Combo preamp/mixer/power amp/speaker cab for keyboards.
Having worked at a company that made atomic clock and GPS-based frequency standard equipment, I had access to scrap 19" rack hardware. As my brother wanted a slave amp for his bass rig to power his outboard speaker cabs, I knocked up one in a 2U rack using a 2N3055/MJ2955 transistor stage and a preamp kit board from the infamous Maplin, power supply designed by myself and cabled to the same standard of work that we used for our military clients. As a bonus, I asked the tool room manager if he could engrave the front panel with a unique design so that it was obvious this was a custom piece of hardware. The result was the DOM-200 (for my brother is Dom and it was a 200W RMS amp).



A few years later after I had moved jobs to testing mixing desks, a friend of mine's husband asked how difficult it would be to make a combo mixer amp for his gigging career as the keyboardist in a Blondie tribute band. There was nothing on the market that would do what he wanted, to be able to hook up three mono keyboards, a stereo keyboard, into a power amp which was compact enough to fit into the corner of the gig van but also have 300 Watts capability.

The parameters for enclosing the available 12" or 15" bass/mids would have made the cab woodwork rather large so I had to go with the only 10" 300W speaker I could find which also neccessitated a rather peculiar crossover frequency to the horn, the only one of which I could find was used in a JBL unit- fortunately JBL speakers were owned by the same group (at the time) that owned Allenn & Heath, so a quick word between shop floor supervisors and a scrap unit was given to me for my task.

As nearly all gigged amps get bashed about, choosing the typical chipboard seemed to be a bit short sighted so I got a 1/2" thick 10x6 foot thick sheet of marine ply and had to saw it up into the right pieces to form the cab. 120 2" screws held it together. Ripper.

Having access to certain schematics, I 'borrowed' a four channel EQ design from one of the A+H mixer input stages and designed/etched/drilled the channel and mixer PCBs for the inputs (3 mono, 1 stereo)to fit into a 3U front panel. This time because of the complexity of the milling and engraving of the front panel, I didn't think that it was in 'favour' territory to ask my friend the tool room manager to do it for free so he quoted me £85 for the work which was fine. The input, EQ and mixer stage was done, the speaker and crossover section was done, the cabinet was finished with buffalo vynide cloth, the speaker and horn was mounted- now the power amp. Design my own? Follow a reference design?

Fuck that shit, I'm not stupid. Bought a pre-made MOSFET 450W amp module from OMP and shoehorned it in. Presto, the job is done. Apologies for the crappy quality of the picture but this was from the days before digital cameras, and my pocket compact and rubbish scanner weren't up to much in those days...


( Rotating Wobbly Hat That's not a banana. THIS is a banana., Wed 17 Oct 2012, 14:33, 4 replies)

I just made
King Kong's finger and now feel so much fresher and ready for the day ahead.
(magic the cat will someone please think of the kittens, Wed 17 Oct 2012, 13:08, 1 reply)

Bike Shelter
Generally I can't build anything without wonky bits sticking out all over, but a bit of planning and I managed to build a bike shelter in my front garden:


Got a tasty scar up the inside of my right arm too after getting a bit over-enthusiastic hammering in the ground anchors, falling over and nearly impaling myself on one.
( chthonic, Wed 17 Oct 2012, 12:09, 10 replies)

Dragons
Every year my brother-in-law's village holds a dragon building contest.
We turned up with some red and yellow spray paint and built this from old bits of fence and roofing we found around his garden:


Didn't bloody win.
( chthonic, Wed 17 Oct 2012, 12:02, 5 replies)

I saw someone trying to make an effort at trolling on here and failing.
So he deleted it.
( Amorous Badger NAKED BEA ARTHUR PHOTOS 4U, Tue 16 Oct 2012, 21:48, 47 replies)

Car stereo
My first car, Ford Fiesta BVF 943 T, had no radio. But I fitted it with a CD player when I was eighteen.

I had a Sony D11 Discman. I got the official 12V car power thingy from Sony and took it to bits. Got a couple of speakers from somewhere and fitted them into the door panels. I then got two 4 Ohm amplifiers - one for each channel you know - and fitted them and the power regulator into a black plastic VHS case. I obtained a 10k logarithmic dual potentiometer which was the volume knob. And a square multimeter case from Maplin, into which the Discman fitted perfectly.

The VHS case went under the dash. I'd hop into the car, and plop the Discman in its suave case into a the centre console, connect the power and the 3.5mm stereo jack and there you go! Wicked. It did tend to skip if you went over speed bumps, but apart from that, I don't remember any other issues.

I later transferred the whole thing to the next Fiesta, PYY 112Y.
(Bob the Builder killed Captain Alex, Tue 16 Oct 2012, 21:33, 4 replies)

Green woodworking
I've started green woodworking this year and I've made a few tool handles and other bits - I'll be starting work on a Yert soon! Below is a new handle for my side axe.




(RJWEcology is just sharpening his axe on, Tue 16 Oct 2012, 19:38, 7 replies)

I'm always making things....
I suppose the best has to be awarded to the item that received the biggest smiles upon completion. A petrol engined trike made from the front of a Ketlar pedal go-kart and the rear end of a petrol powered scooter. My 3 year old son loved that machine - it could go faster than anyone I know could run, as we found when my boy opened her up on a field and went off into the distance. If that hedge hadn't have been there, I dread to think where he would have ended up...

Another thing I am still proud of is the party house/shed that I made for a neighbour from scrap fence poles and telegraph poles. Imagine a suburban log cabin for the middle class socialite, with built in sound system, lighting and feature patio!

may as well stick a third thing in here...my kit car. I loved that car, but I was young and poor so in the end it had to go. If anybody has seen it, I want it back.

If anybody wants to see photos then ask nicely and i may post some in the replies. Up to you, really.

Aside from those things, I have made a multitude of other items....props for films (currently building a stone tomb!), things for houses (Scooby-Doo bookcase is planned for my house!) and things for cars (I once had a hot and cold drinks machine built into the dashboard of my old Ford Fiesta - there was a choice of beverages available, all at the press of a button!)
(INGSOC Room 101 will be awaiting you on, Tue 16 Oct 2012, 17:02, 3 replies)

i was responsible for this...
The Beyonce Castle

www.youtube.com/watch?v=lmVkZdZibmg
( spimf ™ is whoever you want him to be, Tue 16 Oct 2012, 13:50, Reply)

Student project
Not me but one of my students who decided to make a rugby training aid for a technology project.

All went well with the small scale tests which sent ping pong balls scurrying around the classroom. Then he ramped it up to full size and used a car starter motor to launch a full size rugby ball...

..Straight through the classroom wall!
(WholeGrain Using the same sig since, Tue 16 Oct 2012, 12:08, 4 replies)

PeaMatic
A school craze for pea-shooters (well, spit-ball shooters really) was in full swing. But point, shoot, repeat seemed a little pedestrian to me; clearly I needed More Power.

So I built a machine-pea-shooter: a ten-shot repeater, something like a minigun, with ten barrels and a sliding mouthpiece. I could shoot one at a time, or unleash a deadly hail of spit-balls at my cowering victims.

Unfortunately, my playground triumph was short lived, as a) it took about five minutes to re-load, and b) I got beaten up for being a smart-arse.
(moon monkey is busy making memories worth repressing, Tue 16 Oct 2012, 11:06, Reply)

The 4-stroke potato masher
I recently got my hands on an old rotavator, before use I had to make several 'repairs' as it had been sat in a shed for a decade. The starter clutch was prone to jamming, stopping the flywheel and in the process breaking the shear-pin; my solution was to retrofit an electric start feature (read, a big socket, an extension bar and a power drill). The other controls weren't in mint condition either, operation was via yanking and twiddling control cables at the correct time.

Once I'd turned the lawn into a small scale replica of the Somme, my attention turned to the little petrol engine that was now just sat in the garage. After some careful thought I managed to work out that what was missing from my life: a hugely inefficient, cumbersome and risky way to make my lunch. I detached the blades from the bottom, ratchet strapped the engine and controls onto a workmate and made a start on the engine-masher interface. In the end I settled for jubilee clipping the masher to the end of a bit of broom-handle, poking that through one of the work-mate holes and tying a spring on with a piece of string to return it to the 'up' position. The down stroke was powered by screwing a block of wood to the flywheel of the rotavator.

Once I'd lined things up and shaped the wooden block such that it would smoothly push the masher rod down, I got the drill out and started her up. It worked! The masher flailed up and down like a tigger on speed, and nothing seemed to be going wrong. This inspired me go from idle to full throttle, at this point the whole contraption started to topple; I managed to grab it as it went over, cutting the engine by touching together two particular exposed wires. Unfortunately the exposed flywheel had made short work of demolishing the whole masher mechanism; those glorious few seconds of optimism were cruelly crushed as I came to the realisation that I would be forever stuck in a dreary life of mashing potatoes without the excitement of potentially maiming myself.
(madsporkmurderer, Mon 15 Oct 2012, 22:13, 2 replies)

Dan Dare rockets
My brother and I thought we were budding chemists, and had a little lab in half of the garden shed. Our parents thought we were educating ourselves, when really we were hell bent on destruction. I know things were more relaxed then, but we had radioactive salts in there!

Anyhoo, the best devices were our "rockets". Don't do this at home. The rockets were fashioned out of six inch lengths of inch diameter aluminium tube, with the end crimped over into a nozzle modelled on something like Dan Dare had in the Eagle comic.

These were filled with a mixture of weedkiller (full strength pre IRA) and sugar, and sealed with a solid rubber bung hammered in with a mallet as hard as we could. The danger still makes me shudder!

We set this up at a trajectory designed to fly sideways through our terraced house gardens, with no thought of the effect where they landed. A length of Jetex fuse shoved up the nozzle allowed us to light the blue touch paper and retire to a safe distance. Usually they didn't work, falling over or failing to light, but on one truly memorable occasion, we watched in horror as the orange flames shot the damn thing a hundred feet in the air, the angle taking it into the garden, I hope, at the end of the street. It frightened us so much we never made another one. How none of them exploded I don't know.

Length? I already told you, six inches, made of aluminium with the end hammered over.
(Classic Ray, Mon 15 Oct 2012, 21:40, 2 replies)

95% of shooting deaths in the United States are caused by firearms. The rest? Crossbow.

(hathat, Mon 15 Oct 2012, 15:06, 2 replies)

I failed to make a clock-face...
...using a vacuum-former back at school. The face was dish-shaped to house the battery, but I took a small chunk out of it by accident, I think when cutting it out from the plastic sheet.

Anyway, the ruined face made the most fantastic frisbee. It flew like a bloody dream, and always had a graceful curl to its flight. It was so popular that the whole year ended up playing with it at breaktime, until some bugger chucked it about 500 yards and it went on the school roof.

Short-lived, but tremendous.
(Land of Green Ginger It's dreamy weather, Mon 15 Oct 2012, 14:16, 5 replies)

Ages ago...
...I made a lifesize caricature puppet head of Nick Griffin and did some mini-pyro tests for a film, both of which are described in this old b3ta thread, so I won't go in to any more detail here:
www.b3ta.com/questions/amazingprojects/post1439494

More recently, I made a small caricature head of Seb Coe intended for some stopmotion animation tests, but I wasn't happy with the way it turned out, so I'm doing more work on other subjects:


And in the last week I've built a phonograph cylinder shaving machine (you use it to smooth off blank wax phonograph cylinders for recording on) and a cutting stylus made from glass for an Edison phonograph recording head:

The reason there are all those labels on the photos, which will mean fuck-all to people here, is that I put those images together earlier as information for someone else who wants to have a crack at recording on wax.

And with those I've been experimenting with recording on wax cylinders using an Edison phonograph:
youtu.be/2Nz-V208ux4
(Harry Webshiter Spiggley biggley bog., Mon 15 Oct 2012, 1:31, 3 replies)

7ft Cake
As a structural engineer I have alot of good answers, like a film studio. But my crowning achievement is when I built a 7ft entirely edible cake.
It was a competition for the queens jubilee to build the tallest and most interesting cakes between 4 groups of engineers. 3 of which had full corporate backing, Arup (wobbly bridge fame) had bought cement mixers and had all the junior engineers on shifts for a week. Unfortuntely our team weren't as well resourced, we represented the Institution of Structural Engineers and were formed of myself, my mate and 2 random students who we met for the first time 2 days before the event. Our humble background didn't stop us though, armed with 100kg of chocolate and 30kg of Rice Crispies we moulded our cake to look like a giant cake stand with pillars and platforms. We fixed it together with melted chocolate and covered it with smaller cakes, winning the Most Beautiful Cake award!
Of our competition 2 of them collapsed, first Arups, due to over ambition then expedition engineering due to the rain!
So yes, 7ft, totally edible, no dowels, metal, wood or plastic. Chocolate and rice crispies are a very tasty building material.

the best picture on the net is on MSN.
news.uk.msn.com/diamond-jubilee/your-diamond-jubilee-pictures
To see arups collapse check out youtube.
youtu.be/xiLjBM3SEfI
p.s. the crowed took it all away, bunch of scavengers. Even the pieces from the ground!
(Jeff Balls, Sun 14 Oct 2012, 23:43, 2 replies)

Water and electricity......
As a young dad with a mate who demolished factories I received an old burglar alarm system which used ultra sonic detectors rather than the passive infra red ones you get now. The range and detection sensitivity could be adjusted on them so….what to do.

Using some old washing machine valves I fashioned the alarm system and valves into a garden sprinkler system.

All this I set up in the garden, with the sprinklers on each side and the detector pointing down the middle. My boys and their friends had a whale of a time trying to slowly crawl up the garden without getting detected and thus soaked. Worked a treat.

The one real flaw with the system was that the alarm and the valves were operated on 240volts, which was fully exposed (except for a couple of kiddies buckets to cover the connectors) and very likely to kill someone at any time. Got away with it though but I doubt Tomy et al will want the recipe.
(HildaOgdensdogsdead DILLIGAF. Well?? Do I??, Sun 14 Oct 2012, 19:28, 1 reply)

my brother's lamborghini
at the age of 12, my brother suddenly became very secretive, often locking himself in his bedroom for hours at a time. were i older, i'd probably have assumed he'd discovered wanking. curiously, his desire for cans of coke increased greatly. then, my best red nail varnish disappeared. it was all very strange.
after 6 months, all was revealed when my brother unveiled the model of a laborghini diabolo that he'd built from metal pieces snipped from coke cans and painted pillarbox red with my nail polish. it was beautiful, a true work of art, lovingly crafted by a young boy who should be rightly proud of his work.
the twat binned it 2 days later because he was bored with it.
( Smash Monkey lowering the tone of the whole internet, Sun 14 Oct 2012, 19:08, Reply)

i make traditionally girly things
such as cakes and knitted patchwork blankets, not babies. made a furtive blanket for the london bash, for those of you that didn't know. made a decent sum for the kitties, so i'm happy. next week, i start on my next blanket, which will be mario in a goomba shoe. pics of the finished blanket will end up on /board.
aaaaannd that's about it, really.
( Smash Monkey lowering the tone of the whole internet, Sun 14 Oct 2012, 15:42, 10 replies)

I built some mix tapes.

(McChinaman banned, Sun 14 Oct 2012, 8:28, Reply)

I built a home made trolly out of two sack barrows
www.youtube.com/watch?v=N0TbPOCgvdg&list=UUralLxDay4o36dca0U2Hb9Q&index=5&feature=plcp
Im in the white helmut
Great fun.
The making of and testing them is here www.youtube.com/watch?v=UZh87McaFJw&feature=relmfu
( jakedamusss I understand, and dont care., Sun 14 Oct 2012, 5:52, 2 replies)

I built this a few xmasses ago
it got on the popular page of /links. I was so proud.

www.youtube.com/watch?v=ENlKqS7NFS8
(marvin889, Sat 13 Oct 2012, 20:34, Reply)

Built this flophouse for some undeserving children back in '02

was a triumph but the kids got addicted to rock candy and burned it to the ground
( smearballs double bag it!, Sat 13 Oct 2012, 19:51, 7 replies)

A few year's ago..
I built this city, yeah, only guess what?

I built it on rock 'n' roll!
(Barnetboy, Sat 13 Oct 2012, 16:10, Reply)

I made two children.
They're both complete failures.
(Elephant Balderdash attempting to bottle the absurd, Sat 13 Oct 2012, 13:54, 2 replies)

These are the best things I've built


I built these two Daleks between 2005 and 2007. The black Dalek is all made of wood (various thicknesses of plywood and MDF) and non-operable, but the blue one is all-fibreglass and can be sat inside, steered around, etc. All the metal bits are in aluminium. I did buy in the hemispheres from a guy who custom-moulds them for Dalek builders. Someone else made the Tardis for me! If you're interested in Dalek building then www.projectdalek.com is the place to go.
( drdavej, Sat 13 Oct 2012, 12:10, 14 replies)