zaibatsu
March 6th, 2003, 03:58 PM
SafetyLast
Frequent Poster
Posts: 232
From: the cretaceous period
Registered: OCT 2000
posted January 11, 2001 08:39 PM
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Ok we have all heard about how you can make explosive arrows by filling a hollow arrow up with flash powder and using epoxy to secure a shotshell primer to the front of the arrow where the arrow head
(if thats what its called) would normally go and super glueing a bb to the shotshell primer so that it sets off the primer on impact, but would it be possible to use the same principle on a rocket
(estes c size rocket with Kraft paper tube attached which holds 1 oz. of AP, primer is secured by epoxying it to an end plug)
I need to know if the AP would detonate just by speeding up so fast and if the primer would be set off on impact of a hard target.
the launcher will be a 3 foot length of 3/4" PVC pipe with an electric ignition system and an end cap on one end.
Haggas had something on his site about an impact detonated cratermaker rocket, but I don't know what happened to him or his site
[This message has been edited by SafetyLast (edited January 11, 2001).]
ALENGOSVIG1
Moderator
Posts: 766
From: Vancouver, Canada
Registered: NOV 2000
posted January 11, 2001 09:00 PM
--------------------------------------------------------------------------------
well..i think the ap would just go off on impact. And in estes engines the ejection charge would set the ap off prematurely if the rocket was designed to fall to its target. Hehehe..ive had some fun with these engines.. we and muffscres digits tried to make a rocket from scratch...we made our nose come with a blob of hot glue tipped upside down..it was actually paradolic at the end...when we shot it off....it went completely crazy and came a few fwwet from hitting m,e in the head. Fortunately, it zoomed past my head with no injuries...but the rocket proceed to speed in the direction of a tree..when it hit it ripped a big branch off and kept going crazy...it was like a bottle rocket with no stick...also called a wild willie and a "fag finder"..im not gonna try that again
[This message has been edited by ALENGOSVIG1 (edited January 11, 2001).]
Energy84
Frequent Poster
Posts: 82
From: Earth
Registered: OCT 2000
posted January 11, 2001 10:07 PM
--------------------------------------------------------------------------------
Depending on the weight of your rocket, the AP could be set off on ignition. If the rocket is really light, it will accelerate very quickly and possibly prematurely detonate the AP. Also, if the AP is too close to the motor, it could go off because of the heat generated. Personally though, if I wanted to make an impact rocket, I would use the D11-0 estes rocket motor. It has more power than a C6-x and doesn't have an ejection charge. These motors are usually used to launch R/C sail, which don't need an ejection charge and are very powerful. I have built a rocket however that is about 4 feet tall. All I had for motors at the time were C class estes so I used a C5-6. The rocket was a bitch to stabilize but in the end, I had about eight 1/4" ball bearings in front and huge 8 inch fins in the back. She flew, and the beauty of it was that it had a really slow takeoff velocity. It oly flew to about 200 feet but I bet it would be stable enough and powerful enough to lift a really big load of AP. Heheh, lots more too if I took out the ball bearing weights!
------------------
why oh why didn't I take the blue pill?
CragHack
Frequent Poster
Posts: 606
From:
Registered: DEC 2000
posted January 11, 2001 10:07 PM
--------------------------------------------------------------------------------
actually to make sure the parachute charge does not set off the AP, you can easily just put a metal plug between the ejection charge and the AP, and make a few slits just below the plug (between the plug and the engine) to vent the gasses. this would work real well. i say to use metal because the ejection charge will be to quick to heat this up and set off the AP. use a light metal though, like a 1 inch thick Al plug.
------------------
...Æ
Energy84
Frequent Poster
Posts: 82
From: Earth
Registered: OCT 2000
posted January 11, 2001 10:10 PM
--------------------------------------------------------------------------------
Actually, instead of holes, most hobbyists just fit the motor into the rocket just a bit loose. That way, you could get away with a thin cardboard (less weight) plug. Best part is, with less weight in the back (motor is ejected out the back) the more stable your rocket will fly!
------------------
why oh why didn't I take the blue pill?
SafetyLast
Frequent Poster
Posts: 232
From: the cretaceous period
Registered: OCT 2000
posted January 12, 2001 01:42 PM
--------------------------------------------------------------------------------
I removed the clay, the the ejection charge, and the delay so now all there is is 4 seconds of thrust. I'm going to try one of these rockets on a stick before I shoot one out of my launcher just to see if the AP prematurely detonates or not (it might, seeing as there are more G forces acting on a rocket travelling vertically than one travelling horizontally) the charge is around an ounce of AP and I had the idea of using fishing line tied to a target and to a tree and half of a straw attached to the rocket so that the rocket travels on the fishing line.
Im not entirely sure that the AP would detonate if it were to hit a target it might not be hard enough of an impact
Dracul
Frequent Poster
Posts: 73
From: Melbourne, Australia
Registered: SEP 2000
posted January 13, 2001 02:01 AM
--------------------------------------------------------------------------------
I made an impact rocket out of AP putty that was 2 halves with a nail going down the center and a toy cap at the end of the nail inside the warhead and the 2 halves joined togeter around the nail and cap. The warhead was 14g and i used an A10 engine with the ejection charge end filled in with epoxy. I used my timer set for 5 min to launch it because I didnt want to be anywhere near it. It launched at about an angle of 30° from the ground and went about 150m. Didn't need to land on anything hard either, just dirt. I have the sound recorded and some plans i drew up for it if anyone wants them.
[This message has been edited by Dracul (edited January 13, 2001).]
Energy84
Frequent Poster
Posts: 82
From: Earth
Registered: OCT 2000
posted January 13, 2001 11:28 AM
--------------------------------------------------------------------------------
SafetyLast, If you want the rocket to be moderately safe, launch it vertically so that it has more G's on it. Then, if the AP doesn't go off, you'll know almost forsure that it won't go off horizontally. Besides, it's only about 1 G extra so who cares, it's probably going through about 10-20 G's already. I once put a cricket inside of a little rocket (1/2A motor) and the little bastard was squashed to about 1/4 of his original size. And also, before you launch it, make SURE that it's stable. Go find some model rocketry pages on the 'net somewhere and find out how to test the stability of your rocket. It's not that hard. Once you know it's stable, then you can be sure that it'll fly straight. Oh, and don't worry about a detonator for the AP. These suckers fly at around 500 km/h so the impact should be more than enough to set it off.
------------------
why oh why didn't I take the blue pill?
SafetyLast
Frequent Poster
Posts: 232
From: the cretaceous period
Registered: OCT 2000
posted January 13, 2001 03:25 PM
--------------------------------------------------------------------------------
yeah thats what I was talking about earlier, I'm going to test it vertically first. I have a couple of books on rocketry and I know how to keep the rockets center of gravity proportioned by taping a string to the rocket and swinging it around in a circle if the rocket tilts then it's weight is not proportionate and it will not fly straight
I think that if the AP were to be unwashed that it would most likely detonate once the rocket was to gain momentum after ignition
kingspaz
Frequent Poster
Posts: 346
From: UK
Registered: SEP 2000
posted January 13, 2001 04:21 PM
--------------------------------------------------------------------------------
well if i was gonna make an impact sensitive rocket i would make some sort of push button thing.
i mean like a 4mm brass tube with a piece of circular metal in it (nice tight fit) which could slide back and forth.
i'd block one end of the tube in with solder then fill the tube half way with hmtd.
then i would insert the metal and attach it somehow to the end of a rocket.
the idea is that as tthe metal is pushed in fast as the rocket hits its target then the hmtd gets compressed rapidly setting it off.
i dunno if it would work but its just a thought.
kingspaz
Frequent Poster
Posts: 346
From: UK
Registered: SEP 2000
posted January 27, 2001 04:50 PM
--------------------------------------------------------------------------------
does anyone think my idea will work?
SafetyLast
Frequent Poster
Posts: 232
From: the cretaceous period
Registered: OCT 2000
posted January 30, 2001 06:40 PM
--------------------------------------------------------------------------------
it would work, but it wouldn't be as simple as my idea
(putting a shotgun shell primer with a BB attached onto the front of the rocket and firing it at something like a car door) you could also use a cap gun cap instead of a shotgun shell primer.
you might have problems with the rod not compressing the HMTD enough.
If you were going to make a very large rocket you could use a normally open pushbutton switch wired to a 9v battery and a igniter or a detonator attached.
the pushbutton switch would have to be placed on the tip of the nose cone and there would have to be no chance of the rocket hitting the target slanted.
the pushbutton switch could not be one that easily gets pushed in (it would have to be one of those push on push off switches)
as to keep the charge from detonating accidently like if the rocket was handled roughly before launch.
(a toggle would also prevent this)
the rocket in this case would have to be very large, like 12'length x 1'width so as not to disturb the balance too much.
Pyrotek sells Altimeter switches in there magazine (near the back) that can be used with my large rocket idea. The kits are $35 i think. these can be set to eject a chute at apogee and there are other settings for times that it ejects the chute also.
They are about the size of a matchbox and are powered by a 9v battery.
[This message has been edited by SafetyLast (edited January 30, 2001).]
Frequent Poster
Posts: 232
From: the cretaceous period
Registered: OCT 2000
posted January 11, 2001 08:39 PM
--------------------------------------------------------------------------------
Ok we have all heard about how you can make explosive arrows by filling a hollow arrow up with flash powder and using epoxy to secure a shotshell primer to the front of the arrow where the arrow head
(if thats what its called) would normally go and super glueing a bb to the shotshell primer so that it sets off the primer on impact, but would it be possible to use the same principle on a rocket
(estes c size rocket with Kraft paper tube attached which holds 1 oz. of AP, primer is secured by epoxying it to an end plug)
I need to know if the AP would detonate just by speeding up so fast and if the primer would be set off on impact of a hard target.
the launcher will be a 3 foot length of 3/4" PVC pipe with an electric ignition system and an end cap on one end.
Haggas had something on his site about an impact detonated cratermaker rocket, but I don't know what happened to him or his site
[This message has been edited by SafetyLast (edited January 11, 2001).]
ALENGOSVIG1
Moderator
Posts: 766
From: Vancouver, Canada
Registered: NOV 2000
posted January 11, 2001 09:00 PM
--------------------------------------------------------------------------------
well..i think the ap would just go off on impact. And in estes engines the ejection charge would set the ap off prematurely if the rocket was designed to fall to its target. Hehehe..ive had some fun with these engines.. we and muffscres digits tried to make a rocket from scratch...we made our nose come with a blob of hot glue tipped upside down..it was actually paradolic at the end...when we shot it off....it went completely crazy and came a few fwwet from hitting m,e in the head. Fortunately, it zoomed past my head with no injuries...but the rocket proceed to speed in the direction of a tree..when it hit it ripped a big branch off and kept going crazy...it was like a bottle rocket with no stick...also called a wild willie and a "fag finder"..im not gonna try that again
[This message has been edited by ALENGOSVIG1 (edited January 11, 2001).]
Energy84
Frequent Poster
Posts: 82
From: Earth
Registered: OCT 2000
posted January 11, 2001 10:07 PM
--------------------------------------------------------------------------------
Depending on the weight of your rocket, the AP could be set off on ignition. If the rocket is really light, it will accelerate very quickly and possibly prematurely detonate the AP. Also, if the AP is too close to the motor, it could go off because of the heat generated. Personally though, if I wanted to make an impact rocket, I would use the D11-0 estes rocket motor. It has more power than a C6-x and doesn't have an ejection charge. These motors are usually used to launch R/C sail, which don't need an ejection charge and are very powerful. I have built a rocket however that is about 4 feet tall. All I had for motors at the time were C class estes so I used a C5-6. The rocket was a bitch to stabilize but in the end, I had about eight 1/4" ball bearings in front and huge 8 inch fins in the back. She flew, and the beauty of it was that it had a really slow takeoff velocity. It oly flew to about 200 feet but I bet it would be stable enough and powerful enough to lift a really big load of AP. Heheh, lots more too if I took out the ball bearing weights!
------------------
why oh why didn't I take the blue pill?
CragHack
Frequent Poster
Posts: 606
From:
Registered: DEC 2000
posted January 11, 2001 10:07 PM
--------------------------------------------------------------------------------
actually to make sure the parachute charge does not set off the AP, you can easily just put a metal plug between the ejection charge and the AP, and make a few slits just below the plug (between the plug and the engine) to vent the gasses. this would work real well. i say to use metal because the ejection charge will be to quick to heat this up and set off the AP. use a light metal though, like a 1 inch thick Al plug.
------------------
...Æ
Energy84
Frequent Poster
Posts: 82
From: Earth
Registered: OCT 2000
posted January 11, 2001 10:10 PM
--------------------------------------------------------------------------------
Actually, instead of holes, most hobbyists just fit the motor into the rocket just a bit loose. That way, you could get away with a thin cardboard (less weight) plug. Best part is, with less weight in the back (motor is ejected out the back) the more stable your rocket will fly!
------------------
why oh why didn't I take the blue pill?
SafetyLast
Frequent Poster
Posts: 232
From: the cretaceous period
Registered: OCT 2000
posted January 12, 2001 01:42 PM
--------------------------------------------------------------------------------
I removed the clay, the the ejection charge, and the delay so now all there is is 4 seconds of thrust. I'm going to try one of these rockets on a stick before I shoot one out of my launcher just to see if the AP prematurely detonates or not (it might, seeing as there are more G forces acting on a rocket travelling vertically than one travelling horizontally) the charge is around an ounce of AP and I had the idea of using fishing line tied to a target and to a tree and half of a straw attached to the rocket so that the rocket travels on the fishing line.
Im not entirely sure that the AP would detonate if it were to hit a target it might not be hard enough of an impact
Dracul
Frequent Poster
Posts: 73
From: Melbourne, Australia
Registered: SEP 2000
posted January 13, 2001 02:01 AM
--------------------------------------------------------------------------------
I made an impact rocket out of AP putty that was 2 halves with a nail going down the center and a toy cap at the end of the nail inside the warhead and the 2 halves joined togeter around the nail and cap. The warhead was 14g and i used an A10 engine with the ejection charge end filled in with epoxy. I used my timer set for 5 min to launch it because I didnt want to be anywhere near it. It launched at about an angle of 30° from the ground and went about 150m. Didn't need to land on anything hard either, just dirt. I have the sound recorded and some plans i drew up for it if anyone wants them.
[This message has been edited by Dracul (edited January 13, 2001).]
Energy84
Frequent Poster
Posts: 82
From: Earth
Registered: OCT 2000
posted January 13, 2001 11:28 AM
--------------------------------------------------------------------------------
SafetyLast, If you want the rocket to be moderately safe, launch it vertically so that it has more G's on it. Then, if the AP doesn't go off, you'll know almost forsure that it won't go off horizontally. Besides, it's only about 1 G extra so who cares, it's probably going through about 10-20 G's already. I once put a cricket inside of a little rocket (1/2A motor) and the little bastard was squashed to about 1/4 of his original size. And also, before you launch it, make SURE that it's stable. Go find some model rocketry pages on the 'net somewhere and find out how to test the stability of your rocket. It's not that hard. Once you know it's stable, then you can be sure that it'll fly straight. Oh, and don't worry about a detonator for the AP. These suckers fly at around 500 km/h so the impact should be more than enough to set it off.
------------------
why oh why didn't I take the blue pill?
SafetyLast
Frequent Poster
Posts: 232
From: the cretaceous period
Registered: OCT 2000
posted January 13, 2001 03:25 PM
--------------------------------------------------------------------------------
yeah thats what I was talking about earlier, I'm going to test it vertically first. I have a couple of books on rocketry and I know how to keep the rockets center of gravity proportioned by taping a string to the rocket and swinging it around in a circle if the rocket tilts then it's weight is not proportionate and it will not fly straight
I think that if the AP were to be unwashed that it would most likely detonate once the rocket was to gain momentum after ignition
kingspaz
Frequent Poster
Posts: 346
From: UK
Registered: SEP 2000
posted January 13, 2001 04:21 PM
--------------------------------------------------------------------------------
well if i was gonna make an impact sensitive rocket i would make some sort of push button thing.
i mean like a 4mm brass tube with a piece of circular metal in it (nice tight fit) which could slide back and forth.
i'd block one end of the tube in with solder then fill the tube half way with hmtd.
then i would insert the metal and attach it somehow to the end of a rocket.
the idea is that as tthe metal is pushed in fast as the rocket hits its target then the hmtd gets compressed rapidly setting it off.
i dunno if it would work but its just a thought.
kingspaz
Frequent Poster
Posts: 346
From: UK
Registered: SEP 2000
posted January 27, 2001 04:50 PM
--------------------------------------------------------------------------------
does anyone think my idea will work?
SafetyLast
Frequent Poster
Posts: 232
From: the cretaceous period
Registered: OCT 2000
posted January 30, 2001 06:40 PM
--------------------------------------------------------------------------------
it would work, but it wouldn't be as simple as my idea
(putting a shotgun shell primer with a BB attached onto the front of the rocket and firing it at something like a car door) you could also use a cap gun cap instead of a shotgun shell primer.
you might have problems with the rod not compressing the HMTD enough.
If you were going to make a very large rocket you could use a normally open pushbutton switch wired to a 9v battery and a igniter or a detonator attached.
the pushbutton switch would have to be placed on the tip of the nose cone and there would have to be no chance of the rocket hitting the target slanted.
the pushbutton switch could not be one that easily gets pushed in (it would have to be one of those push on push off switches)
as to keep the charge from detonating accidently like if the rocket was handled roughly before launch.
(a toggle would also prevent this)
the rocket in this case would have to be very large, like 12'length x 1'width so as not to disturb the balance too much.
Pyrotek sells Altimeter switches in there magazine (near the back) that can be used with my large rocket idea. The kits are $35 i think. these can be set to eject a chute at apogee and there are other settings for times that it ejects the chute also.
They are about the size of a matchbox and are powered by a 9v battery.
[This message has been edited by SafetyLast (edited January 30, 2001).]