New! The Rocket Store Flippi Fin ll AC Rev-2 Kit

[COSTransplant]

All --

I know, I know -- all of you that did me a huge favor and reviewed this product for me so long ago! But yes, The Rocket Store is finally making the Flippi Fin ll AC Rev-2 Model Rocket Kit available! Here are some of the specifics:

• Complete Build Instructions
• TRS Flippi Fin Can -- ASSEMBLED
• TRS VK 5.5in to 1.325in (BT-55) Custom Nosecone
• TRS 18" .56oz Laser Cut Ripstop Parachute (Experimental) with Top-Flight Backup
• TRS 6”x6” Orange Nomex Parachute Protector
• 24mm Aero Pack Motor Retainer RA24L2
• Full Decal Sheet
• Length: 30.7500 in.
• Diameter: 1.325 in.
• Mass: 309.418 g
• CG: 14.7518 in.
• CP: 20.5474 in.
• Margin: 4.37

Suggested Motors (Preferred)

• E28T-7.17 – Altitude: 1187.22
• E30T-7.23 – Altitude: 1219.04
• F32T-8.28 – Altitude: 1824.97
• G100SK-5.20 – Altitude: 2730.42

ENGINES NOT INCLUDED

Our goal with this kit -- and for all of our kits -- is to hear back from our customers on what we did right and what we did wrong and where we may need to make changes. We want to hear back from all of our customers regarding EVERYTHING to do with this kit -- from components, to build instructions, to whatever. We want to hear it so that we can work to improve our offerings every time out! I am more than happy to address any questions you may have, especially with this first build.

If you order before 5pm MT, we will have it in the mail that night!

Warning: All liability waived! Rocketry is an inherently dangerous undertaking. Make your choices and take personal responsibility for the outcome of your experiment! Protect your privilege to fly rockets by not making the headlines or becoming a statistic. Adult supervision required. Kit requires assembly. Construction supplies required to build this rocket are not included. Contains one model kit.

MADE IN THE U.S.A.

v/r,

John Papp
The Rocket Store
https://www.the-rocket-store.com
[email protected]

 

[troj]

Something fun and unique added to the hobby - very cool!

 

[COSTransplant]

Thank you for the kind comments -- I very much appreciate it! I suspect that everyone that orders the kit will really enjoy the completeness of the kit and the Flippi Fin can itself and the tube launch craziness and the pretty thorough build instructions!

 

[DocSeuss]

Is there a way to select types of shipping? The $50 it defaulted to is a bit steep for me.

 

[COSTransplant]

Well gosh, $50 is certainly not correct. So, I have gone in and corrected the site -- somewhat -- to reflect just UPS Ground Shipping, which appears to be working correctly. That said, please let me continue to work on this further. My shipping is almost always around $13 for my 5" x 5" x 20" kit box. So, for any orders placed, I will refund anything over the $13.50 that I was expecting. I hope that helps everyone!

v/r,

JP.

 

[COSTransplant]

And just an FYI -- I am really great at responding to texts. So if you have questions, you can reach me here: (719) 323-9181.

 

[OZRoc]

Any thoughts about international shipping?

 

[OzHybrid]

Why are you describing your printed VK nosecone as 5.53 inches when its a VK 1.325" BT55
In general terms, all nosecones are specified by the Diameter first followed by the length or diameter to length ratio.
https://www.the-rocket-store.com/shop/VK-5-5in-3D-Printed-Nosecone-ORIGINAL-p666790247
This is confusing.

 

[COSTransplant]

Why are you describing your printed VK nosecone as 5.53 inches when its a VK 1.325" BT55
In general terms, all nosecones are specified by the Diameter first followed by the length or diameter to length ratio.
https://www.the-rocket-store.com/shop/VK-5-5in-3D-Printed-Nosecone-ORIGINAL-p666790247
This is confusing.

Please accept my apologies if I was not clear in my website description for this nosecone. I have found that most folks like as many specifics as possible, so I try and provide the where I can. Certainly my apologies if what I have written out is confusing. This 3D printed nosecone is a VK 1.325" BT55. The length of the exposed nosecone (above the body tube) is 5.5". I hope that helps. I will go over and look at / revise my website description as necessary! Thank you again for pointing out your concern.

 

[COSTransplant]

Any thoughts about international shipping?

I would be happy to make it happen! Just let me know what and where!

 

[COSTransplant]

First SIX Flippi Fin ll AC Rev-2 Kit orders out the door -- woot woot and thank you all!

 

[B_RadB]

I received my kit last week. It's a really cool little model kit. The fin can is a well designed mechanism that's pre-assembled. Parts all are good quality - Rail buttons for the 'launch tube" from RailButtons.com, an Aeropack 24mm retainer assembly, two parachutes, full color vinyl for rocket and the launch tube. Since the fin can is pre-assembled, the kit goes together pretty quickly. I had it all assembled in under an hour, but haven't yet applied any graphics. One thing I did is seal the inside of the BT-60 "launch tube", as it will see direct exhaust from the motor during launch. I used polyurethane, but I'm sure there's other options. I expect the BT-60 will need to be replaced after multiple launches - kind of like piston tubes.

One thing I did note, and have shared with John, is that some of the data included in the instructions needs to be verified by the modeler - specifically check the mass and cg/cp relationship. My "as built" model is significantly lighter than what is indicated in the instructions, so I'm checking cg/cp relationship closely. I created an open rocket file of my "as built" kit, based on an initial Rocksim file that John shared with me. I've attached it for others to use, or modify, as needed for your own purposes.

I really like this kit and I'm looking forward to initial flights at an upcoming club launch.

Brad

 

[COSTransplant]

I received my kit last week. It's a really cool little model kit. The fin can is a well designed mechanism that's pre-assembled. Parts all are good quality - Rail buttons for the 'launch tube" from RailButtons.com, an Aeropack 24mm retainer assembly, two parachutes, full color vinyl for rocket and the launch tube. Since the fin can is pre-assembled, the kit goes together pretty quickly. I had it all assembled in under an hour, but haven't yet applied any graphics. One thing I did is seal the inside of the BT-60 "launch tube", as it will see direct exhaust from the motor during launch. I used polyurethane, but I'm sure there's other options. I expect the BT-60 will need to be replaced after multiple launches - kind of like piston tubes.

One thing I did note, and have shared with John, is that some of the data included in the instructions needs to be verified by the modeler - specifically check the mass and cg/cp relationship. My "as built" model is significantly lighter than what is indicated in the instructions, so I'm checking cg/cp relationship closely. I created an open rocket file of my "as built" kit, based on an initial Rocksim file that John shared with me. I've attached it for others to use, or modify, as needed for your own purposes.

I really like this kit and I'm looking forward to initial flights at an upcoming club launch.

BradView attachment 656574

Thank you sir for all of your efforts on this! Your shared observations are much appreciated and will help us improve our products and our overall efforts every time out! Woot woot!

 

[Rocket-Fan]

The stability in the OR sim looks way off?

 

[B_RadB]

The stability in the OR sim looks way off?

Hence the comment about checking stability. I am adding significant nose weight (110g) to approach 1 cal. stability w/ F44.

 

[Rocket-Fan]

Hence the comment about checking stability. I am adding significant nose weight (110g) to approach 1 cal. stability w/ F44.

I played with it a bit after I posted and felt that a minimum of 3oz was comfortable, depending on motor size.

 

[B_RadB]

Another observation from sims - adjust launch rod length to reflect the 18" launch tube, and keep an eye on launch velocity.

 

[B_RadB]

More observations and comments...

I tweaked the OR model again to eliminate the rods the fins are attached to (modeled as "pods" in the OR model) and added fin tabs to attach them to the motor tube. Should be basically the same, right? Well, that change moves the CP from 16.402 to 18.095! When "optimizing" the noseweight for 1 cal stability with F44 motor in this model configuration, OR recommends 63.5 g vs. previous 112g. I've attached the alternated OR file.

I will say, that I did a swing test of my completed model w/F44 that was stable with the higher noseweight (~112g), but would go unstable with less than 100g, so I'm sticking with the model I created with the rods for fin attachment, and will continue to play with motor and noseweight configurations.

Again, take it for what it is - my observations and comments, your results may differ.

 

[COSTransplant]

B_RadB -- Tweaking is what this hobby is all about! Thank you for playing!

 

[RocketDestroyer]

I am another of the folks that jumped on the FlippiFin 2 rocket kit. Shipping was quick. Both communication and customer support from John have been great. There was an issue with the shipping cost on the website but John quickly refunded the extra. I had several questions while I was building the kit and he responded quickly. I have never purchased another kit that was a complete as this one. My rocket is finished now and I can't wait for the fall launch season here to come around so that I can fly this cool rocket.

 

[B_RadB]

Had an opportunity to fly my Flippi-Fin rocket this past weekend. It flew on an E30-7. Nice flight to approximately 900' (based on OR sim). It was a quick takeoff, as the launch tube 'seemed' to act like a piston launcher. Everyone at the club launch enjoyed it and we're intrigued by the design and construction.

Weather conditions were perfect - sunny skies, mild (less than 5mph) to no wind most of the day. The flight trajectory was straight up, but did show some coning at the end of burn.

Note that my built model has significant nose weight added. I have a thicker wall printed nose cone that John sent to me, plus added bb's for nose weight. The total nose cone and nose weight is close to 114g.

 

[lr64]

Very clever. Some questions, which you shouldn't necessarily feel the need to answer, since this isn't actually my sort of rocket. But they're interesting questions, IMHO.

I wonder, at least if such motors could be found, if the launch tube would allow a longer burning motor of the same total impulse for higher altitude at slower speeds, without requiring as much of an initial burst. Also wonder if, with a somewhat longer launch tube, if a rail or rod could be entirely dispensed with? Or are those buttons just for the tube in the first place? Wondering what launch tube length would give the best initial velocity. I suppose a long, evacuated tube with a delicate membrane sealing the top would be "cheating", or prohibited in some way. Especially if there was a lower membrane which more or less disappeared for launch, followed by a delayed ignition of the motor. ;-)

---------
Also, what happens if it only goes to 2730.41 meters instead of 2730.42?

Just joking, but I suggest you are using an implausible number of significant figures. As is, one could get a different number just by moving the altimeter up or down by an inch. Also, what kind of altimeter reads to the nearest centimeter? ;-p

 

[COSTransplant]

Had an opportunity to fly my Flippi-Fin rocket this past weekend. It flew on an E30-7. Nice flight to approximately 900' (based on OR sim). It was a quick takeoff, as the launch tube 'seemed' to act like a piston launcher. Everyone at the club launch enjoyed it and we're intrigued by the design and construction.

Weather conditions were perfect - sunny skies, mild (less than 5mph) to no wind most of the day. The flight trajectory was straight up, but did show some coning at the end of burn.

Note that my built model has significant nose weight added. I have a thicker wall printed nose cone that John sent to me, plus added bb's for nose weight. The total nose cone and nose weight is close to 114g.

B_RadB --

So great to see that you got your kit built and launched -- woot woot! We've had so much fun getting comments back from folks, and I have no doubt that we will continue to play with things as we go along. We have talked about a tighter launch tube (38mm), something to keep the fins closed until the rocket clears the launch tube, a better way to capture / deflect the exhaust below the fins, the Flippi Twin, etc. Always some tweaking to do! So, if any of you have thoughts to share -- good or bad or ugly -- please do, as our goal is to get better with every kit!

Thanks again B_RadB

(I'll be sending you our next kit -- the EcoRocket -- on the house!)

 

[COSTransplant]

EcoRocket kit (rough draft) should be headed out to you tomorrow!

 

[DocSeuss]

EcoRocket kit (rough draft) should be headed out to you tomorrow!

Cool! Very excited to try to build this.

Gonna try to do a build thread on flippi when I can get past all this work stuff.