18mm Carbon Fiber screamer- The Crow 18

I have been wanting to build an 18mm version of my Crow rockets for quite a while now. Minimum diameter carbon fiber rockets with 7:1 fiberglass Von Karmen nose cones, single deploy at the top. Built for high altitudes and speeds. Once I saw the new 18mm longburn motors come out I knew now was the time. I had my buddy Ryan turn me a 7:1 VK plug for the nosecone and got to building. Yesterday I sprayed the cone with a few thick coats of primer so I can wet sand it nice and smooth in preparation for making the mold. I also layed up the body tube with two layers of carbon fiber and Raka epoxy. First thing this morning I pulled the tube off the mandrel and it came out very nice. It is now back on the mandrel curing fully. The rocket will use right around 10" of body tube possibly less once I figure out how everything is going to fit. The deployment and tracking as well as telemetry will be handled by a Telemini. The fins will be 1/32" carbon fiber plate. I haven't yet decided how I will do the coupler but I will likely measure the wall thickness of my tube and then turn a mandrel out of aluminum so that when i lay up the two layers it comes out to right diameter for a coupler. I am going to try to keep this as light as possible so that I can use the longburn motors without any issue. Right now with a few guesses on weights and lengths it sims to around 3100 feet on a D24. If I get close to 3000 I will be very happy. In fact I am making 3k my goal for this project. Tonight i will print out a template of the nosecone and trace it on to some G10 for my parting board. I am hoping I can have the mold finished by Friday and get my first cone popped out by next Monday. I plan to fly this rocket at our October Skies launch oct. 18-20 so I still have some decent time. Here is a picture of the plug before primer. More pictures tonight.

3K on a D is awesome, any chance there's a record in your future?

chadrog said:

3K on a D is awesome, any chance there's a record in your future?

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There isn't a category for records on D motors or I would shoot for it. If there was the Tripoli Raven wouldnt fit in 18mm though. However in October I am flying for the G and I records with the 24mm and 38mm versions of my Crow rocket. I have the Tripoli altimeter all ready to go.

Oh, I assumed there were altitude records for all impulse classes - guess I should have done some homework.

The NAR keeps records for low power. The record for senior D altitude is 1214 meters. Senior D altimeter altitude record is 799 meters.

Here are a couple pictures of the nose plug coated with some heavy coats of primer and another of the carbon fiber body tube.

Last night I friction fit the tube onto the mandrel and chucked it up in the lathe. Then I wet sanded it from 320 stepped down all the way to 2000. This took a little extra OD off that I didnt want and also polished up the tube. Later I got my electronics together and started trying to get an idea of how this will fit before I start cutting. I haven't yet started on the nosecone mold so I am behind schedule there, but it isn't too big of a deal.

Could you try this altimeter?
https://www.apogeerockets.com/Electronics_Payloads/Altimeters/MicroPeak_Altimeter

Yes, that would fit but would not be able to fire my charges.

Tube looks familiar! I presume you used the CF sleeve from Soller Composites? I can't wait to see how your little bird turns out. I had less than stellar success with mine. Far less... Altimeter got trashed on a ballistic return to earth.
-Ken

Yes two layers of soller sleeve. .75" and then a 1.25". I am hoping to make a lot of progress this weekend.

My rocket was only 1 layer of .75" sleeve. Two crashes into rock hard salt managed to shorten it a bit by smashing the nose cone into the body and the altimeter into the nose cone but no other damage was incurred. Fins were surface mount with proline thick. What motor will you be flying on? Never mind, I see you will be using a D24. Had my C6-0 flights been successful, I would have attempted that. I've got plans when the Featherweights latest small alt comes out to try again
-Ken

Any progress on the nose cone mold?

Not yet and unless there is a miracle between now and OS this won't be ready. I have been so busy and looks like I will be in the next few weeks too.

Ok, now that October Skies launch has passed and I have flown my G motor rocket successfully it is time to get back on this project. Tonight I will print out a scale drawing of the nosecone shape to transfer to a parting board in preparation of making the mold. I have been so busy the last few weeks non stop that I promised myself this weekend I will just stay home, watch all the college football I can and work on rocket projects. That is AFTER I get back from the Susan G Komen breast cancer awareness walk first thing Saturday morning. I hope to get at LEAST one half of the mold done this week, if not the whole mold. There is no rush since the next launch is a month away.

You should head south to ROCstock.


Congrats on the G rocket.

Thanks! When is it?

maxvelocity said:

Thanks! When is it?

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November 9th in Victorville. One of the largest launches in California.

Waiver?

20k

Hmm, I will think about it.

C'mon out, Max- weather should be good!

try flying it on an aerotech e-45 or f-55 : ) those motors rip

g zilla said:

try flying it on an aerotech e-45 or f-55 : ) those motors rip

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I wish I could get my hands on some of those!

still have one of each both long delays believe 12 sec.

Did it fly?

Not yet. Havent had a solid amount of time to make the mold yet. I'm thinking Thanksgiving weekend should get me some time. Our next launch is in January so I have a couple months.

I made a tiny bit of progress on this rocket tonight. I was mixing up laminating epoxy to coat the nosecone on my madcow screech and had to come up with other things to do with spare epoxy. So I made the coupler for this project. It is curing now. I have bought so many new kits recently, and this afternoon was about to start working on some but then told myself I need to finish the already started stuff before moving to new projects. Which brings me back to the 18mm Crow.

A looooong time later, I finally decided this last weekend that I needed to dedicate my free time this week to finishing this rocket. Tonight I glued the parting board to the plywood base with the correct amount of spacing to get the face of the parting board up at the halfway point on the plug. The plug needs at least one more coat of primer and then sanding to get it as smooth as I would like. I am going to spray it right now. Hopefully it dries enough by tomorrow evening for me to sand and then make the first half of the mold. After pulling this project back out I remembered how cool this little guy is going to be, not sure why I have abandoned it for so long! I need to get the nosecone made so I can figure out its weight then move forward with designing the fin size and shape. Also, once the cone is made, this project will go really fast. So I should be ready to fly by our February launch.

Got the top half of the mold layed up today. It is curing now. Tomorrow or Sunday I will do the bottom and then middle of next week I'll make the first cone. Finally some decent progress.