Strykaas

I'm really amazed at the size of the required battery. How heavy is that .55 AX with muffler ? Maybe getting the right cg location could be easier with Webra *light* engines...

See the .50 P5-GT Aero : 340 grams only
http://www.webra-austria.at/neu2008/...08.php?lang=EN
.55 P5-GT Aero : 360 grams...
OS .55 AX : 404 g [X(]

The Webra .50GT was the ideal engine choice for the Northstars ships

Mustang Fever

My Feedback: (2)

Strykaas: near as I can tell, the weight stated for the Webra is without a muffler. The one on the 55AX weighs 4.25 oz. Total on the 55 is 18.52. With a muffler in the same weight range, the Webra would be 15 oz +.

The only place I've ever been able to find to buy a Webra is Revolution models in the UK, and they don't list the 50 P5-GT.
http://www.revolutionmodels.co.uk/ac...ngines_39.html

I suspect anything I bought from them, looking at the prices listed, would run me $300 USD or more, vs $145 for the O.S. Not worth it for 3.5 oz.

I might save a little weight by going to a tuned pipe, but noise is getting to be a big issue in the states. There's never a problem when one sticks with the factory mufflers.

Strykaas

50 at 145 eur : http://www.der-schweighofer.at/artik...eed_55_gt_aero
55 ar 155 eur : http://www.der-schweighofer.at/artik..._55-p5_gt_aero

A rough estimate (incl. shipping) would be USD 256 for the .50 ... Yeah, you're right, not very attractive... Nearly as expensive as a Jett . Moreover, I think the muffler is not included...

It's a shame you do not have a serious importer... A weak USD is not very helpful either...

simhatus

Hi

Flew my arrow again yesterday heres a video:

http://www.youtube.com/watch?v=O6-8zqWF8mI

Simon

Mustang Fever

My Feedback: (2)

Sweet. Really sweet. You guys had a lot of birds in the air at the small pond.

Simon- do you know what control throws you ended up using, and how much expo, if any?

Minnreefer

I don't want to get this thread off track, but a good friend of mine swears by webras and can get them in the states without too much problem, if interested, let me know

Jon

Mustang Fever

My Feedback: (2)

Jon:

Is there a distributor?

Strykaas

First thanks for sharing [sm=thumbup.gif]. We definitely lack Arrow videos !

Actually, yours does seem much more manageable than all the others I have seen. It looks much more stable (CG mod ?) than all others, especially on take off. Rock solid stable attitude and climb up.
Regarding power, I bet yours is fitted with a .46 only, it does not look too fast with a well set up peak. Can you confirm ?
Landing was a bit disapointing, though. I believe wing tip floats could improve in this department. Mustang, what do you think ? I think I would build them.

simhatus

Hi

I'll have a look at the program and send you the settings.

It is an irvine .53 in it with an 11*7 prop and your right its not as fast as some

The landing wasn't good but others have been better, tip floats probably would help but i'm genrally happty without them.

I do have a webra 50 and pipe unrun am in 2 minds weather to put it in the arrow as the pipe would sticks so far out the back but may do now i have it flying right.

Simon

Mustang Fever

My Feedback: (2)

I think this design just puts a premium on keeping the wings level. Good training.

Strykaas

Simon, you could install a mousse can muffler, definitely shorter than a full length pipe... and easy to build [8D]. Very light too.

simhatus

HI

Interesting concept just been looking up how to make one.

The rtv you need there seems to be a large variety available, which is suitable?

Is the different colors just that, or does each color have different properties?

Not sure i know anyone who uses mousse, had to look up on ebay exactly what it was, seems to come in a large variety of different containers to?

Simon

Strykaas

you can read this [8D]

http://webpages.charter.net/rcfu/ConstGuide/MCM.html

Mustang Fever

My Feedback: (2)

Decided to glass and paint the hull, and just cover the wings and elevons.

I used 3/4 oz glass, applied with finishing epoxy thinned 50% with denatured alcohol. After that cured, I put another coat of thinned epoxy (75%) on to fill the weave. The, sand, sand, sand. 150 dry. 220 dry. 400 wet. 600 wet. 800 wet.

The hatch turned out pretty nice, it was sort of my test piece to see if I could get a good finish.

Strykaas

Glassing the fuse will obviously make it more durable... But won't it end up too heavy [:-] ?

Mustang Fever

My Feedback: (2)

I used about a square yard of the 3/4 oz per square yard stuff, so I added maybe 3/4 oz in glass. I used about 4 fluid oz. of epoxy, which probably weighs 4 or 5 oz, but after it all cured I sanded most of it off. The only epoxy that stayed there is the stuff that goes through the glass and seals the wood, and the little bit in the weave, most of which was sanded off. I'd guess the whole job didn't add 4 oz to the bird.

It would probably take a whole roll of monokote to cover, and that's 2.6 oz by itself for the standard stuff. A wash, I think, and the epoxy glass really does a good job of waterproofing and making the skin tough. Seaplanes, I've found, have covering issues in the areas where they get handled, so having the fuse painted should make it very durable.

Anyway, I covered the hull/fin/pod/rudder on my first one, and I don't want to do it again. It was really difficult. I think I'm about done covering fuses in general, it's a pain and very difficult to get a good job.

I think I'd be more concerned with getting too much paint on it than anything. That stuff adds up in a hurry.

I will only sand and cover the wings and elevons, tho. If this one flies ok, which I think it will, I'm going to start building a spare set of wings right away. They're so easy and quick to build.

Strykaas

Regarding painting, I hope you will use an airbrush [8D]. I have always been scared by fiberglassing, as balsa sucks a good amount of epoxy that can't be sanded... The only way to know was to weigh the fuse before and after...
True, fuse covering is not always easy, and especially on seaplanes, a bad covering job is paid at the end when the airframe start to be soaked with water... [&:]. I think using dope might be lighter than fiberglassing...

Mustang Fever

My Feedback: (2)

Nope. I'm strictly a spray can painter. Lustrekote all the way.

I should have weighed it, but didn't. Guess I'll just have to take what I get.

I'd love to do the tissue and dope thing, but I the fumes make me sick. Epoxy I can take.

Strykaas

I'm pretty sure that with a correct gear (mask) you could use dope outdoor... that's what I do ... take care also with epoxy....

Regarding seaplanes, look at that (underpowreed ?) Northstar... http://uk.youtube.com/watch?v=RweEhfJeKj8 very strange !

Mustang Fever

My Feedback: (2)

I could only see three things going on for sure with that one:

1. The engine was a bit on the rich side- it was really leaving a heavy smoke trail.

2. Those tip floats were not helping at all. Did you see all the water being thrown off them? That's a sign of wasted energy. I know they're part of the design, but they extend so far to the rear that they seem to make it difficult for the bird to get up on plane. A planing hull has to get it's nose up in the air before it can rise up and get up on the step, and the aft part of those floats looked to be hindering that.

3. I think the ailerons were way too sensitive. Seems like it was rocking around a lot.

It really did seem awful draggy on the water, but the two or three times he really nailed the throttle it looked pretty good.

knifeedgeyak

You really can't hear what he says, but if you listen real close he had the wrong prop on the plane. That was the reason it not getting up on step. After he changed props jumped up on step and into the air with no problems.

Strykaas

I had no sound indeed for this video (plus I'm French). I suspected such a thing as the spinner had been removed for the second flight .
However, I am a bit suprised a 9xX prop cannot get it on the water...

Mustang Fever

My Feedback: (2)

Simon and Strykaas:

I think I have learned something about flying boats which applies to keeping the wings level, etc.

I had my Mariner 40 out this am on Lake Cadillac, and the wind was blowing much stronger than it does during most of my flights. It was perhaps 10-15 knots. As it was an offshore breeze, the lake was fairly smooth, so I taxied out a long way, and turned around for takeoff. I thought I was directly into it, but as the plane accelerated, the right hand wing refused to come up off the tip float, no matter how much aileron I gave it. I slowed down and turned around, and then it dawned on me that the wind was holding it down. I got the plane up to moderate speed, and then experimented with the rudder to find the wind. Once I was into it, I had no problems getting the wing level.

The wing panels are half covered on the Arrow, and the white part of the hull is painted. Have to do the red and the tops of the wings, then she'll be ready to finish and fly.

Mustang Fever

My Feedback: (2)

Here's some pics.

The wings are covered with Monokote Missile Red stuck with trim solvent to Ultracote Sky Blue w/Silver dots on the bottom, and plain Sky Blue on top. (The tops are not covered in this pic.) The color combination will carryover to the elevons, as well.

The hull colors are Jet White and Missile Red. Looks ok if one doesn't get too close.

I'm thinking about masking off the hatch and painting a Missile Red "canopy frame" all the way around it, say about 1/4" wide. Any thoughts on that?

Strykaas

Nice ! I like the dot-covering, I did not know it existed, it's quite unusual ...
I would have painted the canopy black... all simply !