Sagitta 900 Build

[kmacva]

Well everybody, I got real lucky last year. I was at our local RC Club's Swap meet last January. I had already gotten there late, been there for 20 minutes or so and scanned all the aisles. I was going around the second time while my brother in law was still looking around and talking. This time I was taking a deeper look at what was there. I stopped at this older guys table and he had some kits still in the box stacked up. Toward the bottom of the pile I saw the word Airtronics and having experience with their kits before from buying and building an Airtronics Olympics 650 from the late 80's (which I still have) I pulled the box out and low and behold it was a NIB Airtronics Sagitta 900 all the parts were still there in there original bags including rotting rubber bands holding the wood together (the wood was still in fine shape). I picked it up and he say's "Do you know what that is" he should have known since my jaw was on the floor. Without trying to sound too interested I asked him what he wanted for it. His reply $35.00. I couldn't get the money out fast enough. So I left with it. I started one wing panel after I got it, but due to space limitations and time never got any farther.

It's now building time again and I've pulled it back down. I have since built a garage and I now have enough space to lay the plans out and take my time building and leave it alone for a couple of days if I have to do something else.

I'll post pictures once I get everything laid out again. I'll tell you this is probably one of the most complicated builds I've done in a long time. Hats off to Lee Renaud for designing it and Tim Renaud for Drawing the plans. I'd be willing to scan the plans and the instructions if anybody wants to try scratch building one. I don't know the copy right status, but if they're free I'm not making any money right :) ? Consider this build log Nostalgia from the days before Carbon Fiber, ARF and RTF's.

Kazi

[kmacva]

I've added some pictures of where I'm at now.

[Miraj]

Awesome Kazi, I wish we had swap meets here in Oz. Well maybe we do but i've never seen them adverised.
Nice pick up and the Sagitta is a sweet plane, you will enjoy flying it. May I suggest a few mods?
1. Make the rudder a non-counter balance one and slightly extend.
2. place some circuit board inside the rudder post to stop stab wobble.
3. Enjoy building and flying it.
M

[dion9146]

I was just about to start my own Sag900 build log, but you beat me to it! :D
I built a 600 back in the late 80's as a full house ship. Unfortunately, the weak rear fuselage showed it's true colors during a hard landing, and the plane was never the same.

I'll be watching this with interest, and I've also collected just about every thread I could find with suggestions, improvements and mods to the plane. Some of them I will do, some not.

This is the first I've heard of the circuit board trick. Miraj, can you explain that a bit better?

Thanks,

Dion

[Miraj]

Can do, I cut of a bit of circuit board about 15mmx15mm drill through the center so that the brass rod can fit in snug, cannot be loose. I then glue them to the insides of the rudder post where the elevators pivot.
The timber in there can wear out, also another way i've seen it done is soak the timber in cyno, but i find the circuit board better.
See image

[dion9146]

got it!

Thanks,

Dion

[kmacva]

Miraj good advice. The instructions suggest glassing the fuse which I plan on doing for the extra strength. The circuit board idea sounds right on.

[kmacva]

I scanned in the Building Instructions and converted it to a pdf file. The introduction and design philosophy are pretty interesting reads.

Dion9146 are you building one also?

[jtlsf5]

Miraj good advice. The instructions suggest glassing the fuse which I plan on doing for the extra strength. The circuit board idea sounds right on.


Both good ideas. I would suggest 1.5-2.0 oz glass cloth for the fuse, and use good quality (low viscosity) epoxy. Be careful especially in the tailboom/fin area. Any added weight in this area translates to lots of extra nose weight, and a heavier plane.

JT

[Speedo125]

Hey Kazi: Congratulations on the amazing deal. The 900 has been on my "must build" list for a long time now. I'll be following your thread with great interest. Thanks for posting the instructions. I have a set of plans, but 'til now didn't have the wordy bits.
Thom

[dion9146]

I scanned in the Building Instructions and converted it to a pdf file. The introduction and design philosophy are pretty interesting reads.

Dion9146 are you building one also?


Kazi,

Yes, but I'm probably a week or two off before I start applying glue to wood. I just finished up my workshop in our new house and will be prepping the work surface and collecting some last minute supplies this weekend.

I also took both sheets of original plans to FedEx/Kinkos and had them make copies. It was $15, but I like to cut apart my plans before laying them on the work surface, and I didn't have the heart to do that to the originals. Plus, I'm thinking about building a second ship from scratch sometime in the future with every mod you can throw at it, so I will need the plans again.

Dion

[rdeis]

I don't know the copy right status, but if they're free I'm not making any money right :)

FYI, that's not relevent. It's illegal to copy protected material whether you're making money off the copy or not. Whether the thing is NLA or not isn't relevent either. (I don't know if it's protected anymore or not.)

But back to the subject:

Does anyone still build or sell glass fuses for these?

A friend of mine used a flat-wing aileron Sagitta 900 as his primary contest ship years ago and just found a kit to build another one and get back to soaring. He's looking for one of the glass fuses that used to be available, (and I'm not inclined to let go of mine. :) )

[dion9146]

Kazi,

Yes, but I'm probably a week or two off before I start applying glue to wood. I just finished up my workshop in our new house and will be prepping the work surface and collecting some last minute supplies this weekend.


I couldn't help myself - I laid the keel (or spar) this weekend. Kazi, how are you doing?

Dion

[kmacva]

dion9146 I've started on the second wing, got some ribs laid but have not been able to stay working on it at the moment because of other things I been obligated to do. I hope to get so more picture posted here shortly when I get a chance to get back work on it.

Kazi

[Miraj]

I plan to use 3/4oz glass on the fuse, but before hand on the balsa rear use a balsa lock to stop extra epoxy from soaking into the timber.

[Curare]

I just gave mine a quick spray of "el cheapo" hairspray. Works well enough for me!!

[Ercoupe Ed]

Using carbon fiber strips inside the fuse sides may be a better idea.
Stronger, adds less weight.
I bought two kits from Dreamcatcher, shortly before he went out of business but found that the ribs that come with the kit are off as far as true Eppler 205 airfoil.
I have a book called "Airfoils to Go" and compared the kit ribs with the profiles in the book, and the kit ribs are definetly off!
I am replacing mine.
I bought my fist Sagitta used, and the previous owner had repaired it several times and it was heavy, but still flew very well.
It's still a great sailplane!

[Miraj]

just spray the hairspary over the balsa and epoxy?

never heard of that idea, i'll give it a go on a practice bit.

M

[Curare]

No, spray the hairspray over the balsa a few hours before you epoxy, it stops the soak effect.

[rctinman]

Spray the hairspray on the bare balsa before you apply the epoxy and cloth, that way, the epoxy will just wet the cloth, and won't soak into the balsa and make it heavier than needed.

Stevejust spray the hairspary over the balsa and epoxy?

never heard of that idea, i'll give it a go on a practice bit.

M

[Larry Jolly]

Guys,
I was the Production Engineer at Airtronics during the Sagitta time frame. I wrote the instructions, and Dennis Brandt and I built many prototypes. If you guys are worried about the fuselage breaking, I would suggest that you do away with the pine block holding the wing joiner tube, and instead cap the front of the spar with a 1/16th plywood web. Many Sagittas died when the pine block was cracked on a hard landing, and the wing let go on the next launch. regards Larry

[Miraj]

Arrh gottcha on the hairspray.

I built my spar system for the XC with this method: http://www.rcgroups.com/forums/showthread.php?t=474768&page=9&highlight=Sagitta+XC + i wrapped the end where the joiner box is with carbon tow and epoxy.

I think it makes the wing more accurate as well. I've also switched over to a flat steel blade joiner system rather than the round option.