US Rockets Banshee

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KarlD

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Greetings Everyone!

Working slow, but I have some pictures of my Banshee build. All I can say in a nutshell is get this rocket. I have had a blast with it....
 

KarlD

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As is customary in TRF, my first picture is a photo of the kit bag. The hang-tag type bag arrived in good condition and well packed. Motor mount rings, tube, etc was packaged in the main tubes to reduce size.
 

KarlD

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All the parts are of exceptional quality. The Balsa nose cone is a good handful and is turned from reasonably hard stock. The body tubes are very stout and high-grade ¼” ply used throughout in fins, bulkheads and centering rings.
 

KarlD

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The first step I choose to take is the building of the motor mount. I choose to deviate from the Estes Tri-fold Shock cord mount and install a PML type shock cord mount on the motor mount tube. Another modification is the rear centering ring.
Since I am planning to use my 29/60 Dr. Rocket hardware on this bird, I decided to add some mechanical motor retention. The pictured posted shows the #4-40 T-Nuts that I have installed on the rear ring and a #4-40 hex bolt screwed into one of the T-Nuts. I will have to work on the clips for this system.
The tube underneath is the 24mm adaptor assembly. It is a 24mm tube installed into another tube that fits into the 29mm tube. Simple and strong. The ring of Kevlar is the thrust ring for the assembly. I wanted something a bit more robust that the plan suggestion of masking tape.
 

KarlD

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Here is another picture of the motor mounts with a good reference object.
 

KarlD

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This is the rear of the aft centering ring. I guess 4 #4-40 T-nuts are a bit of overkill, but I like overkill.
 

KarlD

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LOL Helps to post a picture...
 

KarlD

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Here is the business side of the aft centering ring. I think it turned out real nice!
 

KarlD

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The next major module to complete was the fin set. The banshee fin set was a bit splintered ant the tips of the root edge, but this fact was ill relevant due to the kit plans calling for ¼” being trimmed off the front and rear of the fins for the body tube slot. Some Dremel work to taper the leading and trailing edges of the fins and a precision hacksaw for the slot trimmings were all that was needed.
 

KarlD

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Another view of the fins....
Dremels are your friend!
 

KarlD

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The next step was cutting the tube slots. Since this was the first time I had ever cut tube slot, I was a bit apprehensive. The actual operation went very smoothly. Several recommendations from TRF worked well. The major ones are:

Measure twice, cut once.

Use a metal straight edge to cut against.

Use a utility knife/box cutter knife with a fresh blade. It is sharper and stronger than an Exacto knife.

Finally, take your time. I rushed one of the slots and buggered it a bit, but fin fillets will cover this mistake.

Here is the picture of my cutting rig. It worked out quite well.
 

KarlD

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Here is a picture of the booster tubes slots.

Not bad for a first timer...
 

KarlD

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The next step in fin installation. I wanted maximum strength so I decided for fin fillets on the inside…This pictures shows the rear of the booster assembly with my Estes fin alignment tool holding the fin vertical during initial glue. That thing is handy!
 

KarlD

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Here is a side view of the final fin in drying phase.

I used yellow glue for the internal fin fillets. The strength is incredible, and no toxic cleanups or problems were encountered. However, the glue is very slow to dry in the fin can. Typically, on each fillet set I had to let the rocket dry for 24 hours till I could rotate the booster for another set. The external fillets were much quicker to set…typically ½ hour or so. I assume it was the lack of fresh air circulating in the fin can.
 

KarlD

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While those internal fin fillets were drying, I assembled the payload coupler. Us Rockets uses a novel approach to securing the screw eye. The primary bulkhead is 1/8” ply mounted to the inside of the coupler. The internal bulkhead is a 1.5” circle of 1/8” ply glued to the primary bulkhead. The Screw eye is threaded through both pieces of ply, and then glued. The resulting structure is very strong and light weight. I like it.

The coupler itself is a massively thick tube…very beefy. Jerry is not kidding when he states that they use the best couplers in the industry.
 

KarlD

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Here is a picture of the outside of the payload coupler assembly. When the glue is dry it is inserted 1/2 way into the payload tube and glued.
 

KarlD

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I choose to install rail buttons on this rocket. I used the measurements supplied min the kit for the launch lugs for the front and back button, and added a third button 2” ahead of the rear button. This is a recommendation from www.railbuttons.com. I have had no vertical instability issues using this system.
 

KarlD

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Assembly complete!

I still have to paint prep, (yuck) and paint her. She is a little heavy at 380 grams with an empty 28/100mm casing installed, 318 grams empty. The stock streamer will not be usable in my configuration, but I have a quantity of yellow “Caution” tape that will work well.

I will update this thread with prep and pain pictures. The next club launch is the 2nd weekend of November. With luck, I should be able to post some flight pictures.

At this point I recommend US Rocket kits very highly. They are older-school technology, but with stout parts and solid engineering behind them. I prefer old school my self due to the ease of working in this medium, and the weight savings. Not much work was required for my modifications, plus balsa nosecones are a joy to work with.

I look forward to watching her fly to the skies in November.
 

lalligood

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Nice photo-documentation Karl!

I have a USR Banshee that I'l flown 3 times now. It quickly became my favorite mid power rocket in my fleet (although my Art Applewhite 29mm Qubit is a very close second!) Best flight was on a F40-7W (29/40-120 reload), although the SU F50-9T & F22-7J reload flights weren't bad either... I'd really like to get my hands on some G64s now :D

Check out the streamer calculator over at EMRR. My Banshee was built completely stock (except for adding rail buttons too) & I use a 96" x 5" plastic streamer made from a disposable tablecloth (they come in a zillion colors & only cost ~$2 at a party supply store). It's made of the same material as the stock streamer. Recovery is quick but safe & easy to see on the way down.

USR kits for the most part are old school with excellent components. Enjoy! :)
 

bsexton

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Good story board of the construction. I also have the Banshee and have flown it a few times on an E9-4 (small field) with good results.
 

KarlD

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Originally posted by lalligood
Nice photo-documentation Karl!

I have a USR Banshee that I'l flown 3 times now. It quickly became my favorite mid power rocket in my fleet (although my Art Applewhite 29mm Qubit is a very close second!) Best flight was on a F40-7W (29/40-120 reload), although the SU F50-9T & F22-7J reload flights weren't bad either... I'd really like to get my hands on some G64s now :D

Check out the streamer calculator over at EMRR. My Banshee was built completely stock (except for adding rail buttons too) & I use a 96" x 5" plastic streamer made from a disposable tablecloth (they come in a zillion colors & only cost ~$2 at a party supply store). It's made of the same material as the stock streamer. Recovery is quick but safe & easy to see on the way down.

USR kits for the most part are old school with excellent components. Enjoy! :)
I saw that article on EMRR...Lots of good info. On my Banshee, I plan on using 3" wide "CAUTION" tape that is used to mark off hazardous spots. I have a partial roll that was given to me…
I used the EMRR Streamer calculator and it calculated a streamer 3” by 16’. I used an assumed weight of 450 grams. We will see where we stand with finishing and paint, but currently the rocket weighs in at 380 grams. A 16’ streamer seems large, but it fits nicely into my booster tube.
I know some people will not consider US Rockets because they are “Old School”, but I think that is one of their strongest points. Solid tried-and-true methods with Quality components, Classic styling, and light construction for their size are an unbeatable combination. I like it!
 

KarlD

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Finally got some launch pictures developed and scanned!

Here is My Banshee on the launch pad. It was loaded with a RMS F37W-M load. First time for the rocket and first time for the case.....

"Drum Roll"
 

KarlD

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And Liftoff!

Sorry about the quality, but I need to zoom in more on my pictures.

Practice makes perfect.

She jumped into the air on the F37 load. I guesstimate around 1000 feet. Very nice flight.
 

KarlD

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Successful Recovery!

The Caution tape tangled a bit coming in, but it was not enough to damage the rocket. This is a fun mid-power bird to fly inexpensively, but it still has the nice flame and modest noise that AP gives you.

I plan on trying to take closer pictures next month.

Banshee project complete and a success!!
 

Manwithbeers

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Originally posted by KarlD
I choose to install rail buttons on this rocket. I used the measurements supplied min the kit for the launch lugs for the front and back button, and added a third button 2” ahead of the rear button. This is a recommendation from www.railbuttons.com. I have had no vertical instability issues using this system.
Rail Buttons dot com sells rail buttons. Good ones too. I love them and use them on all my mid and high power rockets.

However. I think 3 buttons is overkill and a little dumb. If I were doing rocket inspection duty at a launch and a rocket with 3 buttons came to me I would have 1 removed.

Nobody ever gets 3 aligned perfectly and the result is additional friction in the rail which slows the lift-off speed which could make for a dangerous situation.

Use 2. If they are well mounted that will be great.
 

lalligood

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Originally posted by Manwithbeers
Rail Buttons dot com sells rail buttons. Good ones too. I love them and use them on all my mid and high power rockets.

However. I think 3 buttons is overkill and a little dumb. If I were doing rocket inspection duty at a launch and a rocket with 3 buttons came to me I would have 1 removed.

Nobody ever gets 3 aligned perfectly and the result is additional friction in the rail which slows the lift-off speed which could make for a dangerous situation.

Use 2. If they are well mounted that will be great.
Rail buttons from railbuttons.com do rock!

Three of them on a single rocket the size of the Banshee is overkill. I have only 2 buttons on my BSD Thor which is a several times larger & heavier than the Banshee. The only rocket I've ever put 3 rail buttons on is my Richter Recker. Two were placed about 16" apart & then the third one was mounted into the aft end of the payload tube. That way I could adjust the forward-most button to make sure they were lined up. I used 3 for this application because of the extreme length & thinner tubing. That's the only reason why I did that though...
 

Jerry Irvine

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Originally posted by Manwithbeers
Rail Buttons dot com sells rail buttons. Good ones too. I love them and use them on all my mid and high power rockets.

However. I think 3 buttons is overkill and a little dumb. If I were doing rocket inspection duty at a launch and a rocket with 3 buttons came to me I would have 1 removed.

Nobody ever gets 3 aligned perfectly and the result is additional friction in the rail which slows the lift-off speed which could make for a dangerous situation.

Use 2. If they are well mounted that will be great.
This should be in the FAQ.
 

KarlD

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Personally, I like overkill.

I am just doing the recommendation for three buttons that is posted on the rail buttons web site. I assume one of the reasons for three buttons is to sell more buttons, but the sites reasoning’s for additional stability just as the rocket is about to clear the rail are sound. I have never had an alignment issue, nor have I had a rocket bind on the rail.
From what I have observed on my rockets, speed of liftoff is not a problem either.

Call me dumb, I do not care. I prefer to defer to the side of caution and a high safety margin.
 

Matt Stum

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Originally posted by Manwithbeers
Rail Buttons dot com sells rail buttons. Good ones too. I love them and use them on all my mid and high power rockets.

However. I think 3 buttons is overkill and a little dumb. If I were doing rocket inspection duty at a launch and a rocket with 3 buttons came to me I would have 1 removed.

Nobody ever gets 3 aligned perfectly and the result is additional friction in the rail which slows the lift-off speed which could make for a dangerous situation.

Use 2. If they are well mounted that will be great.
I would agree that 3 buttons on this particular model is unnecessary and overkill.... but certainly not dangerous enough to ban the flight! If *I* were to put 3 buttons on this model I would put 1 each at the leading and trailing edges of the fins, and one just above the break (surface-mount if needed). This helps with alignment and puts the forward button up where it can help stabilize the rocket during loading. But if he were to simply remove the middle button in his current configuration, that would work too.

If your only argument for going with 2 is that alignment is impossible, I have to strongly disagree. It can be done quite easily... no more difficult than fin alignment. Yes, alignment is important, but I'd be more worried about the end-result than the number... you can screw up a two-button installation too if they're not aligned with the major axis. How is that any different? Regardless, there's more room for error than I think most people realize. There's a lot of slop between a button and an 80/20 rail (a bit less with BlackSky rails).

There are configurations where 3 *are* required for consistently safe launches. Otherwise you end up with unacceptibly short guidance lengths. (Remember, 1 button on the rail = 0 guidance). You would never suggest putting a single launch lug at the base of a long heavy rocket... you'd put a 2nd one up near the middle or near the CG to carry some of the weight. Well, that's what the 3rd button's role is. If that role isn't needed, a 3rd button isn't needed.

And it's not just buttons... I've seen quite a few launch lugs that were horribly mis-aligned. I've seen many rockets stick to a rod... I haven't witnessed a single rail-launched rocket stick (there's a lot of room for error). While we're at it let's ban fins because, man, those suckers NEVER get perfectly aligned. :)

As for suggesting 3 buttons is a ploy to sell more buttons, nothing could be further from the truth. My whole goal is to make rail technology the norm. There are two keys to that... standards, and price. BSR created the standard and I expanded on it by tying it to the 80/20 rails. For my part I'm trying to make rail technology affordable. Hence the 25-cent nylon buttons. You don't wanna know what I had to do to keep the delrin prices where they are. :) Suggesting 3 buttons over 2 only makes the solution more expensive for the flyer, and that's 100% counter to my goals. Personally, I'm hoping someone comes up with a solution that's even cheaper and better than the current technology and drives me out of business... it means that my goal will be closer to reality.
 
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