Goin Stompin

[closet astronaut]

I grow weary of building mods and watching them collect dust on a shelf. Thought I'd do something a little more interactive, and something the kids would enjoy. I checked out e-card models and bought the expansion pack 2. Very nice stomp rockets, well designed, these are show class mods. Check out this Sat-V, it's 1/144 scale, the only draw back on this one is a two liter bottle doesn't have the umph to get it off the launch tube. The honest john missles really fly, I got a good 75 feet out of a few launches.
Another problem I've encountered is you only get about eight to ten launches out of a two liter bottle, I need to design some sort of bellow that can be stomped over and over...any one got any ideas?

I also got the Lockheed F-104, this thing is huge, haven't had a chance to launch this one yet but judging by the launch failure of the sat-v I don't think this on will get off the tube either.

[Miles Linnabery]

Dear Closet Astro:
Note not all bottles are created equal. I had a A7W Root Beer Bottle I must have gotten over 150 launches from. that was in the summer however wonder if temp has something to do withit.
MILES

[mbauer]

Nice builds!!

The Saturn V should fly no problems. Is it binding when you put it on the launch pipe?

Make sure to only stomp in the middle of the bottle.

Stomping on the end only once usually breaks them. Yes, I agree with Miles, not all bottles are the same. 7-up bottles last the longest for me.

The bottles are good for only 2-stomps when it gets belo +10F.

Mike

[cgutzmer]

Great stuff! Make sure the PSI tube is completely seated too that can make a big difference! Let me know if you are able to get the replaceable nosecones off - after about 20 launches one of mine was about wrecked (the ecard livery) but after all those landings it was REALLY jammed on there
Chris

[closet astronaut]

Originally Posted by mbauer

Nice builds!!

The Saturn V should fly no problems. Is it binding when you put it on the launch pipe?

Make sure to only stomp in the middle of the bottle.

Stomping on the end only once usually breaks them. Yes, I agree with Miles, not all bottles are the same. 7-up bottles last the longest for me.

The bottles are good for only 2-stomps when it gets belo +10F.

Mike

It's not binding, I even put tape on the tube to shallow up the depth the tube go into the PSI. I'll keep messin around with it, I'll figure it out.

As far as only stomping on the middle of the bottle, thats no good, stomping length ways gets MUCH more power and hight, besides today at work I fished around in the recycle bins and brought home another six bottles. I also found some great high volume foot pumps that look promising.

Judging by you'r avatar you must be a big 104 fan. I resently built one I found on line

[closet astronaut]

Originally Posted by cgutzmer

Great stuff! Make sure the PSI tube is completely seated too that can make a big difference! Let me know if you are able to get the replaceable nosecones off - after about 20 launches one of mine was about wrecked (the ecard livery) but after all those landings it was REALLY jammed on there
Chris

So far the one I've launched the most is the honest john and the cone is holding up very well, of course I,ve been launching in the back yard over grass, some times it sticks pretty deep.

[Retired_for_now]

Neat stuff - of course the big advantage to paper is that you can whip up another rocket whenever you need to (and those bottles are a lot cheaper than rocket motors).
Now, if you really want to bother those low flying birds:
- get a an adapter to mount some 1/2 inch CPVC (smaller diameter, cream colored pipe) to your launcher;
- make a 22" rocket sized to the CPVC (one loose wrap around the tube, enough overlap to connect, tape or glue the seam, stack two 11" pieces with a connector strip, add fins, plug the top - and add a nose cone if you like);
- and stomp that bugger.

Stomp rocket tuning consists of just making sure the top plug stays put, sealing any leaks, and adding some card bushings around the inside of the bottom to contain the launch pressure (rocket tube should be loose on the launch tube with an easy slip fit at the bottom seal).

Yogi

[mbauer]

Closet astronaut,

Yep, understand about the full stomping of the bottle, F104 to.

I went way overboard when doing this stompin craze. Built a synthetic paper bellows, problem? Side keep blowing out!

A fire place starter bellows would be a better choice.

The next try was a carbon fiber tube, with a flared end to seal against the inside of the PVC. Thinking that it would keep the pressure higher. It was possible to launch a 4.5 ounce F16 about 5ft above the system.

In the end it boils down to a simple design that works! Hard to beat the soda bottle.

The other day I tried out my new digital caliper and measured the ID of the PVC pipe. Digital readout = 0.612 inches

Created a chart for different lengths of the PVC pipe, using an on-line volume caluculator, in litters to see how much the length of the launch system holds.

The volume for 6ft long system is 0.34708 L.

The rocket is a 4ft long stomp rocket with a total volume of 0.47955 L.

.34708 + .47955 = .826630 L needed to launch a 4ft tall rocket.

Mike

[closet astronaut]

Originally Posted by mbauer

Closet astronaut,

Yep, understand about the full stomping of the bottle, F104 to.

I went way overboard when doing this stompin craze. Built a synthetic paper bellows, problem? Side keep blowing out!

A fire place starter bellows would be a better choice.

The next try was a carbon fiber tube, with a flared end to seal against the inside of the PVC. Thinking that it would keep the pressure higher. It was possible to launch a 4.5 ounce F16 about 5ft above the system.

In the end it boils down to a simple design that works! Hard to beat the soda bottle.

The other day I tried out my new digital caliper and measured the ID of the PVC pipe. Digital readout = 0.612 inches

Created a chart for different lengths of the PVC pipe, using an on-line volume caluculator, in litters to see how much the length of the launch system holds.

The volume for 6ft long system is 0.34708 L.

The rocket is a 4ft long stomp rocket with a total volume of 0.47955 L.

.34708 + .47955 = .826630 L needed to launch a 4ft tall rocket.

Mike

Wow...rocket sceince at work, even in the stomp rocket hobby.

[mbauer]

Lots of physics too.

They are considered Single Impluse type thrust.

NASA created a PDF that talks all about them.

You want to make them go higher? The longer they are in contact with the launch system, the higher they'll go!

Hence the 4ft long one.

BTW-Curious about how long the PSI Tube is in your Saturn V?

I ask because there is a longer version that reaches to the mid-point of the CSM. (+100Ft Flights possible using 65# cover)

The Saturn V and Rocket set you have is Air Dave's repaint of the rocket set that I originally created. It looks like he has done a great job on the repaint!!

Thank You for your purchase!

Mike