Category Archives: DIY

MyDIYCNC Desktop CNC Machine $20 GRBL Resurrection

About 8 years before the writing of this article i purchased a CNC machine from Amazon created by a company called MyDIYCNC. I was interested in the technology and the price was right at only $250.

It was easy enough to assemble and get working with Linux using their FabCAM software. Well, so it seemed at first…

When the z-carriage would retract, it would skip some steps once in a while and eventually drive the tool head into whatever I was trying to mill. While the company’s customer support was responsive I could never figure the issue out and the project got shelved.

Long story short the company is no longer around but the machine was. Sitting on my shelf, sadly doing nothing.

Then one day while shopping for 3D Printer upgrades, I ran across this Arduino kit on amazon that will replace the proprietary brains, motor controllers, and software with a well supported open source system, GRBL.

I put the Arduino and drivers into this 3D Printed enclosure:

I used the power supply that came with the MyDiyCNC kit as well as the original spindle relay. The two wires on the right go to the spindle pins on the Stepper Hat:

I soldered some female plugs from jumper wires onto my motor wires and attached them to the motor driver output. Color order from top (reset button side of board, see photo) is Blue, Red, Black, Green:

I hooked the 12V+/- output from the power supply to (yellow+, black-) to the controller hat. This is also where I pulled 12V for the 40mm enclosure fan.

Don’t forget to put a jumper on the enable pins (right of reset button).

Once everything was all hooked up I adjusted the motor controllers amperage to 400mA (for the stock motors that came with the kit, your mileage may vary) using this guide.

Now you just need to flash GRBL to your Arduino and get some software for your computer. Here are some helpful links and files that go me through the rest of the setup phase including jumper settings for microstepping:

The last tweaks to get it to work correctly was to set the X, Y, Z max speed to 350mm/min (Firmware Settings) and 1/4 micro-stepping (Jumper under motor driver).

Now you can calculate your steps per millimeter here.

Finally, the software to control it.

I have been using OpenBuilds Control and their integrated CAM software. It works fairly well, though the GUI is prone to crashing. Upside is that when the GUI does crash, the job still completes. Unfortunately he crashed GUI can make it difficult to find perfect zero again.

Universal Gcode Sender will definitely play with GRBL and control the machine. However I have yet to use it to actually run a job. I will post updates after I give it a try.

Feel free to post any questions in the comments section below!

Kenwood TS-440S IC-10 Upgrade and DIY CAT Control for Linux

My radio club, SFARC, has helped me get into an HF rig, namely the Kenwood TS-440S. This radio is a bit old (1986ish) but, IMHO, this thing is awesome. It has a fairly compact form factor, runs of my 12V off grid power without issue, and with the following upgrades will talk to my computer.

I first purchased a digimode cable that has opto-isolated audio input/output as well as a USB PTT coupler which is allowing me to experiment with digital modes on this transceiver. While this is great, I would like to be able to view and control the frequency of my radio from FLDIGI via HamCAT or hamlib. Turns out this will require a little bit of hacking (awesome!) to get it working.

Kenwood TS-440 Digital Interface Cable

Issue #1: The 13 pin DIN, ACC 2, only provides audio and PTT functions. If I want to provide a serial interface I need to use the 6pin DIN, ACC 1, interface. I need to build an interface cable.

Issue #2: This interface is a serial connection using TTL voltage (5.5v) but with the same logic as a standard serial port. I need an FTDI breakout board with inverted logic.

Issue #3: The 440 requires an upgrade kit (IC-10) to provide serial communication capabilities. This kit is semi-rare and costs about 50 bucks.

In this article issue #1 will be addressed with a six pin din plug ordered from amazon.

Issue #2 will be handled by an FTDI USB board I already have on hand and an XP virtual machine running FD_PROG to invert the logic. Unfortunately this makes this solution NOT 100% Linux. To resolve this I will use the command line Linux program ftdi_eeprom to clone my firmware and post it here so Linux only users can use ftdi_eeprom or flashrom to program their FTDI boards with ease.

Issue #3 is easily resolved by ordering the chips individually or by purchasing one of my $15 IC-10 kits from eBay.

IC-10 Chipset for Kenwood TS-440 / R5000

#1: Build the plug.

After receiving the plug from Amazon, I repurposed a shielded USB cable to build the plug. I hooked up all the wires even though CTS/RTS were not required. RFU style as it were. Perhaps adding flow control in the future would speed things up. I don’t know I haven’t tried. Anyway….

Disassembled Plug

These are the pin numbers as viewed from the solder side:

  1. GND
  2. TXD
  3. RXD
  4. CTS
  5. RTS

Here is how I hooked up the 5 wire USB cable:

  1. GND -> Cable shield
  2. TXD -> Green
  3. RXD -> White
  4. CTS -> Black
  5. RTS -> Red
Wiring Diagram

#2: Install the chips.

After I received my chips, I installed them following this guide. To sum up, remove the top and bottom cover from the radio. Then remove the face-plate screws and then loosen the 5 small screws for the metal grounding plate so it may be removed. Once this is done the chip slots will be exposed ( they are the only two empty slots on the back of the face-plate ). You will need to use a flat surface to bend the pins slightly inwards so that they will line up with the sockets when you insert them. Pay close attention and make sure the chips are fully seated properly into the sockets.

Once this is done reassemble the radio and ensure that it is working properly. Now the ACC 1 port has serial com capabilities.NICE!

#3: Hook Up the FTDI Breakout Board

The only pins required for communication are GND, TRX, and RTX. You supposedly can use a 5 wire connection using CTS/RTS flow control but it is not necessary. The FTDI breakout I used for this project only made CTS and DTS readily available so I went with the three wire setup. There may be advantages to having flow control and I would be interested to hear input on this in the comments.

My Notes

Attach the TX from your rig to the RX on the FTDI and the RX from the rig to the TX on the FTDI. GND goes to GND.

FTDI on the proto board

#4: Program the FTDI Board

Although the wiring is done, we still need to invert the logic on the FTDI board. There is no linux app to easily do this so I ran the FD_PROG utility using an XP virtualbox install to run this program. There are multiple drivers available from FTDIChip, make sure you use the correct driver for your system.

If you don’t have a windows install to program your FTDI chip, you can flash the following firmware to your FTDI chip using ftdi_eeprom. This firmware has the inverted logic necessary to communicate with your rig.

  1. FTDI Firmware File
  2. ftdi_eeprom Config File

Download both files to the same location, plug in the FTDI and program it. Something like this:

ftdi_eeprom --flash-eeprom ftdi.config

#5: Time to play radio!

You can now use FLDIGI or similar to read/send the frequency and PTT key your radio. Software config is beyond the scope of this article, but this is what it looks like:

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References:

  1. FTDI Chip Utilities
  2. FTDI Chip Drivers
  3. Installing an IC-10 kit into a Kenwood TS-440S/AT HF Radio
  4. TS 440 Serial Communications Interface
  5. TS-440 SAT Modifications
  6. Kenwood TS-440 mods reviews software and diagrams
  7. Build an Easy USB Computer Interface for Your Old Kenwood Rig

Off Grid Living: Rainwater Collection

I have completed my rainwater collection system. All said and done I think I spent less than $100. The first time I did my dishes with rainwater was the first time I felt truely off grid. What an amazing feeling! Water from the sky!!!!

The barrells were salvaged from a construction company up the road. They originlly contained Blue Def for the company trucks. I figure this is OK as I won’t be drinking the water from this system and, of course, I rinsed the insides out as best as I could before putting them into use.

The manifold is made PVC from the scrap pile and from the hardware store.  The Water filter and Oatey Mystic Rainwater Collection system was ordered from Amazon.com.

For the pump to pump the water into my house I used a water pump salvaged from an RV. If you can’t find one for free you can Buy one Here on Amazon for about $75.

PVC P-Trap for particle / sediment collection. Cap on bottom unscrews for cleaning.
Sediment Filter on Water Output
Tanks installed!
Oatey Downspout
Buy Oatey Rainwater Collector on Amazon
P-Trap
Day one of the build, only two barrels at this point.

Buy Water Filter on Amazon

Buy Oatey Rainwater Collector on Amazon

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Pietenpol Air Camper: Elevator Construction Part 1 – The Plan

My first spruce shipment came in last Friday! I decided to build some of the smaller parts first so I ordered the vertical stabilizer kit and the elevator kit. I already have the space to build these parts and I figured it would be an easy place to start. I was slightly mistaken about the easy. This “mistake” is actually working in my favor. It has given me time to perfect my mental build of the craft, see how the build process will be best accomplished, and is getting me mentally prepared for the meticulous nature of this undertaking.

Layout of elevator parts before milling.

The plans and instructions on building the empennage aren’t entirely clear and must be studied thoroughly. Much googling and reading of forums revealed that I was not the only one that found these pages of the plans “left to interpretation”.

Elevator as pictured on the plans.

There are no definitive dimensions for the gussets. They are numbered with a note that says “These numbers correspond to parts in the kit.” The “kit” from aircraft spruce just contains a peice of 1/8 plywood for the gussets to be cut from. I could not find patterns or dimensions anywhere. Also the dimensions for the center beam seem to be only for the stabilizer and the correct dimensions for the center beam on the elevator must be deduced. The solution ended up being quite simple, I made a full scale drawing of the elevator. Once this was done, figuring out dimensions and designing the gussets was actually quite simple.

Caliper, straight edge, rulers and swoop stencil

I began by constructing a simple build surface that I could screw wood to to form a jig for the elevator. I used some scrap particle board and made some 2.5″ spars with my table saw. I spaced these out on the floor, put a bunch of wood glue on the upward facing surface and then set my build surface (3/4″ particle board) on that. I weighed down the top with  heavy things and let it dry overnight.

Spars for underside of build surface
surface glued to spars weighted down overnight

The next morning I screwed the “table” to my sawhorses with two 6″ screws. I put one screw down from the top and through the middle spar into each sawhorse. Then I used shims under the other spars to make the surface flat in all directions.

build surface attached to sawhorses and shimmed to perfect flatness

Once my surface was ready, I covered it with kraft paper and meticulously translated the elevator blueprint to full size on my build surface. I then came up with what seemed like the correct dimensions for the gussets and used the pictured swoop stencil thingy to do the rounded corners.

Stencils, rulers, a square, and some really sharp pencils.
Translating blueprint to full size.

When it comes to holding gussets in place while glue dries, if you ask 5 builders you will get 10 suggestions on the best way to do this. The original plans call for cement covered flat head nails. It has been recommended by some to use a pneumatic nail gun to staple or nail them into place. Some say pull the fasteners, some say leave them in… Some say use weights, some say light clamps. Goodness… what to do? Well, after drawing up the full size plan, I’ve decided that building with a jig and just using small weights to hold the gussets while the epoxy dries is going to be the method for me. Both elevator pieces should be identical, so building everything in a jig makes the most sense. This also will allow me to miter and assemble the entire unit without having to glue anything until it is perfect.

I will be posting a YouTube video explaining this more thoroughly. I am also intending to come up with full size patterns for the gussets which I will make available on this website.

Stay tuned!

Corvair Engine Aircraft Conversion – Short Block Underway

I have ordered the short block assembly, top cover, distributor, and the rear starter/alternator assembly. It is being built by Bill over at Azalea Aviation in Georgia. I have my “core block” all ready to go, so when my engine arrives I will use that crate to ship my core back. Here is the cleaned and gently assembled core ready for shipping:

Case prepped for rebuild core

Tomorrow I will be ordering the tail section kits and Pietenpol plans from Aircraft Spruce.  Hopefully it will look as cool as Bill’s Piet:

Tomorrow I will also  be core prepping my rods and cylinders for Clark’s Corvair. They will provide hardware such balanced rods, cylinders, forged pistons, lifters and gaskets. Bill at Azalea will do the heads and covers for me. Stay Tuned!

Corvair Aircraft Conversion – Push Rod Tubes

The original push-rod tubes are going to be reused. I was fortunate that all of my tubes were in great condition. Give them a makeover and they will be ready to use.

The Process 

First step is to get them spotlessly clean and set them up to dry. I used Purple Power and hot water to soak them for a few hours.

After soaking I used cheap toothbrushes to clean the inside of the tubes and HFT cleaning brushes to clean the outside. I then stood them up to dry for about 30 minutes.

Next I cleaned the tubes inside and out using starting fluid. I then sanded the tubes with 150 grit sandpaper until they were all nice and shiny.

tubes before sanding
tubes after sanding

I used high temp zinc primer to prime the tubes then high temp ceramic white to do the final painting.

zinc primer and high temp paint
tubes with bailing wire hangers and paper end plugs ready to prime
tubes hanging to dry
The finished tubes

These turned out great. Not sure if I need to remove the paint around the seals or if I should leave it. I am sure Bill at Azalea will know. Almost time to order my fuselage kit from Aircraft Spruce. Stay Tuned!

Corvair Aircraft Conversion – Deburring the case

The disassembly and cleaning went very smoothly. To finish the prep on my core for maximum value all the casting burrs need to be removed from the case. The tools that worked the best for me were a straight deburr tip and a wire wheel tip.

Before Deburr
After Deburr

The purpose of this procedure is twofold. First and foremost, these small extra pieces of aluminum can break off the case and get in the oil and possibly work its way into the motor. YIKES! Second there are sharp edges that will shred your gloves and hands during the detail cleaning process. A deburred case is SO much easier to work on.

Azalea Aviation is doing my Fith Bearing build on the short-block so I will be ordering that today. This means I need to get my oil pump housing prepped for the conversion to a rear alternator/starter setup. This will allow Bill at Azalea to include the alt/start with my block build. Working on my push-rod tubes now. Stay Tuned!

Charge Bauer 20v Lithium Packs Using a Balance Charger

This all started the other morning when I realized I had left my Bauer battery pack and charger outside in the rain. Long story short you can use the plug from a broken charger to make an adapter to charge your battery packs with a RC Vehicle Balance Charger.

Bauer 20v + TBS Charger
Bauer 20v Pack Connected to Balance Charger

The Story

After sitting, plugged in, in the rain, overnight, there was a large amount of blue material on the battery and charger connections.

Pushing the button on the battery showed full charge, so I cleaned off the connections and tried it in my drill. No dice. I dissembled the battery pack by removing the four torx screws on the bottom. There was corrosion on the inside of the connector but everything else looked OK. I cleaned off the connectors from the inside and reassembled the battery.  JOY! The battery is working again.

Things were not so good for the charger. Under the charging board there was a huge black spot where a bank of resistors had fried.

Magic Smoke Stain

I was thinking about repairing it when I noticed that the plug part inside the charger was a self contained unit. Not only that, the connection plug for the sense port was the same as the plugs on the batteries for LiPo  RC batteries (eg Drone Batteries).

The pin-out on the above mentioned plug is not the same as a standard RC LiPo battery, but all the necessary components (and then some) are. If you are looking at the balance plug (on a Drone Battery for example) with the bumps facing down, the leftmost wire is ground and the next wire to the right is the voltage of one cell. The third wire is the voltage of two cells, the fourth wire is the voltage of three cells and so on depending on how many cells you have.

The Hack

In a nutshell we need to make the Bauer battery pin-out match a stander RC Lipo Battery. The finished adapter will look something like this:

Bauer Adapter Dongle
Bauer Adapter Dongle

You will need security torx bits (with holes in the middle) to remove the bottom plate from the charger. Then just unscrew all the Philips screws until you have just the battery plug unit. Unplug the 6 wire plug from the board and cut the red and black wires as close to the board as possible.

Using a small screwdriver to press down the tabs, remove the pins from the 6 pin plug (they need to be rearranged).  The small yellow and red wires (that you just pulled from the plug) are for the battery’s internal temperature sensor, we don’t need to monitor this sensor so we can use these wires to finish our plug. De-solder the small yellow wire and solder it with the main negative (big black wire). De-solder the small red wire and solder to the main positive (big red wire).

Move small red wire to big red wire post. Move yellow wire to big black wire post.

Solder a battery connector (salvaged from old battery pack) to the main positive and negative (big wires). Finally reinsert the pins into the plug as pictured:

Bumps Up: Red, Grey, Black, White, Blue, Yellow

The adapter is finished and just needs to be tested. Plug the adapter into your Bauer battery pack. Using a volt meter your battery plug should show about 20v. With the bumps facing down your 6 pin plug should test as follows (voltages are approximate and will vary depending on the level of charge):

  1. Yellow: (-V)
  2.  Blue: (+3.7)
  3. White: (+7.4)
  4. Black: (+11)
  5. Grey: (+14.7)
  6. Red: (+18.4)

Using the adapter you can now connect and charge your Bauer tool packs. In the program mode set your battery type to 3.7V (Lithium Poly or LiPo). Set the amperage to match the AH listed on the side of the battery pack. The charger will auto-detect the number of cells (5) and  after doing a quick balance on the cells will charge the pack until full.

LiPo Charge, Auto
Charging in full swing
Individual Cell Voltages and Balance Charging

In summary, this hack is very simple and could be considered an upgrade to the charger from HFT. Having the info display showing the voltage of each cell and balance charge mode are both great. There is also a fast charge that I haven’t tried, but this already charges my batteries quicker and more completely than the Bauer charger.

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Amex / Gemplus Smartcard Reader – Usage and Hacking

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Looking for Smartcard info downloads? You have been directed here and download links are below.

Many many years ago I had a post on my old website, artofconfusion.org, oulining the research I did to get the old free Amex smartcard readers to work on Linux. Analytics are showing that people are still looking for the post, so I have added the info and doc downloads here.

A few years back american express introduced the Amex blue, the first US credit card using smart card technology. During the release of this card Amex was giving away, free of charge, no questions asked, a card reader to be used with their cards. This page will provide an outline for hacking that gcr415 smart card reader you were lucky enough to acquire.

The gcr415 is no more than the gemplus serial smart card reader with some fancy Amex stickers on it. Any software or data-sheets related to the gemplus serial will work with the gcr415. 

My progress

Windows: found appropriate driver for my windows 2k unit installs and works to install the driver. Use the driver i have it in the archives for gempc410 serial card reader. Use the install exe then go to the add hardware wizard -> add other device and it should appear with 4 choices. The driver that works is gemplus pcr410p serial smart card reader. Once its installed it is listed in the hardware section under smart card readers. The utility recognizes the device and can tell when a card is being inserted and removed i don’t have blank smart cards yet so its difficult to play further.

Linux:

Got the goodies together to get the card reader working in Linux (slack 10 kernel 2.4). First you need PC/SC-lite installed then you install the driver. Once it installs you need to set up a proper /etc/reader.conf file. You can look at mine:

$ cat /etc/reader.conf

FRIENDLYNAME "GemPC410"
DEVICENAME /dev/ttyS0
LIBPATH /usr/pcsc/drivers/libGemPC410.so.0
CHANNELID 1

it works and if you run

pcscd –fg stdout

you can watch the daemon at work…

Then if you install the perl wrapper for pcsc you can use the tools like pcsc_scan in another terminal or after running the daemon in the backgroud. Cool thing about the perl wrapper is you can build runtime compiling apps to work with the reader.

Smartcard / Gemplus Related Docs

For more information and downloads, check out my old smartcard research page.

The Amex serial Smartcard Reader:

Let’s crack it open and see what’s inside:

Smartcard Dimensions: