Nov 06

ImaxRC X350 Overcharging FIXED!



The Fix:

  • Use a high quality power supply with very low ripple/noise.
  • clean the lacquer off all terminals with a wire brush or fibreglass pen
  • replace the crappy deans connector with a genuine deans connector
  • replace the internal 10A discharge fuse if you have exceeded the rated 40W discharge and have the “Connect Break” issue

The Backstory:

After hunting around for hours on the internet to try and find the perfect LiPo charger, I purchased what looked like a winner from HobbyKing. The ImaxRC X350 Charger:

ImaxRC X350 Charger

It has a whopping 350W charge rating, 40W discharge, touch screen, multiple battery chemistries, etc.

The 2 days that it took to arrive were painful, I was way too excited about this charger… So when it turned up, naturally I fired it up immediately and started charging a LiPo! I watched the nice pretty graph climb to full charge at a rapid pace BUT… it didn’t stop at the typical 4.2V/cell that I was expecting, actually it climbed closer to 4.34V per cell which is a recipe for fire/explosion with Lithium Polymer batteries. The charge cycle terminated at around 4.34V/cell with an “Out Voltage Too High” error.

x350 voltage error

The next thing I tried was discharging the battery to bring it back within a safe voltage range but the discharge cycle only lasted a few seconds and then an internal fuse blew and the display reported “Connection Break” (read on for the fix).

X350 connect break error

I tried several other cells with the same results, different cell counts, capacities, etc and every now and then it would terminate at the correct 4.2V/cell but not often. After trawling the darkest corners of the internet and trying to contact the manufacturer and HobbyKing plus a few other distributors, I was getting nowhere. HobbyKing said that it is a known issue with that charger yet they are still selling them, not even a warning on the website. There were a few suggested fixes by other users on youtube and the hobbyking forums. Theuns Oosthuizen AKA “TheUnsie” in particular was very helpful in determining the cause of the “Connect Break” error but the problem with my charger was still not resolved.

Please see TheUnsie’s youtube videos to repair the “Connect Break” error which consists of replacing an internal fuse:


The other day I decided to take the charger with me to where I would be flying and charged up a few cells from my car battery and quickly realised that the batteries were charging to the correct voltage and not a millivolt higher! consistently, every pack. weird…

So that my car battery didn’t go flat, I started the engine for a while but realised that the batteries were now overcharging again… I thought this had to be something to do with noise from the alternator on the car while it was running.

To test this theory I plugged the charger into my very nice laboratory power supply which has a very clean output and it charged fine compared to my usual modified server power supply. I decided to measure the noise from each power supply and discovered that the server power supply was around 580mV peak to peak whereas the lab supply was around 8mV peak to peak.

The comparison looks something like this:
X350 Noise

Problem solved!

Now that this charger is working as it should, it is exactly the awesome product I was looking for!

Next I just have to find a high-current, low-noise power supply.. Any suggestions? Let me know in the comments below.

Dec 22

How to make a fibreglass subwoofer box



Aug 20

Water Cooled Raspberry Pi




Water-cooled raspberry pi?!?!

Some of you might think “awesome!”, others may think “why bother?” I did it for several reasons:

  • Because I can!
  • It looks cool on my desk
  • I want to overclock it so that I have the fastest raspberry pi on the internet! (also falls into “Because I can!”
water cooled raspberry pi

water cooled raspberry pi

water cooled raspberry pi

water cooled raspberry pi

Fittings

Fittings

CNC Pi Logo

CNC Pi Logo

Leak testing

Leak testing

Micropump

Micropump

Jan 10

How to make Vanilla Essence

The smell of vanilla essence is one of the my favourites… It’s an essential in the kitchen and if you bake often then you probably go through loads of vanilla extract, Vanilla ice-cream, vanilla cake… I’m getting hungry just thinking about it!

Vanilla Essence

Vanilla Essence

Here i will show you how to make your own exceptionally nice vanilla extract for much less than store-bought vanilla.

Vanilla essence is made by macerating vanilla beans in a high-proof alcohol. I’d suggest using a nice bourbon or plain vodka (absolut works well). If you don’t want to use a lot of your precious booze on the vanilla essence, you could grab a few of those small sample bottles like you get in hotels or on a plane. Grab a few different spirits to experiment with.

Split vanilla beans lengthwise stopping about an inch from the end and pop them in the alcohol. For a stronger essence, i find it useful to scrape out the seeds from the vanilla pod and drop them in the alcohol too. The general rule of thumb is 3 vanilla beans to a cup of spirit.

Split Vanilla Beans

Split Vanilla Beans – Courtesy At Home On Paradise Cove

Now you have to wait, about 3 weeks minimum. Give the bottle/jar a shake every few days and then open it for a sniff to see how the extract is progressing. I find after the first day, the extract smells very sharp like high-proof spirit and raw vanilla but as time progresses, the subtle complexity of the whiskey blends with the sweet, warm aroma of the vanilla to make something purely delightful. As with most alcohol macerations, it just gets better with age…

If you choose to leave the vanilla beans in the essence (highly recommended!) you can simply top it up with more alcohol as you use it up. Don’t forget, there are many different types of vanilla beans, try experimenting with different varieties to see what you can come up with!

Dec 12

Cinnamon & Honey Soap

I’ve been eagerly creating batch after batch of home-made soap, trying new things and experimenting with different methods! I thought the result of this batch was worth a blog!

I chose to try something different this time and added Honey to the batch to take hold of all the wonderful natural benefits that honey provides, it is GREAT for your skin.

I won’t bother re-iterating the process because you can find that in my Lemon Myrtle Soap Recipe but here is my recipe for this batch:

Ingredients:

  • 400g Solidified Oil (Beef Tallow)
  • 200g Refined Coconut Oil
  • 100g Rice Bran Oil
  • 200g Olive Oil
  • 270g water
  • 126.8g Sodium Hydroxide (caustic soda/lye)
  • 1/2 cup Oatmeal
  • 2tbsp Honey
  • 15g Cinnamon Essential Oil

Differences from my normal Method:

  • I heard someone mention that if you preheat your oven to about 70 Degrees Celcius and then turn it off and place the soap in and let it cool down slowly that it will make the soap enter the “gel phase” quicker and therefore set faster, the side effect is that the soap turns a dark brown colour… Being the experimental type of person i thought i might like to use this side effect to my advantage to colour the soap. I gave it a go and checked on the soap every 10 minutes until it was a nice “cinnamon” colour, it worked perfectly!
  • I added honey to the soap at light trace because both honey and cinnamon are very sweet, i thought they would go well together, and they really do! The batch smells like a fresh baked cinnamon cake!
  • This point isn’t really a “method” change, it’s more of a “post-processing” change. I have been playing with different ideas on how to make the soap look a little more professional, using different molds, etc but the thing that made a difference for this batch was that i used a vegetable peeler to chamfer all edges of the soap, now it looks nice and feels good to hold!

Nov 15

Excel Series Rally Car

This will be one big introductory post about my new rally car! I hope to keep a progress log about the car here on my blog.

So after hours of trudging through forums and asking everyone i could find about rally cars, i decided to buy a (mostly) ready-to-race rally car, i settled on a Hyundai Excel.

The excel won my affection for many reasons but mostly because it is a cheap(er) way to get into rallying. They are really reliable, readily available and parts (or even whole cars) are a dime-a-dozen!

The excel makes really good power for a 4cylinder engine and is quite competitive on the track. This particular car has had the standard single cam engine replaced with a twin cam engine for a bit more power.

The list of mods goes on and on for this car but the main features are:

  • MECHANICAL:
    • DOHC engine
    • New Exedy heavy duty clutch
    • Project U front brakes
    • Braided brake lines
    • Lightweight sump guard
    • Reinforced exhaust
  • SUSPENSION:
    • Drummond Motor Sports (DMS) adjustable rally coilover suspension
    • Pillow ball rear suspension mounds
    • Front strut brace
    • Seam welded
  • EXTERIOR:
    • Light pod with 4 x Cibie Oscars with HID conversion kits
    • Excel series mag wheels painted toxic green to match the car
    • Toxic green/black paint job
  • INTERIOR:
    • Lightweight dry cell battery mounted behind seats
    • Extensive weight reduction
    • Zero offset satin black autotechnica steering wheel
    • Very comprehensive cold rolled double walled roll cage painted toxic green to match the car
    • Sparco Pro 2000 seats
    • SAAS 5-point harnesses
    • Brantz Laser 3 trip computer (soon to have a foot switch)
    • Stillo WRC noise cancelling intercom
    • Custom Taco dash with white gauges
    • 2 x 1KG fire extinguishers

The car was weighed at Rally Vic last year with mud and ½ fuel at 972kg, (minimum weight 960kg for Excel series)

I picked up the car for $7500 from Victoria, looking at the work that has been done to the car, i saved a hell of a lot of money getting one that was already built!

Nov 15

MSP430 on Fedora 16 Linux – eZ430-F2013

A few months ago, i came across a deal from Texas Instruments that let me get a free eZ430-F2013 development stick. Since i couldn’t resist the temptation of free gadgets, i immediately ordered one and then waited for it to turn up.. a month later…

If you haven’t seen the neat little proto kit, it comes as a USB dongle, not much bigger than a flash drive which consists of a USB debugger (the big bit) and a removable board that holds the F2013 micro controller, each pin broken out to a standard pitch header.

eZ430-F2013

eZ430-F2013

So when this thing finally arrived, (I’d forgotten all about it) I had a quick look and put it aside since i didn’t feel like installing yet another proprietary software package to be able to work with the device.

Having re-discovered the gadget the other day in a box from moving house, i decided to give it another go. Much to my satisfaction MSP-GCC came to the rescue!

eZ430-F2013

eZ430-F2013

Here are the steps i followed to get this thing working under Fedora 16 without the IAR embedded workbench stuff

    • Kernel Support – Under fedora 16, the device should show up as a USB serial device like /dev/ttyUSBx. Double check that the kernel module ti_usb_3410_5052 is loaded with lsmod. In the past, there were a few source changes that needed to be made for this module to recognise the eZ430-F2013 but Fedora 16 works out of the box.
    • MSP-GCC and GDB- Next, we have to install MSP-GCC (the compiler) and gdbproxy (the debugging software) mspdebug is a modern replacement for gdbproxy, with good support for the eZ430 system.

Important!

yum install msp430-libc mspdebug
    • Hello World – Now we get to create a simple embedded version of a hello world application. create led-on.c and paste in the following source:

Important!

#include <msp430x20x3.h>
int main (void) {
// Set P1.0 as an output
P1DIR = 1;
// Turn on the LED
P1OUT = 1;
return 0;
}

    • Compilation – Compile the test code using the following command:

Important!

msp430-gcc -g led-on.c -o led-on.elf
    • Programming – Now we use mspdebug to load the program into flash on the MSP430 microcontroller and run it. You can either run up mspdebug and then issue the commands to load flash and run the app using mspdebug’s command line interface as follows:

Important!

[root@Optimus msp430]# mspdebug uif MSPDebug version 0.19 - debugging tool for MSP430 MCUs Copyright (C) 2009-2012 Daniel Beer <dlbeer@gmail.com> This is free software; see the source for copying conditions.  There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. ti3410: warning: can't detach kernel driver: No such file or directory TI3410 device is in boot config, setting active Initializing FET... FET protocol version is 10002000 Configured for Spy-Bi-Wire Set Vcc: 3000 mV Device: MSP430F20x3 Code memory starts at 0xf800 Number of breakpoints: 2 Available commands:     =         delbreak  gdb       load      opt       reset     simio          alias     dis       help      locka     prog      run       step           break     erase     hexout    md        read      set       sym            cgraph    exit      isearch   mw        regs      setbreak   Available options:     color           gdb_loop        iradix               fet_block_size  gdbc_xfer_size  quiet            Type "help <topic>" for more information. Press Ctrl+D to quit. (mspdebug) prog slowtimer.elf Erasing... Programming... Writing  130 bytes to fc00 [section: .text]... Writing   32 bytes to ffe0 [section: .vectors]... Done, 162 bytes written (mspdebug) run Running. Press Ctrl+C to interrupt...

OR:you can tell mspdebug to program and run the code without having to enter the command line interface:

Important!

mspdebug uif 'prog slowtimer.elf'
  • Done! how easy was that ;D – Now go and make your LED blink!

Nov 01

Sugru – Make your own – DIY

Someone mentioned the words “Sugru” and “Group Buy” the other day at work which got me thinking about Sugru and what it is exactly, which then lead to “How do i make it?”

If you don’t know what Sugru is, check out their website: Sugru.com It is a “self-setting rubber for fixing, modifying and improving your stuff” and can be used for many many useful things such as repairing broken cables/adding strain relief, making custom grips for your bike handlebars, making mounts for cameras and even repairing shoes.

I wanted to be able to make up something similar to Sugru any time i need any rather than ordering it from the UK and waiting for it to arrive. After a quick google, i found an instructable for making “OoGoo” which pretty much covers what i needed :) Here is my attempt at making my own Sugru:

OoGoo

OoGoo

Here is a brief run down on how to make the stuff, for more detail refer to the Original Instructable:

 

How it works:

Normal silicon takes forever to set, the thicker it is, the longer it takes. Silicon sets by drawing in moisture from the air. The way the Sugru substitute works is by using moisture that the cornflour has absorbed and distributing it evenly through the compound so that it dries from the inside out and much faster than normal.

What you need:

  • 100% Silicon (Acetic cure silicon, it smells like vinegar… the cheapest stuff you can find!)
  • Cornflour/corn starch
  • Oil paint for colouring
  • Plastic disposable cups and something to stir with (i used a chopstick)

How to make it:

  • Mix about a pea sized amount of oil paint with 2 teaspoons of silicon, stir it together well until it is an even colour
  • mix in 2 teaspoons of cornflour (1:1 ratio i found is the best.. it sets in about 10 minutes which is long enough to work it into shape)
  • Stir it together until it is well blended. I found that when it was ready to handle, it would start peeling off the walls of the plastic cup easier and it wasn’t so sticky. At this stage, i took it out and rolled it up into a ball in my hands then started forming it into the shape i want.

This stuff sticks to most things really well, it sticks to already cured oogoo very well but doesn’t bond with plastic or metal very well. You can add a small amount of super glue (cyanacrylate adhesive) to the mix to make it stick better.

By changing the ratio of cornflour to silicon, you can vary the time it takes to set and the final strength of the compound. More corn flour will make it set quicker since there is more moisture in the mix. Less cornflour gives you longer to work the stuff into shape. a 1:5 cornflour:silicon mix will give you about a 1hr working time.

Now that you have your own moldable silicon, have fun and see what creative ideas you come up with!

Oct 31

Micro SD, Macro Packaging!

I thought this one deserved a blog post, not exactly a hobby of mine but worth a look none the less.

It’s a great example of waste in today’s society… tiny little SD card in a huge packet!

The only reasons i can think of for this is either:

  • to make it harder to steal or:
  • to make it more visible as an advertising attempt.
Micro SD Card

Micro SD Card

Good one Verbatim!

Aug 07

Nexus 7 Car Installation

What more could a gadget-addict want than to have all the features of Google’s latest flagship tablet, the Nexus 7 embedded in the dash of their car?

I quickly got bored with off-the-shelf car stereo systems, here is my response:

I have installed a Google/Asus nexus 7 in the dash of my MY00 Subaru WRX. I trialled the optus mytab (AKA ZTE V9) in the dash but it didn’t last more than a day since it was a piece of crap performance and audio-wise.

After spending a few months building a nano-itx double din touch screen pc to go in the dash, i changed my mind (for the millionth time) and decided to stick an android in there instead. The intel PC is now sitting in a box at home doing nothing…

The biggest trouble was finding a tablet that would fit in below the A/C controls nicely.. in the end, the N7 was about 3mm too big bit i broke out the dremel and made it fit!

Parts list:
ASUS Google Nexus 7
4 Channel Nakimichi Amplifier
Single Channel Class-D 1000W Nakimichi Subwoofer amplifier
Four-Gauge power/ground
Gold plated Ground splitter and +12v Splitter/Circuit Breaker
Oxygen-Free Copper speaker cables (around 12 gauge)
(coming soon) 1.5 Farad Capacitor (to stop headlights dimming)
2 x Kenwood 1200W Subwoofers
4 x Focal 6″ Splits
Good quality RCA cables
R/A 3.5mm headphone plug to 2x RCA 30cm cable
R/A Micro USB cable
gutted tomtom GPS charger
(coming soon) RCA volume level control (thanks for the idea ahavens17)
20mm wide metal strips
Hook and Loop velcro
Rubber trimming/edging

Update: Added some more pics showing my crude but effective way of holding the tablet in-place.

To hold the tablet in place, i have used some metal straps cut to size that are screwed on using the screws that hold the top of the ash tray to the dash fascia. I stuck some velcro on to the metal straps and 2 small strips on the back of the tablet to dampen vibration and stop the tablet sliding around sideways. The velcro also stops the metal straps from marking the back of the tablet (not that it matters since it is hidden behind the dash)

You can see how it is done in the pictures above. Also, I am using right-angle micro USB and audio connectors so that they fit nicely in the dash.

Update: Nexus 7 is off for replacement

Unfortunately, i had to return my N7 under warranty because the USB port slowly failed to function. At first, it charged really slow, then it wasn’t able to connect or be recognised on any of my computers and then it stopped charging altogether so i sent it off to google. The good news is that the replacement should arrive in a few days!

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