DynaStar AeroDactyl Build Thread

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gdjsky01

Kim's Rocketeer
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Having spent quite a bit of time on a scratch build, and having more kits than any sane person at my age should have, I thought I'd better get crackin' on a kit. I am not sure why I have a the AeroDactyl since it is designed for like 4 motor combos. E12 and F15s. I have given serious thought to adding a straw through the sustainer rings to a payload section. I just am not sure yet. Doing so would let me use composites at a later time with a lot of E and F choices. Couldn't hurt. I may even create a wiring tunnel on the outside... hey real rockets do that.

Enough speculation. Fair warning, clicking on the thumbnails inserted here will get you the full resolution apparently. Unlike my launch reports, I just do not have the time or will to post process these images.

So here is the parts view. Overall the quality of the kit is very very good. You pay a premium at Apogee Components for everything. However there is no arguing with the quality.
Aero Dactyl Build-00001.JPG

And a few close ups

Aero Dactyl Build-00002.JPGAero Dactyl Build-00003.JPGAero Dactyl Build-00004.JPG
 
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If you look at the instructions online they suggest papering the fins and I was all together ready for that. However the fins are 1/8 (3mm) bassword. And there is a little piece of paper telling you the kit not comes with basswood. The webpage for the kit says it is designed to be as light as possible for a big rocket. The basswood will add some weight fo schoor. My 'guess' is the booster had fin snap issues? Don't know. I will say the laser cutter was set a tad 'light' as I had to do a lot more than just 'cut the tabs' to get the fins out. I went through several excell #11 blades to get them out. Though smooth, I may still do a single light seal of the wood. And of course rounding.

I went ahead as I almost always do and did a pass of Bondo Spot Putty on the tube spirals. That are very pronounced. The tubing itself is very light weight as the web site claims. Here they are before I sand them.


Aero Dactyl Build-00006.JPG
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Now the Bondo is sanded off. Things look good. Notice how the humid air here seems to have cause deformation in the booster tube. It'll be fine once I get everything glued together. I assume its humidity. As I said, kit makers... ah never mind.


Aero Dactyl Build-00008.JPG

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Then I rounded the edges of the fins.
I wanted to bevel them. But don't know how to create a jig for a belt sander to do so.
Aero Dactyl Build-00010.JPG

So I am supposed to build the booster's 29mm MMT.
The instructions are online.
Thing is the 29mm MMT is not too tight as the instruction suggest it might be, it's way too loose.

So here is my instructions for me.
  1. No glue yet!
  2. Place the two centering rings in the upper and lower ends of the tube.
  3. Place all three fins in the slots. Don't glue them just place them
  4. Take a coupler and use it to push the lower centering ring up against the fin tab's trailing edge
  5. Take the other coupler and use it to push upper centering ring up against the fin tab's leading edge
  6. Now the rings should be tight against the fin tabs sort of holding them in (straighten out the fins a bit)
  7. Remove the coupler from the bottom and take some thick CA and tack the lower ring in. Don't get anything on the fins... which should be impossible... but don't
  8. Removed the coupler from the top of the booster and tack the forward centering ring in with thick CA
  9. If you want you can remove the fins now as the rings are right where they should be on the TTW fin tabs when the fins are inserted
  10. Now run a fillet of wood glue around the forward edge of the forward CR. When you have waited long enough that is is not gonna drip, do the trailed edge of the aft CR.
  11. Although the instructions don't say how far the MMT should stick out the back of the booster, we can guess. The MMT is so loose it will fall right through the centering rings. So lightly sand the MMT, turn the booster on it's side, and place the MMT through the CRs until something sticks out the back. Carefully take a toothpick or something and tack the MMT in the forward CR with thick CA. Ditto the aft CR.
  12. Fillet the MMT in the forward CR
  13. Fillet the MMT in the aft CR
This is a view looking down the forward end of the booster with the coupler still up again the CR. There is no glue in the image. We don't yet want to glue. Again... don't glue the couplers in (yet)!!!

I'll see if I can image the steps when I do them. :)

Aero Dactyl Build-00012.JPG
 

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I will be watching this build with great interest!

I should mention that Apogee recommends about 30 different 29mm motors for the single-stage configuration, ranging from Es to Gs. Adapting down to 24mm or upgrading to a larger diameter mount unlocks a lot more.
 
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Thanks Shane. Still on the fence about running a tube through the sustainer for igniting composites in the sustainer. I'd prefer to have any electronics in the payload bay... but that means I need a breakaway connection for the wire to the ignitor at the bulkhead. So when the ejection charge goes off, some sort of plug just gets pulled off the bulk as the shock cord extends, if that makes any sense. Or just forget it. Or run the tube, but leave the details for another day.
 
Thanks Shane. Still on the fence about running a tube through the sustainer for igniting composites in the sustainer. I'd prefer to have any electronics in the payload bay... but that means I need a breakaway connection for the wire to the ignitor at the bulkhead. So when the ejection charge goes off, some sort of plug just gets pulled off the bulk as the shock cord extends, if that makes any sense. Or just forget it. Or run the tube, but leave the details for another day.
I would wonder if some kind of contact connection would be possible. Checking continuity might be a bit dicey and it would require cleaning, but you’d get cleaner separation and more usable internal volume.

Still, staging composites seems kind of silly when an E23-8T will get you over 800 ft and you’ll be topping 3500 ft on a CTI G54-9.
 
Still, staging composites seems kind of silly when an E23-8T will get you over 800 ft and you’ll be topping 3500 ft on a CTI G54-9.

Because I might want to. Period. I mean it seems pretty silly to launch silly little rockets to begin with? It's not like they are going anyplace or doing anything.
 
So as I laid out above, here is the booster upside down with the fins in the slots (no glue) and a coupler pressed against the forward CR. The tension keeps the fins in place. The same was done with the aft ring (the one here) then the coupler carefully removed and the CR tack glued with locktite thick CA.
Aero Dactyl Build-00013.JPG


Once the CA is dried / accelerated I applied a fillet of titebond
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Once the AFT ring is setup, the coupler was removed from the front of the booster and the forward CR tacked in place and let dry. That done, I removed the fins and ran a fillet.


Aero Dactyl Build-00015.JPG

As I mentioned the boost MMT was super duper loose. It would fall right through. Strangely enough the sustainer MMT is a bit tighter. I suppose tolerance of paper tubes is like that. So this next picture shows the laser mark where the aft ring is supposed to go if you follow the instructions and install the rings on the MMT (which I did not do). You can just see there is a bit of a gap in that tube and ring combo.

Aero Dactyl Build-00016.JPG

So I slid it forward to the line and tacked the MMT on the rear CR. This shows the gap better. No matter. The fillet will be fine.


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Once the CA setup, I filleted the MMT. Let dry for a bit, and did the front MMT fillet. :)

Aero Dactyl Build-00018.JPG
 
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Okay. Another deviation. I never use wood glue on large tight couplers. Oh yes, I know you can, and I know how, but why slather that much glue around when a few GRAMS of 5 minute epoxy in a thin layer will add no more weight AND the coupler just will not stick until you have it where you want it (within a reasonable time of course)?

So in the coupler went using 5 minute epoxy. Got the vents lined up...All is well.


AeroDactyl Build-00002.JPG


Then it's time for finage!!! Wood glue dripped down the front and back of the slots (recall the CRs are RIGHT THERE) and applied to the roots of the fins. And we let it dry

Not sure if you can tell but the slots still have a bulge to them. Fillets will cure all... we hope. :)
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Because I might want to. Period. I mean it seems pretty silly to launch silly little rockets to begin with? It's not like they are going anyplace or doing anything.
I can’t argue with that, I suppose.

I like your approach with the booster motor mount, by the way. How much room have you got in that thing? I’m curious whether you could get a CTI 3G case in there the way you can in the sustainer.
 
I put the engine block in the booster... why? Brain dead. I'll have to see. But the CTI's are exactly my target in the sustainer as they light on a whisper.


Which brings me to...
Started the sustainer motor mount. Yes I carved out the two notches to fit a small aluminum tube. Maybe I'll never use it. But for 5 grams and maybe 3 grams of epoxy clay, it'll be there.

AeroDactyl Build-00025.JPG

So you can see the sustainer MMT. The CRs are placed as per the instructions. Meaning they will not clamp the fin tabs. You can see the kevlar filleted to the forward CR. And the fillet of the rear CR. The shock cord is run through the back to keep it out of the way when gluing in the assembly.

This is the stuff I will use to secure the tube to the CRs. The tube will allow me, should I wish to, to run an e-match from the sustainer motor to the payload/avbay to do an air start should I wish to. Otherwise it is just 5-7 grams of dead weight. It will not interfere with deployment. I have not used this stuff before but it SEEMS like the same thing (different brand) that Apogee sells for $15 a tube. This was $15 for 3 tubes.


AeroDactyl Build-00024.JPG
 
So this is the stuff I used to attach my aluminum tube to the motor mount.
AeroDactyl Build-00036.JPG


Worked great got three times as much as Apogee charges for the same price.


You can see the glombed on mounds. I sanded the CRs and made sure it all fit.

AeroDactyl Build-00035.JPG


Then used 15 minute System III epoxy to install the motor mount.

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I don't need to use it. I can plug it with a screw. But it is there should I want to

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More filet of fillet.
AeroDactyl Build-00074.JPG


The booster pretty much ready for primer at 90g.



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The payload/avbay bulkhead filleted. Get down to the end. A quick and simple build.

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The "ready to paint" (not!) nose cone getting its mold lines filled. Seriously?

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Not gonna drill anything into the avbay coupler or add a terminal block yet. All that can be done at some time in the future.

Gotta think of some paint and decals... I like some of what is supplied. But the claws can go to the trash ASAP.
 
Not gonna drill anything into the avbay coupler or add a terminal block yet. All that can be done at some time in the future.

Gotta think of some paint and decals... I like some of what is supplied. But the claws can go to the trash ASAP.
Maybe try a random color generator? It’s what I use to get started on coloring OpenRocket projects. Often a name will come out of a particular combination.

One color for the tube and one color for everything else is generally a good place to start.

https://www.random.org/colors/hex
 
My paint scheme is taken from the face card. But not quite. And taken from the rattlecans I have on hand.

Gloss Black for the booster. But "wait you say". "Won't that be hard to find?" Perhaps.

AeroDactyl Build-00031.JPGAeroDactyl Build-00030.JPG


So we cut some vinyl on an old stika for the fins. Will it help? Who knows?

AeroDactyl TS Build-Booster-Vinyl.JPG
 
So the nose is painted with what is left of the Rustoleum Metallic blue.

AeroDactyl Build-00036.JPG

And the vinyl applied to the booster. It will have to be sealed of course. Either clear acrylic spray or a few wipes of future floor wax... not sure which is better.

AeroDactyl Build-00035 copy.JPG


The roll pattern is cut for the payload section (it did not turn out that well), and the payload section is painted a gloss white. But not as glossy as I had hoped. But good enough for the vinyl roll pattern, I hope.
 
My paint scheme is taken from the face card. But not quite. And taken from the rattlecans I have on hand.

Gloss Black for the booster. But "wait you say". "Won't that be hard to find?" Perhaps.

View attachment 541321View attachment 541323


So we cut some vinyl on an old stika for the fins. Will it help? Who knows?

View attachment 541322
I wouldn’t worry about booster recovery. Relatively slow flight and becoming un-aerodynamic right at burnout tends to limit their drift altitude. I don’t think I’ve ever had one land farther away from the pad than the flight line. Still, grabbing a “booster buddy” can’t hurt.

The sustainer might be tricky but if you’re going at SCRA with a relatively low ceiling, I reckon you’re more likely to have it drift off-range than to lose sight of it in the sky.
 
Well I think I am done. Not the best fade job ever... But from 20 meters it'll look fine.
The vinyl added more weight than I thought. But a 1.2 meter rod and calm conditions, it should be fine. Plus I ran the tube down the sustainer to use/ignite a composite motor. I did not clear coat but wiped it down with future acrylic several times. It's heavier than the face card says. So I may rip the lug off and go with rail buttons. Then I can use a 1.5 meter rail and who cares.

Overall, over priced like everything Apogee sells. $70 for something that should be more like $50. However also good quality like most everything they sell. If only they'd find a balance. :)

First flight? MAYBE ROCStock. Not sure. I'll of course add a launch report when it happens!
 

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I like it. The unconventional decal orientation is a nice touch. (I like to read them bottom-to-top on the pad, the same direction the rocket will go)
 
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