Gauss Rifle, Take II -- Part 1

Remember This Shit? Well, I fucked it up. Well, more like 'I tried to use a mechanical switch as a firing mechanism and accidentally spot-welded everything and I didn't want to take it apart so it's collecting dust somewhere' . Anyways, Let's make something with the EXACT SAME circuitry! woo! Oh god this is a bad idea.....

K. Last time, I was a bit too ambitious. A bit too ahead of myself. This time, we'll just make it a single-stage coilgun. One coil. One firing circuit. Less capacitors. Instead, Let's make it a semi-automatic coilgun. Yeah. Compensation for the lack of stages. I guess it's going to be like a pistol? With one coil, I guess the barrel won't have to be long.

The Magazine -- Thinking about Stuff

So, if this was going to be a semi-auto, it had to have a reloading system. At first, I thought of  using the mechanisms of actual firearms. Two problems with this one. 

First, some mechanisms used the blowback from the bullet to eject the casing and pull the next bullet into the chamber. These mechanisms, although very cool, won't suit my design because a).I can't make parts that precise, and b).coilgun projectiles don't have blowback. They are just metal pieces.

Second, I was going to use nails as projectiles. NAILS. nails, unlike bullets, have HEADS. (Wait, is there a part of a bullet called a head?) Nail heads are thicker than the shaft, and they are at the back of the whole nail. So, I couldn't just copy a real gun and call it a day. 

Spent some time doing useless stuff.

So, I had to either modify a existing mechanism, or come up with a entirely new one. I chose the first option, obviously.

After countless hours of googling,drawing, simulating, lofi hip hop radio - beats to relax/study to, and vocaloid songs, I came up with a revolver-like design. I also came up with a helical style magazine that could hold more than 6 rounds, but since the gun was going to be a pistol, and the fabrication of a large helical mag was going to be trouble, I just went with the 6-shot cylinder.

The MagazineCylinder -- Design & Operation

The cylinder is a 6-shot cylinder. It holds 6 nails.(Duh) Since it shot nails, I couldn't reload it from the back, and had to reload it from the front. And since I didn't have a nifty way of removing the cylinder without taking everything apart, this gun would be a muzzle loader. Yes, you read that right, this is a muzzle loaded revolver pistol. However, it meant that I could stick stuff on the back of the cylinder without worrying much about reloading. The revolver needed "accurate" positioning of the cylinder and the barrel. They need to line up in order for the nails to go pew pew(or flop). The cylinder also needs to rotate. So, I stuck a geneva mechanism on the back of the cylinder. What is a geneva mechanism you ask? It converts a constant rotary motion into a non-continuous rotary motion. and it's COOL. google it. you won't regret it. there is an animation gif on wikipedia. it's one of those satisfying machines that you could watch for days. 

The front and back of the cylinder. A shaft and a 604 bearing goes in the middle. Nails go in the 6 holes. On the back, there is a geneva driven.

 

And here is the drive. The small hole on the right is where a long m3 bolt(like 20mm? IDK) goes in. The centre hole is where a screw goes in. The screw holds the drive to the motor. The motor is a generic DC motor in a servo casing.(Or a 360 continuous rotation servo). The servo-drive setup sits in a mount that looks like 

This, and the whole thing bolts on to a mainframe that looks like 

This, so the whole final assembly looks like

This. Once again, the whole thing is going to be 3D-Printed.

The Cylinder and Mainframe

 

AAAAAAWWWWWW YYYYIISSSSSSSSS!!!!

I had to figure out the spacing and stuff so everything would spin well. I did design in clearances and tolerances, but since the printer itself has many problems, I still needed lots of sanding and washers. 

Here's a video of it spinnin'

Here's a video of it working as a nail holding contraption.

IT WORKS!!!! FUCK YEAH! AAAAWWWWW YISSSSSSSSSSSS!!!!

It took a lot of finishing to get it working smoothly, but it was totally worth it.

For some reason, if you want to try and recreate this, here's the link. Instructions are there on the page.

https://www.thingiverse.com/thing:3332687

Fallout 4 inspired, Working Gauss Rifle (coilgun) -- Part 3

The Capacitors, Part II (A.K.A. The unhealthy charging circuit)

I have 3 capacitor banks. Each bank has 6 capacitors. All of them connected in parallel. I used a XL6009 DC-DC boost converter that ramps up 5 volts to 55 volts. (Output is adjustable.) Mine was laying around so I just used it. There are probably WAY safer ways to charge the caps, but I don't give a shit. This thing's probably gonna end up on a shelf anyways. 

Anyway, I got a 1K Ohm resistor, and connected it parallel to the caps and the output of the boost converter.

Screw Everything.

yep. I'll also probably add a relay or transistor or something to control the charge via arduino.

Aesthetic Parts - "Capacitor Boosting Coils"

The In-Game Gauss Rifle (With the "Capacitor boosting coil" mod/upgrade)  has 4 coils on the side.I have no idea how these would boost the coils. My best guess is that they act as air coil inductors for a "booster" circuit. Anyways, My coils are going to be there for just looks. I designed a coil-spool-holder-thingy in Fusion360, and 3D printed it. 

The 4 U shaped pieces  are printed separately and slid into the main holder.

Half-Assed Assembly

After the parts were done printing, (I used grey PLA from an unknown cheap brand) I got excited and didn't take any photos. So here's a photo of the thing now. Starting to take shape. Awww Yesss

Fallout 4 inspired, Working Gauss Rifle (coilgun) -- Part 2

The Arduino Case

Now, for the grip and arduino case. Going to 3D print this too. I drew that in Fusion 360. the thinner box glues to the previously made capacitor/baseplate mix. An Arduino sits in the other box, and the box slides in the top thingamajig. I'll probably have another locking mechanism, but for now, i'll just print that.

Box on the left is the "lid". Arduino sits in the right box.

Hopefully nothing goes wrong. 

The Capacitors

I had some 25v, 6800uF capacitors left from a previous project(And by "some", i mean a shit ton.), and i originally was going to use them. But nah. I ordered some 63v, 2200uF capacitors. (I needed them for a school project anyways).  

The energy stored in a capacitor is calculated by this formula:

W = 1/2 C V^2  

W = Energy stored (In Joules/J)

C = Capacitance (In Farads/F)

V = Voltage (In Volts/V)

Using this formula, we can calculate that each capacitor would be able to hold up to about 4.3 Joules. But, I am a little pussy, and I'm not going to charge the capacitors up to their max ratings of 63 volts.  I'll probably charge them up to like, I dunno. 50~55? I guess. 55v. That drops the energy stored into about 3.3 Joules. Whatever. I have 18 of those.

The Coils

I wrapped the coils around some random pieces of tubing I had lying around. I used 1mm thick enamel-coated copper wire.(Also known as magnet wire or speaker wire) I wrapped each coil about 200 times. By hand. 3 of them. What am I doing with my life.

200 Times each. What am I doing with my life.

Light gate sensors go in the holes.The white material is what I call "Macgyverglass' ,which is a cheap, poor man's alternative for fiberglass made out of toilet paper and superglue. It's there to reinforce the tubing.

Fallout 4 inspired, Working Gauss Rifle (coilgun) -- Part 1

Yes, I know that the game is old, but I like it. I also don't give a shit. So, I'm going to build a coilgun that does it's best to look like the thing from the game.

The Gauss Rifle from Fallout 4 (The Art of Fallout4)

General Ideas and Stuff

Looking at the gun, it has 6 capacitors on each side(With the full capacitors mod), and has 5~6 coils. I'm guessing that it's a 6-stage coilgun, with 2 capacitors per coil. I don't have the skills, time, money, or patience to make a 6-stage coilgun. so I'm just going to make it a 3-stage coilgun.

Some basic plans I drew in MS Paint
because my laptop(With Photoshop) broke and i was too lazy to install photoshop on my desktop

The capacitors go on the side, just like in the game.
I'll probably control the firing with MOSFETs, and control those MOSFETs with an Arduino. those will be shoved in the foregrip of the gun, along with extra capacitors.
The capacitor charging circuits will be in the "box-thing with the nixie tube displays". I'll probably have a 7-segment display to show stuff instead of the nixie tubes in-game.
The batteries will be held in the cylindrical-tube thing along with the charger.
About the magazine... I have no idea. The gun will probably end up as a muzzle-loader so...

Designing the Capacitor and Coil Holders

I drew the thing up in Fusion 360 to 3D print. Since I have a small buildplate, I'll have to cut them up. I'll print 12 capacitor holders and 12 base plates. The capacitor holders have holes for the leads, and the baseplate has grooves for the wires. In the in-game model, each capacitor has 2 holder-ring-thingies. Fuck that. I'm Just gonna have one holder-ring thingy. Because I hate support material. I HATE grinding and sanding the burrs and leftover support materials. 

Capacitor holder. capacitor goes in the round thingy. Leads go through the holes.

Baseplate. Glue this under the capacitor holder. Wires go in the trenches

Preview of the Thingies assembled. The coil assembly goes in the big groove in the middle.

4:3 Screen. Deal with it.
Now just gotta 3D print that shit. And wrap coils while waiting.