Making stuff up

Experiments with aluminium bronze

2012-01-29T15:15:00.005+11:00

Today I made some aluminium bronze, and it was a partial success I think.

I learnt a few things about the material, but I'm sure there's more to learn.

The first thing that I learnt is that it takes a surprisingly long time to melt copper; I was still trying after 20 minutes at full blast. Its melting point is 1084.62 degrees celsius, but either I couldn't get that hot, or there's some trick to melting copper. I got it to a very bright red-heat, but it wouldn't go any further.

So here's the lesson in that: according to The Complete Handbook of Sand Casting by C.W. Ammen, you should melt the copper first (p189), then add the other metals. I got fed up with w

aiting for the copper to melt, so I added my aluminium, which began to melt almost instantly, forming a puddle in the bottom of the crucible. Once this puddle had formed, the copper began to melt really quickly. If anyone can explain this, please do. Anyway, in future, I'll put copper in the bottom, aluminium on top, then more copper, then fire it up.

The second thing I learnt is that either aluminiun bronze is not nearly as golden as the internet would have me believe, or that it's a lot harder to get the ratios right than I thought. I aimed for 10% aluminium by weight, so I put 9 parts copper and 1 part aluminium in (2kg copper, 222g aluminium). One thing that leads me to believe that the ratio is hard to get right is that there was an awful lot of dross (or something that looked like dross) stuck in the bottom of the crucible after the pour. Thus, much of either or both metal oxidized. At what ratio, I can't say, but surely it is likely to skew my intended ratio.

In all honesty, I don't care about the colour, and the colour came out being pretty nice anyway. It looks almost like steel, only shinier. What I care about is the mechanical properties.

Here's an idea of the colour: the watch is stainless steel, the light has made everything a little yellower, though there are some patches about the place on other ingots that actually are that yellow. Also, notice how smooth the side is, and the two big flat bits on the top. The bumpy bits were loose bits of sand. This implies that I can get a pretty good finish with this alloy even with reasonably coarse sand.

The third thing I learnt is that aluminium bronze needs to cool slowly, otherwise it becomes very brittle. I quenched most of the ingots that I cast, with the result that I could break them by hand, or by dropping them from a height of about a metre. This had me worried, until I found an ingot I had forgotten to quench. I couldn't break it at all, I didn't try with a hammer though. In future, NO QUENCHING.

Here is a n ingot that I quenched, it was so brittle that I could snap it in my hand. It leaves a very sharp edge, I discovered the hard way. Notice how shiny the inside is? Also, you can see how it's quite crystalline. This has to be the result of the quenching, as the alloy ratio is almost certainly similar to the range of 'real' aluminium bronze, and I have one ingot, which wasn't quenched, which isn't brittle.

My theoretical pet metal

2012-01-25T18:11:00.002+11:00

People who work with metal tend to have a favourite; under normal circumstances, I would say my favourites are steel and copper. When talking about casting, however, my (theoretical) pet is aluminium bronze. I say 'theoretical' because I haven't yet cast with it. It is, therefore, my favourite only by virtue of what I have seen and read about it.

Aluminium bronze is an alloy of copper (~90%) and aluminium (~10%). It takes on a vaguely brassy look, and I believe that Australian gold coins are made from it. Here are the reasons I like the idea of aluminium bronze so much:

great material properties - it conducts heat well, is highly resistant to corrosion, and is very strong and hard. It's used to make bearings in aeroplane landing gear, boat propellers, engine parts, and many other things.

Great aesthetic properties - it looks a bit like brass, but not as 'bright'. It's also antimicrobial , apparently, as a result of the copper content.

And finally, great castability - aluminium bronze is a 'short freeze' alloy, meaning that it turns from liquid into solid almost instantly. The solidification happens from the outside face and progresses inwards. This means, according to this paper, that, assuming you have enough risers and feeders etc., you can obtain almost maximum density when casting aluminium bronze. Virtually pore free!

These reasons have all combined together to make me want to cast my lathe parts out of aluminium bronze instead of plain old aluminium. I may cast them in aluminium first, to make sure everything goes all right, and then re-cast them in aluminium bronze. But we'll see...

Lathe bench

2012-01-24T15:11:00.002+11:00

I'm thinking ahead now. I'm going to need somewhere to put my lathe when it's done, and given that it's going to be bigger and heavier than Gingery's lathe, moving it around will not be an option. I've drawn this bench up, it's made of 25mm box section painted RHS, welded together. The small box shaped cavity in the top left corner will house the motor at the back, and have a little cupboard or drawer or something at the front. It's a metre long, so I mah have to shorten my lathe a bit, I'm planning on a 1m bed at the moment... we'll see.

A new project: ambitious, but possible

2012-01-24T11:29:00.004+11:00

OK, I have a new major project. I'm going to build myself a Gingery-inspired lathe. If you don't know who Gingery is, google him. In short, he was a man who needed a machine shop, but lacked the funds for one. He had plenty of time though, so he decided to build one. He made many machines out of cast aluminium, which he melted in a furnace in his back yard. I admire his ingenuity, but feel that his lathe design is somewhat lacking in some areas. Those areas are:

size - his lathe is very small

fittings - his lathe has no standard tooling fittings

engineering - there are numerous engineering points that I disagree with, I'll cover these as they appear though

So, the first part that needs doing is the bed and ways. (Engineering flaw #1) Gingery cast his bed out of aluminium, making a 60cm hollow ribbed block for rigidity. Being aluminium, though, it is not particularly rigid. I imagine this lightweight casting introducing many inaccuracies, mostly through flexing and sagging. The other major downside to the bed is that it's a very big casting, especially for novices, at whom the series is mostly targeted.

To counter both of these problems, I have decided to skip casting the bed, and opt instead for a steel I-beam. This should give me the extra weight and rigidity that I yearn for, while also allowing me to scale the whole lathe up a bit (this addresses flaw #1, size). I plan on scaling it up to a 75mm swing, with around 60cm between centres.

Here is my basic idea for the bed: The black I-shaped section is, strangely enough, the I-beam. The thin grey piece is an aluminium match plate that I will cast up, and the red is a piece of bright flat bar.

The purpose of the match plate is simple. I will first scrape one side of it to fit the I-beam perfectly, then I will scrape the other side to match the bright bar perfectly. This will mean that the inaccuracies on the surface of the I-beam won't matter, as they will be averaged out by the aluminium plate. Then, given the very close tolerance of the bright flat bar, the matched aluminium surface will be almost perfectly flat. This will mean that I can bolt the bright bar onto it and not have to worry about it deforming.

Now, the only problem I can see with using I-beam is that it is not designed to withstand torsional force, which is exactly what I will be putting on it. I have two thoughts on this:

1) it may be so grossly over sized that it doesn't matter

2) I could weld straps into it, between the two parallel surfaces, and perpendicular to them. This would change the side view from being a long, wide channel, to a series of boxes. I feel that this should strengthen it sufficiently against the torsional forces.

So, those are my current plans. I'll update you as I build. But for now, google Gingery and see what he's all about.

A gift for Elspeth

2011-12-18T14:54:00.001+11:00

I recently finished making Elspeth a sewing box for her birthday. You can find the instructable I wrote for it here.

Success!

2011-11-16T17:03:00.002+11:00

So, having finished making my immersion heater and insulating jackets, I found the time to put down a new brew. It's an ale with honey making up the bulk of the extra sugars.

Anyway, I hooked the immersion heater up to my arduino thermostat, with the vat snug in its wet suit, and off it went. I did, however, however, have a slight hiccough with the thermostat. Before plugging it in and leaving it, I decided to do a double-check that everything was working fine. It wasn't. Long story short, my power supply wasn't stable enough to form a stable reference voltage, so the temperature reading varied by +/- ~15 degrees C. Ridiculous... Anyway, I plugged the arduino into my laptop, plugged the charger in, and left the whole lot looking after the beer.

6 days later, it was bottling time.

Pictures ahoy.

2011-10-12T17:08:00.001+11:00

The two lovely wet suits, dutifully awaiting the literal and proverbial 'chop', alongside their soon-to-be best friends, the 5 litre jar complete with cider on the left, and the 30 litre vat on the right.

One leg removed to make the sleeve for the jar.

Completed sleeve, I tucked a bit of scrap in to complete the sleeve.

And here's the vat in it's wet suit. Right on the front you can see a line of rough stitches, there's another one just on the edge on the right, these join a panel in to make the sleeve big enough to cover the vat. I also cut out a little slot for the tap.

I would show you the immersion heater, but I haven't got any photos of it, and it's pretty dull anyway. I just bought a length of aluminium tubing that was slightly too small to go over the end of the cartridge heater, then drilled one end out to 8mm, the diameter of the heater, and araldited the heater in. The tube is about 300mm long, and has a terminated mains cable coming out the other end ready to plug into the power outlet from my thermostat.

Wetsuits and cartridge heaters

2011-07-27T17:16:00.003+10:00

Following the advice of Anonymous, I have bought a cartridge heater, found on ebay for under AU$8. It's 220VAC, 400W, which is more than I need, but not way too much, It will probably take at least a fortnight to arrive, and so I'm going to make the glue gun heater anyway, especially considering that I will need two heaters eventually anyway, as I brew in both a small 5L jar and a big 30L vat, sometimes simultaneously. Also, I have a small brew going at the moment, into which I would like to place a heater as soon as possible.

Insulation: I want thermal insulation for my vats, as I think I mentioned. I called up ACT foam and rubber and Clarke Rubber to ask after various foams for this purpose. I was quoted $39.90 p/sm for some stuff called 'form fit', which sounded quite good, or $120 for 2 square metres of neoprene. Being a cheapskate, I decided to find another source of neoprene for my insulating jackets. Wetsuits.

So, today on my way home from uni I stopped in at some op shops and picked up two absolutely hideous wetsuits, one for $15 and one for $20. The leg from one wetsuit provided me with an almost ready-made jacket for my 5L jar, and the trunk of the other, plus a strip from the trunk of the first, make up a jacket for the 30L vat.

I'll post some pictures soon.

Immersion heater plans and ideas

2011-07-25T19:13:00.002+10:00

After struggling for a long time to find an immersion heating solution that was

a) affordable

b) relatively small

and

c) easy to immerse without contaminating the brew

I gave up and built a light box for my vat to sit on. This works well enough, but takes up space and has a light bulb in it, which is prone to breaking.

The other day, I was working on a vacuum box and needed to make a hole behind the electronics panel airtight. I did the obvious thing and filled the hole with hot glue. The problem being that my hot glue gun has a broken trigger mechanism, meaning that I have to manually push the glue sticks through. In the process of trying to quickly fill the hole up, I pushed ab it too hard, and shot the heating mechanism out the front end of the gun.

So no I'm down one glue gun. On the plus side, I got a small heating element that runs directly from mains power. Untouched, it measured about 10cm by about 2.5cm in height, and consisted of a stainless steel tube with the familiar conical nozzle at one end, with a stainless steel block mounted underneath, from which a pair of wires protruded. Guessing, based on the thickness of the walls on the stainless steel tube, that the heating element itself was confined to the block under the tube, I promptly cut the tube off to make the whole thing smaller. My guess was correct, so I now have a stainless steel heating element about 15mm diameter, 50mm long.

My next step will be to mount it in a brass or copper tube filled with mineral oil, this will allow me to mount it firmly throught the top of the vat, preventing it from touching the sides. It will also prevent the brew from conducting the 240 volts that are running to the element. There are two reasons for putting the mineral oil in there. Firstly, it is non-conductive, so the wires will be safe in there. Secondly, is removes air from the vessel, which is a poor conductor of heat, the oil will transfer the heat from the element to the brew more efficiently.

At the end, I hope to have a completely sealed unit about 200mm in length that I can easily mount, and easily swap between brewing vessels.

I'll post pictures and further information as I go.

Homebrew experiments.

2011-07-25T19:00:00.005+10:00

As my previous post may imply, I've been playing around with homebrewing beer and with controlling the various processes involved in this. From now on, I plan to post my various prototypes, ideas, plans, and findings here. At the moment my list of things to integrate into my system includes:

-Improved thermostatic control, possibly using a PID system

-Immersion heater for direct heating of the brew, this also saves space

-Electronic hydrometer to tell me the specific gravity of the brew, the alcohol content, and when it is time to bottle

-A convenient, inexpensive, and space efficient method of thermally insulating the brewing vat.

I guess while I'm at it I'll also post the results and recipes of my more experimental brewing attempts.

Homebrew homebrewing thermostat

2011-04-17T14:54:00.005+10:00

I've just finished my first protoype of my hombrew thermostat. Here is the schematic:

The source code is available at: http://arduino.cc/forum/index.php/topic,58725.0.html

The problem with the bike

2010-02-02T18:25:00.003+11:00

I got an Avanti Blade 2 about July last year, and up until recently, have had no problems. Last Thursday night, however, I was about to ride to Civic for a night of alcohol-fueled fun, when I accidentally bent the rear wheel. I have to say, this was entirely my own fault, I won't go into details, but it wasn't a manufacturing issue. Anyway, it looked like a capital C, this wheel. Fuck, I thought, and found another way into Civic for the night (incidentally, my year 7 English teacher gave me a lift). The following day I took the wheel to the bike shop, where the man gave me a free emergency true (he hit the wheel on the ground until it was straightish). This wasn't enough though, the wheel wouldn't go round. I went back, and bought a new wheel for $110. He changed the gears and the tire over, I paid and left. That was where it should have ended.

On Monday, I cycled into the ANU for some pre-enrollment stuff; when I got there, just as I was about to pull up and get off my bike, the chain came off. No problems, I thought, I'll put it back on, and be on my merry way. WRONG. The chain had come off and become jammed between the gears and the spokes. This bent the spokes and, as a result, the wheel. It wouldn't go round any more. Caught halfway between a bike shop and my next destination, there was nothing for it but an emergency true (I hit the wheel against the ground for a bit).

In the end, I got to my next destination, with my bike. But I had to call in a lift home again, because the wheel re-bent a bit. So now, I have to take the new wheel to the bike shop, and give them yet more money. On the plus side, I've discovered the only (thus far) flaw in the bike, and I've Isolated a problem that was bound to get me one day anyway, but in an infinitely worse time and place, during a chase from angry drug-lords for instance.

The problem was with the derailleur; when I got the new wheel, I should have adjusted it a bit. Oh well, now I know, and have fixed it.

The flaw with the bike, which is irritating, but not fault-inducing, is the positioning of the brake-pads. The pads themselves are located between the rear forks and the wheel, nothing TOO unusual, but... there isn't enough clearance (room) to take the wheel out easily without deflating the tires; even after you've disconnected the brakes. This is incredibly annoying when you're trying to do an emergency true with no tools in the hot sun, as to check the wheel, you have to put it back into place, then remove it again frequently. This is SO FUCKING PAINFUL when you can't do it without applying most of your weight. On top of that, if, as I did, you have to disconnect the rear brakes in order to ride, you also have to twist them and pull them until they're on the other side of the frame, a very difficult thing to do, especially without tools.

Basically, the brakes need a redesign. Look out for Blade 3.

Nick Valentino Guest blogs on Making Stuff Up

2009-11-10T21:02:00.000+11:00

A call to all Australian Steampunks!

Ahoy my Australian Steampunks! Frazer was gracious enough to let me come and guest blog here today. So Frazer, I appreciate you very much!

So, Australian Steampunks… I love it. For some reason in my head, I think you probably have a great Steampunk scene there in Australia. Am I right? Let me know, because I think you could bring a certain nuance to the genre that’s even more adventurous than many other countries. My novel, Thomas Riley is based out of two fictitious countries called West Canvia and Lemuria which are essentially code for The Netherlands and Germany. Most Steampunk literature is based out of England and I have to tell you I’m fascinated with the idea that “what if” Steampunk was happening all over the world? Really, there’s a whole other world out there and if Steampunk was real, it would be the common way of life across the globe, right?

So the Australian Steampunks have a great story to tell. At least generally speaking you have a pretty adventurous past… So why shouldn’t you take center stage to the Steampunk genre? I’m half tempted to include you in my next novel. People want to know what was/is going on not only in Victorian London, but other places as well. So… Hmmm. My wheels are turning. You have such a rich history of outdoor life and sheer adventure that I think Australia alone would make an amazing setting for a Steampunk book. So with that, I leave you with two things. 1) This is a call to all Australian Steampunks. Contact me… better yet; sign up to be a Sky Pirate… You will get some fun things in the mail. And 2) Check out my new Steampunk book “Thomas Riley” just released on Echelon Press.

Here’s the blurb for the novel:

For more than twenty years West Canvia and Lemuria have battled one another in a constant war.

From the safety of his laboratory, weapons designer Thomas Riley has cleverly and proudly empowered the West Canvian forces with his brilliant designs. But when a risky alchemy experiment goes horribly wrong, Thomas and his wily assistant, Cynthia Bassett, are thrust onto the front lines of battle.

Forced into shaky alliances with murderous sky pirates in a deadly race to kidnap the only man who can undo the damage—the mad genius behind Lemuria's cunning armaments—Thomas' own genius is put to the ultimate test.

Learn more about Thomas Riley here:
http://sirthomasriley.com

Buy signed copies here:
http://thomasriley.bigcartel.com/

Buy directly from the publisher here:
http://www.echelonpress.com/index.php?main_page=product_info&cPath=10_31_24&products_id=202

The Berlin Wall

2009-11-09T21:08:00.001+11:00

Just thought I'd make a note that today is the twentieth anniversary of the fall of the Berlin Wall.

Medea and the toilets

2009-10-03T18:35:00.004+10:00

A while ago I saw Medea in the arts centre at the ANU, and while relieving myself before going in I discovered that this

was in the mens' bathroom. Pretty cool, no? Excuse the photography, I only had my phone on me.

Also, I've been playing with making waistcoats recently, I'm still tweaking the pattern to fit me properly, but once I have a presentable one, I shall post pictures.

History

2009-09-06T15:53:00.001+10:00

I'm now a published author! I wrote this essay for history, and now it's published on an online historical journal. How cool is that?

Here's the link.

Doors and mirrors pt. 2

2009-09-03T15:51:00.002+10:00

Here's that mirror I was making. The corners are brass, but the lighting disguises it.

Have a look at my shed

2009-09-02T22:09:00.003+10:00

Here's my shed cum pool room, bask in its glory.

And my wine-case tea cupboard. I made it from a Yattarna wine case that I got for $5.

Anna's lamp

2009-07-27T19:43:00.005+10:00

I made this for my sister's birthday: The base is maple with a jarrah stain, the fixtures are made from copper pipe and fittings, and the globes are CCFLs from Jaycar. The switch on the front is mounted on a small copper plate, and the base is padded underneath with red felt.

Doors and mirrors

2009-07-27T19:35:00.002+10:00

We've had these new doors put on at the front of my house, opening onto the new deck. They look really good. They're cedar on the inside, and powder coated steel on the outside (wood weathers woefully). Anyway, the doors came in, of all things, maple packing. I like maple, it's cheaper than other, darker woods, but takes a stain really nicely, and is good to work with, so I kept the packing. I had two very small pieces (about 1200mm together, and 40mm wide) of it that I looked for a use for, and, after not too long, I found it looking me in the face. A mirror! I have this old mirror, without a frame of any sort, sitting on top of a speaker in my room, and I've been meaning to frame it for a while. I started it the other day. It's a very plain, simple design. Mitred corners, mirror held in a groove in the middle of each side. But I'm planning on some interesting flourishes at the joints. I haven't quite decided yet, I'm tossing up between a couple of different ideas I had revolving around brass pins, but, failing that, I'll just go with brass corners. I'll give it a new jarrah stain when I'm done.

Experimenting with etch resists

2009-07-02T21:53:00.003+10:00

Today I tried two substances as etch resists for electrolytic etching. Etch resist marker, designed for chemical etching of circuit boards, and black acrylic paint. Neither were great, I must say. The etch resist pen worked, but came off very easily when I brushed the surface to remove copper crud. It could work, but I'm not doing any fine art with it. The second, acrylic paint, was a TOTAL FAILURE. Tip: Never use water-based substances as resists. They dissolve in the bath. Photo one is before etching, photo two is after.

I didn't touch the front surface on the second one before taking the photograph. Once I scraped the paint off, I noticed that the whole surface had been etched the same amount. I reiterate: Never use water based substances. Ever.

Under pressure

2009-07-02T21:22:00.004+10:00

Last year sometime I got, free of charge of course, a gas tank, and a car's air-conditioning compressor. I wanted, you see, to build an air compressor. But I procrastinated with it, as per usual, for two reasons: the tank still had propane in it, and I had no safety valves. Well, today I found someone who will sell me the appropriate valves and regulators etc, so I will get cracking as soon as possible. I mean to buy parts on Saturday. Here is my plan of attack:
Note: It's only a schematic, it won't look like that when I'm done.

Card box pt. 2

2009-07-01T19:35:00.005+10:00

I have decided that I hate press 'n' peel blue. It will not work for me. I'm probably doing something wrong, but it took me three goes to get nowhere with it, after that I went back to good ole magazine pages and, lo and behold, perfect first go. Tip for young players, don't buy p'n'p blue. Anyway, I etched the front of my card box today, much better than the old card box I must say. Here's the image:

The old and the new

2009-06-28T22:52:00.003+10:00

I drew this diagram to show you how much better the new hinge is than the old one.

Questacon clock

2009-06-28T18:38:00.001+10:00

I found this, and thought it was great, then I read a bit about it, and realised that it was the one my friend Gary had been telling me about. He and his team built it at Questacon's workshop just down the road from where I work.

My card box

2009-06-23T19:57:00.005+10:00

If there are two types of games that I love (which there are), they would have to be billiards and cards. Last year I made this sweet, if rather chunky, card box of copper. It had a handmade hinge, and I etched a a picture of the mad hatter's tea party into the front of it. It held the cards well, was sturdy, and the bottom never fell out, not like the cardboard boxes that cards normally come in. Anyway, recently I lent it to a friend who wished to continue playing cards in their free period, something I often do, and the next thing I knew, it was gone. I had the cards, but no box. I don't know who lost it, and I don't really care anyway. It gave me the kick that I had been needing to make a newer, better one. So here it is. It's not done yet, but I've made the two parts of the box and done the hinge. Next up is to put an etching on the front. I expect I will do the same picture as before, but I'll do it better this time, the last one was a bit shallow. But I'll also etch a 500 scoring table on the inside of the lid. Unfortunately, I didn't take any photos of the old one, but I do have photos of the new one.

Here are some of the details. The top is unadorned at the moment, but the bottom has a gear from an old broken German cuckoo clock that I found soldered on to it. I made the hinges with some very small copper pipe, I cut it to the length of the (short end of the) lid, plus a little extra, then cut it into thirds. I cleaned the ends up, then put some flux on the pipes and the edges of bot the box and the lid, pushed them into position lying on a tile, and gently heated them, then added a very small amount of solder.

The pin running through the pipes is some brass wire.

The old hinges were made from copper sheet, folded into a rough tube at one end, then soldered onto the rest of the box. Funtional, but chunky and fiddly. These ones, while fiddly, were actually easier than the old ones, and are almost invisible.

Slax

2009-06-22T19:22:00.003+10:00

Micah came over for a bit today to install an OS on the Vectra. He brought with him a Slax boot disk. This is a live session Linux OS. I have to say though, I'm not enamoured with Linux thus far. I can't find anything on it, and it can't even see its own hard drive, which we discovered is 20GB, not the 8 that I had previously thought. I use Windows normally. I accept the flaws of Windows, on the presmises that a) I know how to use it, and b) PCs are modifiable. It seemed to work okay while Micah was still here, but when I tried to put music on it as soon as he left, the hard drive was gone. I have a sneaking suspicion that I will put Windows back on it later, but we'll see.

Vectra PC

2009-06-20T22:09:00.001+10:00

I got a power supply for it today, 19v, 3.16A, usually used for laptops. Having arrived home, I hooked all the different bit of computer together and fired the Vectra up and, lo and behold, it worked. It turns out it's running XP professional, but only has an 8GB hard drive. That will have to be fixed. Micah and myself are going to do some fiddling on Monday. I plan to strip it down to the smallest possible amount of software. I want it to play music, read pdfs and do MS Word as well. And maybe paint. But that's all it needs. Micah has suggested using Live sessions, but we'll see.

Two recent acquisitions

2009-06-17T22:24:00.003+10:00

In the past week I have obtained two quite interesting things. The first, bought from a shop on Geelong St., Fyshwick, is a fan made by General Electric from before 1950, although I couldn't find exactly when. It set me back $20, but I think it's fantastic. I intend to make it work again and set it up in the workshop for the disgusting Canberra summers that we get.

The other is a small 'corporate's' PC that I found on the side of the road. It's an HP Vectra, released in 2000, with a fast-remove, ultra-ata hard drive and DVD reader. Instead of having an internal power supply, it requires a plug pack at 19 V DC, 6.13A. I don't have a power supply to suit, so I'll obtain one and test this little machine, and, if it works, it will become a jukebox in the workshop.

Proposition

2009-06-08T18:49:00.004+10:00

I am going to make a BE reactor(Birkland-Eyde). BE reactors are used for making nitric acid out of air, electricity, and water. The basic principle is that you use electricity to strip nitrogen compunds out of the air, then you dissolve these nitrogen compounds into water, leaving you with nitric acid, or HNO3. I will post pictures and diagrams etc. as I go. So far, I have made the electrodes. They take the form of a pair of copper pipes, one inside the other, but not touching. Air will get sucked through it, making it pass through a disc of plasma in the process. From there the air will bubble through a tank of water. Here's a diagram of the electrodes:

Billiards and time

2009-06-03T21:45:00.007+10:00

I was recently thrilled to discover that I am set to acquire a billiard table in the near future. Being one of those people who is always trying to improve on things that really have no problem, I decided to build a ball return system for it.

My first problem was the design, I went through a whole range of design concepts before I settled on one that looked like it would work. The other problem facing me is maths and physics. I have no idea what sort of angle the return chutes should have on them. The balls need to roll slowly enough that they aren't worn out just by being potted (sunk), but fast enough that they don't just stop altogether.

To overcome the problems that mathematics pose for me, I have come up with a piece of apparatus that will measure the speed of a billiard ball over a known distance, and a known gradient. I've had numerous designs for this too, all identical in practice, but not in implementation. The first method was to mount some micro switches in a piece of PVC pipe, 30 centimetres apart (I only had 40 cm of pipe big enough). The switches were wired in parallel with the start/stop button on a stopwatch. This means that when the ball hits the first switch, the timer starts, and when the ball hits the second, the timer stops. In theory this would have worked, but my construction was lazy and haphazard, so it promptly fell apart. the second method had a pair of wooden rails running parallel, with the same electrical set up, but the switches 1m apart, a nice round number. This should have worked too, but I discovered that by the time the ball reached the bottom switch, it was going too fast to actuate it.

Most recent plan: Same rails as before, but with an optical switch rather than mechanical ones. The circuit diagram is below, and I will put a PCB layout somewhere too, when I've worked out the kinks. It's not a sophisticated circuit, but it works (at least, it did on the prototyping board), and that's all that counts at the moment.

The switching transistor is a BC548. The resistor in the circle is a Light Dependent Resistor (LDR), and the Diode with the lambda next to it is a LASER diode. The 7803 is any 3 volt regulator for the LASER diode, not necessarily a 7803.
You may have to fiddle with the dimensions of the layout to get the right sizes, and you will have to invert the colours if you are going to use toner transfer to fabricate your board.

On a different note

2009-06-03T21:42:00.000+10:00

Up until now, my blog has been primarily an assessment piece for school, one of the requirements being that it have a common thread running through the whole blog. I 'handed it in' last Friday, but have decided to keep blogging. From here on out, my blog won't be just about etching. It will still be mostly about things I'm building or making, but it will have the odd opinion or social commentary as well, I expect.

On inking

2009-05-28T09:33:00.003+10:00

I said I'd tell you about inking earlier, so here it is. This is basically a description with the different inking methods I've tried.

The application method for methods 1, 2 and 4 are essentially the same. You apply some of the ink (or paint), make sure it's in all the etched lines, then squeegee ink off the top with a scrap of copper that has a straight edge. Once you've done this, let the ink/paint set for however long it needs, then rub it down with steel wool until you're left with ink in the etched lines, and nowhere else. Cover with a protective lacquer if you want.

Method 1: Lithographic/etching ink. About $20 a tube from Eckersley's. This is an oil base soft ground used for etching hand drawn images. Because it was what I had available, this was the first ink I tried. While it sticks in the etching reasonably well, it takes days to dry, and the lacquer that I was using at the time dissolves it. It's also really messy. I was finding black oily stains for weeks afterwards.

Method 2: Because of the waiting time involved with the Lithographic ink, I decided to try with black spray paint. Simply spray onto your plate after etching, squeegee the excess off, and allow to dry. I found that while this was quick, the lacquer, once again, dissolved the paint. It's a lot cleaner though.

Method 3: Permanent marker. Basically, colour the etched lines in with a thick black marker, the ones made by Staedtler are the best. The problem with this method, is purely the recurring lacquer problem. This is a very easy method.

Method 4: This is the best one of all. It's the same as method 1, but use black acrylic paint instead of lithographic ink. This paint dries really quickly, after squeegeeing it takes about 15 minutes. It's cheap, about $3 a tube, and it's lacquer resistant because it's water based.

Brass etching

2009-05-21T18:21:00.007+10:00

In a fit of procrastination this evening, I decided that I would do a brass etching with the brass that appeared in the mail yesterday. I went with the airship pilot's badge from earlier. The transfer was really good, the magazine peeled off in one piece, which was a really good feeling. Here's a picture of the magazine page after peeling, with the brass next to it:

I put it into the tank with my new plate holder (left, lovingly turned down on a school lathe), and switched the power supply on, it drew between 1.5 and 2.5 Amps the entire time, and built crud up on the surface a lot faster than the copper did. Some copper also rose to the surface of the brass. There was no surface pitting either. This etch took about 15 minutes.

In case you're unfamiliar with the difference between copper and brass, brass has zinc as well as copper, and looks gold rather than red. The brass is at the top, and copper at the bottom:

Here is the finished etching, after being 'inked'. More on inking later.

A plan for the future

2009-05-20T20:45:00.008+10:00

I was talking with a friend of mine recently, and discovered that her father is a lithographer, and, as such, does copper etchings. She said that he did acid etches, which piqued my interest, so I have done a little research, and come up with this. It's called the 'Edinburgh Etch', and uses Ferric Chloride as the 'acid'. I say 'acid' because it is actually a salt, not an acid. Anyway, I shudder to say it, but...Dick Smith...sell bottles of Ferric Chloride, so I shall purchase some, and start tinkering.

On a different note, a package came from A&E Metal today, containing a sheet of 1mm brass, and a sheet of 0.5mm nickel silver (which actually contains no silver), and some brooch backs. I intend to try and electroplate the nickel silver onto brass and copper. But we shall see.

An experiment in separation

2009-05-13T22:10:00.009+10:00

I have found that when I etch, the plate that I'm etching heats up to a point where the toner flakes off the plate, leaving the copper underneath exposed. This evening, I decided to try and change this. in the past, I have put the two plates very close to each other, about a centimetre apart. While this positioning means that it only takes about twenty minutes to etch a plate, I think it contributes to the heat.

Anyway, I transferred this picture onto a piece of copper, and put it into the etching tank. The picture was from the front cover of the first issue of this magazine.
But this time, instead of putting the two plate really close together, I put them on opposite sides of the tank. Because the resistance would be much higher, I knew I would have to leave it for a lot longer than normal. I put it on at 15 volts, and between 1 and 1.25 amps, and came back 50 minutes later to check it and turn it off, as I was leaving the house to ferry lurkers around town.

When I got home again, I turned it back on again, and got to tinkering around the workshop. Another 50 odd minutes later, I turned it off, this time for good. Not as much toner had fallen off as in previous attempts. Success! I got a nice gradation of depths, deeper in the wider lines, shallower in the narrower. Then I cleaned it off, and inked it. Here's what it looks like.

One thing that I have noticed with using magazine pages for toner transfer, is that parts of the image from the magazine sometimes transfer too.You can see this above and to the left of the bird. So sometimes, my etchings end up with words etched into the background and other things like that. At some point, I will attempt a different paper.

A Glossary

2009-05-13T11:09:00.005+10:00

It has been brought to my attention that some of the terms within the pages of my blog are not clearly defined. This is where I will endeavour to define them for you. If you find anything you are unsure of, please either email me, or post a comment with your request underneath this entry. Thanking you, and I hope I can clarify anything that is unclear.

Acronyms:

DC- Direct Current. The current flows only one way.
LDR- Light Dependent Resistor. A resistor whose resistance changes depending on the amount of light falling on the surface.
PCB- Printed Circuit Board. A sheet of fibre glass with copper traces stuck to the surface. The copper traces are the connections between all the components.

Components:

Collection of numbers and letters: Component identification code (usually arbitrary, sometimes following a pattern). eg. LM7805, LM7812. LM has no meaning to me, 78 denotes a 1 Amp limit, the last number, '05', '12' denotes the voltage output.

Voltage regulator: Takes a DC voltage in at one end, and outputs a regulated voltage at the other, as well as a limited current.
Transistor: These switch, and amplify. Information about their markings can be found here, and further information here.

An experiment in stainless steel and blue paper

2009-05-06T20:36:00.012+10:00

On the weekend I split a packet of Press'n'peel Blue with a mate of mine, because we both wanted to try it out, having only ever used magazine pages. I also bought some stainless steel wall-plates, used for light switches and audio systems etc. For a couple of days I tried to find something that would look good on a stainless steel wall-plate as a replacement for my boring white plastic light switch. I finally stumbled upon the back of a card. After mucking around with it in Gimp for a while, I finally got it scaled to the right size for my wall-plate. I decided then that this would be the perfect opportunity to test out the Press'n'peel Blue. Accordingly, I printed my image onto a sheet of it, and proceeded to align and iron it. FAIL.The bottom picture is my first attempt at the Press'n'Peel, and the top is the second attempt.
My iron was on too high a temperature, it was still on the setting I use for magazine pages. I turned it down to 'Synthetic' and tried again. FAIL. I don't know if it was poor technique, or if P'n'P doesn't work on stainless steel, or if it even works at all, but only about a third of the image adhered to the metal, the bits that I've drawn around were the only bits that adhered. So I went back to magazine pages, and, wha'd'you know, it worked. It wasn't perfect, but about eighty-five percent of the picture was there.

I took it out to the workshop and set up a brand new tank, this time with table salt as the electrolyte. After discovering that yet another fuse was blown in my power supply, I switched to batteries. My smaller battery was too small to have much of an effect, and when I put my bigger one on and tried to measure the current the tank was drawing, the jumper leads exploded. So I hooked it back up, but with three pairs of jumpers instead of one. Much better, and it was pulling about six amps.

After blowing up lots of little hydrogen bubbles, I took it inside and cleaned it off. It's pitted in places, and looks very raw, but it has a certain je ne sais quoi to it, appealingly aged.Here it is installed on my wall, I put some Prussian blue oil paint over it to bring out some of the detail, but the camera doesn't show it.

Intaglio plate

2009-05-04T19:58:00.013+10:00

This evening I decided to try and make a printing plate of the airship wings image. Because I wanted the final image, in this case the print, not the plate, to be a positive, I had to reverse a step.

When I printed out the image on the magazine page, it was a positive. This means that the blank spaces (which are supposed to be white) would be etched out, leaving a negative, once you put the ink on and press it into some paper, it becomes a positive image on the page.

I bought some ink in a bottle today with this in mind, as well as a roller. Both came from the art shop in Dickson. The roller is made of plastic, so somehow I had to protect it from the heat that remains in the copper plate during ironing. I found that I had a roll of aluminium tape in my workshop, so I put a couple of strips on the roller, et viola! A protected roller. After heating the toner, I rolled the copper and the paper with the roller, and then soaked the paper off. I was pleased to find that the roller helped in the quality of the transfer, more stuck down than usual. There were a couple of little spots that came off while I was removing the paper, but they were in non-critical spots so I didn't re-do it.

Unfortunately, while I was drilling the two holes in it, my drill slipped and I bent the plate. I straightened it out again, but I think I may have weakened the toner's grip on the copper.

I hooked the plate up to the new and improved power supply that I did yesterday (which works wonderfully, I might add), and etched for about twenty minutes, after which the toner had started falling off. I suspect this was because the plate was getting quite warm, softening the toner up, and also because of the bending I mentioned.

In spite of this it turned out reasonably well, and I cleaned it off, painted a thin layer of ink on to it, put some paper on it, and went over it with the roller a couple of times.

I think next time I need to etch deeper, and not bend the plate.

I once again apologise for the photos. The lines (particularly in attempts 1 and 4 are actually quite sharp.

Power supplies

2009-05-01T17:37:00.012+10:00

I am very fortunate. I have a friend who works for Questacon, who has lots of fantastic electronic junk. One prime example of this is a trio of variable linear power supplies, each having a range of 9-18 volts DC. In my annoyance at having to recharge my SLA batteries after etching, I finally broke one of the power supplies out in the place of the battery. It's a wonderfully simple device, you just put mains in one end, and a preset and adjustable voltage comes out the other end. Because I had no proper electronics enclosure on hand, and lacked the motivation to build a nice box to put it in, I had decided to mount it in an abandoned lunchbox. This was necessary, because otherwise there would have been bare, live mains wires sitting on top of my workbench, which is both permanently covered in crap, conductive and non-conductive alike, and is within easy reach of my two lurkers. I wouldn't want to zap them, now, would I? Anyway, I set the voltage to about 10VDC, zip tied it in, put a switch and some connectors and a fan for ventilation in as well, and closed the lid. That was my power supply until today, when I mounted it up in a nice box, with adjustment knobs for voltage and the current limiter, and all the connectors. Still to come is an ammeter and a polarity switcher, which will allow me to plate with this supply.

You, however, may not be as fortunate in your friends as I am. Never fear. All is not lost. You can use other power supplies. As I mentioned before, SLA (Sealed Lead Acid) batteries work very well. They're basically car batteries, but they don't spill, and you can get them in different strengths. You will, however, also need to shell out for a charger, and keep the battery charged. What a pain. But, that's not the only alternative. Do you have a phone that's broken? (A land line, hands free phone that is.) Or a broken scanner? How about some dead computer speakers? Most of these devices are powered from a 'plug pack', a step down transformer that plugs straight into the wall. One of these plug packs will suffice as a power supply for etching. Just make sure the output is DC, and at least three volts. You may want to solder some alligator clips onto the end of the wires (after lopping the plug off), to help you identify +VE and -VE, and to make your connections easier.Pictured above are a 7 Amp/Hour SLA battery and some plug packs

Etching

2009-04-30T17:57:00.013+10:00

Now that the toner is on the copper, we can etch it.
This means that you have to have made the tank, and found a suitable power supply.

The power supply needs to be at least three volts, and absolutely has to be DC, or direct current. According to my friend, who is doing second year engineering at the ANU, you need three volts for the copper to start coming off the plate. Much more than three volts is overkill, but it does no harm. However, the higher the voltage, the more leeway you have (theoretically) with the size of the plates and the distance between them, as well as the concentration of the electrolyte solution. If you measure the voltage across the two plates while they are etching, it reads higher the further apart they are. This is because of Ohm's law, which states that Voltage=CurrentXResistance, or V=IR. If you move the plates close to each other, the resistance between them drops, causing the voltage to go up. The same goes if you put more copper sulphate into solution.

The procedure for etching is this: Figure out some way of suspending the plate as close to parallel as possible with the cathode. I drilled two holes, one near each of the top two corners. Then I put some fencing tie-wire through the holes and hung it from a bit of aluminium stock so that it would hang below the water line.

Connect the positive of the power supply to your piece, and the negative to the plate in the tank, and turn the juice on.

Every fifteen minutes or so, turn the power off and scrape the crap that forms on your piece off with a toothbrush. Return it to the tank and continue.

This particular piece only took about half an hour to etch, but that's because it's so small. The bigger it is, the longer it takes. This is because the current will spread out pretty evenly over the surface of the copper. Because there is only so much current, if you have a large plate, there will be fewer amps per square centimetre. I once etched a card box with a picture about 5X7 cm, which took about two hours.

Here's the badge that I etched, based on the picture in the second post. The lines were about 0.5mm deep, and very clean. The only problems with the etching quality are the parts where I failed to transfer the toner properly, i.e the wing tips, and three parts of the zeppelin. The other flaw is that there is some pitting on the wings, but I suspect that that is due to the large spaces of black. It might work better if that part of the picture were made up of lines.

If that is where you're going to leave it, then now is the time to ink it. This can be tricky if you don't have the right stuff, but it's not all that bad. If you're going to do something else, you shouldn't ink it yet.

Interesting fact: I touched the back of the plate before etching, and was left with an etched fingerprint on the back. The back does etch, but not deeply.

Toner transfer

2009-04-29T18:36:00.013+10:00

This is a technique that I used to use to manufacture PCBs (Printed Circuit Boards), but I realised when I read this that it could be used for other things too. The basic concept is this: A laser printer melts stuff called toner onto the page, if you're careful, you can then re-melt the toner, onto something else! The wonderful thing about toner, is that it's both acid resistant, and electrically non-conductive. This allows you to use it for a mask on either electro etching or acid etching. If you want to create your own one-of-a-kind, hand drawn plate, you can use a soft ground, which is a thick oil based ink (the one I've got is at least). You paint it on, wait a couple of days for it to dry, then just scratch your picture on. But I'm using the toner transfer method.

Here's what you need:
As pictured, you need an ironing board, with a cloth on it so I don't burn the cover, a sheet of copper, which I'm using for practice, a nibbling tool, steel wool, isopropyl alcohol, scotchbrite, an iron and a block of wood.

Print your image onto a page from a glossy magazine (I used New Scientist), make sure the image that you are etching is printed in black and white (the colours on the magaine page don't matter at all) , and the exact opposite of the picture you want to have at the end. Ergo, the colours (all two of them) are inverted, and the picture is mirrored.

Cut out your image, and a piece of copper that the image will fit on. That's what the nibbling tool's for, but you can use anything that works. Now you have to clean it REALLY well. Scrub it with isopropyl and steel wool until it gleams, you can use the scotchbrite instead of the steel wool if you want. Make sure there is no dust, dirt or oil on the surface, that includes fingerprints.

Once it's clean, wrap your image around it, with the picture over the cleaned surface, and the edges of the paper behind it. Now iron it. Put the iron on its highest setting, dry of course, and press hard, moving the iron around a little. It sometimes helps to rub it with a roller or the back of a spoon or something. This can take around 2 minutes, but practice will tell you exactly how long. Because ironing boards are padded, I always put a block of wood under the copper, but if you're ironing on your workbench, there's probably no need. But it might still help.

Once the ironing is done, put the copper and paper in some hot or warm water. Let it soak for about 10 minutes, then gently peel the top layer of paper off. Soak it again, and take more paper off. Continue this until there's almost no paper left, then you can rub the rest of the paper off. You want tho be left with a piece of copper with only toner and empty space on it. Nothing else. And that's the toner transfer method.

You should be left with something like this:

My technique wasn't great on this one. Decent, but not fantastic. I missed the wing tips and the bottom tooth of the gear, and I think that I accidentally ironed some of the blue from the magazine page onto the copper too. If you have an etch resist pen, sold in electronics stores, you can go through and touch up bits that are missing, and you can carefully scrath lines out of the toner when bits that shouldn't be there are there. (By the way, don't be fooled by the shaky lines, they're actually very sharp, my camera's not great is all.)

Aims and materials.

2009-04-28T18:10:00.011+10:00

When I'm done with this particular set of experiments, I want to be able to get good quality etches, with nice straight lines, I want to be able to 'etch machine' as well, which is where you etch right through the plate, causing a bit to come off. I want to minimise surface pitting, and master toner transfer, which I'll explain at some point.

The project I'm going to be making for this is a badge, the image I'm using for the badge comes from a web comic called Girl Genius that is quite amusing, and it's an airship pilot's badge. I think it's quite a striking image.

The materials I'll use are:
Large Tupperware container
Copper Sulphate
Plates of brass and copper (Obtained from A&E Metal suppliers )
Variable power supply
Laser printer New Scientist magazine
An iron and ironing board
A Roller
Isopropyl alcohol
Black paint
Steel wool
Scotchbrite
Brass brooch findings, also from A&E

You might also find one of these useful at a later date.

The first couple of steps I have had completed for a while now. They're as follows: Make an etching tank. I had some old float valves, enormous ones, and the float on one of them was bashed in and useless. Or so I thought when I got it. It was made of copper, so I cut a bit out of it for my cathode. I drilled a couple of holes in the side of the Tupperware container and in the copper scrap, then bolted the copper to the inside of the tank. That's the cathode done.

The next step is the electrolyte (the salt solution). I went to the hardware store and got some copper sulphate, a blue crystal used for killing plants, or you could 'acquire' some from the school's chemistry dept. Dissolve some of the copper sulphate in water in the tank. Obviously, you want to keep the water level below the holes in the sides of the tank. If you're not going to use it straight away, put the lid back on and put it out of the reach of lurkers (A.K.A fiendish sisters)

Lurker #1

Galvanic Etching

2009-04-27T11:30:00.001+10:00

I have been interested in making etchings in brass and copper for some time, and in fact made a card box out of copper, with a scene from Alice's Adventures in Wonderland Galvanically etched into the front. Once I had finished that, I lent my etching tank to a good friend of mine, and I only recently got it back. But now that it's back on my workbench, I am going to improve the quality of my existing etching skills, and broaden my repotoire of techniques. I'm going to start with a brief history of Galvanic etching first though. The benefit of the ability to etch images and words into various metals was twofold. They were used in printing, where the plates would be of the Intaglio variety, where the raised part of the image were the lines desired on the final piece, a negative of the final image if you like. As well as this, etched plates can be quite aesthetically appealing. Galvanic etching, also known as electrolytic, or electro etching, is a process that has been known since the 19th century, the original description of the process having been published in 1855 under the name electro-etching. Prior the widspread use of electrolytic etching, acids had been used in their place, these acids included nitric acid, hydrocloric acid, or ferric chloride. None of which are particularly pleasant chemicals (http://www.greenart.info/galvetch/advan.htm). The basic theory of Galvanic etching is this: If you suspend two plates of metal (both based on the same metal, that is, if you have a copper plate, you can couple it with brass, copper, or bronze) parrallel to each other in a solution of the same metal (in a salt form usually), and pass an electric current from one to the other, particles of one plate will become dissolved in the solution, and will then be dposited on the other plate. Electro-etching is essentially the polar opposite of electroplating.

In this diagram, sorry for its low quality by the way, the brass plate is on the left, and the copper is on the right. The plate connected to the negative supply is always the cathode, or K, and the positive is always the anode, or A. When you etch, your piece is always the anode, and a bit of appropriate scrap is the cathode. Reverse this for plating.