Estes Crossfire Upscale

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joekipp

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So for my first "non-kit" build I'm going to try to upscale an Estes Crossfire.

For the body tubes I'm going to go from a BT-50 to a BT-60 and increase the length of the body tubes from 9.5" inches to 26". I'm going to scale the fins by 2 x. My biggest issue is the nose cone, Does anyone know where to find that nose cone in a BT60 shape. The nose cone that comes with the kit is 5.69" in length. So I would need something 6.1 to 1, Or a BT60 conical nose cone that is about 9.6" in length. Once I have a nose cone and I was going to put the whole thing in Open Rocket to check it out to make sure that it will fly and find out what motor to use.

Right now the only nose cone that I can find is the following: https://www.rocketarium.com/Build/Nose-Cones/1.6?cPath=19_209 but it is a solid nosecone and weighs about 4 Oz.

We got the idea from having a Hi Flyer and a Hi Flyer XL

IMG_0576.jpg

Any thoughts or help would be greatly appreciated.
Thanks
Joe
 
Semroc has in the past (and I'm sure if not now, soon will again) carried a conical nosecone that served as an upscale of the PNC-55BB. To protect the nosecone at the joint, Semroc added a 1/8" length of material that wasn't sloped.

Besides the obvious difference in body tube, the Estes PNC-50BB differs from their PNC-55BB. The 50BB has a cylindrical section behind the conic section that the 55BB doesn't. So, you'll need to make that portion yourself from a length of body tube, and a tube coupler (or a balsa bulkhead). I've included an OpenRocket file that shows what the assembly would look like scaled up for the 50BB and the BBII's assembly for comparison.

The new Estes BT-60 nosecone pack assortment (same part number as the old Nosecone Pack Assortment 303165 - NC-60a Nose Cone (4 pk)) that I found recently in my LHS for ~$7.50 now comes with the same nosecone/tail cone you find on the Conquest, QCC Explorer, and that can be the source of your tail cone if you want to include that detail.

Estes P.N. 072665 Tail Cone


View attachment Semroc BNC-60BB (upscale of Estes Black Brant II nosecone assembly).ork

View attachment Semroc BNC-60BB (upscale of Estes PNC-50BB assembly).ork

View attachment Estes P.N. 072665 Tail Cone.ork
 
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K'Tesh

Thanks for the info and the open rocket files. I'm sorry for the late response, work got in the way of life. It's interesting as I think the tail cone is part of the Estes Solar Warrior Rocket Kit that is on sale at Tower Hobbies. That will give me one of the body tubes, the tail cone, motor mount, and parachute. In the AM I'll check with e-rockets to see if they have the nose cone in stock, if they do I should be good to go. I've got some balsa wood from Hobby Town to cut the fins from.

I was not going to cut the fins though the body tube but just surface mount them. My Hi-Flyer XL is constructed in this manor and has really taken a beating. So I'll use that for my construction method.

Thanks for all of your help above. This will be my first upscale. I'll post some pictures as I put it together.

If I cannot get the nose cone from e-rockets I might take a regular nose cone and use it to make one with paper and CA. I have an Aerotech Buullpup AMB 12-B kit that is has you change the nose cone with a paper/CA extension. On Shapeways there's a vendor named Aerobotix that makes nose cones as well. He has a BT 50 Nose Cone - https://www.shapeways.com/product/W...acement?li=search-results-3&optionId=21619280, with it being 3D printed I would bet the he could upscale it to BT-60 pretty easy.

Thanks again for your help! I'll post pictures as I work on it.
Joe
 
Yesterday I called eRockets and spoke with Randy Boadway. He could find the Semroc BNC-60BB, but Semroc has a BNC-60PED, an 8" conical - drilled nose cone. They were out of stock but he put it on the list to be made soon. I've got to say that I've met very few business owners as nice as Randy. He took the time to find me the nose cone as well as explained to me that the letter system and it's lack of consistency. The next time I drive though Dayton I'll be stopping in picking up a kit or two.

Last night I spent some time making the fins for the rocket. I scanned the fin sheet that came with the Crossfire. Once scanned I both the TIFF into Visio and traced it into a vector (line) shape. Once I had it as a vector I stretched it to twice the size and printed it out.

I used a sliding miter saw to cut the fins and stabilizing stakes. I've never cut balsa wood before and was surprised how soft it was. I'm not sure if Estes uses a "harder" type of balsa wood but the sheet that I have seems very soft and seems very flexible along the grain of the wood. When I cut the fins I did where the grain is perpendicular to the body tube. I might paper the fins.

Here's a picture of the fins as cut. A little later today I'll attach them to the body tube.

Rocket Fins.jpg
Thanks
Joe
 
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I love Crossfires!
Not trying to nit pick or anything but I'm just curious as to what you are going to do to re-inforce your fins?
I noticed that you did'nt align the leading edge with the grain of the wood.
 
I love Crossfires!
Not trying to nit pick or anything but I'm just curious as to what you are going to do to re-inforce your fins?
I noticed that you did'nt align the leading edge with the grain of the wood.

You are not nit picking at all. But I am glad that I cut the grass instead of gluing the fins on! :)

I'll recut them with the grain parallel to the leading edge, that'll give me three fins to play with papering on. It's funny because I noticed that the fins in the kits were cut at odd angles out of the wood and wondered why they had you put some of the fins together when they could have made them out of a single unit. I just never put two and two together.

Now I know and I'll recut the fins.

Thanks for letting me know, I won't make that mistake again.....
Joe
 
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After many weeks of work taking me away from home, sports and scouts I finally got around to getting everything ready to build my upscaled version of the Estes Crossfire. I'm going for 2x upscale that will run on C-11's and D's, and E's. I need to run everything though open rocket. I'll be using the following from an Estes Solar Warrior rocket kit https://www.estesrockets.com/rockets/by-engine/003225-solar-warriortm that I picked up on sale:
  • Tail Cone,
  • Shock cord
  • Center ring set
  • Engine Hook Retainer Ring
  • Engine Block
  • Parachute
  • One section of BT-60


I've picked up the following parts
  • Engine mount tube
  • Engine hook
  • BT-60 Coupler
  • BT-60 Body tube section
  • 1 Sheet of balsa wood
  • 1 - Semroc BNC-60PED Balsa nose cone from E-rockets.biz


The nose cone is a conical NS but it tappers a little more at the end, so it's not a perfect match for the crossfire but close enough for me. The original has a straight section that has a black label applied over it, for the build I'll just paint the top two inches black and the rest of the body tube white. I've recut the fins again taking Top Ramen's advice info about the grain parallel to leading edge, Thanks Top Ramen for catching that. In-between I recut the fins at various sizes to see what looked right, in the end 2x looked good. I'll start building the big version this weekend.

I really want to thank Rany Boradway at ERockets.biz for cutting the nosecone for me. My travels for work took me to Mid-Ohio several weeks in a row and I was able to stop in and see his operation. I just so happened to be there on a Tuesday night, every Tuesday they have a build night for customer to come in and build rockets. I learned a thing or two there. I picked up a PML - AGM-256 Pit Bull while I was there. I'll build that later this year.
photo4.jpg

I see that several people coat balsa parts in CA before sanding. I'll attempt that with this nose cone and see what happens.
Thanks
Joe Kipp
 
Well now that I'm getting ready to build the rocket I've created an open rocket file for it. I think I've got everything covered accept for the Stabilizing Stakes. I'm not sure how to put them into open rocket. They weigh almost nothing and add drag so I would think it would only move the center of pressure towards the rear of the rocket. I was thinking of adding a little weight to the front of the rocket to move the center of gravity forward a little. Without any additional weight the stability is 1.4 Cal.

Please let me know what you think.

Thanks
Joe
View attachment Estes Crossfire Upscale.ork
 
I'm a little curious about the tail cone... the motor mount looks like it's not extending out the rear enough to make the tail cone work.

If it was one I was building (and yes, I'm thinking of building a BT-60 version), I'd base my motor mount on the instructions from the QCC Explorer, or the Conquest to make sure that the engine doesn't get stuck inside.
 
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Looks good.
I guess the only things I would change would be to not put a thrust ring in the motor tube and use a micro-buttons and rail for launching.
It sims to 1700 and some odd ft. on an F32-10.
 
Well now that I'm getting ready to build the rocket I've created an open rocket file for it. I think I've got everything covered accept for the Stabilizing Stakes. I'm not sure how to put them into open rocket. They weigh almost nothing and add drag so I would think it would only move the center of pressure towards the rear of the rocket. I was thinking of adding a little weight to the front of the rocket to move the center of gravity forward a little. Without any additional weight the stability is 1.4 Cal.

Please let me know what you think.

Thanks
Joe
View attachment 263249


The strakes can be simulated (kinda) by using a phantom body tube that the strakes would be mounted to. That said, the strakes would be rectangular, and at this time the phantom body tube will likely have an affect on the sim's performance.

I have an idea on how to include simulated strakes in the file (I'm guessing it is the same thickness as the main fin, or thinner). I'd bury it inside the main fin (much the way I do decals). That way a printout of the fin templates would include them, but they wouldn't show up on the 3D renderings.
 
I just managed to pick up a Crossfire ISX, and I've noticed that your fins are not correct in their shape (based on this scale).
 
They look fine to me.
What am I missing???
The nose cone will take some work however.


Oh, and K'Tesh, congrats on your first Crossfire ISX!
I hope you get around to building and flying it.
All of mine are incredible flyers.:)
 
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The fins in open rocket are pretty close. I may play with them a little more to see if I can get them exact. The real cut fins should be 2X and almost perfect. I took a real fin and blew it up 2X then used it to cut the real fins. Here's a picture of the original rocket and the enlarged version side by side. The stakes are a different story, because the originals were so small and the corners rounded it was difficult to get the exact angles and lengths of the various surfaces, so they are overall 2x the original size but the angles are a little different.

photo125.jpg

To make the rocket 2x in height I adjusted the body tube length, that changed the center of gravity and it was a little close to the center of pressure so I'm going to add 1/4 of an ounce to the nose cone to give it better stability. Here's the new open rocket file. I've not corrected the fins to be exact. I still need to play with open rocket to get it right but I think for my purposes its close enough. I just wanted to check it for stability.

Now if I can just get it finished without screwing up the paint I'll be happy. I hate painting.......

View attachment Estes Crossfire Upscale.ork

Thanks
Joe Kipp
 
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I just managed to pick up a Crossfire ISX, and I've noticed that your fins are not correct in their shape (based on this scale).

Ok, so it was bothering me that the fins in the Open Rocket were not correct as to what I built. I've fixed it :) , printed and cut out a paper fin and matched it to what I built. It should be spot on to what I've built now. I'm glad that I did, it changed the weight a little and now I'm really glad that I added 1/4 Oz at the nose cone, that moved the center of gravity enough that it's still stable on C-11's, D's, and E's.

Thanks for picking up on that. If you print them and cut the fins out you should get what I've got less the stability stakes. If I get some time later this weekend I'll see if I can find a way to add them in as well, and in the right spot.

Also I moved the motor mount back a little bit as well. When I dry fit everything I'll take some pictures.

Once last question for the night, so where the two body tubes come together there's a ridge, if I sand it it'll get fuzzy, I was thinking about covering/painting the ends in white glue, letting it dry, putting them together, then sanding it. Hoping that the glue will keep it from getting the frizzes. Thoughts?

Thanks
Joe

View attachment Estes Crossfire Upscale V0.90.ork
 
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Ok, I've got a .ork file (based on the actual kit, not the upscale, but if you copy the fins, and scale them they should be correct (NOTE: The gap will scale too, so that needs to be factored into the upscale).

CAVEAT: For best results, connect the points from the rear edge of the root cord to the rear edge of the tip cord when cutting out the fins to ensure that the trailing edge is straight (then cut the notch)





As to your ridge issue. Before gluing the two parts together (with the coupler), I'd hit the inside edge with some super thin CA glue to prevent fuzzies. I'd then glue the parts together, prime it with filler primer, then hit it with some Bondo Glazing & Spot Putty (the stuff that comes in the tube like toothpaste). After that cures, sand it down, and re-prime/fill as needed until the joint's smooth.

In my .ork file (BT-50/stock kit)), I've got the Stabilizing Strakes buried inside the Main Fins. I've also learned that the original kit has only two of the Silver/Black fin decals instead of four or six as you might expect.

View attachment Estes Crossfire ISX (7220) Fin Templates.pdf

View attachment Estes Crossfire ISX (7220).ork
 
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Ok, so it was bothering me that the fins in the Open Rocket were not correct as to what I built. I've fixed it :) , printed and cut out a paper fin and matched it to what I built. It should be spot on to what I've built now. I'm glad that I did, it changed the weight a little and now I'm really glad that I added 1/4 Oz at the nose cone, that moved the center of gravity enough that it's still stable on C-11's, D's, and E's.

Thanks for picking up on that. If you print them and cut the fins out you should get what I've got less the stability stakes. If I get some time later this weekend I'll see if I can find a way to add them in as well, and in the right spot.

Also I moved the motor mount back a little bit as well. When I dry fit everything I'll take some pictures.

Once last question for the night, so where the two body tubes come together there's a ridge, if I sand it it'll get fuzzy, I was thinking about covering/painting the ends in white glue, letting it dry, putting them together, then sanding it. Hoping that the glue will keep it from getting the frizzes. Thoughts?

Thanks
Joe

Ok, with a true 2X upscale, there should be no problem with the gaps for the Stabilizing Strakes... However, if the thickness of the fins changes, that changes the shape of the strakes too. For me, I'd probably be using 3/32" for a BT-55 based rocket, and 1/8" for everything larger than that (up to 3" in diameter). So for anyone upscaling they should just remember to take care with their gaps.
 
Well the painting is almost done, the white is on the rocket. I'm going to paint the black band on the top of the body tube to match the black band normally on the nose cone. I'm also going to paint the silver and black on two of the fins. As K*tesh pointed out on the small model there are only decals for two of the fins, I'm thankful. So I'll paint the silver and black on the fins and create a decal for the lettering. I'm going to upsize the text using CorelDraw this week and print on clear label stock. The font appears to be Ariel/Helvetica black with a tight kerning, then stretched out. We'll see how the lettering turns out.


Thanks
Joe

IMG_0001.JPG
 
Looks great, nice work. Of all the kits that I've built, the Crossfire ISX is by far my favorite of those stuck in trees :(
 
The paint is done and I didn't screw it up! So the silver and black were painted onto the rocket instead of labels. I'll let it sit this week so that the paint will dry all the way. Lowe's Valspar seems to take an incredible amount of time to dry. I might switch to Rust-Oleum paint as the silver that I used dried hard in less than an hour. Here's what it looks like with all the paint, I've still got to do the text, that'll be next week sometime.

I'm so surprised that I didn't screw up the paint on this rocket. I have a history of messing up paint, just ask my wife. :)

IMG_0008.jpg
 
Great build and thanks for paving the way! I am considering doing something very similar in the near future (just for fun) as I love the design and look of the Estes Crossfire kit.

Apologies about reviving a very old thread...but is there any reason that I would have to include the "stabilizing strakes"? I think the rocket looks more sleek without them but do not want to mess with overall stability for flights.
 
Great build and thanks for paving the way! I am considering doing something very similar in the near future (just for fun) as I love the design and look of the Estes Crossfire kit.

Apologies about reviving a very old thread...but is there any reason that I would have to include the "stabilizing strakes"? I think the rocket looks more sleek without them but do not want to mess with overall stability for flights.
7 year old thread:pWe will have to find out if the original post, Has the author still alive.
:welcome:to the forum
 
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