual S-View functionality. But the cheap covers are about $5. I wanted to hack a $5 to give it S-View functionality. Continue reading

Weekly Report Nov 17 2013

USBXLATER is going strong. Constantly improving and new features. During the testing, I picked up another generic USB hub to test…
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Like the picture said, they do not work, I have other generic hubs that do work. These ones seems to exhibit a signalling issue. The strangest thing is that they’ll work if I plug them into my USB traffic analyzer, which means I can’t even debug the signals…

Weekly Report Nov 10 2013

USBXLATER is going great! I’m using it to play through BF4’s single player, to work out bugs. I implemented anti-acceleration for the mouse, plus some filtering, and it feels amazingly like a PC game. I also gave a USBXLATER to Matlo from GIMX because he’s so helpful.

iOS and nRF51 are talking beautifully now. I feel like I can do whatever I want with BLE technology now.

I got a writable NFC tag keychain, I can use a phone app on my Galaxy Note 3 to write my contact info into the tag, and when you scan it, it asks you to import my contact information. Now I keep it with all my keys.

I went to a Freescale seminar. In summary (from the 3 sessions out of many I went to):

  • Kinetis chips do not have any bootloader today, but starting winter of 2013, they will start to add factory stock bootloaders.
  • They are making new ARM Cortex chips with built-in radio transceivers will be released this winter
  • They are going after the Qi wireless charging market, with some NFC involvement too.
  • I learned more about making PCBs that won’t fail due to bad EM characteristics.
  • I think Freescale is slightly behind on the market, I know NXP and ST both already have factory stock bootloaders. ST has their STM32W family already, and I’m already using nRF51 from Nordic.

Had to fight off a wave of spam to my website, because I forgot to turn on account confirmation on my wiki, oops.

Weekly Report Nov 2 2013

I’ve been working with the VS1000D chip, made by VLSI, who has very cool engineers.

Getting closer to the next generation console launch dates. My USB keyboard+mouse-to-console adapter is going great, adding in configurable data translation and such. Still waiting on new PCBs.

I went to the hacklab.to hackerspace in downtown Toronto. I met some great people there. The space is a bit small but they plan on moving to a bigger space soon. I gave away a few spare blank PCBs while I was there.

I played “Journey”. It is one of the must-play titles of the PS3. I suggest you play it in one sitting, with nobody around physically to bother you, and signed into PSN. This is the only way and best way to enjoy this unique game.

Booooo CSR

I inquired a company (not CSR, but their product uses chips from CSR) about some WiFi Direct modules, this was their reply:

Please note that we just stop any new WiFi CSR solution. Based on previous experience with CSR, we could not get driver source code from CSR and CSR couldn’t support themselves. So we give up CSR WiFi

If you didn’t know, CSR makes a lot of Bluetooth and WiFi chips, but they absolutely do not ever EVER give you access to any documentation or any software. Usually to get access, you have to pay them big $$$. In this case, even if you pay them, apparently “CSR couldn’t support themselves”, how embarrassing. This was from a friend who have used CSR before:

It took 3 months to get access to the BC4 firmware and that has been deprecated for years.

CSR is on my list of companies to avoid.

Review: SeeedStudio Bluetooth Multimeter

I just received my SeeedStudio Bluetooth Multimeter.

I’m not going to talk about the measurement specifications and capabilities, because they are clearly stated, and you should decide for yourself if the specifications and capabilities meet your needs. This review will be more focused on the usability.

The enclosure is made with split Continue reading

Nehebkau, Laptop Controlled Keyboard and Mouse

I got my Raspberry Pi. I do not have an ethernet connection or Wifi dongle available, or an extra keyboard. I don’t have any Bluetooth either. I needed a substitute keyboard to use the Raspberry Pi.

For fun, I designed a little USB device, actually it has two USB devices on a small board in the shape of a stick. Two USB capable microcontrollers are on this circuit. One will connect to the Raspberry Pi, and behave like a keyboard and mouse. The other will connect to my laptop. My laptop will run software that captures keystrokes and mouse events. The laptop will tell the microcontroller what to do, so when I press a key on my laptop, the Raspberry Pi thinks the same key is pressed. (and the same with the mouse)

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Pebble, More Impressions, Scratch Repair (Hiding)

I wore the Pebble every day. The display is still amazing, battery life has never been a problem. There’s been firmware updates and the UI has some great improvements.

Usually when I hit my wall (my desk is in the corner beside a wall, right by my left hand, where I wear my Pebble), the Pebble handles it just fine without any scratches. But this time I hit a stone pillar outside, and it got some deep scratches.

The scratches were too deep for any conventional polishing techniques. I could try sanding it and then running it under a buffing wheel, but I do not have access to one. So I was pretty sad, especially because I already ordered some screen protectors for it.

The first lesson here is that, if you want a Pebble, you want a screen protector as soon as possible.

With that said, I’m not the kind of person who just gives up. When the screen protector arrived, I did an experiment.

Petroleum jelly, aka Vaseline, has a similar refractive index to most plastics. I know this because I know that you can repair scratched LCD monitors by spearing Vaseline over it. The Vaseline will fill the scratch, and since the refractive index is matched, the light travels through it without bending or reflections, this makes the scratch invisible. I smeared some Vaseline over my Pebble, and the scratches disappeared. Great!

The next problem is that the Vaseline will rub off and wash off eventually, unless you cover it up somehow. So the next part of the trick is to install a screen protector to cover up the Vaseline. So clean the screen with soapy water to get rid of any oil, dry it off, smear some Vaseline on it, apply the screen protector, and squeeze out any bubbles. Then let it sit still for an entire day or two. Make sure your hands are clean and no dust ever lands on it while doing this.

I highly recommend using Gadget Wraps for this, because their “wraps” is two parts, one part is a sticky decorative part (the brushed metal one looks amazing on a black Pebble) and a second part which is a clear screen protector. The sticker has a rectangular cutout in the center, where the screen protector sits in, in the end, everything is perfectly smooth. This makes my method of hiding scratches much easier because the sticker traps the screen protector, making it easier to squish out the bubbles.

Some pictures: http://i.imgur.com/QOvWHYz.jpg and http://i.imgur.com/fDLZCHL.jpg