Putting the Electronics together – Planning

The main reason that I’ve been tinkering with electronics is my longer term goal of embedding some interesting lighting effects into a Steam Punk prop. That was where all of this started.

Now I have some decisions to make about which lighting effect circuits I want to include.

I want:

• A pulsing/fading light acting as a power indicator and with a cool translucent – through hole cover (i.e. the Mac power indicator);
• Chasing lights to come on when the trigger is pulled; and
• A torch-light at the front of the prop

I’ve done a couple of pulse fade circuits, all with varying degrees of success (well … appearance). My two favourites are the 9V PUT transistor pulse fade that I found in the Make! book and the ATTiny85 pulsing LED that I modified from the Arduino as ISP sketch. The PUT version is neat and quite cheap, it doesn’t require any expensive parts (relatively), the most costly part is the PUT transistor (2N6027), but, at around $0.27AUD per transistor, I can live with that, this pushes the PUT version to around $0.73 per board. The ATTiny85 version has far fewer parts, but the ATTiny85 is much more expensive than a PUT transistor so it ends up costing around $2.48AUD.

The Chasing Lights is a bit of a no brainer, I’m going to go with the ATTiny85 + LED Sub-board option. The total cost of the board and sub-board comes to $4.37AUD.

Finally, I’m going to rebuild the 2x2 SMD LED Matrix project and change the layout a little. This was a great learning circuit for a couple of reasons and at a cost of around $0.49 it’s nice a cheap too!

There are a couple of additional costs, such as switches. For the chasing lights, I’ll either use a momentary switch or a lever switch, which way I go is going to depend on the way that I design the trigger for the prop. Apart from that, there’s about $1.00 worth of wire.

So, the embedded electronics come in at (PUT) $6.59 or (ATTiny84) $8.34 … plus the switches.

The above block diagram shows the overall design using the ATTiny85 Pulse/Fade component while the one below shows the overall design using the PUT Pulse/Fade component.

With the PUT Pulse/Fade, I’ve dropped a switch and put the SMD LED onto the 9V power source, rather than the 5V regulated power source.

My next step from here is to put these circuit boards together on a prototype “board” to test the overall concept.

Simple NE555 Pulsing LED – In A Box

Now that I’ve made the pulsing LED and soldered it all up on perfboard, I want to make an enclosure for it, ideally, one that diffuses the light and looks cool.
I have some 0.75 mm white PVC sheet at home that I’ve had for years and years (I used to use this for making table-top war-gaming scenery). The PVC sheet should be sturdy enough when it is glued into a solid shape and thin enough to allow light through and to diffuse it.
What I’m aiming for is, simply, a box to put the board in. I’ll probably use some hot melt glue to adhere the board to the PVC and I’ll cut a hole through one of the boxes walls to pass the power connector through.

When the circuit is powered, the light will pulse and the PVC will spread the light through it’s walls creating a glowing, pulsing box.
Last night, I cut the PVC and glued up all but one side of the enclosure (I’ve left the side with the power hole unglued) and I gave it a test run. The result was fairly pleasing … but quite plain.
I’m confident that the enclosure will do what I want it to do (glow and pulse). So, now I’m going to think about how to make it look Lovecraftian. The obvious approach is to cut up more PVC to make some faux pierce-work pieces to apply to the outside of the box. Alternatively, I could design and print out some black and white imagery and glue it inside the box. The thinking there is that the parts of the image that are black would prevent the light passing through the enclosure. Maybe a combination of the two.

Pulsing red LED in a custom PVC box. Now it just needs decorating.

I’ll return to this thread at a later date. I need to do some design work on the box to make it more worthy of being called Steampunk. For now … it’s just a glowing, pulsing box.

Acid Etching … musings and plans – Part 3

Tonight, I got around to having another go at the acid etch of my test piece.

If you recall, the last time I did this, the acid wasn’t bighting very deeply in the metal. The process was OK, but the result was rubbish because the acid wasn’t strong enough.

I went and bought some more peroxide and made the acid a little stronger.

I used a better quality paper (Kodak premium photographic paper this time) and I added some more peroxide to the acid (the peroxide weakens over time with sunlight).

I gave it a good ironing, but the transfer was still missing some bits … so I did it again.

Then I bathed the piece in water to get the paper off … resulting in …

A reasonable transfer. There are still some holes in the transfer, but I’m going to go with this anyway. It has a nice distressed appearance.

Next, instead of wiping the acid onto the piece, I immersed the piece in acid for 30 minutes.

After that, I used some acetone to clean the toner from the surface of the piece and gave it a bit of a light polishing.

You can see that the acid has bitten more deeply into the surface this time. The overall appearance is quite good, and I am happy with it.

As I said earlier, it looks more distressed, and that is a good thing in this case. Of course, I won’t always be looking for a distressed result, so I need to improve my transfer technique so that it does what I want it to do every time.

I’m not really sure what I am going to do with this piece now that I have made it … maybe just cut it out and mount it in a stand … who knows.

Electrolytic Etching Steel

Some time ago, I wrote a puff piece about a reproduction 15th century crossbow that I made. One of the things that I mentioned in passing in that  article, was that I electro-etched the metal on the piece to add design and “age” to the finished product.

It’s probably worth exploring the process, since it certainly isn’t hard, but it is a worthwhile technique to know.

Basically, electrolytic etching is a process where you immerse a positively charged piece into a negatively charged solution. The positively charged ions in the metal (anode) are attracted to the negatively charged point (cathode) through a process of oxidisation. Or … put simply, the solution makes the metal rust, the electricity takes the rust away from the metal.

The art in electrolytic etching is in the design and execution of the resist.

To make the crossbow parts, I painted the steel pieces with a black acrylic paint and allowed it to completely dry. Then I drew the design onto the painted piece and scratched the design using an awl. You could just as easily use a nail, pin, fingernail … whatever will remove the paint, exposing the bare metal underneath. I also attached a copper wire to the back of the steel piece to connect to the anode (connected to the positive source).

I made up a saturated saline solution mixing the salt in until the water is saturated (that is, no more salt will mix into the solution).

The piece was then immersed into the solution connected to the positive rail of my power source (a 12V battery charger). The cathode was then immersed into the solution (via another copper wire) and the charger was turned on.

You should see bubbles rising from the exposed metal on the piece … this is from the oxidisation process. Tiny flakes of steel will be coming away from the piece also and going into the solution.

I gave the pieces about 15 minutes in the solution before taking them out.

Next, I used some steel wool and running water to scrub the paint away from the pieces and gave them a good polish.

These “freehand” etchings are quite nice and are satisfactorily “distressed”. There is some pitting that has occurred in the design, but these are entirely suitable for the end result that I was looking for.

An alternative method for producing the design, that I have used successfully with printed circuit boards and which works just as well with electrolytic engraving, is to print the design on a laser printer (onto a gloss or semi-gloss paper) and transfer the design onto the metal using the iron-on transfer method (remember to reverse the design).

To iron the design onto the metal, turn your household iron up to it’s hottest setting, place the paper onto the metal piece (ink side down) and iron it on. This will take up to 4 minutes of pressing and moving your iron around onto the piece. Drop the metal piece into hot water and let it soak for about 15 minutes. Carefully peel the paper off until you are left with just the metal and the toner.

Use acrylic paint to coat the back of the piece and to touch up any bits that are not in the design. Attach your anode and proceed as described earlier.

Acid Etching … musings and plans – Part 2

Quickly … to the redesign!

After last parts failure to save my design, I have quickly made up a new, smaller design. This one is a simple 5x5cm design as a proof of concept.

Negative and flipped horizontally … I also added the word “Asylum” across the gargoyles brow.

This was then printed out and ironed on to the brass plate.

Now it is reversed through the magic of transfer printing.

I then used a white acrylic paint to block out the edges of the plate and the right-hand edge so that the acid wouldn’t eat away at the rest of the stock. I also painted some white paint onto the back of the stock so that the acid wouldn’t mark the back of the piece.

I had to make a swab for the acid. This is simply two bamboo skewers wrapped together with a rubber band and with a cotton ball at one end.

Next, I poured my acid into an acid proof container and then swabbed the acid onto the design using my home-made swab.

When I thought that I had rubbed enough acid into the design, it was time to clean the resist off the stock so that I could reveal my masterpiece …

Well … not so much masterpiece as, very, very faint etching indeed.

I think that I did two things wrong here:

1. The acid was not fresh … it had been sitting in the bottle for about two months. The acid needs to be refreshed from time to time (add more peroxide, add more hydrochloric acid). I noticed this previously when I was etching printed circuit boards; and
2. I certainly didn’t swab acid onto the design long enough.

No great loss, I have learned my lessons and I can move on. I will get some more peroxide so that I can freshen the acid, print and transfer again, and revisit this design at a later date.

Importantly I learned that, essentially, my plans are feasible with stronger acid. I won’t make those mistakes again and I did not ruin the stock. In a worst case scenario, I could polish the design out of the brass stock (if I really needed to).

I found some other gothic designs that I like and will probably use in the goggle design. I’m going to be going for a steam-punk/Cthulhu inspired design when I finally do get on to that project. Probably working in something like this …

I’ve seen this in a couple of places … including tattooed onto someone's back. Either that or draw my own Cthuluesque design.

Acid Etching … musings and plans – Part 1

I have done acid etching of PCB for electronics, and it isn’t very hard. To take things up a notch, I want to do some acid etching of some brass plate. This is all leading to part of my current down-scale projects.

The idea is very simple … make a design using Photoshop (or another image processing tool). The image is the same size as the piece of brass that I am working with (35 x 5 cm). I want the design to be simply a border with cogs in it (steam-punky) and with a bit of text in one of the cogs.

OK, so I did that bit. I got a good steam-punk texture from the Internet and played with it until I was happy with it as a pattern. I made a pattern filled border that was also a simple repeated design and made sure that the bits that I wanted to be etched were white and the bits that I wanted to remain were black (or shades in between).

I printed out the design onto my black and white laser printer and then ironed the design on to the brass plate.

Sounds simple? It is … except that I stuffed up in two ways:

1. I forgot to reverse the image;
2. Photoshop trashed the image when I saved it (old version … long story).

Still, I got the image transferred on to the brass plate.

The iron was on it’s hottest setting and I kept the iron moving on the paper for about 5 minutes.

You can see that the transfer isn’t perfect, but I thin that this will add a patina to the etch when I’m done.

The next step will be to paint around the transfer so that none of the border will be exposed when I start rubbing acid onto it. I’m going to use an acrylic paint to mask the edges of the brass plate.

After the plate is properly masked, I will move on to the acid etching part of the process.

As a heads-up … the ingredients that I will be using for doing the acid etching are:

• hydrochloric acid;
• hydrogen peroxide;
• heavy duty rubber gloves;
• acid safe plastic container (for the acid);
• cotton wool swabs;
• nail polish remover.

The hydrochloric acid/hydrogen peroxide mixture has already been converted into cupric acid (by adding copper) and there are plenty of good resources for making cupric acid on the interweb.

I will be putting the acid into the container and then wetting the cotton wool swab with the acid and gently rubbing the surface of the brass plate with the acid. This should have the effect of etching the parts of the design that are not covered with the resist (paint and laser printer ink). After that, the plate is bathed in water to neutralize any acid that is still on the plate, then the plate is cleaned off with the nail polish remover. That will remove the laser printer ink and help to clean off the acrylic paint.

What I should end up with is a nicely etched brass plate.

I am practicing this now so that when I come to make the pieces for the goggles, I can pre-etch them. It would be a lot harder to etch the pieces when they are shaped … so I’m going to do that first.

Later, I will make a very simple prototype pair of goggles (with no lens and no moving parts) so that I can get the basic design bedded down.

Now that I’m moved

Now that I have moved to my new abode (temporary accommodation). I don’t have a lot of space to do much … so I have to scale my experiments and prototyping to stuff that I can do in a small room and on a desk. Not a lot of scale really.

So, over the next couple of weeks, I’ll be doing some small scale prototyping of moving parts that I will be working up into a pair of steam-punk style goggles.

The basic design of the goggles will be a simple affair with two ocular apertures, ideally with some slotted eye-piece covers and a working mechanical iris.

The prototype goggles will be all about the “how to” and won’t necessarily involve a whole working model at the end of it.

I am going to start by making a single eye piece and see what I can make to “gussy” it up.

I also want to use the prototype as a workbench for acid engraving. I have some cupric acid that I have produced from doing some electronic PCB engraving, and I want to see how far I can go with this technique for an artistic design on brass-work. Later, I might even do some Dremmel pierced work on the frame as another piece of experimentation.

So … on to the plan.

I have bought a couple of brass rod and brass cylinders (including some nifty hollow hexagonal pieces). I want to use the brass rod and tube to make some brass nuts for the goggles. This should be fairly straight forward. Cut the rod, cut the tube, flux the rod, and braze. When the rod and tube are in one piece, use a tap and die to cut the thread on the nut and the goggle body where the nut will attach.

If you are interested in seeing some awesome steam-punk goggles … do a search for gogglerman, his stuff is truly inspiring.

Steampunk Electronics–LED Goggles Part II

The circuit for this project is pretty straight forward. Basically, each of the LED connect to the positive through the anode and to the negative via a 150 ohm resistor.

On a breadboard, it looks like this.

There is a jumper going from the positive to each LED anode. The cathode is connected to the negative through the resistor.

When it is powered up, it looks like this.

There are 20 LED in parallel.

This is enough LED for two eye pieces, making up a pair of goggles. I need to work out how long it takes before the LED drain the 9 volt battery. To do this, I’ve simply charged the 9 volt battery and marked the time when the LED were connected.

I did a rough test last night, but with 100 ohm resistors instead of 150 ohm. I started to get no light from some of the LED after 3 hours. That’s not a bad outcome. So long as I use rechargeable batteries, it shouldn’t be a problem.

I don’t know if the increase in resistance will make that much difference in the power consumption … but I guess that it will increase the glow time by about 33 – 50%. The power went on at 7:14pm today.

I don’t have any data on the LED power consumption.

Next image is at 8:30pm

Definitely less bright after 1 hour 15 minutes of operation.

9:30 and some of the LED are dark and overall, much less light output from the array.

I kept the LED array powered all night and there was still a very faint glow in the LED after almost 12 hours. Not enough light for anything practical and almost invisible … but still going. I would say that the acceptable level of light was after 1 hour 30 minutes of continuous running. So, this means that either I decrease the number of LED in the array or increase the number of batteries (2 x 9v for instance). The most practical approach would be reduce the number of LED to, say 6 LED per “lens” rather than 10. That works for me. So now the next task is to design and build the PCB for the lens.

That’s not going to happen very quickly at the moment, as we are moving house in 3 weeks and I have a shitload of stuff to pack.

Steampunk Electronics–LED Goggles

I’ve had an idea for embedding 12 LED into a ring structure that will fit into goggles.

The idea is fairly straight forward, 12 x LED, 12 x 100Ω resistors on a PCB ring with a power supply. I want to make the LED array into a single solid unit.

The LED will be arranged in parallel, that is, all of the anodes will be connected to the positive side of the battery and all of the cathodes will be connected to a 100Ω resistor and each of the 12 100Ω resistors will connect to the negative (ground) side of the battery. Also, the LED and resistors will be arranged around a PCB that has been cut into a ring shape.

The battery leads and  the resistors will be soldered onto the bottom of the PCB so that only the PCB and LED will be visible from the “top” of the board.

I will make a silicone mold that will embed the LED side of the project and this will be filled with a clear or slightly opaque resin. The other side of the project will be filled with a black resin (so that the light from the LED doesn’t come back into the eyes).

I’m going to need to make the PCB layout a bit more elegant and the LED equidistant so that it doesn’t look too crappy.

I want to make the LED ring sit inside of the ocular tube of the goggles so that they cast a bright light where the goggles are facing.

12 LED should drain a 9 volt battery fairly quickly, so I don’t expect that this will be a suitable torch, so I’m going with colour instead.

The battery leads will come out on the under side so that they can be attached to the inside of the goggles. I’m going to make a battery clip /pocket out of leather that will attach to the back of the goggles strap. But, first things first. Make the prototype, then make the molds, then see how the LED like being in resin.

The goggles will be another article much later. First I’ll be making the LED ring.

Steampunk Electronics–Buzzer

Another part of the internal electronics that I want to incorporate into the Steampunk gun, is a buzzer that sounds when the trigger us pulled.

I found a simple schematic using a 555 IC that flashes an LED and makes a kind of buzzing sound through an 8 ohm speaker.

This schematic seems to be pretty widely available on the Internet, so I thought that I’d give it a go.

The circuit uses a small number of parts and, all together, it cost me about $1.25 using components sourced from eBay.

• J1 – 2 pin (2.54mm pitch) right angle pin header
• VCC1– 2 pin (2.54mm pitch) right angle pin header
• C1 – 1μF non-polarised capacitor
• C2 – 10μF electrolytic polarised capacitor
• R1 – 220kΩ resistor
• R2 – 470kΩ resistor
• U1 – 8pin DIL socket and NE555 IC
• LED1 – generic blue LED

J1 connects to the 8Ω speaker and VCC1 connects to the 9V battery.

I have added DuPont female connectors and housing to the wires soldered on to the speaker and 9V snap to make it easier to connect and disconnect them.

I’ve used Fritzing to do the layout of the board (as shown above). This board is approximately 4cm x 3cm, so it would fit nicely inside the prop.

First, I laid the components out on a prototype board and set up the jumper wires to test the arrangement. Once I was happy with the circuit, I used Fritzing to lay out the design (and make the schematic). Then I printed the circuit out onto some photographic paper and cut it to size.

My first attempt to print was pretty poor … I heated the PCB too much and the copper blistered away from the board. This may have happened because the board was a bit scratched from a crappy cut that I made previously.

When I had successfully transferred the design to the board, I then went over the transfer and fixed any breaks with some enamel paint and a fine paintbrush, then … into the acid bath.

I cleaned the board using acetone to remove the resist and drilled the holes with a pin vice.

I then went over the board on the silk side and marked what each of the components and their orientation should be and then populated the board with the components and soldered them up.

I put DuPont connectors onto the speaker wire and the 9V snap so that I could more easily attach/detach them (an so use them on other projects later).

The circuit is described, on the Internet, as a “Laser” sound … frankly, you would need a pretty good imagination to believe that. It’s more of a Geiger Counter sound … but that may be the way that I constructed the circuit. It probably needs a higher hertz to fix that.

Steampunk Electronics–Heartbeat Part 3

Well now … I have duplicated the circuit that Charles Platt shows in his book.

The circuit makes use of direct component soldering rather than using jumper wires or using routes from a printed circuit board.

The resulting circuit works fairly well, although I believe that the capacitors are shorting somewhere in the circuit as the LED does not pulse as the prototype board version did, rather, it pulses on and flashes off. When the power is removed from the circuit, the LED powers down completely, without any capacitor leaking.

Anyway, this is a prototype and I am working on that basis.

As you can see from the picture, the circuit is very small.

You  can see from  the under side, that the legs from each component is used to connect to the next component(s) in the circuit.

I am using some very cheap circuit boards that I bought from eBay. I neglected to clean the board first, so the soldering job wasn’t all that successful (part of the reason that I think that there is a soldering fault). However, as the components are directly soldered, the perf board is used merely as a strata for the circuit.

And here it is.

I need to make a printed circuit board next to improve and refine the prototype.

Steampunk Electronics–Heartbeat Part 2

In the first article, I was talking about using the Charles Platt design for creating a pulsing LED using a 2N6027 PUT, a couple of resistors, a couple of capacitors and an LED.

Today, I took the schematic from Make: Electronics (by Charles Platt) and built it on a prototype board.

The first thing that I did was to transfer the resistors from the schematic onto the prototype board. It’s a simple design with not many components, so I decided to have the resistors spanning the separation channel in the middle, and then use jumper wires to connect them all.

Next, I put the capacitors  in place along with the transistor and the LED.

Finally, I jumped the components so that they were connected according to the schematic.

I connected the battery (9V) to the board and waited … and waited. There was something wrong.

I needed to get out the multimeter and work out what was wrong.

I tested the battery … it was measuring 8.94V so that wasn’t the problem. Next I tested continuity on all of the jumpers … they were working fine.

Test the resistors, also OK. Interestingly, the resisters that I bought from eBay … all within the stated tolerance, so, Yay.

Test the capacitors … also fine.

I tested the LED and it was also peachy keen … so what had I done wrong?

I noticed that the prototype board power rails had a break in the middle and that I needed to jump between the gaps (d’oh!) I should have realised that this was the case, but then, this is the first time that I’ve used the prototype board in earnest.

After putting in the jumpers, I powered it up and … presto! it works just like is says on the box.

I’ve colour coded the jumpers so that I know what is going where.

White jumpers connect to a resistor, Green jumpers connect to a capacitor, Blue jumpers connect to the transistor, Yellow jumpers connect to the LED. Black and Red are Negative and Positive power respectively.

I’ve just been playing with the circuit a bit and I’ve decided that the timing for the LED was wrong. The LED flashed too quickly for my taste with a cycle of on-off in about 1 second. I’ve replaced the capacitors in the circuit. Now the capacitors are:

C1 – 220 µF electrolytic capacitor; and

C2 – 470 µF electrolytic capacitor.

The on-off cycle is now about 2.5 seconds and much more pleasing for me.

Next, I’m going to transfer this to a perf board and put it in a project box. I think that this will work well for the Steam Punk prop. The prototype perf board will be larger than the one that I will use with a PCB, simply so that I have space to wire it. I will be using a standard copper padded perf board and the holes are all pre-drilled, so there won’t be much opportunity to compress the design. Also, because I will be using wire between the components rather than copper route, I will need some extra space for soldering and general jiggery pokery.

Anyway … it’s time to go and play with perf board and project boxes.

Steampunk Firepower–Electronics

I bought some lighting electronic kits from an electronics store that perform some of the lighting jiggery-pokery that I want to put into the Steampunk props, such as the flashing light and chasing lights.

These are not particularly difficult or complex circuits and they fall within the ambit of my level of skill with electronics (i.e. not much).

The kits were pretty cheap ($7 – $15) and the printed circuit boards are very paint-by-numbers so it wasn’t very hard to build them.

Here is the chasing lights circuit, the red LED light up left to right and then right to left continuously. In the Steampunk prop, the LED will be mounted around the barrel when the trigger is pulled.

The flashing light circuit simply oscillates between the green and red LED. In the prototype, the lights will be mounted in the body and be viewed through a bunch of resin ports in the side of the gun.

The next trick is to duplicate the printed circuit in a wired circuit so that I can make sure that I understand the circuit properly. I also need to be able to change the shape of the boards so that they fit into the prototype better and run from a single 9V battery.

I’ve ordered all of the components that I need to be able to build these circuits, and I will make some modifications to the design by including some trimmer potentiometers (so that the frequency of flash and speed of chasing lights can be tuned). I’ll make these on the prototype board first and then transfer the design to a strip-board PCB.

Steampunk Firepower–Prototype Encased

Well, I think that I have given the prototype gun enough coating to make it sturdy enough.

There are some small bits that still need touching up due to the fact that I can’t give it an all-over coat at once, but have to build the coat up in stages (I have to hold it somewhere while I apply the filler). But, overall, I’ve given the prototype 5 coats of filler. There are also some coats of 2 part epoxy and paint under the filler, but I’m not counting them.

The last couple of coats have been very thin so that the finished surface is as smooth as I can make it. I’ve rubbed the prototype with 120 grit sandpaper between coats to knock off some of the grainy bits in the filler and to smooth out some streaks left by the paintbrush.

You can see the overall shape of the prototype now too. Large body, thick barrel, chunky pistol grip, wavy bottom of the body and flat top.

Next I’m going to be drawing the design onto the prototype to mark out all of the areas that I’m going to etch with the Dremmel rotary tool and the cut-line where I’m going to cut the prototype in half.

Etching the surface is going to be another experimental stage. I know that the directions for the filler say that it can be drilled, sawn and sanded, but the subsurface has a lot of give and the vibration from the rotary tool may cause the filler to lift from the prototype. If it does, I’m going to go over the whole thing with a clear acrylic paint to help to stabilise it.

When the etching is done, I will be moving on to the next stage … making the prototype ready for investing. That’ll involve cutting it in half, removing the polystyrene core using acetone, building up the interior surface with more filler (so that the shell is at least 5mm thick), and of course … fixing anything that goes contrariwise to me.

So far … so good.

I’ve now ordered a truckload of electronic components from eBay (resistors, transistors, capacitors, timer IC, decade counter IC, LED, potentiometers, PCB, e.t.c) so that I can do some more work on the prototype electronic gubbins. I want to have a pulsing LED glowing through some cut-outs in the body and some lights chasing around the barrel of the gun. Here is a crap visualisation of the lights.

The cut-outs will be covered with some inset resin panels and will have a single large LED with a pulse circuit while the chasing lights will be some 3mm LED. Chasing just means that each light comes on in sequence (kinda like the “eye” of a Cylon). The above picture is pretty bad … just something I knocked up in MS-PAINT in a couple of seconds.

The body will not be that colour when it is in the final material, so don’t worry about that!

I want the circuitry to be fairly simple and I’m going to use trim pot resistors so that the cycle time can be varied manually.

Steampunk Firepower–More Prototyping

Today I bought some water based multipurpose filler … Agnew’s Water Filler. This is a great filler and works on lots of different materials, but, importantly, it works on polystyrene.

The filler mixes 3 parts powder to 1 part water to make a thick paste. I made a mix of 1 to 1 to make a thin slurry of the putty and applied it directly to the polystyrene with an artist paintbrush. So far, I have applied 3 layers and it takes about 10 minutes for the putty to dry sufficiently to apply another layer. So that’s about 30 minutes to get about 2.5mm thick coverage over the polystyrene.

The putty can be sawn, sanded, drilled and carved, so I’m pretty pleased with the scope for the putty as a modelling medium.

I needed to extend the grip on the gun as it was about a finger too short. To do this, I used a hacksaw to cut the end of the original handle off and then carved a 1” polystyrene block and glued it on to the end. The putty slurry was then painted on to the stock to start building it up and blending it in. I also painted the slurry on to the new barrel of the gun and started to smooth out some of the lumpy bits.

Now I’m waiting for the putty to cure entirely so that I can start to sand and smooth the surface. The putty is still very thin on the gun, so I’ll probably need to give the surface some protection. I will use a clear matt finish acrylic paint to achieve that.

Soon, I’ll be able to start carving the detail into the surface.

I have an old urchin shell on the veranda, I’m going to fill the interior with some plaster to make the shell less fragile and then I’m going to cover the outer surface with some silicone moulding medium. The shell has such a fantastic texture, and I reckon that, if I flatten it out, the texture will look awesome as a surface on the gun … maybe on the grip.

When the prototype is all surfaced and carved, I’ll need to cut the gun in half along it’s length so that I can remove the polystyrene from the middle. I will also need to make the shell a bit thicker by adding more filler on the inside of the shell. When I’ve done that, I can start making the transparent sections of the gun. Oh well, that’s probably a long time into the future yet … how many chickens do I have now?

Steampunk Firepower–Design Sketches

As promised, I have compiled a bunch of scans of the sketched designs that I have done. These are designs inspired by various sources, mostly science fiction fantasy novels, television and movies.

I’ve tried to honour the feeling of the sci-fi genres that I have drawn from while still thinking about how the props would feel in the hand.

I must stress that these are NOT real guns, they will not work.

This is the Rocky Horror design, it’s a basic shape. The movie version was such a lovely and slick design. The ray gun here seemed to have no moving parts and was a simple shiny metal object.

The Marshall is a pistol design based on the Colt Navy. The addition of a bayonette onto the end is a bit of a unnecessary hardware, but it gives the impression that the hand holding the gun is resolute.

This is a plasma gun. The idea is that the panel at the rear of the gun would be a transparent plastic panel with glowing swirling lights.

A personal flamethrower is always something to pack when you are heading out for a night on the town. Especially when the likes of Nyarlhotep are about.

The Angels Wings is a personal cannon for the fashion conscious lady adventurer.

Another in the personal cannon range. The Big Mumma packs the kind of punch that even Dagon would envy. This is the kind of firepower that would be handy when the odds are stacked against you.

The third in the personal cannon range, the Heavy Handed is simple and straight forward. Point and Kablooie … problem solved. The Heavy Handed is the sort of gun that makes even the smallest adventurer a force to be reckoned with … although an enhanced arm would not go amiss when trying to cope with the recoil.

The Duelling Pistol is a reproduction flintlock pistol, this sketch is more about the lines and the dimensions. The old duelling pistols were pieces of art.

As were  the trigger plates for the duelling pistols…

I am very fond of the design of The Ray Gun. There is a very satisfying balance to this sketch, when I have completed the Unearthly Power, this will be my next project.

The Unearthly Power is a fairly simple design and the overall shape is based on a Bosch drill. This is my first design that I am producing as a physical prototype. So far … so good. I’m going to have to remake the prototype as I am also experimenting with materials, but … meh, whatever. The prototype is based on the sketch, I will be making deviations from the design as my skill limits are reached.

I also plan to make a backpack device that can plug in to several of the designed guns.