I bend headers with a propane torch, a large dowel and a vice. I clamp the header into the vice, heat the area that needs to bend, slip the dowel as far as possible into the header and with the torch still in place to maintain the heat, use the dowel to bend the header. I don't do anything else as far as cleaning or prep and I've never had a problem.

John

Thanks for the great tips guys. That actually sounds like something I can handle. I'll Give that a whirl once I've finished the underbelly. The dowel is a good Idea. I heard about a guy who blocked each end of the pipe and filled it with sand, but that was brass tubes I think. I'll try and heat it and bend carefully. Not much bending is required so I'll manage one way or the other [8D]

Mated the wing to the fuse today.

Webra has a history of slide valve carbs in airplane engines. I have one on my .32. They call it a "Dynamix" carb. I've heard the .60 size and up engines require a pump when using this carb. I really hope that's not the case with my .32 since there's no room for a pump unless I strap it to the nose of the model

John

Hey Jon.
Nice progress on your Skystar. Looking good!!
BTW: You can pick up a small propane torch at Clas Ohlson for approx 150 spenn, only 20 minutes from your house:-)

ECK

I know when I was racing cars I sure did like the slide carbs...so easy the to set up the throttle linkage and I could dang sure feel the improvement in a race...totally linear.

Boss

Got the header bent. It took a lot of heat but some industrial equipment got it right. Just heated until it was glowing red and bent it twice. Fits like it was tailored. The Webra pipe is so long I had to make a big recess in the rear fuse out of glass and resin.

The stab was tricky to get straight. It's tapered every way and no jigs or prop-ups are included so it's lined up with eyesight. Hope it stays straight when I sheet it.

Looking good Jon. Get that bird finished!

John

Hey Jon,
How much does the WEbra .80 weigh? I looked into getting one here in the USA, but the cost was $412. I can get a pumped WEbra 1.20 for about $250 (plus a nice wrap around header - about $45). I haven't started my Skystar yet, but this post is motivation!! I'm looking forward to reading your flight report!! MK kits are #1.
Will B.

Flywilly, the Webra weighs 525 grams without header but with the built-in pump. It is very light and well machined. It is extremely expensive, I know. I paid about that price for it here in Norway. I could have gotten a YS 1.10 for that price but I didn't want a 4-stroke.

Webra did make a 1.20 rear exhaust which, if you can find it, can be had cheap. I considered it for the skystar as my dealer had a 30% off sale on it but I think it's overkill in the Skystar. A 1.20 two-stroke is extremely potent and far to big for the skystar's nose. If you're willing to try a swan-neck header, maybe you'd consider the Webra 91 P5 which is brand new and should be the most powerful .91 available, judging by the specs: http://www.hoehn-modellbau.de/1067.html
3.25 horsepower, and recommended props are from 14x12 to 16x8... [X(] And it's much cheaper than the Webra 80.

Thanks for the information, Jon. I have a couple of Bully 1.20s (which are basically WEbras) - the pumped, rear exhaust version. Yes, they would be overkill in the Skystar. I also have a new Hanno Special which I'll probably use. I think the plane can be built at about 7.5lbs (about 3.25Kg) using film covering; so the Hanno may be enough power. I've flown a 2 meter pattern ship (the Fascination) with the Bully 1.20. Good luck with your Skystar,
Will

The Hanno would be so sweet in a 7.5 lb. model! You will not wish for more power. Well, you may wish, but you really won't need it. Hanno's handle 8 lbs. with ease!

John

Jon...did I read somewhere that you are expecting a 7.5 lb. plane RTF??my god man...if that is true...that .80 is going to be to much power...I may have read that wrong on one of the previous post.
Back in the Paleo Monolithic period when I flew comp. pattern it was not uncommon to have a 10.5 lb. plane with a piped .60 doing the work but that was when the box was from one end of cave to the next cave at Barney Rubble's cave house My god ..I am getting old[:-]
We only dreamed of horse power like the Webra but that was when the dis. limit was .61.

Boss

If that header was glowing red during heating, it must have been steel ?? I have never seen aluminium glow, not even at the point just before you burn a hole in it. Also, it was chromed, and I have never seen a chromed aluminium header.

I think filling with sand ( for aluminium headers) is against collapsing of the material. I make all my headers myself, but bending the aluminium is always a problem []

That Skystar looks great!

KrisG

Hatori headers "appear" to be chrome, and the finish is hard, but I'm not sure it's chrome. I've seen aluminum glow red when hot, but the lighting has to be dim. My garage is such a place OTOH, there are companies who make steel headers. I'm not sure who they are, but I did some custom bending on a pair of headers for a 3W twin and they were most certainly steel.

John

Webra headers are made of steel and are chrome or nickel plated.
"Header from Steel", excerpt from Webra homepage http://www.webra-austria.at/fra_mot.htm

Hatoris are made of aluminum and polished shiny and chrome-like.

ini

Nickel plated steel sounds about right yes. It was definately not aluminum. Pretty heavy for a header.

The plane is very light and I'm taking care to build it light too, I've hollowed most blocks, omitted some strengthening etc but as long as it's under 8 lbs I'll be happy. But 7,5 lbs seems achievable as it sits right now. I'll try and get the parts on a scale soon and try to add it all up and see. It will be film covered.

Hey Jon,

I am very interested in the Webra 80. Please let us know how it performs for you when you get that plane in the air. It cost about $350 in the USA as far as I can tell, so I hope it is quite an engine.

Lem

I'm not really a pattern nut. But I like pattern planes and how they fly. I see lots of you guys looking at the webra 80's. May I make a suggestion? How about the MVVS 77. Easily available here in the US. You can even turn the cylender from side to rear exhaust. You can only do this before you run it. But maybe this engine will do for you guys instead of a webra. They work well on low nitro fuel and there are pipes for them. They are also timed to run a bigger prop. i believe they would work well for pattern. This is just my suggestion. Maybe someone here with a little more experience can chime in. I have 2 40's that are real stump pullers. They are very strong and well built.

Mark Shuman

I would like to ask you about your Calypso. I've had one for quite awhile just sitting in the corner while I finished
two other projects first. Do you like the way it flies? How much does it weigh. I can't make up my mind to
finish it or sell it.

Thanks
Tommy S

The Modeltech Calypso is a very good plane. I'm very happy with mine. It really shines after I got the pipe on it. OS 61 FX is enough, a 91 would be overpropping it. Send me a PM with your address and I'll e-mail you some close-up pictures.

All-righty then! Parts built, first weigh-in is ready!

Here's the tally:

[ul][*] Engine, header, prop, spinner and MK engine mount: 700[*] Webra pipe (heavy!) 200[*] 5-cell battery 100[*] 4 std servos, 1 micro 200[*] Empennage, Not hinged or sanded 175[*] Misc. hardware - Switch, receiver, elevator bellcrank, pushrods, servoextensions, tailwheel, horns and hinges, remote glow connector ++ 150[*] Undercarriage incl bolts and wheels 150[*] tank 50[*] Fuse, sanded/shaped 500[*] Wing incl belly fairing, wing hold-down, ailerons, not sanded or shaped tips or edges 450[*] Cowl and fasteners for cowl 30[*]SUM: 2705 GRAMS
[/ul]

Note that the scales used are far from accurate but results seems very consistent and for servo, batteri and engine and pipe weight I've used official weights compared to my own and they seem pretty accurate. Weight of items NOT included here is of course covering materials, expoxy for hinges, engine mount screws, clevises, pipe mount, wing bolt, aileron servo mounts (not made yet!), fuel lines and anything else that might make it's way into the final product.

The weight of a roll of monokote is about 150 grams. Take off all plastic and the cardboard roll and I assume that one should be left with about 100 grams pr roll used. Say three rolls in total, that's 300 grams added, plus all the very small items mentioned, say +100 grams and the fact that the grams of expoy used for tail assembly will be sanded off elsewhere on tail and wing means the final ready to fly weight should be 3.1 kilos. I have added it up twice, weighed it twice. I gotta get a second set of scales for a second opinion, this is unheard of...

Been skiing a lot lately and whole weekends go by when I don't build. Oh the humanity!

Still I've managed to get the throttle done (HS81) and mounted the engine. The belly pan encloses the engine very nicely. I'll make another hole for cylinder head cooling I think.

Jon...if my math is correct(which it always is) then you are looking at 6.82 lbs....that seems very lite. After looking at the list you comprised it seems complete. I don't think it will be under powered

I know, I couldn't believe that weight either. But since I've skipped a lot of fibreglass reinforcement that I think is overkill and the fact that the YS engine the plane is intended for is 250 grams heavier I think 3-3,5 kilos is acheivable. Just hope I don't have to add weight in the nose for the lighter engine.

Jon,

After a lot of time deciding on the engine for mine I have a YS 1.10 & hatori pipe set up coming from Radio South. Like you I have my plans tacked up on the wall...and after looking at the tail moment I decided it really needs the mass up front from the 4 stroker.

I am going to glass & paint the fuselage and do the wings and tail with Ultracote. Will comparre flying notes hopefully later this year. It will be at least 2 more months before it is warm enough here to paint, by then everything will be finished.

Regards,

Scott

PS: Will- ya gotta tell us more about the MK "Wild 7" you picked up. Similar in looks to the Beetle but designed around a 1.20 YS, no?