Ok, so I have a plan to build a functioning bazooka with common hardware store and hobby components. Thoughts?

Ok, so I have a plan to build a functioning bazooka with common hardware store and hobby components. Thoughts?

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Unless you are confident enough to manufacture your own inertial/centrifugal locks that separate the detonator from the actual charge that shit has a huge chance of detonating inside the tube.
This is one of those things where if you have to ask, you're not ready.

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One inch diameter warhead?
What are you hoping to blow up? An ant-hill?

Mainly just make a loud noise and a puff of smoke, but i suppose you could cram some BBs in there for shrapnel and maybe take out a rabbit.
I was counting on the inertia of the rocket to keep the plunger back from the percussion cap until the motor's ejection charge forces it forwards.

that will not be stable...
it's gonna spin around in the air and possibly fly back at you. Don't do this unless you can actually do rocketry user. Just make a spud gun to do the job instead.

I ran the rocket through a simulator and it said it has a stability of 1.38

Was it open rocket? Either way, I can’t see a projectile with aerodynamic surfaces that far forward being particularly stable.

Yes, it was. I've launched forwards-fin rockets before and they worked fine, although that was launching them upwards instead of horizontally.

let me guess, you installed openrocket and you don't know what "1.38" actually means.
it's 1.38 cals, as in that is the distance apart the center of pressure is from the center of gravity based on the width of the body tube. This isn't exactly what you would call a direct measurement of stability, but it is an indicator towards it. A positive cal measurement means the center of pressure is behind the center of gravity, which is stable for upwards flight, but not horizontal. You would be better off using a program that simulates RC planes, as they follow a trajectory closer to what you are trying to do.

Ah, I didn't know the intricacies of the measurement. Thank you.

I mean, if you have some experience launching rockets, it’s worth a shot. Just don’t put explosives on it or fire it anywhere near your body.

You don't need two sets of fins.
You also don't need the fins to be protruding that much, or even need fins at all if you know anything about aerodynamics (CoM forward, CoP in the back). Ideally, you want the fins to be in line with the rest of the bore, so as to keep its cross-section as small as possible and as tight as possible in relation to the launcher.
I don't know why you didn't take a look at a real bazooka and base your design on that. Your design is just ASKING for trouble. If one of the fins so much as warp (or worse, break), it'll pretty much blow up in your face. Anything that launches out of a tube should be cylindrical, unless you're willing to go through the trouble of making fold-out winglets.

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no problem. I would still recommend making a spud gun instead tho. A simple sprinkler valve modified for pneumatic actuation will fire an explosive payload just as far as your rocket and will cost you much much less to shoot (and possibly even build). A combustion is even cheaper and can often get you faster velocity at the cost of higher variance between shot velocity (unless you make a fuel regulator).

you dont have a plan you have some scribbles on a piece of copier paper. read a book nigger

What is the point of the small fins on the back of the projectile then if it doesn't need to be stabilized?

I'm not him, but don't bazookas have a much faster burning propellant which produces faster velocities and therefore more airflow over the fins? Simple sugar rockets won't be stable with the fins being the same diameter as the head unless the body is very thin and very long.

you had to tell him

you had to tell him

god I hate summer.

Look, if he dies he can't post the video on Youtube later.

The warhead's shape is predetermined (and works best if the cone-linings are as free of obstruction as possible. The rocket motor is also shaped precisely (better long and thin than short and stout for various reasons). This gives it a the profile on one axis, but not the other. On easy solution is to also use the fins as tube stabilizers (hence why they're not just small nubs and have flat surfaces in contact with the tube).
Removing fins outright might not be good, but you definitely don't need them to be oversized as all fuck like in OP's 'plan.' Big-finned missiles are usually launched from rails, like the Russian Swatter/Fleyta or the Sagger/Malyutka. If you want to see good aerodynamic profiles, which can be scaled-up effectively, rifle grenades are also good examples.

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Is there any data on how the weight is distributed in rifle grenades?

Believe me, I've looked but there's no good data on this. Getting the total weight is rather staightforward but not exactly how the weight is distributed. The only 'reliable' data I've got is secondhand and about the French APAV40. The balance-point is about a two-thirds forward along the whole length, or maybe slightly less than that.

I've built rifle-grenades, and I usually try to put the CoM about that far forward. Works well for me.

why americans can't into design or manufacturing by themselfs?

Looks like a 5min sketch from a 10 year old retard. You really needed to write this down?

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I just graduated with a B.S. in aerospace engineering from UC Berkeley and my advise is don’t do it unless you want it to blow up in your face or on your neighbor or on your neighbor’s neighbor.

Lost-foam method casting with PLA?
How well does it work?

Not mine, but I think it was just a cavity, not lost-foam. The 2nd pic is 3d printed.

Didn't the IRA publish the BPs to some can cannon they had

It's still 'lost-foam' even if it doesn't use actual foam, kinda. Sure, I could have said evaporative-pattern casting instead but nobody uses that term colloquially. I checked, and the guy did use the PLA print as his positive in the casting.

Quite neat.

There used to be spring loaded rocket fin cans available from aerocon systems or something. They were from surplus tube launched naval flares. I owned two just for kicks but I ended up broke and hawked them on eBay. Now they're out of stock and I've never seen them anywhere else :(

>It's still 'lost-foam' even if it doesn't use actual foam, kinda.
the formal name is "lost wax" despite it not using actual wax, not "lost foam", you fucking invalid

have you considered looking somewhere other than totse for your ebin ""blueprints""?

>the formal name is "lost wax" despite it not using actual wax, not "lost foam", you fucking invalid
Lost wax and lost foam do not work on the same fucking principles. One of them is used to make negative, rigid-standing molds, and the other is used as the positive itself, which will be lost in the final process.

Investment casting and evaporative-pattern casting are not the same fucking thing, get stuffed.

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lost-anything casting is equivalent to lost-wax because either way you are using a positive that is replaced by molten metal (causing it to burn and/or evaporate away) to create a negative at the time of casting by burning/melting it away with the much hotter liquid metal (or whatever you're using that has a higher melting point than whatever you made the positive out of)
fag

Lost-wax is a process older than the Roman Empire.
Lost-foam was patented less than a hundred years ago.
Tots the same thing, surely.
>but they both use molds and metal and high temperatures so they're the same thing!
Also, no. The lost-wax method is only to create the mold itself. No wax is left when you're up to pouring. Lost-foam also requires you to cast in greensand. One technique lets you pour with cores, not the other. One method is more suited to low-temperature pours metals like copper, tin, aluminium, brass, while the other will let you cast anything without any risks of the mold cracking. One method lets you make hollow casts, not the other. Get double-stuffed.

>No wax is left when you're up to pouring.
modern backyard tinkerer lost wax procedures pour that shit right in there like madmen. it's the same shit. kys

No, they do not pour directly into the wax. I checked and sure enough all 'backyard thinkerers' do their wax-burnout like they should. You do not pour molten metal into a wax-filled ceramic mold because:
A. Wax actually burns and it will fucking blow into your face if you pour molten metal on top of it.
B. Ceramic molds do not breathe like greensand does.

Why the fuck are you arguing about something you've never done personally anyway? If only you had the decency of being right about it, it wouldn't be so fucking objectionable. In the first goddamn place, PLA isn't fucking wax so I don't know why you're arguing as if was lost-wax when it's not wax, nor is it cast using the lost-wax method. For the love of god, stop being dumb for once in your life.

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thinks I'm summer

I want to see his grease spot in my morning paper.
"man kills self with homemade bazooka"

not knowing how casting works

he's sand casting you retards

No shit, but that isn't the point of contention here.