RE: Seagull Model Cessna 337 ARF
 

Sonny, I'm in no hurry to maidenbut certainly anxious to. I'm sure everyone is curious what this bird is gonna do. I think Mike is right about opening up the hole around the spinner. I was thinking of just opening the hole almost to the lip and leaving about an 1/8 in. orso then using a smaller spinner. It would certainly allow more air to escape.

Joe
aka
rcflunky

RE: Seagull Model Cessna 337 ARF
 

Hey Guys;
Be very careful of the stock spinner. This happen to me today as I was doing the final tune on the rear engine!! I had just started the engine and was placing the starter on the ground when something hit me in the right eye!! I am glad I had on safety glass at the time or I would have lost an eye!! In over 35 years in this hobby, this is the first spinner I have seen to let go like you see in the pictures[X(][X(] I am going to change both spinner to Great Planes Aluminum spinner. So I would say to be on the safe side change the stock spinner!!!
Sonny
aka
jet22b

RE: Seagull Model Cessna 337 ARF
 

You were lucky, I always use aluminium spinners never the stock ones as they are rubbish, I have never had an ally one fail,
farfar

RE: Seagull Model Cessna 337 ARF
 

Hi Guys;
Well she is all done!! Here are a few shots of her. I Am still replacing the spinner. Now just to get some good weather to maiden her. Both engine are tune and ready to work. I hope she fly like the full scale. I still think this plane will fly on one engine if needed. But for me, if I loose one, the good one will get me back for a safe landing. If this fly great, I will pick up one more!!!:D
Sonny
aka
jet22b

RE: Seagull Model Cessna 337 ARF
 

Hey Guys;
Here is a ground report on the Seagull Cessna 336 ARF.
Today I did some ground testing in my drive way to see how this plane act on the ground. I must say, she did very well on the ground!! On both engine, she handle very good. Now for the one engine taxi test. First test was done with the back engine running, the back engine taxi are fun but also can be a pain!!!!:D The engine try to push the plane to the outside of the turn!! The front engine was spot on!! Everything was sweet!!! Next was high speed taxi test. I must say if I had the room, she would have flown today. She was light on the wheels in no time flat!!! Next test was with the front engine running. The take-off run was a little long, but the nose wheel did come off of the ground. I don't know how the plane will act after she is in the air. Could not do the back engine high speed, because to many cars was on my street.[>:] Don't they know this is my test strip!!!:D:D
Over all, I was very happy with the way she handle on the ground. When the weather break, there will be a flight report, so stay tune.
Sonny
aka
jet22b

RE: Seagull Model Cessna 337 ARF
 

Just a quick update since I haven't posted in a few days...

We have everything hinged and glued and all servo's mounted with the exception of the second elevator servo. We decided there was just a little more play on the non-supported side of the elevator than we'd like and since servo's are cheap, we are going to mount another servo for the other side of the elevator just to be safe. We figured it's only $20 more and in the grand scheme of our project, it's worth it for the added insurance. Also, we plan to fly this sucker fast and don't want any possibility of flutter! :D Both engines and fuel valves are final mounted and cowls are in the final coat of primer. We also have installed the remote glow set up and temp sensor on the rear engine for the telemetry. The lighting system is nearly wrapped up and is AMAZING. We will try to get vid of that soon. Shawn programmed it all himself and made a really sweet demo mode to test all the lights and it will almost make you have a seizure to watch. We are going to start the paint work Saturday. Once paint is done we can apply the final fuse graphics which are already cut and ready to go. From there, all we need to do is mount the batteries, receiver, switches, and exhaust extensions and we will be in the home stretch. More pics after we get it all buttoned up.

I'm currently waiting to see how it flies to decide if I will buy another Seagull for myself (and of course ARF-bash it again with a different color scheme), or if I will build the 120" Hostetler Skymaster that I have been pondering for more than a few years and do it up in the Red Bull scheme as well. Decisions, decisions.... ;)

Sonny, glad you are OK. We are going to try to run 3 blade props so won't be using the stock spinners anyway. Thanks for the heads up. Glad your taxi tests went well and you didn't get it run over by a car. [X(]

Joe, don't rush your maiden. I'm sure we will start getting flight reports soon. We just have to wait until AFTER our local Static Show in March.

Adam
aka
Herc Pilot

RE: Seagull Model Cessna 337 ARF
 

Well guys I finally got to maiden this beast. The twin OS 46s ran flawless. The sound of both engines running wide open was awesome. My final weight I thinkwas just shy of 11lbs.with a wing load of 32oz. Take off took about 100ft or more but I had added about 4oz. of weight to the nose which was too much. It took a lot of elevator to get the nose up but when it came off the ground it climbed with no problem. I only had time for one flight because I ran out of daylight. It flew so goodI did two loops and a barrel roll. Landing was perfect. The wind was a slight cross blowing close to 10mph. Our runway is 300ft long and I got it down in less than half that greasing it in with no bounce. All I can say is it looks and flys great I can't wait to fly it again. I'm hoping next time I can get some pics or video of it flying. Well good luck guys with your maidens hope you get to do it soon.

Joe
aka
rcflunky

RE: Seagull Model Cessna 337 ARF
 

Joe,
Congrat on your maiden flight!!!:D:D
Sound like this is a keeper. Can not wait to maiden my baby!!
Again, congrat on your maiden flight!!
Sonny
aka
jet22b

RE: Seagull Model Cessna 337 ARF
 

Joe, congrats on your flight! Glad to hear it flew well and the engines ran well. I'm curious, being nose heavy, did you have a fair amount of speed on the landing and use up a lot of elevator? Also, how much trim did you need and was rudder effective in the air? Thanks for your input!

Adam
aka Herc Pilot

RE: Seagull Model Cessna 337 ARF
 

Thanks Sonny and Adam I think you guys will like this plane. Adam I had set my dual rates on the elevator and ailerons to 60% so I didnt have a lot of throw and when I took off the nose had a little trouble coming up so my take off rollmight be longer than it has to be. When it finally did I was pulling the stick back all the way and had to put a lot of clicks on the up elevator to keep the nose from wanting to go down. Thats why I think my cg was to far forward or I just have to much weight on the nose. I put a 2.5ounce brass prop nut on mine and2ounces of lead on the firewallto get mine to balance on my cgmachine. When I finally got it trimmed out it flew pretty good. When I turned it did look like it was slipping quite a bit more so than other planes I have so putting some rudder in was verynecessary. My guess is because it has two big rudders and not one.</p><p style="text-align: left">I plan on mixing some rudder with my aileronson my radio the next time I fly. As far asthe landing goes I did have to keep the power up some becauseas it slowed the nose kept falling even with full elevatorso I probably came in a little faster than I needed to.I did have about 30 degrees of flaps on when I landed. I hope this helps.

Joe
aka
rcflunky</p>

RE: Seagull Model Cessna 337 ARF
 

Joe,
Thanks for the flight report. If you ran out of up elevator on take-off, you may be a tad nose heavy!! I would leave the 2 ounces on the firewall and take the 2.5 off of the prop and see how she fly, or you can up the dual on the elevator from 60 to 70% and see how that fly before removing any weight. Can not wait till we get some more good weather so I can maiden mines. Please keep the flight report coming!!
Sonny
aka
jet22b

RE: Seagull Model Cessna 337 ARF
 

I'd be interested in seeing non-contact infrared temp readings on the engine heads. I am wanting to buy this plane and install two Saito 72 engines but I am worried about cooling on the rear engine....

RE: Seagull Model Cessna 337 ARF
 

Hi Guys
Got my 336 for Christmas and just unpacked the kit last night. I've enjoyed following this thread and thanks for all the work you have done with picures and postings, it sure helps. This is the third Seagull model for me, and I've found their builds are a bit complicated for arfs. Your planes look great!
Adam, where did you locate your rear engine throttle servo?

Don

RE: Seagull Model Cessna 337 ARF
 

Hi Mike,
When the weather break for my part of the world, I will do a good flight report on engine temp on both the front and back engine. From on the ground, I can tell you that with the cowling on, the back engine, the head temp was flash at 220-F degs. This was after a 4 min run!! Like it was said before, start the front engine first, then the back and get her in the air as fast as you can!!
Stay tune for this flight report!!
Sonny
aka
jet22b

RE: Seagull Model Cessna 337 ARF
 

Hi Don;
And welcome to this thread. If you need any help or have question, please post!! We are here to help!!
Sonny

RE: Seagull Model Cessna 337 ARF
 

Thanks Sonny! It's a beautiful looking plane and I can't wait to get it assembled and into the air. Busy ordering servos etc. and thinking this thing through.
Those lights look pretty cool.
Don

RE: Seagull Model Cessna 337 ARF
 

Joe,

Thanks for the details. I asked about the rudder authority because I'd heard on a few different models of the Skymaster, that rudder had very little effect in the air. It seems yours was just fine so no need to set up crazy rudder throws. Also, one sure way to tell if it's nose heavy... next time you have it in the air and if it's comfortable, roll it inverted and see how much down elevator you need. If it's nose heavy, you will need a fair amount. One last thing, how fast is it at full song? I can't wait to do some high speed passes to lazy wing overs like the real ones I have seen. :D


Mike Early,

One of the reasons we went with the smaller Magnum 52 4-strokes over the 70's is because the size of the bigger ones would have involved lots of cutting of cowls and the distance from back-plate to firewall was much to long for the cowl/mount setup included. The entire top of the engine would stick out of the cowl, (which might help in cooling anyway). I'm sure the bigger motors can be used, but imagine some re-engineering is in order. Nothing new there I guess. ;) Not trying to change your mind by any means, just thought you should know what to expect.


Don,

Welcome to the thread. Hope you enjoy the build as much as we have. I really enjoy sinking my teeth into projects like this and think it will pay off in the end. We built a new tray and relocated the throttle servo right beside the tank in the rear. It's pretty snug and not much different than the original location, except on a smaller mount. I'll be over there in the next day or two and take a couple pics of the inside of the fuse. We relocated the forward throttle and nose gear servo as well. It turned out pretty clean.



As for our project, it got stalled a little. We had done the paint work on everything except the blue on the rear cowl and the fade on the wings a few weeks back. We took it to a buddy who is a magician with an airbrush. It all turned out beautiful and the match was as good as you can ask for having it mixed. Problem was, two days later, it was still soft. Three days, four days, a week later... still not set up. After doing some research, we discovered we used acrylic enamel paint with regular enamel hardener. Totally an oversight on my part, but really set us back.. We have another windshield on order and can probably get by using the smaller parts, but will probably have to start all over on the front cowl and spinner. Oh well, lesson learned. Guess I'm just glad we held off on painting the covered parts. ;) Hope to get back to work on it in the next week or so. Only 6 weeks until our Static Show!

Adam
aka
Herc Pilot

RE: Seagull Model Cessna 337 ARF
 

Great review!

Can someone measure the standoffs for the electric conversion? My kit came with 30mm pieces. Using the recommended size motor I think it should have come with much longer bits.

RE: Seagull Model Cessna 337 ARF
 

Ahh, yes. Definitely something to be considered.

RE: Seagull Model Cessna 337 ARF
 

Thanks Adam will look forward to the pictures. Too bad about the painting mishap, hope you are back in order soon. The Red Bull scheme looks awesome, can't wait to see pictures of the final result.
Your point about the 52's is well taken. I've had my 56's in the box for 8 years waiting for something like this, but they will be very cozy in the cowl, I have had to make some alterations to the engine mounts, might take some effort to make it work. On the rear engine the muffler can point aft, so that should be a plus.
Minor setback, my kit didn't include the light covers for the wing tips, Horizon will be checking with Seagull and that might take some time. Lots of other things to work on till then. Like tracking down a reverse-cut aluminum spinner for the aft engine.
Don

RE: Seagull Model Cessna 337 ARF
 

MMallory, my standoffs are also 30mm.
Don

RE: Seagull Model Cessna 337 ARF
 

Don,

I've attached some pics of the rear throttle servo and also what we did with the front throttle servo and nose gear steering as well. Pretty simple. I also took a couple pics of how the rear engine set up turned out so anyone considering mounting something larger will have something to reference. All we have left to do on ours is put a 90 degree elbow on the tip of the muffler to bring it out one of the holes in the bottom of the cowl. We will put a dummy tube in the other hole and call it good. Also, you mentioned getting the light covers for the wing tips. We have ordered lots of spare Seagull parts in the past and have a windshield on order now. If you have issues getting them, let me know. My dad works at the local hobby shop and he can usually get these parts fast at a good price. Oh yeah, one last thing.. both Dave Brown and Tru-turn will cut a spinner to any prop you want. Only thing is, if it's a strange size, they may have you send them the prop so they can get it dead on. We have done this many times on the 150cc birds.


Mike,

A while back you had asked about wheel pants. I finally took pics of the Top Flite 182 ARF's with the Skymaster. Not sure how you could make the front one fit, but it could probably be done. They all look a little big to me. Anyway, pics below.

RE: Seagull Model Cessna 337 ARF
 

Adam, thanks for the pictures and info. And, my fault, the wing tip covers were hiding from me but I did find them. Time to get my eyes checked. I like what you did to the rear cowl it looks very scale. And the three bladed prop is sweet!

RE: Seagull Model Cessna 337 ARF
 

Adam, did you fiberglass the two cowl halfs back together? How did you fill and finish the seam? It looks great. I'm not changing the covering scheme on my plane but if it's not too big a task I'm thinking about emulating your cowl work. Did you have to modify the front cowl as well?

RE: Seagull Model Cessna 337 ARF
 

Thanks for the compliments! The front cowl fit was very good, so we only added the vents at the bottom by cutting and scoring existing material, bending, and gluing. For the rear, we took out about a quarter-inch of material along the line in the picture below. It then fit the outline of the fuse very well. We tack glued the halves back together with CA, then laid a one inch strip of glass cloth along the seam on the inside. With a careful hand while cutting, there is minimal filling and priming. Ours took little to no filler. The whole thing only took a few hours. I can take more detailed pics if needed.

Adam