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mbauer
05-22-2010, 03:49 PM
Hi,

Since I don’t have all of my model airplanes with me at this time, I decided on a new project/model type.

The original plan was to make a small bellows to power the “Blow Rockets” that Phil designed and posted on the Z forum.


Searching for a “Paper Bellows” and then browsing to the different links, showed a couple of designs. One was really small the other was a big surprise!

The surprise was it had already been done, the bellows and rocket link went to a free downloadable rocket and bellows. After posting the link here on PM, another very exciting and pleasant surprise arrived!


Retired_For_Now sent me a link for a “Stomp” Rocket launcher. Also included was a “Straw” launcher system.

The last few days, most of the computer time spent has been drawing rockets to market for this great designed launcher! The launcher can be found in a couple of spots, after PMing, permission was given to post a link to the launcher at http://jleslie48.com/chronlist.html (http://jleslie48.com/chronlist.html) . Look for the Ares Stomp Rocket 7/07/2009 link.

The Ares that comes with the launcher is a simple, easy to build great design!

But, I still wanted my own rockets.

Something that has been planned since 2002, but because of model airplane designing, these projects were put on hold. Moving around found the desktop with all of the airplane models in Idaho, when, in a big rush, Idaho was departed to arrive in Alaska for a job interview.

Bought a laptop and then started loading in my CD roms with the airplanes on them. That is when the unpleasant surprise verified that none of the models on the Cds, had the newest upgrades.

That left two choices, redoing about 3-months of work, or starting the rockets. Tried to get my brother to send the autocad drawings to me, but he is clueless about computers.

Anyway here are some photos of the rockets and one of my F16 flying models redone to fit the launcher. As you can see on the F16, I didn’t catch all of the old issues until after it had been printed, since this was just a quick test to see if would launch, went ahead with the build. Red line, black areas are the issues.

Will be listing them on eBay soon as a CD rom for 6-rockets with the Honest John missile as a bonus. Price hasn’t been decided on yet, but should be at or around $10 to cover ebay/paypal fees and shipping too.

When considering the cost now of launching Estes rockets, the Stomp Launcher is a great/cheap easy to do project! Less than the cost of 3-Estes D12-3 engines.

Ok, now for the rest of the story.

After building the first stomp launcher and asking questions, it was mentioned that possibly a ˝” size conduit might work better. So, for less than $10 the parts were purchased.

Yes, the ˝” version seems to work better. Besides finding that out, other testing followed with the following results:
-A wrap of duct tape helps seal the bottle to the launcher.
-1/2” conduit slides inside the soda bottle with a good fit, duct tape seals the gap.
-Used a small diameter cardstock plug to plug the crosslegs of the launcher. Superglued the plugs to the end of conduit, where they insert into the 4-way cross piece.
-The soda bottle is good for several stomps, if you make sure to stomp on the [U]middle and not the end!
-Paper bellows has been drawn to fit the launcher as well as the rockets. Plan is for more volume than the 2-litre soda bottle. Updated one will be twice as big as one in photos.
-When creating bigger rockets (large diameter) the best option is to create an internal “pressure” tube. This keeps the volume (limited by the 2-litre bottle size) of air compressed enough to lift the rocket. The size of the tube needs to be 0.892” I.D.. This allows a seal, but doesn’t create excess friction. The psi tube needs to be as long as possible. The reason is the longer it is, the more it is in contact with the “pulse of air” that sends the rocket skyward. Once the rocket clears the conduit, it starts to slow down.
-Using a handheld Anemometer shows 11 mph wind speed from launcher assembly.
-A simple streamer recovery system was made for the 28” tall (39gm) Saturn V.
How to make streamer:
Use a super small lead fishing weight, shave it down until it just barely counters the weight of the plastic grocery bag streamer. A small wire loop is glued inside of psi tube at the capsule/plug end. A short piece of lightweight fishing leader (2lb test) was superglued to the weight and streamer. The leader allows the weight to reach the bottom of the rocket. The streamer is cut so that it sticks about an inch from the tube.

How it works:
When ascending, the weight is at the rear, but after apogee the weight falls forward and rests on the plug, allowing the streamer to deploy out the rear of psi tube.

This has been an incredibly fun project! The rockets fly great and the Redstone reaches about 40ft AGL. The streamer isn’t really needed just yet, but after installing the newest bellows this could change (I hope).

Will be posting a link to youtube for some short videos, once they are loaded.

Rocket specs:
-Saturn V is 28” long, weighs 39 gm
-Sat 1B is 17.5” long, wt = 18.6gm
-Gemini Titan is 17.5” long, wt = 14.06 gm
-Mercury Atlas is 16” long, wt = 15.86 gm
-Mercury Jupiter is 12.5” long, wt = 11.32 gm
-Mercury Redstone is 13.5” long, wt = 7.6gm
-Honest John is 1” = 1ft, 27” long, wt = 33.42gm

F16 Specs;
-30” long, 17.75” wingspan, wt = 3.2oz before weight/balance (model was finished 3-minutes ago, glue is drying before weight/balance test flying).

There are build photos, which will be added to this thread, eventually. Need to edit pictures and do the write-up first.

Best regards,
Mike Bauer

Retired_for_now
05-22-2010, 09:07 PM
Now that is a neat collection of rockets! Nicely drawn, they look robust enough to launch several times (on a dry day?).

Looking forward to seeing more on the F-16 flier as well.

Yogi

mbauer
05-22-2010, 09:31 PM
Now that is a neat collection of rockets! Nicely drawn, they look robust enough to launch several times (on a dry day?).

Looking forward to seeing more on the F-16 flier as well.

Yogi

Hi Yogi,

Thank you for the comments and the help with my questions/project!

Yes, they are. Forgot to mention that they have replaceable nosecone/capsules.

Only damage is when they are launched inside and hit the cieling, replaceable doesn't fix the damage, but outside is no problem.

Mike

mbauer
05-28-2010, 04:10 AM
Got a youtube video of a 17" Tall Saturn 1B that weighs 18.6 grams.

Went to about 75 ft AGL (above ground level).

YouTube - Stomp on a Soda Bottle, Air Powers Paper Saturn 1B Rocket to 75ft AGL.AVI (http://www.youtube.com/watch?v=JO1HKRFicZw)
http://www.youtube.com/watch?v=JO1HKRFicZw

Hope this works!

Best regards,
Mike Bauer

airdave
05-28-2010, 07:21 AM
That is awesome.

Any way you can show the launcher while you launch?
How hard do you stomp on it?
Any repairs yet?

Where can I see more about the launcher construction?

Ever think about a compressed air launcher?

Retired_for_now
05-28-2010, 09:51 AM
Dave, stomp rocket launcher plans can be found with the ARES stomp rocket in the download section (currently 6 pages deep in the sci-fi & real space section) or at Jon Leslie's Lower Hudson Valley Challenger Center in the post-Apollo downloads.
You'll need to check with Mike for his rocket set - ARES I only included with the launcher plan.
Yogi

mbauer
05-28-2010, 11:21 AM
Hi Dave,

Thanks for the interest! This has been a Blast!

Yogi shared this launcher awhile back. The first post of this thread is fairly long, but I do explain some of the intial testing results of the launcher, also invented/describe a recovery system for the really high flyers.

Yogi's launcher is the Cheapest, Best idea I've seen for quite awhile. That launcher really works! Estes Rocket engines cost $19.95 for three of them here in Alaska. Total cost for the launcher comes in under $15 total.

At The Lower Hudson Valley Paper Model E-Gift Shop - Chronological Model List (http://jleslie48.com/chronlist.html) you will find a straw launcher as well. Just scroll down and look for the Ares Rocket. Within a couple of uploads you will see the link for it as well. Great site that has many rockets for download.

When you download, it comes with a great Ares rocket that even goes higher!

Mine are heavier due the inside psi tube system.

I'm in the process of re-doing my rockets. Yesterdays test found a big problem with the internal "pressure" tube. Way more psi than I expected and it blew the internal components apart.

Will modify and then test again.

Just so that you know, my plan is to sell a CD on eBay with seven models and a little paper bellows that can be attached as well as the soda bottles. Would like to make $5 profit on each CD, after eBay fees etc. so, the price hasn't been determined yet.

Furthermore will be working with the Challenger Learning Center here in Kenai, Alaska.

They have many great programs and need support from all of us. The President/CEO has been working for 4-years+ to keep it afloat. He is doing all this without pay!

Probably will give them a CD of the rockets to sell as well as some of my airplane models, to be sold from their giftshop and on-line. They need money worse than I do, and I've been out of work for 20-months. Will be helping them with their Summer Camps.

Will post pictures later of the damage needing fixed, with a short post on how it was fixed.

If I can fix it!

Also working on launching some free flight gliders, but need to loose lots of weight...

Cars will be the next step, this launcher has so many possibilities...

Mike

mbauer
05-28-2010, 11:29 AM
Quotes from airdave,
That is awesome. Thank you and be sure to Thank Yogi for the launcher!

Any way you can show the launcher while you launch? Can with help from an assistant.
How hard do you stomp on it? Firm and fast stomp! Must be done in the center of bottle, the end will break if it is stomped on!
Any repairs yet? Oh, yea, see prior post!

Where can I see more about the launcher construction? Link is posted in prior thread.

Ever think about a compressed air launcher? Presdient at the Challenger Center invented a utility cart with compressor, solenoid valve with electronic arming/launching switches. Plan is to take photos the next time I stop by, or as Larry the CEO said, show up on their door step...

Mike

mbauer
07-13-2010, 08:50 PM
It has been a few days since my last post to this thread.

Here are the latest updates!

Inside the early Stomp Rockets I designed was an internal Pressure (PSI) Tube. This PSI tube was invented to allow more flexible/bigger Stomp Rockets. It works great up to about 55grams rocket weight.

To get the heavier models to fly, something else is needed.

After much testing I have a few findings:

-Paper Bellows does not work very well, due to the sides blowing out, instead of air going into the pipe system. Made a huge bellows that has more volume than the 2-liter bottle.

-PSI Tube works great on models that weigh less than 55 grams.

-Carbon fiber shaft with a flared tip, aligment guide discs, and a cardstock "push shaft" at the top, will lift a 4oz model to about 20ft. This shaft slides inside of the launch piping and seals against the walls with the flared end. Guide disc along the length stop binding. Problem is the shaft weighs 8.65 grams and goes almost as high as the model. So not all of the enegy is transfered. Plus the weight is added to the model until it clears the piping.

-PSI tube length effects how high the model goes. The longer it is, the longer it "interfaces" with the energy of the launch system.

-PSI "Plug" was built today for testing. PSI Plug is a long shaft that slips inside of the launch piping like the carbon shaft mentioned above. It has a smaller diameter and the overall rocket weighs less, than a comparable sized rocket with a PSI Tube.

I haven't tested the PSI Plug yet because it has been raining all day. But the hope is, it will interface better than the PSI Tube, allowing a much less pressure drop as the rocket travels up the launch pipe. Since it is inside of the piping, the launch piping pressure should stay constant, without the loss of Pressure when you use the PSI Tube (bigger diameter on the outside of the piping = bigger volume to fill with the pressurized air from the stomp).

Here are some photos of what I'm talking about. Notice the Plug vs Tube photos and the identical rockets that are being constructed. Both the Tube and Plug have identical lengths, diameter is duffernet as well as mounting system.

After constuction the PSI Tube version weighs 15.79 grams, while the PSI Plug version weighs 15.15 grams, difference of 0.64 grams.

Which one do you think will go the highest?
How much higher?
A little because of the weight difference?
or drastically higher because pressure difference?

Keep checking the download section, I plan to upload a complete Tutorial Rocket set. The set has 4-rockets that if built will hopefully take a beginner paper model builder thru advanced skills needed to build my version of the Stomp Rockets.

Best regards,
Mike Bauer