Lakeroadster's Tractor Motored - Ring Finned - Slinky

[lakeroadster]

Spurred on by @jgavins odd roc challenge thread here I'm going to take a stab at making a slinky rocket.

Basically I'm taking the ring fin booster from my Ahpla rocket and attaching a standard size slinky to it. Here's the conceptual Open Rocket studio screen grab.



I bought a 75th Anniversary, American made Slinky and did a mockup. The Slinky docks to the booster via (3) connectors, made from paper clips. It basic threads through the clips until it is tight up against the fins, and it is remarkably rigid.

Motor mount is a 24mm. Weight is 8 ounces, without a motor. I wasn't planning any recovery system, but could easily add a BT-55 above the booster with a chute.

Think it'll fly?

Is there a maximum allowable tumble recovery weight limit?

 

[teepot]

I'm doing the slinky challenge too. I got a plastic slinky. My idea is quite different from yours. When do you think you will fly it?

 

[lakeroadster]

I'm doing the slinky challenge too. I got a plastic slinky. My idea is quite different from yours. When do you think you will fly it?View attachment 502401

In the spring as long as we don't have any fire restrictions.

 

[Daddyisabar]

Spurred on by @jgavins odd roc challenge thread here I'm going to take a stab at making a slinky rocket.

Basically I'm taking the ring fin booster from my Ahpla rocket and attaching a standard size slinky to it. Here's the conceptual Open Rocket studio screen grab.

View attachment 502366 View attachment 502365

I bought a 75th Anniversary, American made Slinky and did a mockup. The Slinky docks to the booster via (3) connectors, made from paper clips. It basic threads through the clips until it is tight up against the fins, and it is remarkably rigid.

Motor mount is a 24mm. Weight is 8 ounces, without a motor. I wasn't planning any recovery system, but could easily add a BT-55 above the booster with a chute.

Think it'll fly?

Is there a maximum allowable tumble recovery weight limit?

View attachment 502361 View attachment 502363 View attachment 502362 View attachment 502364

The slinky could be considered the recovery device...like a streamer! That story kinda worked with an RSO at a national event when I flew a tapeworm with similar characteristics. A parachute up front won't hurt, bringing it down more horizontal. Will be interesting to see the stretch on the spring. An F44 motor would rock ! A D12 0 would be very mild.

 

[Daddyisabar]

In the spring as long as we don't have any fire restrictions.

There are no stinking fire restrictions within your spring!

 

[jqavins]

Is there a maximum allowable tumble recovery weight limit?

Since your "airframe" is mostly metal, I think the recovery weight limit is the least of your worries. If you're trying to stay within the NAR safety code then you're probably already out of luck. If not, well, I'd put a parachute in it, but it's all up to you.

 

[boomtube-mk2]

Some people are like a Slinky.
They are not good for much, but they can bring a smile to your face if you push them down a flight of stairs.

 

[lakeroadster]

Since your "airframe" is mostly metal, I think the recovery weight limit is the least of your worries. If you're trying to stay within the NAR safety code then you're probably already out of luck. If not, well, I'd put a parachute in it, but it's all up to you.

NAR MODEL ROCKET SAFETY CODE

1. Materials. I will use only lightweight, non-metal parts for the nose, body, and fins of my rocket.

The body and fins are all wood based. It has no nose.

I'm confused, the guy who started the Slinky Challenge, thinks using a slinky doesn't meet the NAR code......

 

[Cape Byron]

In the spring as long as we don't have any fire restrictions.

I see what you did there...

 

[lakeroadster]

I see what you did there...

Spring hasn't yet sprung. It is slinking around, just steps away.

 

[OverTheTop]

Interesting idea . I think it will fly, but I'm not sure how well.

I suspect the slinky will be attracted to the motor exhaust. That will likeley toast the slinky in a small area and result in it breaking off. That is my expectation but I am happy to be proven wrong. Enjoy the build and flight!

 

[jqavins]

NAR MODEL ROCKET SAFETY CODE

1. Materials. I will use only lightweight, non-metal parts for the nose, body, and fins of my rocket.

The body and fins are all wood based. It has no nose.

I'm confused, the guy who started the Slinky Challenge, thinks using a slinky doesn't meet the NAR code......

I concede that it's a debatable position, but I take the slinky to be part of the body in this configuration. One might use a plastic slinky in various ways, but obviously not in this one. One might use a metal slinky in a manner that's not nose, body, or fins, and therein lies the matter of judgement.

Even as I started to think about the use of a slinky and before I decided not to pursue it, I was thinking that if a metal one is used it would have to relegated to secondary functions. But, to repeat myself, it's debatable here.

P.S. And it's not really my concern. Build what you want to build.

 

[lakeroadster]

Slinky Data

Regular Slinky Dimensions.. ref. "The Physics of a Falling Slinky, circa Oct. 31, 2007"