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Launch Lugs Alternatives?

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EliTheClasher

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Hey all!

I am working on a completely homemade rocket, and am wondering if there are any plausible alternatives to launch lugs. I currently use a simple fiberglass rod staked into the ground with a metal duct cover to protect the ground. It works well, but seems as though the system kills the velocity. In OpenRocket, estimates show that using launch lugs decreases my maximum velocity by about 30 m/s which is quite significant.

Any advice appreciated!
 

Zeus-cat

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For competitions our club uses launch towers. Essentially, the rocket sits in the middle of three rods that keep the rocket pointing up for the first meter of travel. They can be rather expensive as they are designed to be adjustable to handle rockets of many different diameters. If you are only making one for a specific rocket you could just use three or four rigid poles. Make sure you look at designs online and note that they all have something at the top or along the length of the rods to keep them rigid enough to keep the rocket trapped inside. Three rods stuck in the ground will NOT be sufficient.

I assume you are not in the U.S. as you are using meters. You might want to look for a local club and see if they have a launch tower.

Are you making your own motors too? That isn't something we talk about in the open forum for a number of reasons.
 

EliTheClasher

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For competitions our club uses launch towers. Essentially, the rocket sits in the middle of three rods that keep the rocket pointing up for the first meter of travel. They can be rather expensive as they are designed to be adjustable to handle rockets of many different diameters. If you are only making one for a specific rocket you could just use three or four rigid poles. Make sure you look at designs online and note that they all have something at the top or along the length of the rods to keep them rigid enough to keep the rocket trapped inside. Three rods stuck in the ground will NOT be sufficient.
Do you have a picture of what it should look like?
 

soopirV

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A piston launcher is another, albeit rather complicated, method you could consider. I've no experience with one myself, but have read a good deal about them in some books I'll recommend to you: Handbook of Model Rocketry, G. Harry Stine (Bill Stine), available on Amazon. Tim Van Milligan had one too, quite a bit thinner, but a good read as well...name escapes me, google will help. And Mark Canepa (sp?) has a seminal tome out on high power...but that will have more about towers as Zeus-cat explained, and not pistons, since those are Low power only (to my knowledge and hope).
 

Zeus-cat

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you're much nicer than I am, and that's a good find- combination piston + tower!
Yes I am. :wink:

I didn't even notice that it had a piston. Pistons make a huge difference too, but are tricky if you don't know how to set one up.
 

EliTheClasher

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For competitions our club uses launch towers. Essentially, the rocket sits in the middle of three rods that keep the rocket pointing up for the first meter of travel. They can be rather expensive as they are designed to be adjustable to handle rockets of many different diameters. If you are only making one for a specific rocket you could just use three or four rigid poles. Make sure you look at designs online and note that they all have something at the top or along the length of the rods to keep them rigid enough to keep the rocket trapped inside. Three rods stuck in the ground will NOT be sufficient.

I assume you are not in the U.S. as you are using meters. You might want to look for a local club and see if they have a launch tower.

Are you making your own motors too? That isn't something we talk about in the open forum for a number of reasons.
Thanks for the help. I AM making my own motors and I knew there was a separate forum for it. Do you have a link to that? I cant find anything from this site. I am in the US I probably use meters just because I am used to it as a standard unit from AP Physics.
 

dhbarr

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18+, Lvl1 cert w/ either NAR or TRA to be added to the research forum.
 

Zeus-cat

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I assume you are not a member of the Tripoli Rocketry Association. To make your own motors and launch them in a rocket at an organized event in the U.S. you need to be a member of Tripoli. You also need to be level 2 high power certified in that organization to make motors. However, you can do this on your own, but you will need to find a launch site and you won't be covered by any insurance. You also need to comply with FAA regulations. This is all MUCH easier if you are in Tripoli.

Also, and most important, making motors can be VERY dangerous. It is best to learn how from someone that knows how to do it. Again, that is more easily accomplished if you are in a club and working towards high power certification.
 

caveduck

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Don't let any of this discourage you. We do have a process for own-design motors, and many people are doing it successfully. But it will work much more smoothly if you get involved with a TRA club and get your level 2 certification. I would highly recommend getting started with commercial motors anyway, in order to get familiar with construction and flying of larger rockets, neither of which are trivial.
 

DavidMcCann

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Fiberglass rods are not very rigid. You may see a benefit simply moving to a 1/4" stainless rod.

Rail buttons and micro buttons are other options.

a tower is of course, likely best.
 

Incongruent

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The Tim Van Milligan Book is called Model Rocket Design and Construction
 

afadeev

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Hey all!

I am working on a completely homemade rocket, and am wondering if there are any plausible alternatives to launch lugs. I currently use a simple fiberglass rod staked into the ground with a metal duct cover to protect the ground. It works well, but seems as though the system kills the velocity. In OpenRocket, estimates show that using launch lugs decreases my maximum velocity by about 30 m/s which is quite significant.

Any advice appreciated!
If you are seriously going for maximum height (competition?), then fly-away rail lugs are the way to go.
More info (and videos) here:
https://www.apogeerockets.com/Launch-Accessories/Fly-Away-Rail-Guides/18mm-Fly-Away-Rail-Guide-2-pk


If you are primarily concerned with rocket stability on a wobbling launch rod (which you staked into the ground), there are a few things you can do to improve the situation:
1). Invest into a proper launch pad. Something like this will work well up to 1/4" rods:
http://www.hobbylinc.com/htm/aro/ar...XLLjppGLdAcvCheUpiFRurI2uLON9uIBoCBvcQAvD_BwE
2). Get a longer solid stainless still 1/4" rod (fiberglass is way too flexible) and use 1/4" lugs.
3). For larger (HP) rockets, you have to go with rail buttons (e.g. 1010). To use these successfully you will either have to come out to local rocket club launch days, or buy your own "rail launcher".
https://www.apogeerockets.com/Building_Supplies/Rail_Buttons/1in_1010_Rail_Button_Standard

I don't know if this is the best approach, but it looks like you can buy assorted launch lugs on amazon for a reasonable price:
https://www.amazon.com/dp/B009EZS252/?tag=skimlinks_replacement-20
That can work.
You can get them even cheaper here:
http://www.hobbylinc.com/estes-model-rocket-launch-lug-pack-302320

a
 
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