Iron Scenery III : Da Big Gen!

[omgitsduane]

So here is the initial sketch I drew up for a lay out and design of all the components...


Ingredients :

A coat hanger
Plasticard 1mm thick
Plasticard rod of varying diameter
Cereal boxes and other thickness cardboard
Soldering wire
A single LED
Lego gears/electronic gear sets
A 3volt gearbox

Electronics cost : 17$
Plasticard cost : 10$ (but can be made entirely out of cardboard)

Instructions!


The Fan Box
First I started with a set of 5 different sheets of cardboard, roughly the same size and length to make the fan, adjust if you feel its necessary to have sharp corners. Cut a small block out of ONE of the plates for the gear to run through to the main building. Now start by using only small drops of glue to glue the fan pieces together, until all 5 pieces are connected at least one end.

Fold them all into a position that you are happy with then put glue on the top and hopefully it will cascade down into the join, sealing it properly.
Once its dried a little, cut a piece of card(plastic or regular) fairly thin and just a little longer than the inside of the fan in a position you are happy with. Keep constant measurement and cut it until it fits in there nice and smoothly then glue it into place.


The Fan Shaft
The shaft can be made out of coat hanger or plasticard rods if available, simply cut 4(or more, or less) pieces of very thin cardboad in a long triangle shape with the pointed end slightly angled off. Glue these to the shaft on a small angle, about 35degrees should be fine, so it can capture the wind as it races past. Also attach a piece of card to the end of the shaft that will sit at the top, just to stop it from dropping down when its active.


The Fan Box continued
Do the same again on the top side to give the fan shaft some strength while it spins around, glue heavily into position just to be safe. Grab a drill, size isn't a big factor and poke a plasticard rod/coat hanger down there cut a little longer than the entire length of the box. Either a plasticard rod of slightly larger diameter or a piece of cardboard glue the end of the shaft to stop it from falling inside the fan box.

Cut another thin piece of cardboard and glue it to the top of the fan box to support the shaft, don't be afraid to over-glue it as it will take a bit of strain during the operation. Loosen the holes if nesseccary to allow the fan shaft to spin freely inside the box



The Armature

I used a piece of plasticard rod but a metal coat hanger would do the same job just as well, the shaft was pretty simple, and I cut thin pieces of card up and glued them to the sides with a plank across the top of them. Then I glued soldering wire to the top and ran 4 separate lines along the insides of the gaps in a simple zig zag pattern, each one goes around the entire shaft 4 times and ends up on the bottom of the shaft opposite of where it started.
Then a simple lego gear was glued to the bottom.



The Building

This started off with some very simple cardboard shapes, cut 4 squares and just glued them together on the sides. at this stage the thin cardboard seemed fine for the "cat walk" section but I would prefer a thicker card if possible as it needs to be more stable than the one I made. Also cut a small block out of the front of the building and take 2 cuts off the front where the cat walk will be to angle down the front of the building.

[omgitsduane]

The Building continued

At this point, before a roof is installed it is good practise to cut up lots of thick cardboard and use them as bracing for the sides and corners of the building to stop it from collapsing as the pressure of the rubber band and gearing system will take its toll.

Cut up two pieces of thick cardboard/plasticard and drill holes into them that will support the armature shaft, two of them should be plenty of support, but if you do decide to use cardboard, you may need to consider maybe placing metal coat hanger pieces INSIDE the actual cardboard to give it more strength, once that is done simply glue it to one or more of the support beams inside the building.

[gauss_storm]

Wait.... your actually making a functional terrain piece here?

*impressed*

[omgitsduane]

Yes gauss, I am making a functioning piece of terrain


The Building continued

Take a scalpel and take it against the side of some thick cardboard, the rougher the better, if any of the cardboard starts to peel off, then let it, as it gives it a much rougher texture that can be used to show a rusted look, and if the right type of cardboard with the waves in between, take the whole layer off if desired and use it as a corrugated sheet look.



A thin piece of cardboard was used to make this temporary roof, which the real roof will be placed onto, to make sure it has a flat surface I propped up the space between where I wanted the roof and where this fake roof is, so it will sit nice and flat.

[omgitsduane]

The Circuit

Parts needed for this will be a small amount of solder, a soldering iron a, a battery case, a switch, batteries and the gearbox.

A diagram of what we are after.


Key:

Long and short vertical lines = battery with the longer line being positive
Circle with M inside = Motor
Small circles with diagonal line = Switch
Circle with LED written inside = LED

The battery pack has a red and black lead, the red will be positive so remember that for the future, the switch will depend much on the TYPE you do buy, I bought one with 6 prongs and a simple 2 position swing, but only 2 of the prongs will be used.

If we make the assumption you buy a 6 prong switch similar in design to mine, we will label them all from 1-6. With the left side being 1-3 and the right being 5-6 then the positive lead from the battery pack will be soldered onto #3 prong, it is also a good idea to set up some heat shrink before soldering to prevent a short circuit down the track. With the positive lead done, a free wire that will go to the motor will be attached to #2.

Once the free wire is attached, perhaps you have either bought a fresh LED or decided to take one out of an old computer like I did, by chance the LED I took out was almost 3volts which is good, if you know anyone with a mulitmeter then it would be best to use it before attaching your preferred LED so it doesn't burn out from being over powered.

You want to have an LED that matched the amount of power that your batteries are putting out, AA batteries are 1.5 volts each for the record and its better for the life of the circuit if you have most of your electronics flowing with the same voltage.

Continued next post

[miasma]

Sweet!

Excellent work on this. There surely isn't enough functionally moving/rotating/shining/do0mlaz0ring scenery out there. This is a step in the right direction.

[omgitsduane]

The Circuit continued

If you bought a similar gearbox to what I did with a 3volt motor and 5 steps each gear being 12 and 48 teeth, a very useful formula is RPM x teeth of smaller gear (divided) by the teeth of the larger gear, now if you have a teeth ratio of 4:1 like I did this means each step down will be a quarter in speed.

Some simple examples are as follows
300 RPM x 5 teeth = 1500 / 20 = 75RPM
100 RPM x 10 = 1000 / 50 = 20RPM

I chose the speeds 187 and 46 RPM as I wanted the fan to spin much faster and my gearbox came with 2 shafts so why not make use of it.
With the "free" wires attached and the gearbox assembled, its time to attach the entire piece together and start revving, make totally sure that the gears do spin freely enough and if need be, glue them to the shaft so that torque won't loosen them and make your entire system fail.

Continued next post

[omgitsduane]

The Circuit continued

If you have taken an LED from a computer, the green lead is positive, and on a store bought LED the long wire will be the positive, motors do NOT have a positive or negative as depending on the way the electricity flows through them, they will spin one way or the other.

The advantage over a computer LED as to an old one is there will be wires already attached, otherwise you will have to solder the leads and heat shrink it before you go anywhere.

With the ends of the wire simply bite them off a few CM or half an inch away from the tip, or with the side of a blade, scrape away around the wire until the protection comes off, then you are ready to solder, with every wire end now free of plastic, its time to start the soldering!

[WARNING]
Be extremely careful with the soldering iron as they CAN and WILL cause bad burns, I myself am suffering a large 3 inch burn on my forearm because I slipped up.

The way we will set up the connection is as follows:

Battery positive -> switch prong #3
Switch prong #2 -> motor prong #1
LED positive -> motor prong #1
LED negative -> motor prong #2
Motor prong #2 and LED negative -> battery negative

[If this is unclear, refer to the video at the end of this post for a picture of the set up.]

The reason for this is that when the two items are parallel it doesn't slow down any of the functions to the speed which it would if they were all linear.

I found the easiest way to solder without either a friend helping or clamps is to curl the exposed wires around themselves to keep it together and then wrap them around the prong. Once you are happy and certain that everything is in its correct position then place the item in a comfortable position and place the soldering iron on the prong directly, after a few seconds it should heat up then you push the soldering wire into the tip of the iron, which should melt into a blog and ideally cover the prong and any wires very thoroughly.

If you don't get it perfect the first shot, just place the tip of the iron back on the cooled solder and let it heat up again then add more or move it around as needed.

Repeat until circuit is complete, switch on and see your work come alive!

Video of Testing my generator motor - Photobucket - Video and Image Hosting

[omgitsduane]

The Action

So now that we have the circuit built, it comes down to the actual pumping mechanism now, which is pretty simple really as the movement comes around the shaft at the back, a gear is needed to divert it to the horizontal plane, this is where 90 degree gears come into play.

I'm not sure if these are available on the market at modeling/RC shops but surely they would be, just keep an eye out for it or ask around if all else fails, at the very least someone should be able to point you in the right direction.

With the circuit all hooked up, and room inside the building made for the whole gearbox 2 rubber bands of very different lengths were used, I measured the distance up first between where the motor would be held and where the rubber bands had to reach and aimed to find rubber bands a few millimeter smaller to provide enough tension to turn the shafts.

With a thicker piece of plasticard on the roof, I made a hole and used a small lego gear with coat hanger on the inside to turn the arm that will crank the pump. Make sure that you have the gear not sitting too hard on the angled gear or else the motor will freeze up under the pressure, so as a precaution I actually have the gear quite loose so although it can move around quite a lot it will always turn, as long as its support is still attached to the roof!

The pump support was made using just sprues with the ugly pieces shaved off the side and banged up a bit with a knife, I used a pulley on the top to give the middle of the support a more important appearance over a simple plasticard piece with a hole inside it.

The main arm was made from sprues again, with barely any work done besides a simple plasticard piece with a hole drilled in on each end to hold the pump arm and the counterbalance.

The pump arm I thought could be made of the metal coat hanger but that turned out to be very heavy for the gears and would of required a lot more balance of pieces I didn't feel would be good to have floating around on such a flimsy support so I settled for a simple plasticard square rod with a hole in the end for the pump gear arm to sit in, also made of coat hanger.

Video of The pump working! - Photobucket - Video and Image Hosting

[Chaos877]

ooooohhhh! It's nice and noisy, just as an ork machine should be!