Launch lugs

I'm getting into tiny rockets but haven't built one yet. What about launch lugs? They seem large compared to the small airframes. Do they have a noticeable effect? Is there a special tiny lug, or any no-lug solution?

Suppose your mini rocket fit really really well inside of a long mailing tube and the tube had a launch lug on it. With the tube's lug on the launch rod, do you suppose you could launch the rocket out of the tube? Has anyone ever tried this before?

Da Dog

Without having something to physically hold it straight, she won't come out of the tube straight. Typically, the tips of the fins wouldn't be enough. I've *done* this, but by using a jig that attaches near the top of the rocket (to hold *that* end centered) and would fall away as it cleared the top of the tube.

A better option would be a small/short rail. A simple one can be made with some wood dowels (1/2" - 3/4"). Use 3 of them 120 degrees apart with enough separation to allow the model to fit inside. For 4 fin designs, use 4 dowels 90 degrees apart.

jim

You just can't beat experience. Thanks for the tip.

Da Dog

The jig that jflis referred to is often called a sabot. The Arcas is an example of a professional rocket that was tubed launched. It used drop-away plastic spacers.

I have built a couple of micro-maxx tube launched rockets that employed small skinny fins near the top of the rocket to keep the front end centered. It worked but is not efficient.

Aerocon https://www.aeroconsystems.com/ sells a rocket called the Flippifin that uses a military surplus folding metal fin unit. The fins are shaped so that when folded they will keep the whole rocket centered. Pretty cool. IIRC there is a thread here on TRF discussing this rocket.

MicroMaxx uses a short (8 to 10 inch?) piece of small music wire in its ready-to-fly starter kits. The music wire looks like it is 0.040 or 0.032 or something small like that. The plastic MMX rockets have small loops molded into the bodies to serve as launch lugs. You could accomplish the same thing by rolling a scrap of paper around a SLIGHTLY larger wire, gluing, and making your own mini-lugs.
You can also use the graphite rods (I think they are available from Totally Tubular) about 1/16th inch diam, but I am sure you don't need the entire three foot length. This is more expensive, less durable, but much more rigid than the itty bitty music wire.

Another common no-lug approach is the launch tower where the rocket is guided at the star of the boost by metal rods or even dowels. er...I guess that's what jflis was describing in the 2nd 1/2 of his post.

I have a Vanguard VI that flys from a standard 4 rail tower, with the use of 2" x 2" x2" styrofoam blocks, the blocks are split diagonally seperatiing into halves as the model clears the tower, This is a similar arangement used by the ARCAS sounding rocket, in it's closed breach launcher. It's a kick to see the blocks peel off as the rocket clears and does away with the need for launch lugs.
If you are makeing Micro-Maxx models and would like to use a smaller Launch lug, Q-tips have a hollow shaft that works well, coffee stir sticks is another but must be sanded before glueing.

I'm fairly sure a pair of foam rounds will work inside a smooth type clear plastic mailing tube, not so sure about the reqular cardboard mailing tubes. This will work using a standard estes type body tube, that I have done The Trick is to set the diagonal split so it aligns with one fo the fins, while resting against the other.

Actually the Micro-Maxx launch rods are .049", I'm using .050 carbon fibre rod as well.

Go to your local hobby shop (bring your launch rod with you) and go over to the Plastruct or Evergreen styrene plastic display stand (most hobby shops have them).

Get some styrene tube that fits your rod.

I've also used the tiny aluminum tube as a launch lug.

sandman

I just use a short piece of insulation stripped from 12 or 14 gauge housewire (Romex); epoxy was used to glue it down.

Bruce S. Levison, NAR #69055

Q-Tips. The ones with the plastic handles. Cut of the cotten part, and walla! 500 for what? $1 or 2?

Here's a picture of the tower block system Dick and I were talking about in the earlier post.
If you just looking for Launch lugs for micro-maxx models. Q-tips hollow sticks work wonderfully, or plastistruct 1/16" tubing drilled out to .052" or 3/32 which is a bit large for my taste.