TLP Gabriel III/AS Fins And Build Thread

Began assembling the Front Fins. It's funny, because it turned out that the Original TLP Design is actually much simpler than what I'm doing, but I'm having fun engineering these to my Specifications.

Having a Printer is an excellent Asset when building Rockets. I drew up the Skins for the Fins then made Copies to use.

Even thought they are essentially going to be solid, as opposed to the original Design, I will still paper them and soak them with CA before Final Finishing.

Looking good!

JP

Okay, looks like I'm not going to use Bondo Spot and Glazing Putty to build up the Fins. As it started to dry, I came to my Senses and decided that a Lightweight, Non-Shrinking Spackling would be much more appropriate for this. The Bondo was already Shrinking and Cracking after less than an Hour, and it just became clear that for what I was trying to do, it would not be the right Material. I scraped it off before it dried, and will just wait til' I go to the Hardware Store to get the right stuff.
Patience.

I've noticed that as well. Just a little too thick and it cracks like crazy.

JP

I need to go get this stuff.




I have other Rockets to work on, so I'll get back to this once I have the right stuff.

They say it won't shrink or crack, I bet it will if applied thick.
Can you layer the job out?

JP

Yeah, we'll see how it goes.
Good thing is, even if I screw up a Fin entirely, I've now got ample Stock of Materials to make more Fins.
I enjoy Building much more than Flying, so I don't mind however long this takes to finish.
Paintin' Weather still seems to be a ways off anyhow.

I have been using lightweight spackling for years to fill BT spirals and smooth over transitions . It won't crack if you don't go to thick. Better two thin coats rather than trying to get it done with one. Any primer seals the porousness easily making it easy to paint. You can thin the stuff with water if you use it very sparingly. The more water used, the more likely you get a crack. This stuff is obviously much lighter than Bondo filler.

I've used that stuff for work....works great. I've only put it on about 1/8" thick though & it didnt crack....shrunk a lil bit maybe but not much.

I'll do it in a couple of light Coats then.
Thanks for the Info guys.

Got some Primer on the Noce Cone yesterday, so I was able to Bondo the spots that needed it.

The Spackling is working great, and I have the first Paper on the first Fin. It's kinda' slow, as I'm doing one side of each Fin at a time, but I am out of money for Primer and Paint anyway so it does'nt matter if it takes a couple of Weeks.

I got the second Paper on the Fin, and after waiting for it to dry, put Super Thin CA on both Sides. This made the Fine as hard as a Rock, allowing me to sand the excess Paper down. I'm very happy with the Method I've developed for assembling these Fins, even though it would have been simpler to use the TLP Method.
Are they Heavier? Ofcourse, the Rocket is flying on 29mm, not 24mm. Do I care? Nope!
Now to make the second Fin....

Those sure do look purdy. - J

Thanks.
I got the second one almost complete. As others have suggested, I am using a method of building up the Spackling, and have the first layer down on the next two Fins, so I should be able to finish them all up in the next couple of days.

Can't wait to see some of them fly!! Should be fun!

Indeed it should be fun! Especially considering all of the revisions I have made to the original design. The front Fins now each weigh in at .9oz, as opposed to the original Fins at .2oz., and my Solid Balsa version at .3oz.
This means that I may need to add a tiny bit more Nose Weight to get my CG and CP where they need to be, and the added weight may limit my Motor Selection, but we'll cross that bridge when we get to it. I have a clever way of adding the Weight to the already weighted and sealed Nose Cone if I need to.
Pulling off this Build and posting a Video of a Successful Flight will vindicate my Building Style, and that will feel good.

The Fins are going on tonight. To achieve a good bond I made lots of Holes and scrubbed off the Glassine with 80 Grit SP.

There's plenty of Epoxy, and these Fins are not going to face any Impacts, so it should be fine.
Yes, a mock up for testing would be ideal, but I don't feel that the bond will be an issue here.

TopRamen said:

There's plenty of Epoxy, and these Fins are not going to face any Impacts, so it should be fine.
Yes, a mock up for testing would be ideal, but I don't feel that the bond will be an issue here.

Click to expand...

Oh I was sure it'll be fine as well either way.
Just wondered if some was really better than more than some or more than some better than some, so to speak.

It's crazy how thick the Glassine Layer can be.

3rd Fin on.

And here's Gabby!






Now I just need a Chute' and Shock Cord, and Primer, Paint and Decals.
I'm very pleased with how this is turning out.

I will sleep well tonight.
This Build, mostly the Fins, has taken quite some time. Now all the interesting parts are done.
I have finally triumphed over the Gabriel III A/S Fins!!!:w:

Looking great! :clap:
-J

Thanks.
Today I'm focusing my efforts on sanding the rest of the excess Bondo off of the Body Tube. Once that is done I will apply the slightest of Fillets to the Front Fins wth a Syringe and TB Trim and Molding Glue. I don't want Fillets that will be noticeable or interfere with my Vinyl Wrap.

Got the rest of that ugly Bondo sanded off.

Got my Fillets put in with the Titebond Trim&Molding. I used a Syringe to get it deep into the small voids that were present in certain parts of Seams where the Fins meet the Body Tube. I used plenty of Epoxy to begin with, and made sure the Holes I made were full of it before mounting the Fins, so strength won't be an issue. The Fillet was mostly to fill any imperfections rather than build up a Structural Reinforcement. As such, it is near invisible and not worth taking a Picture of.