User Panel
|
Printed M202 Flash Rocket Launcher Update |
|
|
|
|
Originally Posted By JonathanwFL: New barrels look way better and more original. Hoping to test fire a couple rounds this weekend https://i.imgur.com/90ED1Ma.jpg https://i.imgur.com/DuYYLFq.jpg https://i.imgur.com/kJ45pqJ.jpg https://i.imgur.com/EdDJJPL.jpg View Quote |
|
"the science" /duh si-ens/ noun: progressive postmodern religious dogma not based in tested hypothesis or facts used to advance an authoritative political ideology
|
|
Can’t wait to buy this book. |
|
|
What is the plan to avoid getting a face full of rocket exhaust?
|
|
|
Sneak Peek - Firing the M202 Flash |
|
|
Nice, was it a weighted projectile?
|
|
|
|
Death to quislings.
|
"the science" /duh si-ens/ noun: progressive postmodern religious dogma not based in tested hypothesis or facts used to advance an authoritative political ideology
|
|
Initial Testing of The M202 Flash Rocket Launcher - More to come The stabilizing fins were remarkably intact post-firing. That's a lot of excellent testing data compressed into a short video! |
|
|
It looks cool, good job.
I've been watching the videos and giving it some thought. It looks like you may have some accuracy and stability issues (you can see the rocket wobble around as it exits, especially in the slowed down video. I have a theory on why: If I understand correctly, the real M72 LAW and M202 Flash completely burn the motor in the launch tube, leaving what I'll call a "residual" or tracer looking burn in the air. I also think this is why the shooter doesn't need to mask/goggle up or have a panzerschreck style shield on the launcher, and I suspect this is why the tubes telescope; to make it a little longer to contain the burning motor just a bit more before it burns out and exits. This lets the projectile exit the tube, unfold the fins, and fly like a shuttlecock (nose heavy with drag stabilization on the rear from the fins). In effect, it's getting thrown and flying unpowered. You're pushing the projectile the whole length of flight (or in the air at least). I think the original projectile and fin design is suited to unpowered flight, but probably becomes unstable when you put a motor on the back while it's in the air. Especially during the launch when it's burning, in the air, and the fins haven't completely unfolded. Unless I'm mistaken, all rockets using this projectile/fin arrangement are unpowered in air. You may be able to improve the accuracy and projectile stability by abandoning the effort to visually resemble an original projectile and go with a projectile designed for powered flight. It's been a while since I've used it, but I remember there were software tools for model rocketry/amateur rocketry design that would help you predict the stability of a rocket based on the motor, fuselage, and fin arrangement. You might want to look at that and go with a more conventional rocket design to match the longer burn motors you're using. Just my theory YMMV |
|
|
Originally Posted By mechanical: It looks cool, good job. I've been watching the videos and giving it some thought. It looks like you may have some accuracy and stability issues (you can see the rocket wobble around as it exits, especially in the slowed down video. I have a theory on why: If I understand correctly, the real M72 LAW and M202 Flash completely burn the motor in the launch tube, leaving what I'll call a "residual" or tracer looking burn in the air. I also think this is why the shooter doesn't need to mask/goggle up or have a panzerschreck style shield on the launcher, and I suspect this is why the tubes telescope; to make it a little longer to contain the burning motor just a bit more before it burns out and exits. This lets the projectile exit the tube, unfold the fins, and fly like a shuttlecock (nose heavy with drag stabilization on the rear from the fins). In effect, it's getting thrown and flying unpowered. You're pushing the projectile the whole length of flight (or in the air at least). I think the original projectile and fin design is suited to unpowered flight, but probably becomes unstable when you put a motor on the back while it's in the air. Especially during the launch when it's burning, in the air, and the fins haven't completely unfolded. Unless I'm mistaken, all rockets using this projectile/fin arrangement are unpowered in air. You may be able to improve the accuracy and projectile stability by abandoning the effort to visually resemble an original projectile and go with a projectile designed for powered flight. It's been a while since I've used it, but I remember there were software tools for model rocketry/amateur rocketry design that would help you predict the stability of a rocket based on the motor, fuselage, and fin arrangement. You might want to look at that and go with a more conventional rocket design to match the longer burn motors you're using. Just my theory YMMV View Quote IINM, the TOW missile gets kicked out by a recoilless charge, then lights its engine once clear of the operator and flies to the target. I believe it uses folding fins as well. It's a simple enough design the Iranians directly copied it, use it, & export it. |
|
Death to quislings.
|
Originally Posted By backbencher: IINM, the TOW missile gets kicked out by a recoilless charge, then lights its engine once clear of the operator and flies to the target. I believe it uses folding fins as well. It's a simple enough design the Iranians directly copied it, use it, & export it. View Quote |
|
"the science" /duh si-ens/ noun: progressive postmodern religious dogma not based in tested hypothesis or facts used to advance an authoritative political ideology
|
Originally Posted By backbencher: IINM, the TOW missile gets kicked out by a recoilless charge, then lights its engine once clear of the operator and flies to the target. I believe it uses folding fins as well. It's a simple enough design the Iranians directly copied it, use it, & export it. View Quote Yes, lots of missiles and rockets use folding fins. I may have explained that poorly, but I meant the wasp-waisted shuttlecock looking thing with relatively tiny, simple fins that fan out the back (looking sorta like a shuttlecock), reduced diameter midsection and rocket body, with a larger warhead stuck on the front. I don't think any of those are powered in flight with a rocket nozzle on the back end. The AT4, M72, M202 use that design. All burn in the tube, then the fins drag stabilize in the air. The TOW uses folding fins, but it's got front fins, rear fins, fins with meaningful surface area. The rocket nozzles are in the middle of the missile to allow for the wire dispenser in the rear, and it's guided, so a little wobble on exit won't hurt things too badly. The RPG-7 has a similar folding fin arrangement to the AT4/M72/M202, but the rocket nozzles are up in front of the fins, in the middle of the projectile, meaning the stability issues are different. I'm not sure on the exact sequence, but I think the RPG-7 does its recoilless launch, coasts while the fins unfold, then the rocket ignites. This would prevent it from having a period of no fins/partial fins while under power (an unstable arrangement). I'm not an aerodynamics guy, but my suspicion is that a more conventional rocket shape may be more stable when you're putting a nozzle on the back end and pushing it along while it's outside the launcher (ie, a tube, like most rockets/missiles that fly under power) I also suspect that eliminating the "under power, but totally unstabilized" state seen right when it leaves the tube would help. Either a soft launch allowing the fins to deploy before the primary motor lights, a faster/more effective fin arrangement, a more inherently stable rocket, I'm not sure, but there's probably a few ways to do it. |
|
|
Open Rocket
Main thing to watch is the relationship between center of gravity and center of pressure. Center of gravity needs to be a caliber or two in front of the center of pressure |
|
|
Originally Posted By scottr: Open Rocket Main thing to watch is the relationship between center of gravity and center of pressure. Center of gravity needs to be a caliber or two in front of the center of pressure View Quote Kerbal Space Program is a good place to learn various aerodynamic/CoG stability issues. |
|
Death to quislings.
|
The first two were unstable as I had not added the steel vanes that spin the rocket on the rear of the rocket , I think that initial upward wobble on the 3rd rocket was partially the warhead being slightly rear heavy until majority of the propellant had burnt up shifting the CG toward the front and leveling out the rocket. I think some added weight in the front should solve that issue. However after that , the rockets are flying extremely straight with the spin stabilization added
|
|
|
Did we do this already?
M202A1 66mm FLASH (Flame Assault Shoulder Weapon) Rocket Launcher |
|
Death to quislings.
|
YouTube also sent me this one, did you post it already, OP?
“Your Printed Rocket launcher is going to melt” |
|
Death to quislings.
|
Originally Posted By backbencher: YouTube also sent me this one, did you post it already, OP? https://www.youtube.com/watch?v=PieZwsOed3Y View Quote I don’t think it was posted here, that was more for social media when one of my videos went viral and that was the biggest comment |
|
|
m202 flash a1 |
|
Death to quislings.
|
We do these yet?
An Incendiary Rocket Launcher - The M202 FLASH Rare American Weapons of Vietnam - Explained |
|
Death to quislings.
|
Big test fire this weekend if weather holds, should have a ton of high speed footage and other cool related experiments
|
|
|
Sweet.
|
|
|
@JonathanwFL
If you don't stencil a butt on the side of your M202 I'll be mildly disappointed. Context for those who might be confused. |
|
|
LOL, Sucks that there was a setback.
|
|
|
Yeah we got some good early footage before things went down hill. I was saving the footage for a YouTube video until I can get more footage when we can get out and safely test the remaining rockets lol we got hit with some snow storms so hopefully in a week or two we can get to
Our testing locations |
|
|
We Built Arnold’s Rocket Launcher from Commando |
|
Death to quislings.
|
Firing The M202 Flash Rocket Launcher from Commando |
|
|
Amazing job! Can't wait to watch more videos
|
|
|
|
|
|
M202 Flash Rocket Launcher |
|
|
View Quote I don't know how I missed this! I am so very glad you're not just offering your books through Amazon now. I just bought a copy of each. |
|
|
|
Originally Posted By JonathanwFL: I appreciate the support! And it’s been great working with KommandoStore to slowly move away from Amazon View Quote View All Quotes View All Quotes Originally Posted By JonathanwFL: Originally Posted By Third_Rail: I don't know how I missed this! I am so very glad you're not just offering your books through Amazon now. I just bought a copy of each. I appreciate the support! And it’s been great working with KommandoStore to slowly move away from Amazon I am delighted to hear that they've been treating you right! The fact that your books were only available from Amazon kept me from buying them this whole time. I got close a few times - I've really wanted to support your work and have your texts in my library - but it is what it is. I'm glad I no longer have such temptation. |
|
|
Sign up for the ARFCOM weekly newsletter and be entered to win a free ARFCOM membership. One new winner* is announced every week!
You will receive an email every Friday morning featuring the latest chatter from the hottest topics, breaking news surrounding legislation, as well as exclusive deals only available to ARFCOM email subscribers.
AR15.COM is the world's largest firearm community and is a gathering place for firearm enthusiasts of all types.
From hunters and military members, to competition shooters and general firearm enthusiasts, we welcome anyone who values and respects the way of the firearm.
Subscribe to our monthly Newsletter to receive firearm news, product discounts from your favorite Industry Partners, and more.
Copyright © 1996-2024 AR15.COM LLC. All Rights Reserved.
Any use of this content without express written consent is prohibited.
AR15.Com reserves the right to overwrite or replace any affiliate, commercial, or monetizable links, posted by users, with our own.