Show off your Dodgy Brothers workmanship - Page 1
Forum section: electronics / projects

author: joeqsmith
author_rank: Super Contributor
timestamp: November 26, 2015, 06:48:51 pm
content: After seeing Dave's video of the medical tablet and seeing just how bad it was built, I thought I have made some pretty crappy stuff over the years. Normally things get really bad if it's something that I am just playing around with ideas and have no plans to keep. I thought I would show some of my workmanship and hope you will do the same.I just posted about making some sort of isolated AC current/voltage monitor for my scope to measure power. To get the isolation, I just tossed in a 9V transistor battery to power the LEM sensor. Here is the battery holder. Now if it does not look bad enough, consider it was partly made from Apple gift cards....And let's not forget about how my last home made high voltage probe started out.....

author: sarepairman2
author_rank: Frequent Contributor
timestamp: November 27, 2015, 07:43:38 am
content: there are numerous cardboard chassis things at my job lol, they do not like spending money on things like metalyou will do t hings you could have never thought yourself capable of when you get a job.i spent a day beating a metal box out of old equipment (literary using a hammer and a hacksaw) to try to make something half decent (i was not satisfied using sticky tape and zip ties for a 1kW energy device). If you end up working for a place that has cheap management that wants things done for free and instantly then you will find these kind of skills very handy.i call this the "spartan" management style. steal/recycle everything you need because no one is gonna sign a request for ANYTHING.

author: DTJ
author_rank: Super Contributor
timestamp: November 27, 2015, 08:42:18 am
content: Home brew CNC router.Why mount things correctly when you've got cable ties.An old door hinge for a spindle mount.Mains flex for 12V DC work.... why not.

author: Berni
author_rank: Super Contributor
timestamp: November 27, 2015, 06:25:35 pm
content: I think i lost the photos to it but my laptop has a pretty ugly USB repair hidden inside.I had issues with my USB ports not working so i opened it up and found a blown 5V switch/overcurrent protector IC. It was in some tiny package but i had some chips that do the same thing in SOIC in my parts bins. I didn't want to bother ordering the proper one, i just wanted the damn thing to work again so i soldered some wires to the SOIC chip i did have, soldered the wires to the footprint or to near by capacitors and taped it down next to the original footprint with scotch tape. It looks ugly as hell but hey my USB ports work again, besides you can only see it if you take it apart.

author: kolbep
author_rank: Frequent Contributor
timestamp: November 27, 2015, 07:23:55 pm
content: Dont have a picture,but had a dmx usb interface (where the board actually fits in the XLR connector)The SOIC 8 pin RS485 Chip was fried.Deadbugged a DIP 8 pin RS485 Chip floating above the board, with solid core comms wires used to jumper to the pads/nearby components.Of course it no longer fits inside the connector shell, so I put it into one of those little boxes that remote control receivers are in.Ugly, but works....

author: rdl
author_rank: Super Contributor
timestamp: November 27, 2015, 07:30:25 pm
content: I wish I still had the variable power supply I built as my first ever electronic project back in the 80s. I started with a homebrew CB radio power supply that my brother had built. It was pretty crude but I was able to reuse the metal box, a filter cap and the transformer (all from RadioShack, of course).I copied a circuit from a Forrest Mims book. I bolted an LM317 to a small heat sink and glued them to the back of the box on the outside. I had scavenged a decent Simpson analog meter from work and managed to figure out how to change it from 50 uA (or whatever it was) to 15 volts. All the wiring and resistors were on perfboard. It was very ugly but seemed to work, at least as far as I could tell, and I used it for several years. I finally took it apart to use the box for something else, but I kept some of the parts.

author: sarepairman2
author_rank: Frequent Contributor
timestamp: November 27, 2015, 07:54:06 pm
content: do your work places give you guys free bentleys too??

author: nali
author_rank: Frequent Contributor
timestamp: November 27, 2015, 08:34:34 pm
content: Quote from: sarepairman2 on November 27, 2015, 07:43:38 amAhh a fellow CAD (Cardboard Aided Design) user!No pics I'm afraid, but back in 1981 I did build a Wireless World Nanocomp using stripboard and a reel of tinned copper wire with silicone sleeving - which was all I had available to me then as a lowly apprentice (could scrounge the components but couldn't afford the PCB). The wiring bundle was > 1/4" thick in places but hey, it worked first time!http://www.keith-snook.info/wireless-world-magazine/Wireless-World-1981/Nanocomp%20by%20R%20Coates.pdf

author: technix
author_rank: Super Contributor
timestamp: November 27, 2015, 09:26:12 pm
content: Quote from: nali on November 27, 2015, 08:34:34 pmI am a solid fan of BBS (Board-as-Box System) - using PCB etched and drilled accordingly as box of my devices, held together with either solder joints, or copper spacers.

author: TerraHertz
author_rank: Super Contributor
timestamp: November 28, 2015, 01:50:27 am
content: A couple of examples.First is a car battery charger, designed and built from scraps in about an hour and a half one morning I had to go to work but found my car wouldn't start. Sometime in the early 80s.Second is a 'mains common mode spike and ESD simulator' built to torture commercial poker machines during the design phase. Customers like to play with piezo spark guns to see if they can get the machines in pubs etc to glitch. So... at one place I worked, I built this (at home, from scrap.) Used a variable 10KV supply to power it. Basically it just repeatedly discharges a HV cap via an air gap to the selected mains wire (A, N or E), and also has a wand to allow sparking to the machine cabinet.

author: Whales
author_rank: Super Contributor
timestamp: November 29, 2015, 05:33:34 am
content: 18650 (battery) holder for an RC car. Plastic right angle, thin ply from a deceased estate, springs, metal hanging hooks (flat) and hot glue.It worked perfectly well, but I wanted something that would not melt apart if the batteries overheat so I replaced it.

author: miguelvp
author_rank: Super Contributor
timestamp: November 29, 2015, 08:06:53 am
content: Quote from: sarepairman2 on November 27, 2015, 07:43:38 amPizza box monitor:Upgraded to wine box monitor:can do 1920x1200 at 60Hz

author: picitup
author_rank: Regular Contributor
timestamp: December 06, 2015, 08:21:03 pm
content: Well, sorry no pics but my first electronics project was a crystal radio. The coil was wound on the card tube from a toilet roll, a variable cap, some 'high impedance' headphones that looked like ex-mod and a proper germanium crystal, not the kind with a springy coil of steel which you poked into a piece of germanium, but a proper glass encapsulated one.The aerial was a piece of wire run from my bedroom to a wooden mast on the shed which was 60 foot long and the earth was connected to the central heating radiator.No soldering, just twisted wires. I was only 10 at the time and when it worked I was so excited. This is what got me into electronics. That was about 1969 lol.Being a crystal set, it was powered by radio waves, but I used to unplug the headphones at night in case I wasted the electricity.Yes, it's true, I'm a coffin dodger.CheersSteve

author: RobertBG
author_rank: Regular Contributor
timestamp: December 07, 2015, 02:28:25 am
content: I've used cardboard more than I care to admit but the best was something I didnt make.I once ferried a Cessna 206 back from Guatemala with a buddy of mine that had a Dodgy Brothers engineered special installed behind the panel.We didnt notice it until ATC gave us some issues with our altitude and we went back and landed.That's when we found the mystery box and it had a few pots,a home etched pcb and a rats nest of wires that looked like lamp cord stuffed inside a kids lunchbox and it was wired into the transponderNeedless to say we canned our IFR plans and flew VFR back to the states praying to god that ATC didnt watch us too closely.After we got back the mechanic "found" it and reported it but they never did tell us exactly what it did.Honestly we didn't want to know all that much either.While we had hoped it was just a bodged repair it most likely modified the signal that the altimeter was sending the transponder.

author: Cyberdragon
author_rank: Super Contributor
timestamp: December 07, 2015, 06:55:50 am
content: Lol. Time to share embarrasing secrets. List of some of my dangerous and stupid electrical work (Do not attempt) :-p-shocked myself as a kid trying to fix an electric clock motor. Scotch tape != electrical tape-Soldered wires on vacuum tube pins-I have a direct mains rectifier built on a terminal strip attatched to the wood base of a mousetrap, at least it's fused with the plug from christmas lights. It has one coil and capacitor for a filter and a resistor and flourescent starter for an attempt at regulation and there is a Y capacitor across the regulator resistor. I have no idea Y that cap is there. :-P Need to replace the rectifier, I did the dumb and tried to measure ripple.-Fixed an old tube radio AC switch by soldering then nutting large wires to a toggle switch then superglueing it to the case. Yes, the wiring is exposed, at least it's taped with electrical not scotch tape.-Fixed an old tube radio resistance wire cord with a wirewound resistor in series with the cord stuffed inside a toilet roll tube taped to the back of the radio. Of course it got too hot so I used solid core speaker wire to solder a night light bulb (yes, soldered on the bulb, no socket) across the resistor. Then I wrapped the base of the bulb in electrical tape and stuffed it in among the tubes to hide it. The toilet paper tube is not hidable though.-being lazy and not changing my rusty soldering iron tip, sometimes gets little black burnt bits in the solder-just recently fixed a blown AC wafer switch (my fault, did the dumb with the scope again) with a blob of solder and a bit of solid wire bent into a VAnd thats just what I can think of right now. I'll post pictures when I get a chance to.