Estes 3" x 38mm 'Crossifre ISXL' scratch build thread -- L1 cert --

[bad_idea]

I plan on doing the cert flight at DARS in Dallas, which has a field with a 4k limit.
. . .
I choose the biggest park I can find locally because I *really* don't want to risk losing it to trees, power lines, or roads...*especially* on a test flight. There's no reason for me to impart unnecessary risk when I have a massive public soccer complex 30 minutes from my house.

Even in my neighborhood park with LPRs/MPRs, I try to keep my flights within 500 feet or so.

Are you located in DFW, or just nearby? If the former, in what parks in what cities are you flying? I fly some in Bob Woodruff Park in Plano during the months allowed (April through October) but would love to know of more local options.

 

[shanejohnson2002]

Are you located in DFW, or just nearby? If the former, in what parks in what cities are you flying? I fly some in Bob Woodruff Park in Plano during the months allowed (April through October) but would love to know of more local options.

I'm located in Texarkana, but I drive to Grand Prairie monthly for USAR drill.

I'm not a DARS member, but from what I understand they have 2 main launch sites: Gunter and Arlington. Gunter is the "high" limit (up to 5k) and Arlington is the "low" limit (800ft or so).

I'm hoping to join this year since I'm out there so much, and maybe one of these weekends I can bring my kids to see some big TARC / L1/2/3 launches as well.

https://www.dars.org/

 

[bad_idea]

I'm not a DARS member, but from what I understand they have 2 main launch sites: Gunter and Arlington. Gunter is the "high" limit (up to 5k) and Arlington is the "low" limit (800ft or so).

Yes, Gunter is a cow pasture a good ways north of Dallas, Arlington is a city park in the middle of the Metroplex. Look forward to see you out at Gunter, and good luck on your L1!

 

[shanejohnson2002]

Didn't get much done yesterday, unfortunately. I had planned on filling / priming but life had other plans. Not a huge deal...I'll just try again today.

I did finish sanding the nosecone. The bottom perfectly matches the body tube now.

I began designing my own 29/38 adapter. That part is pretty easy actually. I'll have to order some more plywood but that's no issue either.

I also refined and updated the OpenRocket file to reflect reality a bit better, since I learned how to properly model fin tabs:


That's whith an H73J...looks promising for a cert flight.

 

[shanejohnson2002]

DISASTER AVERTED!!

I was showing my wife my 29/38 adapter, holding the main body tube of the rocket in my left hand and....my hand just let go. For no reason.

The rocket fell and I heard a sickening CRACK when it hit the tile floor.

Luckily, it only broke the back half of one of the fin tabs. And it wasn't all the way through. 5-ply aircraft-grade plywood for the win! I carefully inspected all of the other fins and there doesn't appear to be any damage at all. The tab took one for the team!

I applied a little bit of wood glue, clamped it between some aluminum bars to ensure straightness, and it's almost as good as new.

I'm not really concerned with it failing on a cert flight. It hit MUCH harder on the tile than it would with a chute (I think, anyway), and it was angled so that it landed directly on the tab that broke. Uner a chute, it *should* fall generally straight down, motor nozzle first.

Either way, I"m still moving forward with it. I plan to do finish some CWF work today, if I have time.

 

[shanejohnson2002]

6 foot 1010 launch rail ordered. It should arrive around the 15th of this month. I hope to make a test flight soon after, with video.

Right now I'm working on filling in spirals and attending to minor details (wicking thin CA into the tube ends, etc). I also realized...I need to update this thread with some pics. I'll do that tonight.

After that, the entire thing will get its first coat of primer on the first warm-ish fair weather day I have.

 

[bad_idea]

In case you're not on the DARS mailing list, club president George announced this morning that due to a high number of expected ARC qualification flights, the club won't be doing any certs at the Gunter launch in March. February or April should be fine.

 

[shanejohnson2002]

In case you're not on the DARS mailing list, club president George announced this morning that due to a high number of expected ARC qualification flights, the club won't be doing any certs at the Gunter launch in March. February or April should be fine.

I'm not on the list yet, thanks for the info. That works out well because I will be out of pocket until at least late April.

I wouldn't mind watching some of the bigger ARC flights though. It's a decent time of year, weather-wise, and my kids would love it.

 

[shanejohnson2002]

First coat of Duplicolor Filler. I sprayed it on pretty thick over the tube spirals and nose cone. There are definitely areas I missed with the wood filler that I'll have to revisit, but nothing too crazy. Also a couple of drips / runs but that's not a huge deal either ,since this is filler... I'll just sand them out.

 

[shanejohnson2002]

I also updated the list of motors, at least up until the cert flight. They all look pretty good to me, with safe launch velocities. Ignore the deployment velocity....OR doesn't know how to properly handle JLCRs.

 

[jmasterj]

Why the vastly different JCLR altitudes? It's all the same rocket with the same recovery system, right?

Personally I wouldn't bother with it on a flight below 1000ft, but I understand the need to practice.

 

[shanejohnson2002]

Why the vastly different JCLR altitudes? It's all the same rocket with the same recovery system, right?

Personally I wouldn't bother with it on a flight below 1000ft, but I understand the need to practice.

Those are just the "optimum" settings. I.e. in perfect conditions (no wind, etc) they will land within 100' or so of the launchpad. I only use them to get an idea of where I need to set it for real-world conditions...kind of like a baseline.

IRL, I'm not going to fly them at those settings....it'll be something far more realistic.

 

[samb]

Well, you certainly seem to have embraced the low and slow concept. Those G74 and F67 numbers don't feel right to me with the projected apogee so close to the chute release setting. That said I've not used a chute release with any flights under 800 feet or so with deployment set at 300 or 400 feet. What are you trying to accomplish with those flights ? Also, as you may know, motors with average thrust greater than 80 newtons are high power motors that require a high power certification to fly. If you want to follow NAR/Tripoli rules anyway.
Since you're going to fly with DARS I think you should go ahead and sign up on the email list. That's the best way to get breaking launch info.
Good luck!

 

[shanejohnson2002]

Well, you certainly seem to have embraced the low and slow concept. Those G74 and F67 numbers don't feel right to me with the projected apogee so close to the chute release setting. That said I've not used a chute release with any flights under 800 feet or so with deployment set at 300 or 400 feet. What are you trying to accomplish with those flights ? Also, as you may know, motors with average thrust greater than 80 newtons are high power motors that require a high power certification to fly. If you want to follow NAR/Tripoli rules anyway.
Since you're going to fly with DARS I think you should go ahead and sign up on the email list. That's the best way to get breaking launch info.
Good luck!

Like I said, those numbers are not representative of real life. They are "perfect world" baselines I use for setting the altitude in the field.

I have plenty of MPR flights under 1k with a chute release. Most of mine are under 500 feet due to field limitations...and the 100 or 200 foot setting hasn't failed me yet.

About the motors, I'm tracking the rules. DARS follows the NAR guidelines, as far as I know. That said, it is right up to the line, as you can order G80s legally with no cert.

I'm not super concerned with getting on the email list just yet. I have a lot of things coming up on my calendar that will probably prevent me from attending. I follow them on Facebook so that's close enough for now.

 

[shanejohnson2002]

Update:

After some testing and internal debate, I decided to apply some CWF instead of Bondo. It seems to be working just fine over the Duplicolor filler. I'm at the stage where I'm ready to begin sanding. The weather is pretty terrible for painting right now, so I'm taking my time with it. I'll inspect it, sand a bit, then put it down and do something else for a bit. Rinse/repeat until it's all sanded and the weather improves.

My rail is arriving today instead of the 15th. I'm going to put it on a homemade PVC pipe tripod base, like my other 20mm and Makerbeam rails.

 

[shanejohnson2002]

Paint work started. I began with Duplicolor Filler



Then filled any remaining low spots with Elmer's CWF.After I allowed that to cure for a week or so, I applied black Duplicolor Sandable Primer to the nosecone:


Here's the results for the nosecone and extension section, after sanding with 220 / 400:


First light/tack coat of primer:


Second light/tack coat to fill in the thin spots:


And the final medium/wet coat of primer to finish it off:


I'm still sanding the body, and will probably prime it with white tomorrow.

 

[shanejohnson2002]

Tried to get some priming done, but the wind picked up and made it just about impossible.



It's not a total loss because the sunlight showed a couple of tiny spots I missed with filler, or that needed to be sanded a bit better.

I don't want to obsess over the finish *too* much, since analysis paralysis is a thing with me... but I don't want it to look like hot garbage either.

Planning on getting at least a primer coat down, and sanded before the end of this week.

 

[shanejohnson2002]

Low spots filled. I used thinned CWF and an old arcade card to scrape / press it into the low spots. I'll edit this post with some pictures tonight.

Today and tomorrow are on the colder / wetter side where I live, so I'll avoid painting until the weekend. That gives me 2 more days to re-inspect everything and do more detail sanding. That said, I'm fairly well committed to the fact that this is the final pass of filler before paint.

My chrome and black chrome vinyl also came in. I will be recreating the stock logo, but with "ISXL" on the fins instead of "ISX". Also, the main "Crossfire" label will have a chrome drop shadow.

 

[shanejohnson2002]

Nosecone and extension are painted!

Step 1: Sand to 800 (basically the same as the black primer picture before, only shinier).

Step 2: Duplicolor Metalcast base coat - 3 coats. 2 light and one medium/wet.

Step 3: Duplicolor Metalcast red - same coats as above



Remaining steps:
Allow it to cure for a week or so. The paint looks pretty good as-is,, but it gets an even deeper, smoother candy chatoyance after a few days. I need to allow it to harden so I can apply the black chrome vinyl to the lower half of the extension. I tried to get a closeup, but cameras can't seem to capture the effect quite right. The BT60 Crossfire in my thumbnail is a good example of how it looks when it's fully cured.


I also am putting the finishing touches on the body. I'm still finding annoying low spots here and there. Once I'm satisfied they're mostly gone, I'll give it a coat of primer.

I also made some SVG files of the decals I plan to use


We're on the home stretch now!

 

[shanejohnson2002]

Body has been primed with white primer. It's going to be rainy this week, and I'll be out-of-pocket over the weekend, so I'll get the scuff / smoothing sanding done and give it one last inspection before a base coat of paint next week. The body tube will be Duplicolor White Pearl. Once that dries, it'll get a sealing clearcoat, then vinyls, then I'm planning on putting a couple of coats of their Effex holo flake on top of that. One last application of clear over everything will finish it off.

I also have the holes drilled for the camera mount. I didn't want this to be a permanent fixture, which is why I didn't glue it. Instead, I'm screwing it into the forward centering ring, and using JB weld to help hold it and form threads.

 

[shanejohnson2002]

Update:

White primer applied and sanded, ready for paint. It's supposed to be rainy here so I'm not doing much else paint-wise until it dries out.

My wife is cutting the vinyls for me on her silhouette today. I'm also experimenting with different sealing techniques and I think I may have a winner. Elmer's clear school glue (or other PVA glue) is often used to seal vinyls in other hobbies, and it has the benefit of drying completely clear. I cut some small 1cm square test pieces out of the vinyl, applied them to an index card, and brushed on the Elmer's with a fine-bristle brush. So far it looks like it worked very well. Today I'll give it a quick clearcoat with Duplicolor 1k in the garage to see if there's any strange interaction between the elmers and the clear.

As I'm painting, I keep noticing tiny areas that I'm tempted to go back and fix up. I have to keep telling myself it's not a beauty contest and to keep pushing toward the goal of flying it.

At this rate, I'll be doing a test flight by the end of March.

 

[shanejohnson2002]

Aaaaaand epic fail on the clear over the vinyl.

I don't know if I didn't have enough PVA covering it or what, but the chrome vinyl IMMEDIATELY turned milky white when the clear was applied. Luckily that was just my test piece so not a huge deal...but frustrating.

I guess I'm on hold until I find a good way to apply a decent finish.

EDIT: Looks like it's un-milking as it's drying/curing. I see more chrome now than before (which was none). I'll give it a couple of hours and check again.

 

[Handeman]

Aaaaaand epic fail on the clear over the vinyl.

I don't know if I didn't have enough PVA covering it or what, but the chrome vinyl IMMEDIATELY turned milky white when the clear was applied. Luckily that was just my test piece so not a huge deal...but frustrating.

I guess I'm on hold until I find a good way to apply a decent finish.

EDIT: Looks like it's un-milking as it's drying/curing. I see more chrome now than before (which was none). I'll give it a couple of hours and check again.

You might want to try nitrocellulose lacquer also as a clear finish. You can buy guitar lacquer. It can be had is spray can I believe.

 

[shanejohnson2002]

You might want to try nitrocellulose lacquer also as a clear finish. You can buy guitar lacquer. It can be had is spray can I believe.

Not a bad idea. Luckily this cleared up after a couple of hours. I was immediately disappointed and thought it had melted the vinyl somehow. I tried BSI 20 minute one time and it DEFINITELY damaged the vinyl, so when I saw this start to act up I assumed it did the same thing.

The good news is: it (finally) worked.

AND I was able to get the nosecone extension vinyl cut and applied, thanks to my wife.


That's where I'm stopping today. We have some bad storms coming in so I couldn't get any more finishing work done anyway.

Next (hopefully final) steps:
1) sand to 800
2) color coat
3) sand to 800/1000
4) apply decals
5) apply clearcoats (PVA, Duplicolor Effex, Duplicolor 1k)
6) reattach all hardware

 

[shanejohnson2002]

The rest of the vinyl has been cut. Thanks to my wife for doing basically all the work for this part. I'm using Vvivid Chrome and Black Chrome. I basically duplicated the original waterslide decals, only slightly fancier with chrome shadows below the logo. And added 'XL' to the roll logo, and changed the "ISX" to "ISXL" on the fins.




I'm hoping the large mirror chrome sections help it 'flash' at altitude. We'll see.

I'm waiting to apply the lettering until tomorrow. My digital micrometer died and I'm not going out at 10:30 to get a new battery.

 

[cwbullet]

Beautiful build. Please post photos and/or video fo the flight.

 

[shanejohnson2002]

Beautiful build. Please post photos and/or video fo the flight.

thanks!

I'm planning on several cameras for the first 3 flights:

- On-board 808 cam with 120 degree lens
- Pad-adjacent Gopro
- Cell phone on tripod at launch control

 

[cwbullet]

thanks!

I'm planning on several cameras for the first 3 flights:

- On-board 808 cam with 120 degree lens
- Pad-adjacent Gopro
- Cell phone on tripod at launch control

Now that will be one well covered launch. Thanks.

 

[shanejohnson2002]

Now that will be one well covered launch. Thanks.

My failure shall be recorded in glorious 4k

 

[shanejohnson2002]

*forum technical issue...double post*