Motorized Assault Cannon

Been a long time, I know.

Still have all the other projects in various states of 'almost done', and I occasionally tinker with them to make their wiring/arrangement better.

After one of my mini servoes broke, I of course tore it apart to see "how it works", and wound up with a teeny tiny 3 volt motor to play with. After looking around to see what/how to implement it, I eyed one of my Space Marine Dreadnaughts, and had an instant vision of its torso pivoting under radio control, and its assault cannon whirring away... as in the first Dawn of War intro movie.

A few destructive moments with the Dremel, and here it is, mocked up:


I'm not sure yet if I want to add the whole RC kit to it, as it would all have to be in a big clunky base.. or if I just want the motor direct wired to a mini puchbutton somewhere on the Dread.

While I'm adding batteries and pushbuttons, I might as well add some LEDs and stuff.. right? We shall see.

Lit-up Plasma Rifle

Now its time to attempt a lit up plasma rifle. I had done something similar to this before, but this was before I knew how GOOD the flying bases conduct light! However, since I did this before, I already know what bits will fit what and where, if yaknow what I mean.


Here I sanded down a flying base with the sanding drum seen above, carefully sanding it down all around to get a constant diameter smaller than the plasma rifle barrel to be, and high-speed ground the rear end to its smooth finish (high speed cutting wheel actually polishes quite good and quickly)

Then I got a piece of tubular styrene, and reamed the inner diameter out a bit, so that it would fit both the sanded flying base stand, and the 3mm LED bulb.

This piece was going to be the jacket that would fill in the gap between the rifles' barrell and breach/stock... but at the end of things I discarded this piece entirely. I also ground away the rounded tip of the led... this is kindof dangerous (for the LED, not me), as the high temp and vibration can often break the LEDs' internals.


But in the meantime, I fitted everything together, and tested the light after all the abuse I put the LED through


This pic shows the real work part of the project: the barrell. I hollowed it out enough to fit the clear rod. This was time consuming, as I had to be carefull. First, I drilled through the center with a teeny drilbit, then a medium sized drillbit. Then, very carefully, I manually spun the cone shaped router bit through the barrell from rear to front, using the drillbit holes as an auto-centering guide as the teeth slowly dig through. When the tip finally got to the end, I stopped just soon enough so it wouldnt widen the barrell tip, and rounded that area out with the little ball router bit, again manually. Then, With the tiny drillbit, I drilled out the barrell tip vents (cant really call it a recoil brake, seeing as how its plasma), so that the light will come out of there too.



Here we see just how thin the barrell walls are after running the router through it. This light is shining through, and thats with the roughed up plastic rod in the way, so it shows just how good the plastic rod conducts light as well! Plus, you can see how much light shines out in weird place, like the rear! All that is no good for the purposes of this model!


Here I went with a simpler arrangement, after seeing how much room I had in the breach/stock... which was not much! I routered out a good sized cavity, for the LED taps to lie in, and drilled 2 45 degree holes through one of the mounting blocks for the wires. If you look closely, youll see a bit of whire inbetween the wires where the hole is. This is a piece of styrene strip, so that when I cram the LED and taps in the hole, they cant ever touch each other; resulting in a short, resulting in none of the lights working. Also, if you look reeeally close, youll see some milky white stuff. Thats school glue, good ol schoolpaste. I glob this on over all the taps, and cram it all in the hole so the paste fills in the voids, to mount the LED in a temporary way, and to keep things from moving around and possibly messing up inside. Also, in the pic, clearly seen, is the blacked out areas with paint... I left the li of the LED clear so that there will be a glowing ring of green at the point between the barrell and stock, which looks cool and techno. The beginning bart of the barrell is blacked out as well, to cover the LED-clear rod gap, and the clear rod is blacked out as well, but not all the way: I left the tip exposed, for lighting up the vent slots.



These two pics show the gun assembled without teh plastic rod, and this is a close match to my first attempt, and while it looks decent, it seemed... I dont know... fake somehow.


And heres the gun with the clear rod... much much better, in my opinion. plus all the stray light glitches went away, thanks to the black paint.



Now, on a final word: The wires emerge from the arm mounting block in such a way that the wiring can be continued on up the arm, within the arm and out of sight, all the way to the chest. no wires is god wires, in some peoples' opinions.



But maybe I'll have the wires clearly visible: having them serve as modelled power wires for the actual weapons, looping out and around to the reactor in the backpack.



Either way, the Plasma Rifle itself is done, for most parts.

Lit-Up Shield Generator

This time I wanted to make a fancy Shield Generator look all glitzed up. The Shield as is is just a small frisbee on the forearm, and is supposed to be a forcefield that protects the entire suit! Anyway, I mostly started this project because it seemed simple, and would look extremely cool!

So, starting from top left, and going clockwise: First is the shield generator piece itself. I smoothed away the bumbs on the bottom so it would lay flat on its forcefield. Next, is the arm the shield attaches too. I put a big hole in it (big is relative, its actually 5mm!), big enough for the next part. The LED. I trimmed the wires very close and soldered wires in a very compact little arrangement, so that it could be covered by- The rear cover. I used a Fusion Blaster to make this vented 'box' to cover up the solderpoints, and to cover the light emmiting from the base of the LED (yet still allow some to spill out of the vents I carefully carved out). Below is the forcefield itself: a large flying base. The LED wil poke through the forearm, and the base will fit over the tip of the LED, and the shield piece will cover the hole on top, and block the main beam of light. Last, the metal bit is a dremel attachment, and the only tool, besides an exacto knife to do this whole thing! (ok, and a soldering iron too) That little router bit is simply amazing! And it eats through this plastic like butter.

The plastic of the flying base conducts light so well, that the flat surfaces didnt light up at all, resulting in a bright blue ring around the edge only. That was not good enough. So, I scratched the flat surface of the base with an exacto knife, first by holding the base in my left had, and sweeping from the center hole to the edge using my wrist, then rapidly repeating that motion as my left hand spun the disk in small incements (Red arcs). Then, I reversed the procedure: holding with my right hand and sweeping with my left (Green arcs), to get a nice 'weaving lines of force web' effect, that should light up as the light passes through.

Pretty straightforeward, all in all. the result?

Hrrmmm not very awesome... wait! lets try the pic withOUT the flash...

yeah, thats much better, and more how the eye sees it. As a preview, heres the shield mounted on a suitably posed Suit, with a sneak peak at my next project: a lit-up plasma rifle!

I dont know about anyone else, but to me: this is the height of coolness, and the techno-flashy style that made me pick the Tau race to begin with! Stuff like this just wouldnt look right on any other races' models, but fits this races style perfectly!

Kitted Burst Cannon

'Kitted', as I define it for my little hobby, means 'bunch of gizmos added'. This little side project started as a 'wouldnt it be cool if..' replies in the forums... The idea was:

"Mount a motor inside a burst cannon so that the barrels spin. AND, have one spot on the gunbarrells lit up by an led, so that as the gun spins, the light looks like the gun firing."

So, I just jumped right in!

First, I had to find a motor small enough to fit in the small small area of the burst cannon 'breach', and luckilly I found a neat, cheap little toy that might do the job!

Opening it up, I isolated the motor, and tested its sie to see if it would work. (a term called kit-bash), and looking at it, the motor may juuust be small enough!

Getting the motor free, I got to planning on how to make the idea actually work in practice. Above is the general layout, in relation to the gun itself. I really would have loved to use that 5mm LED, as its bright and very very blue. But, all things tested, only a 3mm would actually fit without massively changing the appearance of the whole gun (making it look stock is one of the primary goals)

Finally, I settled on this config, and reamed the plastic out to fit the motor within. The cylinder at the back of the gun was removed, and I plan on using the body of the motor itself as part of the gun body, and would fit the cylinder over the end of the motor. The power wires for the motor will be coming out of the rear of the gun, and slung under, and back up to the 'magazine', where the wires would run up and inside the vehicle where the batteries are.

The barrells will be made of clear plastic flying base rods, which actually conduct light very well! In this pic they are roughly ruberbanded together, and need to be made with a stiff and strong centered axle, and be balanced for spinning. This was actually harder than it even sounds.

Here is the near final test fit for all the components. I got the barrell arrangement all finished, and actually quite balanced as well.. while at the same time looking not too shabby if I do say so myself... hehe You can see the green LED tucked in, and its 'wires' bent and fitted to route up the magazine feeder as planned. The superglue left some frost visible in this pic, but thats easilly scraped away after drying. The plan is to greenstuff the rear of the led and wires to blend them into the bottom of the gun: all told, the only change will be a slight bulge on the underside of the gun.

If you look closely, you can see that there are two separate pairs of wires going to these two systems: light and motor. That was because, after many attempts, there was just no way for a 3v pair of AAAs to power both at the same time. So, for purposes of this project, it had two separate battery packs.

Here is the view with the LED lit up, obviously, and you can see, with high speed grinding/polishing of the rear, how well it conducts light! I was impressed with it, to say the least! The light spills out a bit too far to the adjacent barrels and I hope to later greenstuff around the LED to make its light a tighter beam.

Finally, we come to the 'test run', where I got everything moving smoothly, and couldnt wait to fire this puppy up:

WOW that little motor is a speed demon, even with the weight of the barrels it had to spin (the axle and barrell grid weighed about twice what the motor itself did)!! Its more of a phalanx chaingun speed that a gatling gun where you can actually see the individual barrels light up in turn.... but that wont be very visible at 10000 rpm!!

Thats as far as I got with this little project, still with some things to do:

- Try adding a rheostat to the motor circuit, to see if it will slow things down without losing all of its power.

- Try to rig up a 555 flasher chip to the led circuit, to make it flash (even a flast of 40/sec would looke better)

- rig the two separate circuits through a relay so they both activate at the same time.. activated by a pushbutton switch somewhere on the vehicle model itself.

But this little project has stalled. I am in a frenzy (binge?) of lighting projects, and maybe when it comes time to mount this to a vehicle, work will progress on it. But in my head, the challenge was met, and it works.. sorta. and theres more stuff I wanna work on! So, so be it for this!

Battery switchout and servo switched lights

After finding that the little R44 batteries were dying already (not too suprising), I went to get replacements, and found another problem with using those types of batteries: they were $4.99 EACH! If they were going to go dead after a few days of occasional use, and that much, well then; its time for a Plan B

So I found this little AAA battery pack at radioshack, and thought I could make it work. I was a little over-big, but luckilly it was also over-roomy inside, so I dremeled away the pack to the barest of essentials, and now have a pack that will fit nicely in the empty left side of the rear cabin.


It would slide in (needs to be made removeable, so sliding in was one of the objectives) more or less like this. You can see its still a fraction of an inch to long, so I had to get really, fancy: and remove that overlarge gap where the spring are: I clipped the spring coils just enough to still be functional, then cut the entire black box in half, and shaved away the difference before gluing it back together. Long story short (too late!): it fits. Barely

When I was at Radio Shack getting the battery box, I saw something that caught my attention: a momentary pushbutton switch that was micro-mini... which means it may actually fit in this project (Its amusing to me how the tinyest micro mini switch still looks all huge and clunky at this scale.). The plan was, as shown in the red boxes, above: to mount the pushbutton in the vertical rectangle, and the last servo in the lower horizonal rectangle, set up on radio channel 1 (the one that doesnt 'spring load' back to center... perfect for this), so that when I move the throttle lever on my radion, the arm on the servo would swing up and depres the switch- thereby turning the lights on remotely.

So heres the layout (look at that huge clunky switch! sheesh!!), in its general position. The pushbutton is screwed onto a flat styrene strip (seen edge on), and will be glued to the stack of square tubes that were used to brace the turret servo (seen behind the tip of the needlenose)

And heres how the arm will actuate the switch. I will trim the white bar so it will be a more deadon-strike. Se seat on the right side of the cabin has been markes up for cutting away the lower portion. I need the seatcushion to hold the servo battery up in place, but ned the lower area for the servo to fit and line up (not apparent in this pic)

All in all this swtichout to a beefy twin AAA setup will give me more options: I can tie more lights to the terminal block, and even add 1.5v leds with a separate wiretap at the end of just one battery (I believe that will work)

360 servo mod

Before getting started on the turret mechanism, I dusted off the modified servo and gave it a test-run. Uh-oh! it was broken! One of the solder points inside broke loose, so I had to go back in and fix it. Perfect time to show how to modify a servo to move 360 degrees, eh?

OK, so a little walkthrough: The potentiometer (black circle far right) is getting disconnected, but first I made note of where the wires went. In this pot, the yellow wire was the 'center', or 'neutral' wire, and was the common point between the resistances both clockwise (red) and counterclockwise (green).. Representing 'Zero'. Servoes match the radio transmitters' thumstick by trying to constantly 'zero out' with the pot reading from that transmitter channel.

This little explanation is important for really only one reason: you need to know which solder point on the circuit board is the 'common'. In this particular servo: the common (yellow) wire went to the point of the <

Heres a better view of the circuit board, and how the resistors were situated. This was a particularly roomy servo, yet was small- making it perfect for this sort of modification. There was room to cram the pots wires back in the cavity, and STILL have room for the resistors. Side note: I cant remove the pot from the servo, since its shaft, which is geared into the control arm gear, also holds another gear in place on its shaft, so it needed to stay.

The resistors are obviously the same rating, as the stripes match, but the important stripe for this application is the far right one: its gold (cant really tell in this pic, but it is). This is the Tolerance stripe, meaning that this resistor is within 5% of its designated rating. This is better than normal, which is 10%. All resistors have this 'slop', and I went through several with an ohmmeter to find two that were as close as possible. (because this balanced Resistor-bridge is what represents 'zero', the same as the pot in center position, and it aint zero if they are lopsided!) But thats all thats needed to modify a servo to spin coninuously one way or the other on command.

I guess I should explain WHY it works, since I went though the trouble of showing HOW:

The pot in the servo is linked to the poition of the servo control arm. as the Arm swings around it turns the pot. The servo is set up to stop when the pot reads 'Zero'. If the pot finds itself lessthan [<] 'Zero', its setup to drin one direction intil the pot reaches 'Zero'. same way the other direction.

Now, 'Zero' is in quotes, because its actually not Zero Zero, but what the radio transmitter channel is commanding, and its command varies depending on how far you move the thumbstick on your transmitter one way or the other. In this way, the servo matches the thumbsticks position pretty much instantaneously, checking probably thousands of times a second.

Thats all well and good on how the servo channel works, but how does adding the resistors make it work? Well, by cutting out that feedback number from the pot, and replacing it with a matched set of resistance, we are 'faking' that its always at 'Zero'. You would think that it would make the servo never move again, but thats not quite the case: The "am I [<] than Zero??" part of the microchip is still working, and listening to the radio channel. So when you move the thumbstick left, the microchip goes "OH! Im [<] from where I need to be! that means drive left.. not there yet? then keep going... keep going" and will continue spinning left until it believes it has finaly reaches Zero - which is actually when you released the thumstick to center. At that point the servo stops and stays there where it wound up.

Presto! a 360 Modified Servo! Hope I explained it clearly enough.

Back to the turret mechanism, now that I had a functional Servo again, I mounted it to the turret piece to give it a little test, and also to eyeball if I got he center hole right (looking for a wobble), and shot another little movie:

Looks good! Hehe Side note, hear the stereo in the background that suddenly goes quiet when the turret starts moving? Thats because my Futaba transmitter flooded out all other radio signals in the immediate area. And the stereo was receiving only "LEFT ON CHANNEL 4! LEFT DAMMIT!!!" to its antenna, and was unable to pick up any other signals... hehe thats what old CB-ers call a STOMMMMP! Even though my transmitter was on 72 mhz (khz?), it still flooded all weaker signals out of existance.

hmm maybe I should'nt hold it so close to my lap when filming...

Servoed Hammerhead: Windshield and Lighting

Next, I dug out the windshield as a side little project, since I was going to light it as well.

Its going to have an amber backlight, but needs a window that will let a glow out, yet not let anyone see the servo thats directly behind it.










Someone reccommeded the perfect sort of translucent material to use as a windshield: milk bottle plastic. Thats ust perfect, aint it?








So, with the batterypack made, I wired up the LEDs, and made a little terminal block (the white thing), to make its a clean and as organized as possible.




Next came the difficult problem of mounting the lights, and making a light trap to keep the light from bleeding out through all the panel gaps, and even through the plastic at the top of the wing. The solution I finally came up with was this Ballast putty I had. Its kindof like playdough, but is the consistency of warm cheesecake, never dries, and comes off clean. Its not very sticky, but makes for a good gap filler, and will be the perfect solution to themany problems I would normaly have placing, mounting, and aiming the leds just right.







The ballast putty is the whie stuff, and I plced two globs of it in the area where the headlights would be.

Then I just squished the belly plate into place, and let the putty shift and ooze.. wherever. The great thing about this stuff is:





The belly plate pulled away clean, leaving me two perfect molds that filled all the areas where the light may peek out. The bumps visible match the pits on the bellyplate, showimg me where the light channel actually ends (it was very difficult to position/line up everything before: as the placement was completely out of sight as the pieces were put in place. The putty mold made it eas for the next part



I had to aim and place the bulbs of the LEDs just right. Not only did they have to point directly out the slits (focused directional beam), but also needed to be tilted slightly 'ground-ward' to make the light beams of the headlights perfect. The putty made it relatively simple. I just smashed them in place, letting the putty shift away... then I squished it back into the area, so that when I pressed the bellyplate in place one more, everything was filled in and final.



Then I dug out all the putty that was in the way of the beams of light. Presto! Now the bulbs are in precisely the perfect position and angle... something that would have been very very difficult to arrange any other way. The putty that was removed was combined and placed centerline, to solve another difficult problem: the cockpit light, for the windshield



The trick of the windshield light is that the bulb has to be indirectly lighting the area, and out of line of sight of the window. This simulates backighting from an illuminated cockpit control panel.. or something like that. Dim, yet definately lit is the objective. The putty made it simple to place where you see it, where otherwise it would have been tricky, with all the curved angles and such.

Next came routing the wires, and preparing the terminal block for connection. I used the channel trips of styrene to make a couple of wire trays to pin the wires in place, out of the way. Looks nice, huh? Can you tell that I'm an electrician by trade by looking at that?

Here the wiring is made permanent by soldering, and the servo system is put back in place. You may notice that the wires for the amber LED was not permanently connected. This was because the amber LED seems to be a lower resistance than the blue/whites, so that when they are all wired up in parallel, the power took the path of least resistance, leaving the white LEDs dead. Good thing I tested everything before making it permanent.

Isnt it neat how all those little gizmos are crammed into the nose area? I plan on leaving everything in the top half of the tank, so I can pop the bellyplate off to show off all the goodies inside.

Heres a reality check, on just how tiny all this stuff is, so: a Quarter. No thats not a gimmick giant sized quarter. Isnt that shocking?

Now that its all complete (except for the windshield itself) in this front section, its time for another movie, dontcha think?

And there, Whew! All caught up! From now on further updates will be about current events.