I've not slept for 36 hours so this maybe a little incoherent. Since my last post I've completed the 3D Printer project. On a personal note it only cost me £50 to complete as I've an array of junk parts to source from. The stepper drivers amazingly were only £1 each the A2 stainless rods were $15.50 and the rest was for the extruder as I didn't fancy building that. One of the steppers is from a 1990 era dialysis machine and boasts 0.8 degrees a step. I'm overrunning these steppers to 200% for speed Vs. moving mass and they require heat sinks else they bind up and loose steps (yee-haw).
Secondly; I've made the smallest watch in my collection (32x32x7mm). It's only on the second prototype so it's a little junky-funk. expect some images to appear in a day or so. The third prototype will incorporate Blue-tooth (BLE) a nRF8001 chip from nordic. I'm still wrestling with the ACI (Application Command Interface) Thats has some silly features like command credits. my C++ Fu isn't strong so understanding some of the *euch* Arduino examples is tricky but getting there slowly. It's probably going to just have a UART link between the watch and phone with a custom app that bangs all the notifications to it.
while( !BrainWorking ) {_nop;}
work( );
Friday 28 November 2014
Tuesday 29 July 2014
Use the source - XC32 on android
This post is to remind me to edit it into the how I compiled XC32 1.22, or 1.31 (I forget) into a chroot debian on my Nexus 7 android device. With or without a commented line of code I shouldn't have modified, but hey It's my device and I'm never releasing it.
Also add the pic32prog AN133?something bootloader and pic2/pic3 programmer so I can even start from an out of the box chip (or a dev board without USB)
Also add the pic32prog AN133?something bootloader and pic2/pic3 programmer so I can even start from an out of the box chip (or a dev board without USB)
DIY 3D Printer
Ach, Garr! Ok I'm going through project boxes like a beast. Also going through 6061 like boeing on a Friday before clocking off. I finally give in to 3D printers after grumbling and flaming at makerbots and the like, deciding to make my own for under £80. Here's a draft I've started making. I Started with the frame, rails and electronics. Electronics are undecided as I refuse to buy Ardweeeenoe or anything Atmel due to their ethics on many levels that I won't go into detail about. But I'll be basing the communication protocol on one of the popular platforms and translating the source as I go. I saw this great post using a 4550 that I have a box full of.
The most costly part I've seen is the heated bed. I'll be making it from home etched PCB with a soldermask bonded to tempered glass that luckily a friend had kicking about. It's the PCB or the 6 meters of Ni-chrome that I've had for 10 years. Yes I know, my biggest problem is not researching others but diving in. It's half the fun, right?
Ok, I gave in to buying an extruder that is half the project cost as the part cost equals the final cost of £33. The individual parts cost £30 minus machining and a stepper, plus the true and tested design.
This is a bit of a rant I know. But the prices and markup of even the modern kickstarter printers are silly, well silly for someone who enjoys making mechanical devices.
For the stepper motors I may steal some from the CNC mill as I found that the ones that I thought could be used were too high a voltage for my drivers (134Ohm). They'll probably work but I want some reliability on not slipping steps. I found a nice Japan Servo Co.LTD 0.9 degree from some old medical equipment (a pump from a dialysis machine) that's 7.6 Ohm, but only the one, this maybe able to be compensated in firmware? This £80 Project may become £116 If I need 4 motors. 3 I'm sure will suffice with only one on the Z-axis with a timing belt to the opposite thread screw.
I find making a quick sketchup of the device will allow me to obtain materials at random and not necessarily in order. Example ordering 4x8*880 long stainless bar and calculating that the Y + X length * 2 = 878mm.
The most costly part I've seen is the heated bed. I'll be making it from home etched PCB with a soldermask bonded to tempered glass that luckily a friend had kicking about. It's the PCB or the 6 meters of Ni-chrome that I've had for 10 years. Yes I know, my biggest problem is not researching others but diving in. It's half the fun, right?
Ok, I gave in to buying an extruder that is half the project cost as the part cost equals the final cost of £33. The individual parts cost £30 minus machining and a stepper, plus the true and tested design.
This is a bit of a rant I know. But the prices and markup of even the modern kickstarter printers are silly, well silly for someone who enjoys making mechanical devices.
For the stepper motors I may steal some from the CNC mill as I found that the ones that I thought could be used were too high a voltage for my drivers (134Ohm). They'll probably work but I want some reliability on not slipping steps. I found a nice Japan Servo Co.LTD 0.9 degree from some old medical equipment (a pump from a dialysis machine) that's 7.6 Ohm, but only the one, this maybe able to be compensated in firmware? This £80 Project may become £116 If I need 4 motors. 3 I'm sure will suffice with only one on the Z-axis with a timing belt to the opposite thread screw.
I find making a quick sketchup of the device will allow me to obtain materials at random and not necessarily in order. Example ordering 4x8*880 long stainless bar and calculating that the Y + X length * 2 = 878mm.
Saturday 26 July 2014
HAKKO 907 24v Soldering Station
HAKKO 907 24v Soldering Station
I never had a nice soldering station. At best it was an Antex SX25 (great iron but eats up elements) on a variac. It's still not great as this iron costs £4 on fleabay - dont fear, this was just a test. A nice original HAKKO iron is on the way. I prepared by making this PID loop controller for it. I was amazed at how linear the thermistor is. Compensation in the software help accuracy to be ~+/- 2c. It only ramps the duty cycle up past 50% above 400c to help prevent thermal shock.
Friday 25 July 2014
LT3958 High Voltage Flyback
LT3958
Never made one of these before. This flyback supply is set to give between 30-300v. I pushed it to 660v for a laugh with set resistors. Large components are again from the junk box but the transformer I wound by hand 5tp:50ts. The IC is a pig to make a footprint for in kicad
LM2596 Step Down Supply
LM2596
Slapped together this board using nothing but junk parts and some nice 3A Step-Down Voltage Regulator chips from TI. Blew the arse out of one feedback pin with a short and a CC supply on only 500mW.
You can get 10 modules from China for £6! "WTFlaygen hoy with the switching and the bloooyg'n zabble" - Prof. Frink.
Bet they don't have Coilcraft inductors
Watches Watches Watches!
Watches Watches Watches!
Binary LED watch
I made this using a PIC18F2550 (overkill) The readout is 0-9 hh:mm:ss for easy easy reading. It also scrolls swear words at ~10mph with persistence of vision. LEDs were taken from an alarm system. It sports a chunky mobile phone battery in the rear.
SPI TFT Watch
My most complicated watch to date. PIC32MX250D with USB and MicroSD. Firmware update from USB or SD, needs lots of coding to make pretty and functional.
VFD Watch
A Russian IV-21 (NB-21) 1982? not looking very bright as the battery was low and there's no feedback for compensation. One of the first projects I did in KiCad
7-Segment watch
The thinnest of all my watches, the Li-Po battery goes in the front... yes, another bloody watch
There's more somewhere
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