James

i3 Detroit Plasma Cutter

CNC Plasma Cutter, i3 Detroit No Responses »

May 182012

i3 Detroit Plasma Cutter

Here is the new (vintage 1985) Plasma Cutter getting cleaned up before getting installed on the CNC Plasma Cutter located at i3 Detroit. A couple of decades of gunk was just too much for me. So, off come the covers and in goes the compressed air!

This is a Thermal Dynamics model PAK5XR which is capable of 55 Amps at 100 Volts. For reference, this Plasma Cutter uses electrical diagram 42B669F. Scroll down to the bottom of this page for a scanned image of the electrical prints.

Here is a closeup of the nameplate on the Plasma Cutter.

Plasma Cutter Name Plate

Relay Driver Board

Promat C30/S, ProtoMat No Responses »

May 172012

Relay Driver

Just a quickie – it’s cool being able to pump out a quick board without a lot of fuss. The ProtoMat C30/S makes it easy to go from schematic to actual board in just a day. No long delays waiting for boards to come back from a manufacture. Very cool.

The next pic shows the bare board, except for the FET, ready to have all the parts soldered on.

Bare Board

ProtoMat C30/S CNC PCB Mill Tips & Tricks

ProtoMat No Responses »

May 072012

10X Overhead View

This post is just a quickie place to dump a bunch of info just so I don’t forget anything. I’ve come to depend on my own posting for reference information.

All the information on this page was gathered while working with the Protomat C30/S CNC PCB Milling machine owned by the Hacker-Space i3Detroit. The machine at i3 Detroit was purchased from Craig’s List for $1,000 dollars in March of 2012. I’m one of four or five owners of the i3 Detroit machine.

Learning to use the C30/S is not for the faint of heart. The learning curve is steep. The manufacture, LPKF, intended new owners would attend a LPKF training classes after purchasing their machines. That’s really not an option for a bunch of hackers using a 10 year old, second-hand machine at a hacker space. So, to put it mildly, the LPKF manuals are spartan.

$10 Dollar Harbor Freight Cordless Screwdriver Teardown

Copper No Responses »

Mar 142012

Chicago Electric Cordless Screwdriver

OK, I admit it, I thought I couldn’t go wrong buying a $10 dollar cordless screwdriver. Yeah, nice idea – but not so much. My backup plan, in case the screwdriver really stunk, was to adapt the parts into a robot drive motor. As a robot wheel drive this screwdriver might not be a bad buy.

As a power screwdriver this model kinda stinks. It’s rated at 4.8 Volts / 180 RPM and comes with a 6V / 300mA charger. The motor / gearbox does not generate a lot of torque. However, the worst aspect of the screwdriver is the charger. Both the charger and the screwdriver get very warm after a day on charge. Not good. In other words, you can’t just leave the screwdriver on charge for days on end. What a waste of energy!

$10 HFT 4.8V Screwdriver

Given the screwdriver stunk as a screwdriver, it only seemed right and OK to rip apart the brand new screwdriver to see if option B was going to work. Below are some findings from the teardown:

Of course, the batteries are cheap-o Ni-Cd 600 mAh.
The gearbox, which is a nice planetary two-stage, needs to be mounted in the case to stay together. Without the case screws, there is nothing holding the motor and gearbox together.
To use the motor / gearbox in a robot much of the original housing around the motor and gearbox would need to remain. The housing would be needed to hold the motor and gearbox together.
While the front of the screwdriver looks made of metal, it is not. The gearbox is all plastic except for the sun gear on the motor.
Testing the motor on my power supply I found the motor does not even start to try to turn until 1 amp of current is flowing! Not the most efficient motor / gearbox combo. After a little break in, I found the minimum motor speed / current was 1/2 Volt and 1/2 Amp. So, just to free-wheel, the motor / gearbox consume a 1/4 Watt of energy. Not great.

So, bottom line, not the best choice for either option A or option B. In hindsight, I should have known that a $10 cordless screwdriver was going to stink!

Hacking Capacitive Encoders

Uncategorized No Responses »

Mar 102012

Gutted Digital Micrometer

A long time ago a friend of mine, and I, decided we were going to build a capacitive encoder. Our big idea was some 15 years ago when we were a bit younger (and more foolish). My friend took the guts from a digital micrometer and mounted it all to a large Plexiglas block. One of us mounted a wires to all the pads around the perimeter of the sensor. The pads allowed us to probe the signals on the pads. This poor little encoder is amazing, it has a resolution of 500 counts per revolution.

Typical Digital Micrometer

Cree MT-G Super Duper 6 Watt HBLEDs

HBLED No Responses »

Mar 062012

Cree MT-G 6W 540Lm LED

Got a tip from Cree that they have some new LEDs on the market. Their newest little buggers are amazing! The really big news is the voltage requirement for the MT-G. This new Cree LED is available with a Vf (forward voltage) of just 6 Volts.

About six months ago Cree sent me a CXA2011 that was very interesting. However, it had one major drawback. The Vf required was around 40 volts. That’s a problem for a lot of applications. Even using a charge pump, 40 volts is hard to generate. Here is a link to my previous writeup about the CXA2011.

Well, the new MT-G comes in two different models based on Vf. My latest efforts have been with the 6V version of the MT-G LED. Here are the basic specs on the new 6 Volt MT-G Cree LED:

Part Num: MTGEZW-01-0000-0B00G040F
Natural White – 4000K
540 lm @ 6 Volt / 1.1 Amp
Typical Vf: 5.6 Volts @ 1.1 Amps
120 degree optical pattern
9mm square package
Digikey Part Num: MTGEZW-01-0000-0B00G040FCT-ND
Price for One: $17.45 ea.
Price for 100: $13.42 ea.
Price for 1000: $8.39 ea.

RC Transmitter / Control Anything

Uncategorized 4 Responses »

Mar 012012

HobbyKing $23 Dollar HK-T6A 6Ch Radio

I recently stumbled upon how easy it is to hack into / repurpose the HobbyKing 6 Channel transmitter / receiver RC radio. The specific model I’m using is the HK-T6A V2 6 Channel 2.4GHz transmitter and receiver pair. This is an awesome hacker’s delight mainly because of the price. At just $23 bucks you just can’t go wrong. Note, I have zero affiliation with HobbyKing – I simply think this radio transmitter / receiver pair is amazing considering the price versus functionality / performance. This radio is designed to transmit up a mile without any glitches so you can fly your RC airplane without any problems. There is some crappy HobbyKing software you can get to reverse and mix channels. To use the software you must purchase a special USB to Radio cable from HobbyKing. At only $3 bucks I bought one just to see what extra “features” I could play with. All cheap fun!

Anyway, read on for the hack to control anything with this transmitter (for now on known as Tx) and receiver (for now on known as Rx).

*** Note, I’ve only tested this method with this particular HobbyKing radio Tx / Rx pair. You’ll have to test your radio to verify it operates in the same manner to use this hack.

Pinewood Derby Mars Rover

Uncategorized No Responses »

Feb 182012

Pinewood Derby Mars Rover

Hey Pinewood Derby Race Fans!

Need an idea for this coming Pinewood season? Have a look at our Mars Rover from the 2012 race season. I’m proud to announce we won first place for the “People’s Choice” award. Good thing too, this car design is not the fastest car on the track.

The three blinky LED lights are all hacked from other sources. The big dish on top came from K Mart. The dish was a sphere before we broke it open. It was originally designed to float in a fruit punch bowl. K Mart sold them as a pair for $5 bucks.

The two tail lamps were tea LED lights. Bought these in the grocery – these can be had for around 30 cents each. We hacked them down and be smaller then the originals. The on/off switch also got reworked so that it now accessible along the back edge. Otherwise, the switch points out of the bottom of the lamp.

The top deck is covered in aluminum foil. The bottom chassis is covered in copper tape. The copper tape was some 1″ sticky tape I’ve had forever, and a day. The two covering gave the car a nice two tone look. Note, the middle wheel is non-functional and is mounted a full 1/4″ above the track.

Well, hope this give you some more ideas for you next car. If so, post some comments below.

Running FreeRTOS Demo within TrueSTUDIO

Copper, EPS - Electric Power Steering 11 Responses »

Jan 062012

Atollic TrueSTUDIO Lite

This posting is how-to for getting FreeRTOS running inside of TrueSTUDIO using my demo code.

My TrueSTUDIO installation is goofy because I’m running TrueSTUDIO inside a VMWare virtual Windows XP machine. My host machine is Ubuntu 11.xx and I can report the STM32F4 Discovery board USB drivers, passing through to VMWare / Windows, and work just fine. With this setup, I can do all my editing using GVim on the Linux side and my compiling and debug on the Windows side. Strange but true – works for me.

So, to straiten out the project setting takes just a couple of changes. No big deal. The jpg images below should be all you needed to setup the project on your machine, however you have your machine setup. Continue reading »

STM32F4 + FreeRTOS + TRUEStudio = Awesome-O

Copper, EPS - Electric Power Steering 11 Responses »

Jan 052012

STM32F4 Discovery

ST Micro really gave the world a nice Holiday present this year by releasing the STM32F4 Discovery board! You can get yours at Mouser for $16.25. An amazing dev. board for $16.25.

32-bit ARM Cortex-M4F Core
1MB Flash, 192KB RAM
FPU (Float Point Unit), 16-Channel DMA
Ethernet MAC 10/100
USB 2.0 OTG HS/FS
6x UART (LIN, Strtacard, IrDA)
3x SPI, 2x I2S, 3x I2C, 2x CAN 2.0 B
3x 12Bit ADC (24 Channels 2.44MSPS), 2x 2-Channel 12-Bit DAC
2x 16-Bit Motor Control PWM, 10x 16-Bit Timers, 2x 32-Bit Timers

Discovery Board Extras:

ST MEMS motion sensor (LIS302DL 3-axis digital accelerometer)
ST MEMS audio sensor (MP45DT02 omni-directional digital microphone)
Audio DAC with integrated class D speaker driver (CS43L22)

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