First Succesful 2-Stage Rocket

[Blenderite]

Saturday I was able to test my staging mechanism and it worked brilliantly!!! The rocket had a 2-Litre spliced pair for the first stage and the second stage was a single 1-Litre bottle. The 2nd stage nozzle was about 1/8". I only put 80psi for the first launch. The whole rocket only weighed 220 grams. Based on this, the Clifford Simulator says that my 2nd stage went about 600'. I hope that this isn't out of possibility, but I am kinda of suspicious. Seems a bit too high for such a small rocket. Hopefully I am wrong!!! What do you all think?

-DogLover

[PTrockets]

Saturday I was able to test my staging mechanism and it worked brilliantly!!! The rocket had a 2-Litre spliced pair for the first stage and the second stage was a single 1-Litre bottle. The 2nd stage nozzle was about 1/8". I only put 80psi for the first launch. The whole rocket only weighed 220 grams. Based on this, the Clifford Simulator says that my 2nd stage went about 600'. I hope that this isn't out of possibility, but I am kinda of suspicious. Seems a bit too high for such a small rocket. Hopefully I am wrong!!! What do you all think?

-DogLover

Did you use the 'Air command water rockets' stage mechanism?
If you used: I think that both stages have to be equal. The second stage can't be small because it has enough weight to pu the system working!

PTrockets

[Blenderite]

I have tried Air Command's stager and didn't have success. This was just a piece of aquarium tubing with a one way valve (made from a old pen). The second stages cap had a hole that was slightly smaller than the OD of the tubing. The second stage slid onto that and was held in place by a ring fin that slid over the 1st stage. The pressure in the 1st stage kept the 2nd stage in place until the 1st stage lost its pressure. Then the 2nd stage was released. Fairly basic I may put up a diagram once I get some time.

-DogLover

[SaskAlex]

DogLover- sounds like a nice staging system. Nice and simple. I had thought about doing that in the past, but never got around to it. Kudos for making it work. Did you have a parachute system on the sustainer, or was it a ballistic rocket? If you are just going for altitude, it's difficult to make a two stage rocket that's worthwhile, but they sure are fun to make and launch.

[air.command]

I have tried Air Command's stager and didn't have success. This was just a piece of aquarium tubing with a one way valve (made from a old pen). The second stages cap had a hole that was slightly smaller than the OD of the tubing. The second stage slid onto that and was held in place by a ring fin that slid over the 1st stage. The pressure in the 1st stage kept the 2nd stage in place until the 1st stage lost its pressure. Then the 2nd stage was released. Fairly basic I may put up a diagram once I get some time.

-DogLover

Good work on the flight! Sounds like it went great. Definitely, the more simple you can make the stager the better, and it sounds about as simple as they get. By your description it is similar to what Anti-gravity Research use on their 2 stage kits. The 600 feet does sound a little high for 80psi, but it would be at the upper range of what to expect. My guess would be closer to 500 feet for actual altitude. You just need to put an altimeter on it and see.

- George

[Blenderite]

DogLover- sounds like a nice staging system. Nice and simple. I had thought about doing that in the past, but never got around to it. Kudos for making it work. Did you have a parachute system on the sustainer, or was it a ballistic rocket? If you are just going for altitude, it's difficult to make a two stage rocket that's worthwhile, but they sure are fun to make and launch.

It was a sinch to make. Here are a couple of pictures.

IMG_0089.JPG (2.9 MiB) Viewed 255 times

IMG_0086.JPG (2.37 MiB) Viewed 255 times

Good work on the flight! Sounds like it went great. Definitely, the more simple you can make the stager the better, and it sounds about as simple as they get. By your description it is similar to what Anti-gravity Research use on their 2 stage kits. The 600 feet does sound a little high for 80psi, but it would be at the upper range of what to expect. My guess would be closer to 500 feet for actual altitude. You just need to put an altimeter on it and see.

- George

If I am not mistaken I think that Anit Gravity didn't have a actual one way valve but was just a piece of tubing with one end sealed. Then I think they poked a pinhole in it to allow air into the second stage and yet the hole was too small to allow the water to leak back out. I was pretty sure that the simulator was a little on the high side. As far as the altimiter, I found this site that sells these altimeters and apparently Anti Gravity used one of them for their world record rocket. I was wondering if anyone had every used any of these altimeters and if so how well do they work? Here is the link to their price page: http://adeptrocketry.com/prices.htm Right now I am particularly looking at this one: http://adeptrocketry.com/ALTIM1cart.htm It seems to be the type that beeps out the altitude. I am thinking of getting this one if no one knows anything bad about the company or product. Thanks in advance!!!

-DogLover

[PTrockets]

DogLover- sounds like a nice staging system. Nice and simple. I had thought about doing that in the past, but never got around to it. Kudos for making it work. Did you have a parachute system on the sustainer, or was it a ballistic rocket? If you are just going for altitude, it's difficult to make a two stage rocket that's worthwhile, but they sure are fun to make and launch.

It was a sinch to make. Here are a couple of pictures.

IMG_0089.JPG

IMG_0086.JPG

Good work on the flight! Sounds like it went great. Definitely, the more simple you can make the stager the better, and it sounds about as simple as they get. By your description it is similar to what Anti-gravity Research use on their 2 stage kits. The 600 feet does sound a little high for 80psi, but it would be at the upper range of what to expect. My guess would be closer to 500 feet for actual altitude. You just need to put an altimeter on it and see.

- George

If I am not mistaken I think that Anit Gravity didn't have a actual one way valve but was just a piece of tubing with one end sealed. Then I think they poked a pinhole in it to allow air into the second stage and yet the hole was too small to allow the water to leak back out. I was pretty sure that the simulator was a little on the high side. As far as the altimiter, I found this site that sells these altimeters and apparently Anti Gravity used one of them for their world record rocket. I was wondering if anyone had every used any of these altimeters and if so how well do they work? Here is the link to their price page: http://adeptrocketry.com/prices.htm Right now I am particularly looking at this one: http://adeptrocketry.com/ALTIM1cart.htm It seems to be the type that beeps out the altitude. I am thinking of getting this one if no one knows anything bad about the company or product. Thanks in advance!!!

-DogLover

Your stage mechanism seems to be very good ... But I don't understand very well. Do you have any wire attached to the launcher our ground?
I also wanted to know if that altimeter that you are interested have quality. If you have news about the altimeter, contact me.

Ptrockets

[Blenderite]

There is no wire attached to the ground. The way it works is that the staging mechanism is screwed onto the 1st stage and the 2nd stage slides onto that. The 2nd stage has a ring fin setup that slides over the 1st stage. When pressurized, the 1st stage expands by 1/16" and holds the ring fins, which are attached to the 2nd stage, very securely. This holds the 2nd stage in place until the 1st stage has expended all of its pressure and water. At the moment that this occurs, the 2nd stage detaches from the 1st stage and continues on. The beauty of this type of system is that the ideal moment for staging is just after burnout, which is when the rocket is travelling its fastest. Since the 2nd stage is being held on by the pressure in the 1st stage, the staging occurs exactly at burnout. This results in greatest altitude. Hope this helps.

As for the altimeter, I have not got one yet and was wondering if anyone has ever used one of them. I am thinking about getting one though since it is so cheap. I will post how that goes if I end up getting one.

-DogLover

[PTrockets]

There is no wire attached to the ground. The way it works is that the staging mechanism is screwed onto the 1st stage and the 2nd stage slides onto that. The 2nd stage has a ring fin setup that slides over the 1st stage. When pressurized, the 1st stage expands by 1/16" and holds the ring fins, which are attached to the 2nd stage, very securely. This holds the 2nd stage in place until the 1st stage has expended all of its pressure and water. At the moment that this occurs, the 2nd stage detaches from the 1st stage and continues on. The beauty of this type of system is that the ideal moment for staging is just after burnout, which is when the rocket is travelling its fastest. Since the 2nd stage is being held on by the pressure in the 1st stage, the staging occurs exactly at burnout. This results in greatest altitude. Hope this helps.

As for the altimeter, I have not got one yet and was wondering if anyone has ever used one of them. I am thinking about getting one though since it is so cheap. I will post how that goes if I end up getting one.

-DogLover

Oh! Now i get it
Like AntiGravity Research?
But what is the material that the tube that expands is made of?

[air.command]

Oh! Now i get it
Like AntiGravity Research?
But what is the material that the tube that expands is made of?

No, the system Doglover uses is different to what Anti-Gravity Research uses. http://antigravityresearch.com/ozone_pr ... _parts.htm. They grip the second stage with the actual tube, whereas his system grips the second stage by the ring fin.

@Doglover: How do you secure the tube to the booster cap? Or does it get partially forced into it during staging? Have you tried the stager at higher pressures?

- George

[Blenderite]

Oh! Now i get it
Like AntiGravity Research?
But what is the material that the tube that expands is made of?

No, the system Doglover uses is different to what Anti-Gravity Research uses. http://antigravityresearch.com/ozone_pr ... _parts.htm. They grip the second stage with the actual tube, whereas his system grips the second stage by the ring fin.

@Doglover: How do you secure the tube to the booster cap? Or does it get partially forced into it during staging? Have you tried the stager at higher pressures?

- George

I was thinking about making one exactly like Anti Gravities, but from what I can tell their systems work at lower pressures. I was a little concerned that the sustainer might try sustaining before it was supposed to!!!

The tubing has a one-way valve in the end of it which holds it in like the one-way on one of your Mk3 Stagers, I hope that made sense. Here is a diagram:

sketch.png

I have so far tested it up to 80 psi successfully. I only went to this due to field size. I am going to a friends farm tomorrow that has a lot larger place than my current launch site.

-DogLover

[bugwubber]

I've been thinking- one of these, using the smallest pop bottle I can find, gluded inside a larger bottle, would make an excellent non-electronic chute deployment system. Just need to work on the delay so it doesn't fire off at top speed.

Great design!

[U.S. Water Rockets1]

There is no wire attached to the ground. The way it works is that the staging mechanism is screwed onto the 1st stage and the 2nd stage slides onto that. The 2nd stage has a ring fin setup that slides over the 1st stage. When pressurized, the 1st stage expands by 1/16" and holds the ring fins, which are attached to the 2nd stage, very securely. This holds the 2nd stage in place until the 1st stage has expended all of its pressure and water. At the moment that this occurs, the 2nd stage detaches from the 1st stage and continues on. The beauty of this type of system is that the ideal moment for staging is just after burnout, which is when the rocket is travelling its fastest. Since the 2nd stage is being held on by the pressure in the 1st stage, the staging occurs exactly at burnout. This results in greatest altitude. Hope this helps.

As for the altimeter, I have not got one yet and was wondering if anyone has ever used one of them. I am thinking about getting one though since it is so cheap. I will post how that goes if I end up getting one.

-DogLover

Oh! Now i get it
Like AntiGravity Research?
But what is the material that the tube that expands is made of?

Their system uses the long splints on the sides to hold the stages in alignment when the rocket lists off. Their inter stage system does not provide much structural rigidity, so the rocket would fold at the stage connections with the long splints. It works well enough that they can make a reliable 3 stage rocket.

[Blenderite]

I was able to fly a couple of flights with this system and it worked great. Then I tried to make the tube a little stiffer so it is easier to slide the 2nd stage on to the 1st. I used a pen tubing and super glued it in place. Unfortunately the super glue hardened and split the aquarium tubing. I have not rebuilt it yet because I have no parachute system for the second stage. If anyone has any ideas for a second stage parachute release system let me know.

-DogLover

[Tony]

Could you attach your parachute system with the same type of mechanism used for the stager? Using a spring instead of water pressure in the final/parachute stage? When stage 2 loses pressure it releases its hold on the tube, releasing the spring and expelling the parachute. Maybe something like that.

I might have to try this myself... let me know if you do anything with it. (please... and good luck)