Bolaero-Endgame

[SteelyEyed]

I’m working on a new HPR design project that I envision as a futuristic, experimental, hypervelocity, ramjet powered, active radar guided, air-to-air missile thingy. I need a good name for it, or an acronym (if anybody wants to help out), but for now I’ve given it a working title, “Bolaero-Endgame.” Bolaero, because I got some of my design inspiration from the Shrox designed “Bolaero-Z” and Endgame, just because I like the way it sounds. I may upscale it to an L3 size project, but for the first version I’m starting off with a 3 inch airframe and a 54mm motor mount tube.

I already had some of the components for this one (a LOC nosecone, a GLR slimline retainer, and a 54mm MMT) and I ordered the rest of the parts this afternoon (so this thread will be slow to develop). Below are some RS9 3D images of the design.

 

[sylvie369]

"The Colbert".

 

[SteelyEyed]

Here's more of a top view. From this view you can see that the design includes forward and aft strakes. The two rectangular objects are there to simulate ACME rail guides.

 

[SteelyEyed]

And more of a bottom view that shows the intake scoops a bit better.

 

[SteelyEyed]

"The Colbert".

Colbert? Doesn't have that scary cool, intimidating weapon ring to it that I'm looking for...

 

[SteelyEyed]

Here's a view that provides a closer look at the ramjet nacelles.

 

[SteelyEyed]

And a view of the business end...

 

[BsSmith]

Endwar
Heelbiter
XP-123A (eXperimental Projectile 123 A, that means build a B!!!)
Kinetic Impacter (Wouldn't be air to air then)
RAM-2
Starfire
HAAM (Hypersonic Air to Air Missile)
HVR (High Velocity Round)

Very nice design, can't wait to see it done.

 

[SteelyEyed]

Endwar
Heelbiter
XP-123A
Kinetic Impacter (Wouldn't be air to air then)
RAM-2
Starfire
HAAM (Hypersonic Air to Air Missile)
HVR (High Velocity Round)

Very nice design, can't wait to see it done.

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Thanks BsS. You got me thinkin'...

How about XARGRAAM - eXperimental Active Radar Guided Ramjet Air to Air Missile ???

Or maybe just XRAAM or XARG-HV.

 

[blackjack2564]

Reminds one of the Coyote.

 

[sylvie369]

Colbert? Doesn't have that scary cool, intimidating weapon ring to it that I'm looking for...

But it beats "Serenity", right?

 

[BsSmith]

How about XARGRAAM....

That would be a fun one for the LCO to try and read!

I like it.

 

[Handeman]

That would be a fun one for the LCO to try and read!

I like it.

Ya, if you can remember the initials when you fill out the flight card.

 

[SteelyEyed]

Reminds one of the Coyote.

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Yep, that was another one of the designs that influenced this one. In fact, I did one of these (Bolaero-Endgame) designs with four ramjet intakes like the Coyote, but it looked a bit "blocky" to me. Like I said above, the Shrox designed "Bolaero-Z" was one of the rockets that inspired this design;

another design that influenced this one was the Meteor (see below).

The strakes make my design a bit more unique.

One of the cool things about this particular design, is one could leave off (or add two more of) the ramjet tubes and/or the strakes; and/or you can choose to install the forward fins with a more conventional rearward sweep and get lots of different optional looks from one fundamental design. I offered this design to a couple of different manufacuturers and no one wanted it because it would be a bit labor intensive (and therefore expensive) to kit, so I thought I would just share it with my TRF friends.

SE

 

[SteelyEyed]

BTW, this is also a zipperless, baffled design as can be seen in the RS9 2D view. You can also see how I did the 1/2 nosecones inside the intake scoops to give it a bit more of a realistic looking ramjet appearance. And this view shows the shape of the the forward and aft strakes more clearly. These are some of the cool things you can do with the new version of RockSim (thanks Tim, I've been waiting for this for a long time).

SE

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[SteelyEyed]

But it beats "Serenity", right?

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Okay, now I know how NASA felt when there was public pressure to name the Space Station after a comedian... but I'm looking for a more serious name. How about the "O'Riley NSD" (No Spin Drone)?

 

[SteelyEyed]

Okay, some parts are starting to arrive for this one. I got some centering rings, shock cord, and a 54mm Slimline retainer from GLR. Also, I decided to build this design with the new Blue Tube product, just to try it out. The airframe tubes arrived a few days ago. OMG, this Blue Tube stuff feels nearly indestructable. I am seriously amazed with the strenth, stiffness and resiliency of this product. Cutting it with a hobby knife is out of the question. I used a chop saw to cut the pieces to length and I plan to build a jig for my Dremel tool to cut the fin slots (and this design has a nearly ridiculous number of fin slots). Cutting the intake tubes lenthwise will be a bit of a trick too, as will the cutting of the nosecones for the center of the intake scoops ...

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[deandome]

I don't know to what degree this has been simulated or not, but the asymmetrical nature of the ramjet tubes (two in one hemisphere, none in the the other) is a little concerning...to me.

They will create some unique drag/vortex effects, and not having them balanced might make it fly in an arc. I guess Bomarc models fly, and they have two honkin' pods hanging off one side...but they're balanced to some degree (weight and/or aerodynamically) by having the wings & fins mounted asymmetrically on the other side. And I THINK that 'disturbing' the flow around the body tube itself is worse than having the 'disturbers' mounted on fins...away from the tube (kinda like how jet airliner engines mounted on pylons vs. directly on/in the wing don't disturb the airflow on the wing as much).

Thoughts? An besides the aerodynamic 'balance', is it important to have the weight of the rocket balanced around the vertical axis? You know....if you mounted it on an imaginary spit on down the center of the BT & spin it, does it need to spin 'cleanly', or is it OK if it wobbles?

OH....cool design, BTW.

 

[shrox]

I don't know to what degree this has been simulated or not, but the asymmetrical nature of the ramjet tubes (two in one hemisphere, none in the the other) is a little concerning...to me.

They will create some unique drag/vortex effects, and not having them balanced might make it fly in an arc. I guess Bomarc models fly, and they have two honkin' pods hanging off one side...but they're balanced to some degree (weight and/or aerodynamically) by having the wings & fins mounted asymmetrically on the other side. And I THINK that 'disturbing' the flow around the body tube itself is worse than having the 'disturbers' mounted on fins...away from the tube (kinda like how jet airliner engines mounted on pylons vs. directly on/in the wing don't disturb the airflow on the wing as much).

Thoughts? An besides the aerodynamic 'balance', is it important to have the weight of the rocket balanced around the vertical axis? You know....if you mounted it on an imaginary spit on down the center of the BT & spin it, does it need to spin 'cleanly', or is it OK if it wobbles?

OH....cool design, BTW.

It will be fine, Look at the Snarky or the Firefox.

 

[BB-ROCK]

It will be fine, Look at the Snarky or the Firefox.

agreed with shrox, flying these type of rockets will be fine. I have many of shox rockets and many others of this type rockets. They are fun to fly and also you get a lot of attention when bring these cool rockets to the flight line.

 

[SteelyEyed]

I considered the symetry question as I developed this design. I originally had 4 symetrical ramjet nacelles and no strakes. But, I decided I wanted a cruise missile look (like it was intended to fly horizontally). Based only on experience (and the fact that this design has lots of fin area), I'm thinking it will fly just fine even though it's a bit assymetrical. I will certainly report on its performance when I get that far on the project...

SE

 

[SteelyEyed]

I just returned from two weeks of business travel and when I got home all the parts I had ordered for this rocket were waiting for me, so now I can get back to work on it. I started on the coupler tube and drilling the holes in the baffle bulkhead. I have gotten into the habit of building almost all of my projects with a zipperless baffle configuration. I really like the convenience of a baffle to protect the parachute, no need for Nomex wraps, just fold/roll the laundry, and stuff a motor in it and go...

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[SteelyEyed]

Mike Fisher at Binder Design did a great job producing me a set of fins cut from 1/8th inch birch plywood. I think they will do the trick. When I build the upscale 5.5 inch, 75mm MMT version of this I'll have him cut me a set of fins from G10 stock...

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[SteelyEyed]

Like I said above, this Blue Tube material is incredibly tough. I ended up cutting the fin slots with my Dremel tool and a cutoff wheel. I printed out a fin wrap guide from VCP6, measured and marked the slot locations, outlined the slots with masking tape which served as a guide to cut the slots. It was not perfect, but it worked...

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[Diosces]

Nice job on the wing/fin slots!

 

[SteelyEyed]

Nice job on the wing/fin slots!

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Thanks John. My primary purpose for using Blue Tube on this rocket was to get some experience with it before I use it for larger airframe birds. I really like it. The standard sizes are easy to work with too. Given its price/performance ratio I think I will use it on almost all my future builds. I may do some CF stuff down the road, but I don't ever see a need to buy fiberglass tubes when this stuff is available.

 

[SteelyEyed]

If you take it slow, drilling Blue Tube airframe material results in nice clean holes. In addition to the fin slots, this shot shows two of the four mounting holes for the PML linear rail lugs that I intend to use for this project. I have typically been using ACME rail lugs in the past, but one of the 3 clubs that I fly with does not allow the use of aluminum rail lugs, thus all my future builds will be done with these or rail buttons.

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[SteelyEyed]

The 54mm MMT in a 3 inch airframe makes it a bit tight when it comes to doing internal fillets at the fin/MMT joint. So for this project I decided to try a technique that I have not used before. I used balsa strips to form small troughs that will allow me to keep the epoxy where I want it when I install the fins. Note also, this shot shows the mounting block for the aft linear rail lug.

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[SteelyEyed]

Here's a view of the entire MMT showing the troughs, rail lug mounting blocks, and the internal baffle. The MMT is long enough to handle a Pro54 K570. With that load it sims to 8370 ft with a peak velocity of 896 mph. Unless I add an AvBay and convert it to DD, I doubt I will ever put that much motor in this bird. If it's flying with DD electronics and not utilizing motorbased ejection, I can cram a Pro54 K1440 in it. Don't know if it would survive that...

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[SteelyEyed]

To accommodate the forward rail lug mounting block, the tube coupler had to be "keyed" to fit.

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