Anyone Have A "D" Powered Estes Crossfire?

Up she went today on a C11-3.
Awesome flight!

Nice flame to rocket ratio

I was quite surprised at how High the C11 put this little bird. With the new Nylon Streamer she took quite awhile to make it to the ground, but thanks to little wind and a little bit of the proper angle on the Rod, she came down surprisingly close to the pad.
If you look to the right of this Pic' you can see the Streamer on the Snow. About 60 Feet or so from the Pad.
I estimate Altitude to have been 700ft.+. She really dissapeared until the Tracking Smoke and deployment.
I can't wait to fly her again with the C11 and compare it to the D12 on the same day. It was only 3 Degrees today, so there was no time to be out there doing multiple launches.
C11 is my new "Favorite Motor".

I love this idea so much, I'm gonna see what I can hack together from spare parts right now. I also love the DX part of the name, so maybe look for a TopRamen Crossfire DX knockoff build thread soon.

dward said:

I love this idea so much, I'm gonna see what I can hack together from spare parts right now. I also love the DX part of the name, so maybe look for a TopRamen Crossfire DX knockoff build thread soon.

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Glad you like it!
It's a real joy to fly, as it has plenty of Smoke, Fire and Noise for such a small Rocket.
I'm kinda' in love with the Fin design too.
When I find a big enough field, or the Lakes ever freeze over, she may yet taste an E20 Composite.:eyepop:
I'll be building a couple more of these in the Spring anyway.
I have a 29mm Version "On the Back Burner" now too. I'll finish that up in the Spring too.

I'll be keeping an eye out to see what you come up with. Enjoy!

I finally finished my rendition of the Crossfire DX. Instead of starting a new build thread I thought I'd just put a mini-build here--hope nobody minds.

Conical Nose Cone
I decided to do mine with BT-55 so that I could keep the transition on the bottom of the rocket. I have a hefty supply of low-power stuff, body tubes, couplers, nose cones, etc., but I did not have a conical nose cone for a BT-55, so that had to be handmade. I will try and attach a pdf with the template below.

I use the usual roll the bristol paper over ever smaller dowels to get the curvature, but I could never stick a tab in a single step, so I work my way up from the bottom, taping as I go and then glue a tab on from the inside with the tape and some rubber bands holding everything in place. I follow that up with a soak in thin CA. Sand. I epoxied the bottom of the nose to some BT-55 to keep the curvature right.

I've never made a paper nose cone before, but I did make a really long boattail once and it looked good for awhile, but eventually somehow got out of round. As a safeguard, I used the template again and glassed the nose. (8.5 oz, west systems). After a full 24 hour cure, I sanded and filled any gaps with epoxy clay and finally applied a thin layer of my usual filler (Equal parts West Systems epoxy, colloidal silica, and phenolic microballoons).

After that cured I sanded until it looked right. Finally, primer and paint red.

Transition
I used a section from a BT-55 elliptical nose cone for the transition/inverse boattail at the bottom. That's 1/4" pin striping for the cutting mask--works nicely on non-uniform surfaces like nose cones and boattails.


Motor Tube and Motor Retention
I decided to put in a motor retainer (24 mm) because I had one and I don't often build 24 mm. I configured the motor tube to accommodate up to 90mm of motor but did put in an engine block so that I could fly motors like the D-12 that doesn't have a thrust ring--just add a couple of spacers and screw on the cap. The centering rings are from an Estes Designer's Set.


Fincan
I decided to make these through-wall fins. I used the fin guide from openrocket to cut the slots into the body tube after I epoxied in the motor tube. I just wasn't in the mood to fill and prime so I papered the fins (even the strakes). The procedure I have outlined elsewhere, but basically rubber cement on both fins and paper, let dry a few minutes, slap on the fins, using the fins as a guide cut the paper. Do the same for the other side. Let soak in thin CA and once it dries, sand until smooth (120 followed by 320 grit).


I used a posterboard fin jig to mount the fins. For fillets I used dripless carpenters glue and one-at-a-timed them, because it does drip a little. Also had to do a little filling with Bondo glazing and spot putty. After the fins were cured, I attached the strakes with wood glue. Fins are 1/8" basswood. Strakes are 1/8" balsa.



Final Product
It came in at 513 mm long, a gross weight of 131 grams, and a margin of 2.56. I added clay to the nosecone before attaching the bulkhead (1/8 basswood) to match the margin on the Crossfire ISX. Any details missing from this mini-build, assume they were standard practices.


Here's a side-by-side of the ISX and DX. I couldn't get the waterslide decals to look very gray. They came out a bit bluish despite having designated the color as black with transparency, killing off the C,Y,M values entirely.



I'll post a video of its maiden flight when that happens. Probably fly it on a D12 first. Openrocket sims suggest a D12 would take it to almost 700 feet, but a G55 might see 2700. I used the square fin profile instead of rounded because of the drag from the strakes, so the apogees could be higher.

Here's the nosecone template file.
View attachment finguide (2).pdf

That is AWESOME!!!! Very nice work indeed!!!:clap:

Looks like a BT-55 is in order for me too!

TopRamen said:

Looks like a BT-55 is in order for me too!

View attachment 253560

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Sweet!

I was just thinking, it might be easy enough to make this rocket use CHAD Staging to use a C11-0 as a Booster.
If it had rail buttons or guides, it would probably get plenty of speed up before leaving a 60" rail as opposed to my 48" 1/8" rod.

A quick OR sim says you could probably chad stage a C11 to a D12 if you could get it to be stable (Sorry, I know how much you hate that word ). About an ounce in the NC should be enough. A D12 to E9 suggests over 1700. That would be a he!! of a cool flight. It'd really put that sucker up there. C to C could keep it in sight at 600, though, and would have it stage at roughly 50ft off the ground!

Nate

nute said:

A quick OR sim says you could probably chad stage a C11 to a D12 if you could get it to be stable (Sorry, I know how much you hate that word ). About an ounce in the NC should be enough. A D12 to E9 suggests over 1700. That would be a he!! of a cool flight. It'd really put that sucker up there. C to C could keep it in sight at 600, though, and would have it stage at roughly 50ft off the ground!

Nate

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Thanks!!!

I was thinking if you wanted to add some drag to slow it down a little to keep the apogee from getting way up there, those fin strakes or chines could be made as 3D shapes instead of the flat profiles, i.e. - shape some light balsa blocks rounded out using the strake profile as a guide.

But, then again, what am I thinking, why would you want to slow it down?