Lakeroadster's X-Wing Alpha Build Thread

Looks good. I know you are up in the thin air, but no spill hole?

I like this tool for cutting mylar and plastic sheet.

https://olfa.com/craft/product/45mm-straight-handle-rotary-cutter-rty-2-g/

Wouldn't buy one just for making parachutes. In fact, I only have one because it seemed a little safer than an Xacto in the hands of a 4th grader, but it has come in handy for making long cuts in card stock, balsa sheets, poster board, foam core, rip-stop nylon...

jlabrasca said:

Looks good. I know you are up in the thin air, but no spill hole?....

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I'll initially launch on a C6-5. If it is to "floaty" I can always add the spill hole. I'd rather walk an extra bit than do repairs due to broken pieces parts. Lots of rocks up here in the Rockies and not many nice soft manicured lawns.

should definitely be easy to see!

That's a plus for certain types/colors of chutes and streamers that people don't always think about.

BABAR said:

should definitely be easy to see!

That's a plus for certain types/colors of chutes and streamers that people don't always think about.

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Agreed.. getting a visual on the shiny mylar should be much better than the generic "Sky Blue" chute.

You'd think the sun would light it up.. similar to how polished aluminum airplanes seem to look in flight.

Booster Stage?

Yesterday I was thinking about the feasibility of adding a booster stage to the X-Wing. Then I thought, how about Vader's TIE fighter as a booster?

Open rocket says it's a turd... which makes sense since the TIE fighters are about as aerodynamic as a rock. Remember the Estes Kits "Darth Vaders TIE Fighter" that had the big long body tube attached to it . link --- https://www.rocketryforum.com/threads/estes-darth-vader-tie-fighter-build.14580/

I made a CAD model anyway. Rear eject chute for the TIE fighter.

Thoughts? Yea, Nay or MEH?

Turn that Vader 90deg, eliminate most-to-all of the intermediate tube as long as it's fairly light weight it should be a goer.

No chute likely required for Darth, will almost assuredly tumble down.

I'm voting somewhere between "Meh" and "Nope". Kind of distracts from your very nice X-wing.

you could make that TIE fighter into it's own rocket, like the Estes version. If you wanted to add a booster, you could make one that fits in with the look of the Xwing fins and sort of mates up to them, kind of mirror image them, but it may get really too tail heavy. But, 24mm...???

I think it is a GREAT idea. Would need some mods, make the lateral pylons flat like fins. Main source of remaing drag is that round "ball" cockpit. Not sure of your scale, would a ping pong ball work?

As far as detracting from your X wing goes, since X wing has to be stable by itself, you have the option of flying with and without the booster.

Recovery is a problem. I agree it would naturally tumble, but unless you can make it really light, probably will tumble too fast. Won't hurt anybody if it conks them on the head, but would probably break a fin unless it lands on really soft ground. There are ways to rig a streamer on single motor blackpowder boosters, but they are tricky (at least to me) and may involve even more compromise of the aesthetics you are trying to achieve.

Easy to put a chute or streamer on black powder boosters if you are willing to use a TWO ENGINE cluster for the booster, a Zero delay direct to sustainer for sustainer ignition, a short delay (A8-3 works) for the chute or streamer deployment. Two engines in the booster adds a LOT of weight, so need to upsize the fins accordingly. You are also up a foul smelling creek if only ONE of the booster engines ignites..........

Well they lifted the fire ban here, which means launching rockets won't get me arrested.

I modified the nose cone today as previously discussed. I knew the balsa had a hole in it to glue in a hardwood dowel... but I would never have thought it was 2-1/2" deep? CWF to the rescue..

What's the consensus..

Better like this, X-Wingish


____________________

Or Rocketish

I’m going to vote X-wing-ish. I think the uniqueness adds to the cool factor.

Looks Great! Love the "nose gear"

I like the flattened nose. Much more character

Looks great! keep the pics coming!!

Look deep inside yourself, Master Luke, er, Lake. Only you can decide what is the true path. But I vote for XWingish.

I finished up the mylar chute today, added 50# Kevlar chords and a swivel. Did some research here in regard to shock chord lengths and it seems there are a lot of opinions.

In order to get a visual I created the parachute, swivels, and elastic / kevlar shock chords and added them to the CAD model and drawing.

Please take a look and let me know what you think. As always your input / tutelage is sincerely appreciated!

Right now you don't have any elastic between the nose and the body, although the Kevlar cord seems plenty long enough. I like to have some elastic in there. And, you know about putting some kind of tape on the Kevlar cord at the body tube opening to help reduce zipper risk, right?

For LPR I usually clip the shroud lines to a swivel, and then clip that right to the nose cone. Then I would have some elastic cord attached to the end of the Kevlar cord, and connect the end of the elastic cord to the nose cone.

GlenP said:

For LPR I usually clip the shroud lines to a swivel, and then clip that right to the nose cone. Then I would have some elastic cord attached to the end of the Kevlar cord, and connect the end of the elastic cord to the nose cone.

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Thanks for the comment.

Thinking through this, won't your configuration increase the likely hood of the nose cone getting entangled in the shroud lines?

lakeroadster said:

I finished up the mylar chute today, added 50# Kevlar chords and a swivel. Did some research here in regard to shock chord lengths and it seems there are a lot of opinions.

In order to get a visual I created the parachute, swivels, and elastic / kevlar shock chords and added them to the CAD model and drawing.

Please take a look and let me know what you think. As always your input / tutelage is sincerely appreciated!

Click to expand...

Maybe more elastic and less kevlar.

Somewhere in the thread somebody probably warned about the shock cord cutting through the tube (zippering)?

https://www.rocketreviews.com/zipper--zippering-180703140820.html

Small diameter Kevlar string against unreinforced cardboard makes this more likely. You've got a really small space for the recovery, so it might not be practical with this rocket, but the kevlar leader doesn't need to extend outside of the airframe. It just needs to be in that part of the tube between the wadding and forward end of the motor.

Also, GlenP has it right. The nosecone, with ballast, would probably be better at the end of the elastic farthest from the motor. Kevlar isn't very elastic. The nosecone and rocket body will come to a very sudden stop when the kevlar is fully extended. That means a greater force acting at the attachment points, and wherever else the kevlar comes in contact with the airframe (zippering).

The idea of the elastic is to reduce the forces acting at the points of attachment and to help dissipate the energy of the ejection. Ideally, the elastic will have a low elastic modulus (the farther the rocket body and and nose cone go, the more energy is dissipated by drag, A longer shock cord also means less chance that the snap-back will bring the nosecone into contact with rocket-body), a high ultimate strength (so that it won't break), and a low coefficient of restitution (so that it doesn't bring the two haves of the rocket back together at the same speed with which they came apart) Look up the phrase "Estes Smile"

https://modelrocketbuilding.blogspot.com/2010/07/fixing-estes-smile.html

jlabrasca said:

Somewhere in the thread somebody probably warned about the shock cord cutting through the tube (zippering)?

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Posts 112 and 113...

lakeroadster said:

Posts 112 and 113...

View attachment 358139

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Well, there you go <smile>

lakeroadster said:

Thinking through this, won't your configuration increase the likely hood of the nose cone getting entangled in the shroud lines?

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Not to say there are not better ways to do it, but attaching the shroud lines directly to the nosecone is pretty standard for Estes kits.


Its hard to say what will happen with the rocket up in the air. Parachutes do get fouled. With your design there will be all kinds of opportunities for the recovery harness to get hung up.

jlabrasca said:

Well, there you go <smile>



Not to say there are not better ways to do it, but attaching the shroud lines directly to the nosecone is pretty standard for Estes kits.
View attachment 358147

Its hard to say what will happen with the rocket up in the air. Parachutes do get fouled. With your design there will be all kinds of opportunities for the recovery harness to get hung up.

Click to expand...

I have had the plastic “ring” of these built in nose cone attachments break off. So I drill some 1/16 holes through the side wall next to the ring and through the bottom, put a loop of f Kevlar through that, and then use that loop to attach the chute. I haven’t had a failure of the nose cone attachment since I started this.

jlabrasca said:

Well, there you go <smile>



Not to say there are not better ways to do it, but attaching the shroud lines directly to the nosecone is pretty standard for Estes kits.
View attachment 358147

Its hard to say what will happen with the rocket up in the air. Parachutes do get fouled. With your design there will be all kinds of opportunities for the recovery harness to get hung up.

Click to expand...

There are pros and cons to every method, but to say that Estes uses a standard method doesn't mean it's the best method. After all, this is the company that routinely provides shock cords that are way too short in their kits. Everybody acknowledges this. This is also the company that has NEVER used any Kevlar leader or shock cord in any of their kits. Not even their Pro Series !! mid power kits. Does this mean that we should not be using Kevlar in our builds? I think we all know the answer to that.
After having experienced a badly fouled nose cone hopelessly entangled in a dual parachute setup ( Custom Equinox ) which I eventually gave up on and cut out and replaced the chutes and shroud lines entirely, I am a fervent endorser of the method advocated in Chris Michielssen's blog:

https://modelrocketbuilding.blogspot.com/search?q=parachute+attachment

I may have posted this link elsewhere, so forgive me. But it's sound reasoning and advice from someone with a lot of experience. "Nuff said.

kuririn said:

There are pros and cons to every method, but to say that Estes uses a standard method doesn't mean it's the best method. After all, this is the company that routinely provides shock cords that are way too short in their kits. Everybody acknowledges this. This is also the company that has NEVER used any Kevlar leader or shock cord in any of their kits. Not even their Pro Series !! mid power kits. Does this mean that we should not be using Kevlar in our builds? I think we all know the answer to that.
After having experienced a badly fouled nose cone hopelessly entangled in a dual parachute setup ( Custom Equinox ) which I eventually gave up on and cut out and replaced the chutes and shroud lines entirely, I am a fervent endorser of the method advocated in Chris Michielssen's blog:

https://modelrocketbuilding.blogspot.com/search?q=parachute+attachment

I may have posted this link elsewhere, so forgive me. But it's sound reasoning and advice from someone with a lot of experience. "Nuff said.

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Chris's method (which I have used) has the nose cone at the end, and the parachute 1/3 of the way down the shock cord.Your picture shows the opposite, with the parachute at the end, and then nose cone part way down the shock cord. I think that's the question here..

kuririn said:

... to say that Estes uses a standard method doesn't mean it's the best method.. I am a fervent endorser of the method advocated in Chris Michielssen's blog:

https://modelrocketbuilding.blogspot.com/search?q=parachute+attachment

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That is a good link.

In fact, no one did say that attaching the shroud lines to the nose cone was the "best method".

neil_w said:

Chris's method (which I have used) has the nose cone at the end, and the parachute 1/3 of the way down the shock cord.Your picture shows the opposite, with the parachute at the end, and then nose cone part way down the shock cord. I think that's the question here..

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Sort of. The issue is that the nose cone is at the end of the kevlar leader. That there is no elastic between the nosecone and the rocket body.

neil_w said:

Chris's method (which I have used) has the nose cone at the end, and the parachute 1/3 of the way down the shock cord.Your picture shows the opposite, with the parachute at the end, and then nose cone part way down the shock cord. I think that's the question here..

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AAh, I see. Didn't notice that break in the drawing. Needs clarification.

jlabrasca said:

That is a good link.

In fact, no one did say that attaching the shroud lines to the nose cone was the "best method".



Sort of. The issue is that the nose cone is at the end of the kevlar leader. That there is no elastic between the nosecone and the rocket body.

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You're right, I stand corrected.

Lake, some clarification please, your CAD drawing is a little ambiguous. Does the nose cone attach to a Kevlar leader with the parachute following further up, or is the nose cone on an elastic shock cord with the chute tied further down?

Now that *I* look closer, I think there are two separate questions here.

The lack of elastic between the nose and the rocket that jlabrasca points out is one.

The apparent placement of the parachute at the end of the shock cord with the nose in the middle is the other. I can't think if I have seen that sequence ever recommended; I think it's more typical to have the nose at the end of the shock cord. Trying to reason it out, the shown sequence means the nose cone will not (necessarily) be pulling out the parachute, which is what you want. The ejection charge fires the nose cone out of the body, and it should pull the shock cord and parachute with it. In Lake's drawing it will not work like that.

neil_w said:

The apparent placement of the parachute at the end of the shock cord with the nose in the middle is the other. I can't think if I have seen that sequence ever recommended; I think it's more typical to have the nose at the end of the shock cord. Trying to reason it out, the shown sequence means the nose cone will not (necessarily) be pulling out the parachute, which is what you want. The ejection charge fires the nose cone out of the body, and it should pull the shock cord and parachute with it. In Lake's drawing it will not work like that.

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I'm going to amend my statement: given the lengths of the various things in the drawing, the nose *should* pull out the parachute. However, the sequence of connections leaves much less margin for error, and I don't think it makes sense. The nose should be at the end of the shock cord, and at some point in the connections it would be nice to have elastic between the nose and the body (not strictly *necessary*, but useful unless you have a very long shock cord). Within those requirements (I use that loosely) there is plenty of room for variation and personal preference.

Just MHO.

I like the TIE Booster concept. Cluster up the TIE with 1 D12-0 and 2 D11-P for plenty of take off power. Deploy a small chute or streamer packed in the TIE booster cockpit. This would let you put plenty of no good, stinking, performance robbing nose weight in the X wing for assured stability for the entire variable CP and CG associated with the stager. Do what you must to fly this rocket you love and your journey to the Dark Side will be complete!

kuririn said:

Lake, some clarification please, your CAD drawing is a little ambiguous. Does the nose cone attach to a Kevlar leader with the parachute following further up, or is the nose cone on an elastic shock cord with the chute tied further down?

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• X-Wing has 2 ft of Kevlar, then,
• a swivel that the nose cone attaches too, and then,
• 18" of 1/8" elastic, and then,
• a swivel that the parachute attaches to.

If you read the leader line text shown in the drawing at the right it defines the components.

Since the nose cone has it's own swivel it will be easy to enough to hook it directly to the chute chords.

I thought the ejection charge pushed the entire contents of the recovery bay out, not just the nose cone? As is shown in this video:

And this video:

Might be another good reason for a static test?