Rats! It's not. 
The red ends where the fins begin, so I need to paint a small band of red at the top of the bottom half.
The red ends where the fins begin, so I need to paint a small band of red at the top of the bottom half.
Dragon Rocketry 4" Exocet MM38 Unboxing & (Eventual) Build
- Thread starter KenECoyote
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So I figured I'd need to paint ASAP since this weekend is getting very cold (negative F temps at night by me) and it's sunny today... albeit quite nippy!
What's with the fried egg and asparagus? (Note the asparagus is animated and moves up and down.)
What's with the fried egg and asparagus? (Note the asparagus is animated and moves up and down.)
Sooo... I quickly sanded the top portion and then I searched for red paint at home and couldn't find any... go figure!
I then went to the local hardware store and picked up a few cans of fresh minty paint... why take chances with "who knows how old" paint?
Quick spray... not full fast, but halffast:
Yeah, looks like a halffast baboon job. Lol
Still, I figure that this will allow me to continue sanding tonight and maybe put down a coat of black tomorrow and when it's time to paint the upper half red, I'll add one more coat to the band.
BTW Red paint doesn't coat very well over dark colors like gray, so I would've added a layer of white primer if I had more time.
I then went to the local hardware store and picked up a few cans of fresh minty paint... why take chances with "who knows how old" paint?
Quick spray... not full fast, but halffast:
Yeah, looks like a halffast baboon job. Lol
Still, I figure that this will allow me to continue sanding tonight and maybe put down a coat of black tomorrow and when it's time to paint the upper half red, I'll add one more coat to the band.
BTW Red paint doesn't coat very well over dark colors like gray, so I would've added a layer of white primer if I had more time.
Sandy.
Sooo...I sanded down the rest of the rocket last night (indoors, which is quite a mess!), but something seemed a bit off...
Then I noticed that the red painted section had scratches and slight gouges visible despite being painted. Egads!
I checked my sanding sponge and apparently I was using a new coarse one instead of my usual fine ones.
This is related to having Bern away from rocketry for a few years and having forgotten that I had a supply of coarse sanders that are the same color as the fine ones.
Oh well!
So looking at the red section, I wasn't very happy with the result, so I did some light sanding with an old used fine sanding sponge and today I added another coat of red...
(Boy, that looks awfully red lol!)
...despite it being even colder than yesterday!
I may re-sand the bottom portion with finer grit after I get some more of it this weekend or I may just lay down some black first to see how it looks.
Sooo...I sanded down the rest of the rocket last night (indoors, which is quite a mess!), but something seemed a bit off...
Then I noticed that the red painted section had scratches and slight gouges visible despite being painted. Egads!
I checked my sanding sponge and apparently I was using a new coarse one instead of my usual fine ones.
This is related to having Bern away from rocketry for a few years and having forgotten that I had a supply of coarse sanders that are the same color as the fine ones.Oh well!
So looking at the red section, I wasn't very happy with the result, so I did some light sanding with an old used fine sanding sponge and today I added another coat of red...
(Boy, that looks awfully red lol!)
...despite it being even colder than yesterday!
I may re-sand the bottom portion with finer grit after I get some more of it this weekend or I may just lay down some black first to see how it looks.
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Today was great weather out (~50F and sunny) considering it is February in NY, so I taped off the upper red band and applied a first coat of black to the rest of the lower section.
I was using new can of paint and did end up with some drips on a mid fin, but luckily I started on the back/rail button side first (on purpose) and I had heard that masking tape can be used to remove drips and it worked pretty well!
Here's the front and the Dragon logo shows up!
I'll let it dry and them decide if I want to do any further sanding before more coats (if the weather stays nice this week).
I was using new can of paint and did end up with some drips on a mid fin, but luckily I started on the back/rail button side first (on purpose) and I had heard that masking tape can be used to remove drips and it worked pretty well!
Here's the front and the Dragon logo shows up!
I'll let it dry and them decide if I want to do any further sanding before more coats (if the weather stays nice this week).
Eventually you get an update! 
I've been stalled because I've been waffling over the dd setup. This one doesn't have a vent band and all my previous dd builds have had one, so I wasn't familiar with this setup.
A few messages to Scott cleared things up for me. I believe this is the traditional dd setup (where the bay is attached to the forward bt section and the nose cone is ejected out).
The bay is held to the forward bt with three screws, which allows access for prepping as well as moving the bay to different rockets (very cool!).
The upper bt was marked for the three bay attachment screws as well as access holes for the Schurter switches provided.
There's detailed directions on the Dragon Rocketry Technical page.
I've been stalled because I've been waffling over the dd setup. This one doesn't have a vent band and all my previous dd builds have had one, so I wasn't familiar with this setup.
A few messages to Scott cleared things up for me. I believe this is the traditional dd setup (where the bay is attached to the forward bt section and the nose cone is ejected out).
The bay is held to the forward bt with three screws, which allows access for prepping as well as moving the bay to different rockets (very cool!).
The upper bt was marked for the three bay attachment screws as well as access holes for the Schurter switches provided.
There's detailed directions on the Dragon Rocketry Technical page.
I followed the directions and drilled the holes, CA'd and sanded them down, followed by a trial fit.
Then I tested the assembly fit on the lower section and marked lines for the side wood strips.
Then I tested the assembly fit on the lower section and marked lines for the side wood strips.
Now it's time to give the upper bt some attention!
For the first time, I tried filling the spirals before laying down Rusto filler primer. However, it didn't work so well since much of the filler came off the spirals when sanding.
Oh well, time for gluing the upper strips!
I also did two rounds of wood glue fillets on the sides of the strips. It was necessary because the strips are flat, but glued to a convex bt.
For the first time, I tried filling the spirals before laying down Rusto filler primer. However, it didn't work so well since much of the filler came off the spirals when sanding.
Oh well, time for gluing the upper strips!
I also did two rounds of wood glue fillets on the sides of the strips. It was necessary because the strips are flat, but glued to a convex bt.
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You will also need to drill vent holes for your electronics. The switch holes do not allow for venting as the switches are very close to the holes.
Ah, thanks for that. I was actually wondering about it and normally I add venting near the finish.
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This is making me want to build one finally. I printed a nose cone just have not gotten any further. Got to many projects going on at once.
It was nice out, but a bit windy for spray painting, but I got to prime the upper bt through unwavering patience and steely will.
After some sanding and paint, I still have work to do on the nose cone and electronics (maybe this weekend).
That's it for now, but getting closer!
After some sanding and paint, I still have work to do on the nose cone and electronics (maybe this weekend).
That's it for now, but getting closer!
I have to say that with the side wood strips, this bird (fish?) feels STRONG and it looks very impressive given the size, mid fins and paint.
Then again, I may be biased lol
Trivia time! 
Anyone a Top Gun fan?
Did you do a "Huh?" when you heard "The Migs carry the Exocet missile"?
(From Moviemistakes.com)
Ah, gotta love Hollywood!
Anyone a Top Gun fan?
Did you do a "Huh?" when you heard "The Migs carry the Exocet missile"?
(From Moviemistakes.com)
Ah, gotta love Hollywood!
I honestly think that the only thing factually correct about that movie was that sometimes Navy guys play shirtless volleyball. :haha
Some updates! I've finished the red paint on the upper to a satisfactory finish (the Rusto 2X Red seems to be hit or miss with how well it comes out with some spots a bit less glossy, but I plan to add gloss clear at the end anyway).
I also started working on the nose cone. I added the included BBs weight and enough epoxy to cover it along with some all thread (my go-to for nose mounts, which allows me to add more weight if needed).
I actually noticed a small blemish spot on the inside when the cone was held to a light, so I covered that spot with JB Weld.
I also started working on the nose cone. I added the included BBs weight and enough epoxy to cover it along with some all thread (my go-to for nose mounts, which allows me to add more weight if needed).
I actually noticed a small blemish spot on the inside when the cone was held to a light, so I covered that spot with JB Weld.
For HP builds I would normally also have some wood or metal rods going through the nose weight to hold it in place.
Like this in a 4" Phoenix nose cone with a triangular lead weight before the epoxy pour:
However, for this one I initially figured the ridges in the 3D printed nose cone would be enough to hold the weight in place.
Later, I decided to use some expanding foam to help hold everything in place as well as strengthen the 3D structure in case of a hard landing.
Like this in a 4" Phoenix nose cone with a triangular lead weight before the epoxy pour:
However, for this one I initially figured the ridges in the 3D printed nose cone would be enough to hold the weight in place.
Later, I decided to use some expanding foam to help hold everything in place as well as strengthen the 3D structure in case of a hard landing.
I tried Bondo on the nose cone, but it didn't work out so well for me (could be this version of Bondo) and after a lot if hand sanding I wasn't getting very far.
I ended up using a 1/4 sheet sander and that made very quick work of getting the surface smooth enough for my liking.
I ended up using a 1/4 sheet sander and that made very quick work of getting the surface smooth enough for my liking.
Exo the red nose rocket...Paint!
This initial coat looked good at first, but when it dried I realized I had made a boo-boo.
New lesson: DON'T use a Swiffer dusting cloth on a 3D printed part. The sanding lifted up 3D strands which hooked a LOT of the Swiffer fibers.
Here is one of two bunches of fibers I had to pick off using tweezers...
After that fun exercise, I added another coat of paint.
Not bad!
Here's a pic of the rocket put together at this stage to see how it looks along with some of my other 4" diameter phenolic rockets for comparison:
That's it for now. I've built the e-bay and currently testing, but hit a snag and may build a Quantum to use instead.
Club's launch is April 22-23, so I'm still on schedule so far.
That's it for now. I've built the e-bay and currently testing, but hit a snag and may build a Quantum to use instead.
Club's launch is April 22-23, so I'm still on schedule so far.
Tim51
Well-Known Member
Just read your thread in its entirety - great build - looking forward to a flight report! The Exocet has bad associations here in the UK (it caused Royal Navy ship losses during the Falklands War) which is probably why I've never seen any scratch, model or HP scale flights.
I spent alot of time in and around Chinatown during a year working in NYC over twenty years ago, 2001-2002. Very fond memories of having breakfast in the Dragon Land Bakery on Walker and occasional lunch or dinner in the Excellent Dumpling House on Lafayette!
I spent alot of time in and around Chinatown during a year working in NYC over twenty years ago, 2001-2002. Very fond memories of having breakfast in the Dragon Land Bakery on Walker and occasional lunch or dinner in the Excellent Dumpling House on Lafayette!
Thanks!Just read your thread in its entirety - great build - looking forward to a flight report! The Exocet has bad associations here in the UK (it caused Royal Navy ship losses during the Falklands War) which is probably why I've never seen any scratch, model or HP scale flights.
I spent alot of time in and around Chinatown during a year working in NYC over twenty years ago, 2001-2002. Very fond memories of having breakfast in the Dragon Land Bakery on Walker and occasional lunch or dinner in the Excellent Dumpling House on Lafayette!
Yes, weapons of war can be sensitive subjects, but imo anger should be directed towards those who use them to do unwarranted harm vs. the object itself. Heck, there are MANY V2 model rockets (and rocket models!
) made and shown here.Yeah, I miss Chinatown... you can eat like a king with a bill fit for a pauper!
Salty Bay...
For me, the e-bay of a dd rocket is the most difficult part of a hp build. There are SO many ways to set it up as well as so many different electronics you can use with each having different requirements.
I had a TRS in mind for the prime dd altimeter and tracking as well. It also uses two batteries. I figured on using a Quark for backup... very simple and easy, but really no frills - which is fine for a backup!
Ok, there were TONS of deets as well as back-and-forths, but I'll just let the pics show them with just sone notes added.
Schurter switches installed, altis in baggies...
Using PVC caps for charge wells and figuring out placement of everything (terminals were supplied with the kit).
For me, the e-bay of a dd rocket is the most difficult part of a hp build. There are SO many ways to set it up as well as so many different electronics you can use with each having different requirements.
I had a TRS in mind for the prime dd altimeter and tracking as well. It also uses two batteries. I figured on using a Quark for backup... very simple and easy, but really no frills - which is fine for a backup!
Ok, there were TONS of deets as well as back-and-forths, but I'll just let the pics show them with just sone notes added.
Schurter switches installed, altis in baggies...
Using PVC caps for charge wells and figuring out placement of everything (terminals were supplied with the kit).
Stuff epoxied in place, wires fed through drilled hole. I also added a layer of epoxy to both Bay lids to protect them.
Quark on the "top" of the sled because the TRS has an antenna that needs to route out and it was straighter through on the backside.
Above you can see where I placed the third battery. It's resting on top over the other two batteries and about where the centerline is for better weight distribution.
Because there are three batteries, I added a layer of fiberglass to the bottom of the sled as a precaution.
The TRS! You can see the connection to the antenna extension going out.
Quark on the "top" of the sled because the TRS has an antenna that needs to route out and it was straighter through on the backside.
Above you can see where I placed the third battery. It's resting on top over the other two batteries and about where the centerline is for better weight distribution.
Because there are three batteries, I added a layer of fiberglass to the bottom of the sled as a precaution.
The TRS! You can see the connection to the antenna extension going out.
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For the second TRS battery, I hooked up a pull switch for safety.
Bay ready for testing!
Bay ready for testing!
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Next... lots of drilling, epoxy and CA!
I may insert brass shims where the shear pins go... will see how they fare after charge testing.
Drill baby!
I coated the inner walls of the bay tube as well as the body tubes (past the bay) to protect the walls against charge blasts.
I may insert brass shims where the shear pins go... will see how they fare after charge testing.
Drill baby!
I coated the inner walls of the bay tube as well as the body tubes (past the bay) to protect the walls against charge blasts.
"Behind the backyard shed" charge testing!
Reminder to use protection (on the rocket upper).
I made charges based on some website calculators, but they seemed much too low to me and sure enough the main didn't pop (it "piffed!") and the drogue barely separated.
View attachment 20230414_142159.mp4
View attachment 20230414_142513.mp4
I'll make more charges and also sand down the nose shoulder some more (fit seemed a bit tight). Will test more this weekend!
Reminder to use protection (on the rocket upper).
I made charges based on some website calculators, but they seemed much too low to me and sure enough the main didn't pop (it "piffed!") and the drogue barely separated.
View attachment 20230414_142159.mp4
View attachment 20230414_142513.mp4
I'll make more charges and also sand down the nose shoulder some more (fit seemed a bit tight). Will test more this weekend!
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Ken you can move that battery that is not in the battery box. You can turn the battery on its side and get 2 together in the same spot. See the picture below.
Yes, I thought of that too, but also did it this way to move weight forward (old habit). Plus I had already drilled for it. Thanks though!
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Only problem if that zip tie fails you just lost that electronic as it will beat it like a hammer.
Also here is what my charge sizes are for a rocket the same size. I use 1.5 grams for drogue and 2 grams for main with 2 #2 shear pins.
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