Restoring Old Sailplanes, don't Give up

[alstrahm]

I have a penchant for old Sagitta's and a few people have asked me for advice. I am in no way an expert. Just have done it a few times. Only got a few pics as I never thought anybody would be all that interested. Restoring an old Bentwing is a challenge. The worst part is removing all that 20 year old monocote, hate that job, never did find a perfect way to do it, finally figured you can't see it at 50 feet. but there are some things I learned on the Sagittas, If the elevator linkage is stiff that means the cable housing is kinked, what I found is you can get guitar strings in .001 increments drop .010 and the cable will work great, if you do remove all the monocote, reglue all wing joint's.And on the wing joiner box you can wrap it with kevlar thread, and throw away the wing rod and get a ejector rod, twice as strong, and will take a pretty good good launch. And there is the issue of remonocoteing. any and all additions to this to this thread are welcome. Give us old guys some more advice
Al

I have attached two pics of my 2 900's and my 600

Keep the old planes flying

[sparkysko]

Have to be careful about charring the wood, but you can remove covering with a heat gun. Epoxy dies at ~140F tho.

[Ralph Walton]

Alstrahm. Your planes look beautifully done in the photos. Well done!
Sounds to me that you have a well rounded grasp of whats required to rebuild these classics.

I've done a few myself,(no saggatas yet) but usually don't get carried away enough to do full recovers. I agree that most of the time you will be looking at you plane in the air, so up close appearances are not so important. I've seen some awefull repairs, that don't seem to have much affect on performance at all.

I'm not shure about the USA but here in New Zealand, the best way to devalue a sailplane like this is to build it from scratch. A freshly built sailplane, whithout radio gear or servos, can be bought for less than 1/2 the price of buying a kit and covering materials. Prices go down from there. This means there's a huge number of very reasonably priced second hand gliders out there.

Often they need a bit of TLC, but far less than the full rebuilds you do.(Admittedly though, a full recover looks great). Less than satisfactory elevator linkages and mechanisms seems to be very common, and not enough rudder is close behind. RE ships need a small amount of crisp elevator and as much rudder as you can get, and often alot more.

45 degrees of rudder each way from the center line is good and alot of RE ships will benefit from increasing the rudder area by 50% or so (great planes spirit comes to mind)

[Hossfly72]

Great pics Al,

What would be the best way to repair the wing sheeting? I've been sliding a knife blade into the break and lifting it back up level with the rest of the sheeting. Then I drizzle just a drop of CA into the crack so that it flows the whole length of the crack. Do you think that will be strong enough or should I (ugh!) remove the entire sheeting and replace it?
You inspired me to get back to work removing Monocote the other day. I would really rather CA my butt cheeks together than do that again though! The fuse has been sanded, primed, sanded, primed, and re-sanded and primed. A few more times and it should be good to go. I fixed a wing saddle that had been put back together crooked (after a crash I'm guessing). I also pulled lots of lead out of the nose and figure I'll be adding it back in later.
The elevator control has gotten a lot smoother because I sit and work it back and forth while watching the History channel on weekends. That's my favorite work. Just mindless, kind of like petting a cat.
The original spoilers were hooked up to a single servo in the fuse and connected via threads and a long wire that they hooked to. I wonder if it would be easier or work better to just add servos inside the wings?
I'm having trouble picturing how the wings stay attached to the fuse. There are short metal bars with small holes in the end. When the wings are on the fuse, the bars poke through into the fuse. How are they joined? A wire running through them or some type of screw on attachment?
That's all the questions I can think of right now, but I'm sure I'll come up with more soon.

Thanks!
John Haas
(Hossfly72)

[FrogChief]

Beautiful Birds Al, hope my Spirit 100 gets restored as well as yours! :D



'Because old airplanes still deserve to fly.'

[alstrahm]

thanks Froggy ,your spirit is looking fine! John My wings use two rods, the front one is 3/8 and the rear one is 3/32, they slider thru the fuse and into both wings, and I have eyelets screwed in each wing and they slide thru two holes and I use a little spring to hold the wings togeather. The one servo works fine for the spoilers, been using it for years, in fact Merrills marauder uses the same setup simple and light, as far as the sheeting sounds like your on the right track, just take it slow and don't get in a rush, the 900 with different colored wings took me 2 1/2 years to remaiden, if I found myself rushing I would put it away for a week or 6 months!! As far as the lead both my 900's took 6 oz's to balance and I mounted everything as far forward as possible, I will shoot some pics this weekend of my wing rod and radio setup and post here, don't hesitate to ask questions, if it's a sagitta I have probably run into it
AL

[Hossfly72]

A spring!! Thats how my old 600 was!! I couldn't remember. I miss my 600. That plane flew like it was on rails, but I was so new to flying that I don't think I ever caught a thermal with it. Sloped like the devil though! That was Nashville at Percy Priest dam, where the Hobby Lobby guys slope. Lower Alabama has nothing close to a slope that isn't covered by pine trees.
Thanks Al. I'll stay tuned for more pics and info.

Hoss

[Leadchucker]

One of the few model aircraft related activites I dislike is removing old covering. I am presently doing a resto on two sailplanes I built around 30 years ago, an Olympic 99 and a Legionair 140,both are great flying thermal ships. But the 30 year old MonoKote is an absolute mess to remove and is really brittle with no skin strength at all. The heat trick seems to be the way to go though...if you use heat to apply it, seems it sould follow to use heat to remove it.

[JAMESDONOHOE]

Hi,

I Have A Graupner "cirrus" Which I've Had For Near To Forty Years Now [on Which I Learned To Fly] . It Has Been Re-built So Many Times I Can't Remember
But I Hold It With Such Affection I Cannot Chuck It Out.
The Fuselage Is An A.b.s. Moulding Which Has Been Repaired A Number Of Times And What Was Originally Quite Heavy Is Now Too Heavy.
Any Ideas On How I Could Make A Grp Fuselage Using The Old A.b.s. One As A Pattern?

Your Comments Will Be Welcome!

Jim

[alstrahm]

James that is an interesting question, I have no idea. maybe you use the old one as a mold and make a fibreglass one? I hope someone chimes in with some better ideas, darn I just saw one on Craigslist for $100 here in the bayarea.
Al

[Curare]

Here's a few of my grand old dames, I love the oldies, more than the moldies. wow, I'm a poet and I didn't know it!

[alstrahm]

C that is one nice plane, keep the old one's up and flying, here,s a link to another great guy who likes the old ones.
http://www.thermalrider.com/

Joe has my first aileron ship. I am sort of a weird guy I am working on a few moldies but love the oldies, go figure.

In any case, Happy 4th to all ,and here are some pics of my Sagitta and my little tiny garage and how I store them.
Al

[fnnwizard]

And on the wing joiner box you can wrap it with kevlar thread, and throw away the wing rod and get a ejector rod, twice as strong, and will take a pretty good good launch.
Keep the old planes flying

Very, Very nice Al! I will be doing a S600 soon here and was wondering what the heck is an ejector rod? I actually have a few oldies that use 1/4" steel rod I would like to replace. Thanks!
T

[yyz]

The Sagitta 900 is a fantastic plane and Al's look absolutely beautiful. Curare posted a white, blue and gold one that is really nice as well. That's a great color combination.

I heard this second hand, but the Nostalgia Class rules drew the line, date wise, right beneath the Sagitta as it was such a step forward from previous gliders. The MTS Gemini is supposed to be a similarly great plane.

Several people have built flat-winged versions with flaps and ailerons. I'd like to hear someone chime in about that.

The only thing I would add to the removing Monokote thread is to think about how nice the Oracover is going to look when you're done! I've given up on Monokote; the other is so much better, in every way.

Re the Cirrus...

I have a set of molds for the Graupner Cirrus, built from an original ABS fuselage, and can share how I did it if you like else I can make you a fuselage. Don't want to hijack the thread so PM me if you're interested.

Mike

ps: Don't be tempted to fully sheet the Sagitta wing. The E205 was designed to be "built" as shown on the plans. I can speak from experience on this one. :mad:





Hi,

I Have A Graupner "cirrus" Which I've Had For Near To Forty Years Now [on Which I Learned To Fly] . It Has Been Re-built So Many Times I Can't Remember
But I Hold It With Such Affection I Cannot Chuck It Out.
The Fuselage Is An A.b.s. Moulding Which Has Been Repaired A Number Of Times And What Was Originally Quite Heavy Is Now Too Heavy.
Any Ideas On How I Could Make A Grp Fuselage Using The Old A.b.s. One As A Pattern?

Your Comments Will Be Welcome!

Jim

[sawman]

I second the vote on that 900! Wow, don't know how you guys get covering to look like that. Mine usually end up looking like wrapping paper on Christmas morning . :(

[alstrahm]

Mike, nobody can hijack this thread, only add to it! I was hoping somebody could help James out. I just started this due to a few questions on some pics I had posted on other threads as I love the old birds and the Sagitta was the first plane I flew in a contest and did very well with it. And there is the fact that my dad and Lee Renoud worked togeather at Lockheed before the Airtronics days, Well enough of the history, Wizard,an ejector rod is used in the injection molding industry, very high tensile strength ,comes with a head on it that needs to be cut of with a chop saw, these are preferable on the Sagittas due to the small, 6", wing rod. The stock standard steel ones would develope some more dihedral after several winch launches, you can get injector pins at Macmaster-Carr. And please anybody looking in, chime in with your pics ,advice or just plain thoughts.
Al
AMA3959

Mike check your PM's, still want to know about the custom Sagitta fuse. Think it would be a fun project over the winter.

[alstrahm]

Curare, that has got to be the most beautiful Sagitta 900 I have ever seen!!! And what a great shot overlooking the ocean!You on the left or right coast? What is the plane with the upturned wingtips? Inquiring minds need to know.
Al

[EK XL3]

I have a Saggita 600 built 20 years ago. Hangs from the ceiling. It's been re-covered 3 times due to many thermal flights with field/grass landings after lots of patches. Good memories of flying Santa Cruz, Ca. slope and thermal. I also have a new in box, Graupner Cirrus. I bought it at an annual R/C auction in the South Bay area. I've had it for around 20 years. Has all the factory glue, covering, plans/engineering drawings, ect. Not for sale, just chatting. Every now and again I get it out and spead out all the stuff and look at it. One of my earliest memories of R/C was in Shawnee Mission, Ks. when I watched a guy hand tow a Cirrus then thermal it for an hour, searching for lift at low level. I will build it when I retire...................

[John Cole]

Al, nice subject. I like the heat technique to remove old Monokote, but at best, it's still a big job. Depending on how old the covering is, how many times reheated, etc. determines how this job goes. Nice looking Sagittas!

John

[John Cole]

I have a Saggita 600 built 20 years ago. Hangs from the ceiling. It's been re-covered 3 times due to many thermal flights with field/grass landings after lots of patches. Good memories of flying Santa Cruz, Ca. slope and thermal. I also have a new in box, Graupner Cirrus. I bought it at an annual R/C auction in the South Bay area. I've had it for around 20 years. Has all the factory glue, covering, plans/engineering drawings, ect. Not for sale, just chatting. Every now and again I get it out and spead out all the stuff and look at it. One of my earliest memories of R/C was in Shawnee Mission, Ks. when I watched a guy hand tow a Cirrus then thermal it for an hour, searching for lift at low level. I will build it when I retire...................

EK, I have a soft spot for the Cirrus as well. Far from being a high performance sailplane, brittle plastic fuse, old foil, etc. But still...

[EK XL3]

On the way north from Santa Cruz to Redding, Ca. I stopped off at Lagoon Valley Soaring (since closed) and helped a guy assemble a full scale Cirrus. I couln't believe how heavy the wings were. Still a classic, clean design.

[Curare]

Curare, that has got to be the most beautiful Sagitta 900 I have ever seen!!! And what a great shot overlooking the ocean!You on the left or right coast? What is the plane with the upturned wingtips? Inquiring minds need to know.
Al


Thanks for the compliment on the sagitta, yes I do live about 100m from the ocean, but the dunes are really too small to slope off only bout 15m tall and they dont face into wind!

As for the sailplane with the upturned wings, it's a graupner cirrus, but has been revised to look like one of the last surviving cirruses still flying.


While we're on the subject of covering. THe sagitta is a glassed and painted fuselage, as is the cirrus, the covering on the cirrus is all white Profilm (oracover) and the sagitta is white profilm, and the blue is metallic monokote and the gold is also metallic monokote, take your time getting the underlying surfaces as smooth as you can, vacuum the wings before you start covering and pull the monokote as taught as you can before you start to shrink it, it'll work much better for you.

Curare.

[alstrahm]

John ,I need a pool and some Grand Esprit 's like yours, those are very ,very nice! Keep the old one's flying and let's see some more!
Al

[yyz]

The guy flying the Cirrus has some serious "game face" on! Must be flying against George Moffat :rolleyes:

The Graupner Cirrus is such a sweetheart. What a fantastic ship! I have one with obechi over foam wings waiting to be finished.

EK, I have a soft spot for the Cirrus as well. Far from being a high performance sailplane, brittle plastic fuse, old foil, etc. But still...

[alstrahm]

So, I did not say how old.Just picked this up over the weekend my latest project, sharon 3.7, man this thing is big!! Got both fuses, V-tail,and X tail, all the servos, 9 channel RX and the really kool part was my buddy was able to download his program from his 9C to mine. Needed some work on the V-tail, so asked locally for some composite guys help and found another buddy who had a new V-tail in his attic for free, go figure. So really not much to restore, new batts cycling now, a little clean up. Would have it done tonight but my garage is at 112F . Keep the olds ones up but don't forget the new ones.
Al