Bomarc Beginnings

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Well-Known Member
Jan 20, 2009
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Hey Gang-

Here are a couple of shots of the beginning of our Big Bomarc project.

It'll be very close to 1/4 scale. Roughly 12'x8.75" with a 54" wingspan. As none of us are L3 yet, we are going to use the biggest L that we can find. Probably a Pro75 L1115, with small motors in the ramjets for smoke effects and a little tiny bit more launch speed.

I'll keep posting the pics as we progress.
We are laminating 1/8" sheets of ply together, with 1/8" ribs between. This seems to give incredibly good strength while keeping the weight down... We looked at Baltic Birch at first, but the weight and cost did really bad things to the project...
Thought you might enjoy this one as well...we got a good laugh from it. Boeing is just whacky!
Holy Carp !! Thats gonna be sweet and huge..Please keep posting the killer pics. 8)

That bottom pic could be a caption photo, something like..

" Unknowingly, Thelma married Mr. Bomarc sight unseen..but then she realized just how sexy he is"


Advertisement " Our bomarc rocket is so hot, you build this one, and the women will come running"


" Lewis couldn't resist having his wife stand next to his creation, but then he saw that twinkle in her eye and regretted it "
Very cool, can't wait to see some more pics. I'm helping my son (or is he helping me?:) ) build a 4" IM-99B. Main airframe is glassed and almost all the parts needed have arrived. I have collected a bunch of data so if I can be of assistance let me know.

One of the guys on the build team has built bomarcs from bt-20 up to a 4" that he just launched last month. It was a spectacular launch and flight right up until the K motor burned through, shooting 5' flames out both ends of the rocket...all while many many people were shooting photos.
Do you happen to know how much nose weight was required in the 4” version? I’m trying to figure out cp/cg relationships. I’ve thrown out trying to compare mine with the Estes and NCR versions, as these are longer than scale, especially the NCR version. (The nacelles are also too small in diameter.) By the dimensions you posted (8.75” x 12’) puts your model very close to the scale length so I though perhaps you could help me out here.


very cool, that thing is going to be really big. Should be interesting on the L

I have a big sheet of the same plywood, when it cuts it chips but it seems pretty strong and if you layer it I am sure it would be fine

On the 4" version, 7 lbs. on noseweight was added. According to my friend, the CG should be roughly at the forward point of the wing. This seems to me to be a little extreme, but he's the one with the bomarc experience.


Thanks for the vote of confidence on the plywood. I got the vertical stabilizer from my wood guy today, and it seems very light and very solid.
...and a top view!

We have glassed the main airframe and are working on shaping and glassing the ramjets next.
Nice work Todd and crew. The bomarc has always been one of my favorites.

The CG for my X15 is at the front of the wing so you are right about yours too. I would estimate you will need 25-30 pounds of nose weight so take that into consideration. Use the "fastest" full L motor you can and a long rail or it will tip.

Bomarc's are notorious for tangling chutes and shock cotds in the nacelles. Use a Skyangle free bag and let the heavy cone come down on its own chute.

GL and keep us posted......Bill
Here's the next batch of pics.

First the nosecone has been psuedo-glassed with 2 layers of panty-hose. We have added a 3/4 ply ring to the base as an anchor point for the recovery system. The nose is hollow so that we can add ballast if needed (we expect to need it...)
Here's a shot of the MMT coming together. We are using a 98mm tube, but plan to adapt down to a 75mm motor, probably the Pro75 L1115. We want the flexibility to come up in size once one of us gets our L3!
Here's a shot of one of the ramjet pods. The silly things are almost as large a diameter as the main airframe! Looks kinda weird with the "little" 38mm motor mount in it, doesn't it? The Pro38 G69 SS we will load in the outboard motor tubes are mainly for just smoke...
Last one for this week, but we are hitting the ground running now that it's stopped raining constantly and the NSL is just over a month away!

This is the assembled tail planes. They are made out of laminated strips of luaun and reinforced with pine striping that has been screwed in and epoxied with milled fiberglass filler.
Tasty !

Some excellent photo work there and I am so looking forward to seeing more on this. 8)

Cheers and ty for posting,
What a bird. I can't wait for pic's of the flight. Great work RocketmanTM. Assuming that this is dual deploy will look forward to the electronics bay photos.

We don't expect it to get high enough to need a dual deploy. We will need to use electronic deploy though as no motor even close to what we need uses an ejection charge!

I should have update pics over the next few weeks, as we hope to launch at the NSL! This is quite a step up from our original target date of Plaster Blaster in Oct.!
Here's the next batch of photos.

This one is the nose cone with it's airframe extention at the base and the motor tube with the tail attached.
Here is one of the ramjets. We are pseudo-glassing them with panty hose. This should help to keep our weight and cost down, and it conforms to the taper without having to figure out how to lay the glass on and keep it flat....
These are some amazing pictures. That rocket is like what most of us are doing, but on steroids, lots of them:D
Last one for this week, but we are building again next weekend. Our chute got here this week, so that is one less thing to worry about getting in many details, NSL getting soooo close! And it's possible that we aren't even going to make our weight cut off.... To use the CTI Pro75 L1115, we gotta stay under 53 pounds, dry weight...
Wow Todd, it's coming to life! I heard your friend mention this project at PB last year so I made plans to come see it this year. Having you fly it at NSL would be even better!! I look forward to seeing you there!!

Thanks Reed! We are having a blast on this build. The team is coming up with some great ideas together, problem solving through some interesting engineering problems. This build, due to some scheduling issues, it has taken us over a year to get through the designing and the build so far. It's great working on something this huge, which would really be beyond what any of us could handle individually.:D
Hey Chris!

If we don't get this done, we will be launching our 6" upscale Starship Excaliber and Dragonship 7! We are pushing as hard as we can, but the friggin' "medium" epoxy is sloooooow.... This will be great for strength, but not so good for getting done fast...

Glad to hear that you'll be at the NSL! Can't wait to get all of the TRF'ers together this time!