Finished Air Brake recovery , hopefully made practical

[Daddyisabar]

Persistence is a virtue!

 

[BABAR]

Mark hub apex for band hook placement
Black line

 

[neil_w]

I don't mean to be snarky but I've been following this thread (no pun intended) and trying to understand in what way this is "made practical". Is this simpler in some way than any of your previous builds?

Don't get me wrong, I really like these airbrake rockets of yours, I'm just struggling a bit with the "made practical" concept.

 

[BABAR]

I don't mean to be snarky but I've been following this thread (no pun intended) and trying to understand in what way this is "made practical". Is this simpler in some way than any of your previous builds?

Don't get me wrong, I really like these airbrake rockets of yours, I'm just struggling a bit with the "made practical" concept.

Understood.

Next one will be much better!

 

[jqavins]

Next one will be much better!

Next air brake rocket, or next post? Not that the posts have been bad, but that didn't seem like an answer to Neil's question, so maybe the "next one" will be.

Maybe I just need to invade your home and look at it in person. (Actually, it's much clearer now, and getting clearer all the time [with apologies to The Beatles] but I may just have to anyway.)

 

[BABAR]

Next air brake rocket, or next post? Not that the posts have been bad, but that didn't seem like an answer to Neil's question, so maybe the "next one" will be.

Maybe I just need to invade your home and look at it in person. (Actually, it's much clearer now, and getting clearer all the time [with apologies to The Beatles] but I may just have to anyway.)

Unfortunately next rocket.

This one is turning out much more complex than was intended. The hope is for something almost Robert Edmonds CiCi like in simplicity. Not gonna quite get there, but hoping for something that kind of JigSaws together. The 1/32 plywood was a mistake, much harder to cut by hand, and really too thin for the purpose I need it for (ironically I need more bulk/thickness, not strength.

 

[BABAR]

Well, not coming out as I had hoped.

Measure twice, cut once.

I saw this early, lost 1/2 inch off both the hub and blade ends. That gives me poor orientation for band pull. I had hoped for a 2 inch hub, got 1.5.

Band displacer/blade stop is also 1.5.

Usually the rear attachment for the band is ON the brake (or blade for a helicopter.). Here I think I need a more peripheral (from central long axis) attachment.

First time I have tried this, attaching on the outside of fin. Floss runs around fin, penetrating about about 1cm from each end. Running it around the full cord gives me more strength. Yeah, aerodynamics are not optimal.


This above is without using band displacer

 

[BABAR]

Can’t label it in edit but next is WITH displacer.

Last pic is snapped open.

 

[BABAR]

Something else new, internal support to prevent brake/blade breakage. Internal 3/16” dowel.

 

[BABAR]

Change of plans.

With the fin attachment, the stress past the dowel is to high.

Turns out old school works.

 

[BABAR]

Pretty darn well, too, had a tough time holding it open for the first shot!

 

[Daddyisabar]

Dang! Why is rocket science sooo hard! Especially when going to the school of hard knocks. How many unsuccessful flights did Von Braun and his team have before they got ir right?

 

[BABAR]

 

[BABAR]

I have rarely had the balsa catch fire from “tubeless” ejection. So I routinely lay down a layer of either Mylar tape or in this case foil (my picture of spray adhesive got lost) to protect inside.

I have settled on #16 rubber bands, Crochet Hook US 8 (2.25 mm), and a 5/32 drill bit hole.

I drilled holes earlier, they get covered with foil, just repunch with the crochet hook.

 

[BABAR]

 

[BABAR]

Load a motor to bring the pieces in line.

Lay down glue on the hub pieces.

Bring them together.

Hold with rubber bands.

 

[jqavins]

OK, now I get it.

Measure twice, cut once.

For me it tends to be "Measure twice, cut once, screw it up anyway, do it over." But the last part is sometimes replaced by "sand a lot", "apply filler", "burry it in the fillets", or "just live with it."

 

[BABAR]

One of our more respected members likes the terms “Hell for Stout” and “Belt and Suspenders”.

I think the glue would be enough, but floss is cheap and strong and light.

 

[BABAR]

The nose pyramid

 

[BABAR]

Centering squares for central dowel

Extra glue for protection from ejection charge

 

[BABAR]

Core. Allows for motor retention post deployment.

 

[Rktman]

Core. Allows for motor retention post deployment.

Hmmm...you lost me. How does dowel function to retain the motor?

 

[BABAR]

Hmmm...you lost me. How does dowel function to retain the motor?

Great question.

In fact, in light of the wise comments and questions from you, @jqavins , @neil_w , etc, it hit me. Almost all the Masters here, with possible exception of @Daddyisabar , start their build threads with an OpenRocket file or in @lakeroadster ‘s case, detailed awe inspiring CAD drawings . So pretty much people have at least a rough idea (or in @lakeroadster case, an EXACT idea) of what to expect.

I will finish this one, but any future scratchers from me will be “built” rather than “build” threads. I will take pics to document, but won’t post until the product is complete. Then people can look at the final product and decide if the thread is worth their time.

In answer to your question, there will be at least one part (a wire) and possible 2 (a short tube segment) for flying with motor retention.

At my old fields (Memphis and Jackson Tennessee) I had no problems with just dumping casings (I’d look for them but didn’t sweat it if they didn’t get easily found.). Because “I have a dream” of a rocket that might eventually become popular enough to get someone to kit) it needs to have an option for either motor retention or streamer motor recovery.

What I think Won’t work is a Kevlar line from the hub to the motor, since it might tangle. So I need something rigid to keep motor (if retained) from hanging up on blades/brakes.

 

[Rktman]

Because “I have a dream” of a rocket that might eventually become popular enough to get someone to kit) it needs to have an option for either motor retention or streamer motor recovery.

Didn't FlisKits kit your Tiddly Wink helicopter/gyrocopter design? (Or at least base it on one of your designs, with your permission)?

 

[neil_w]

I will finish this one, but any future scratchers from me will be “built” rather than “build” threads. I will take pics to document, but won’t post until the product is complete. Then people can look at the final product and decide if the thread is worth their time.

This is a good thought. Without understanding the final product, it’s hard to interpret the build steps along the way.

Just for fun I’d thought about doing a build thread without first showing an OR render, but mostly abandoned the idea for the exact reasons given above. The most I might do is not reveal the paint scheme until the end, maybe.

 

[lakeroadster]

Keep up the good work @BABAR ... looking forward to more photos.

 

[BABAR]

Didn't FlisKits kit your Tiddly Wink helicopter/gyrocopter design? (Or at least base it on one of your designs, with your permission)?

Believe it or not, they were independent. To my knowledge (which is certainly far from omniscient!) these were the first rockets that integrated the rocket FINS into the rotors. One of my passions is designs where one part serves two functions.

My build thread for Gyskelion was 2012

https://www.rocketryforum.com/threa...non-competition-helicopter.39114/#post-365709
But Jim Flis mentions the TiddlyWink at the end of post 19 in 2009

https://www.rocketryforum.com/threads/27-june-09-fireside-chat-jim-flis.3471/#post-35954
I never saw his model until after I built mine . I did think it was cool that I came up with the same solution as a professional.

I do think I am the first (and probably only!) person to build and fly “tubeless” rockets.



In the case of @jflis and the integrate rotor-fins , I prefer to think of it as “great minds think alike.” Then again, HE might know if fin/rotor integration had been previously used.

 

[BABAR]

Hmmm...you lost me. How does dowel function to retain the motor?

The missing piece

Wire to tube.

BTW, the tape around the back of the tube allows me to use external tape wrap for motor retention to the tube. I like Mylar, but cellophane works too. Gives you a base for your actual tape wrap, so when you pull it OFF you don’t delaminate the tube .

This rocket diameter was intentionally oversized a bit, so a wrap of crepe paper to get it snug and centered.

 

[jflis]

Believe it or not, they were independent. To my knowledge (which is certainly far from omniscient!) these were the first rockets that integrated the rocket FINS into the rotors. One of my passions is designs where one part serves two functions.

My build thread for Gyskelion was 2012

https://www.rocketryforum.com/threa...non-competition-helicopter.39114/#post-365709
But Jim Flis mentions the TiddlyWink at the end of post 19 in 2009

https://www.rocketryforum.com/threads/27-june-09-fireside-chat-jim-flis.3471/#post-35954
I never saw his model until after I built mine . I did think it was cool that I came up with the same solution as a professional.

I do think I am the first (and probably only!) person to build and fly “tubeless” rockets.



In the case of @jflis and the integrate rotor-fins , I prefer to think of it as “great minds think alike.” Then again, HE might know if fin/rotor integration had been previously used.

Not sure if it was previously used (I’m sure it has). I first did that back in the 80’s when I was into competition. Never had much luck with the concept, but then I learned a lot in the 20 years leading to FlisKits

 

[Daddyisabar]

Old concepts never die, they just fade away...