magyarbacsi

I'm in the process of buying a Sea Monster that will be powered with a Magnum 70 4 cycle. Need input on flight characteristic and is that motor enough or too much for the plane. Compared to a Mariner, that I did not have much luck with, how does it fly and does it also take a ton of up to get it off the water?

TopShelf

My Feedback: (4)

I have the SeaMonster with a Tower Hobbie .46 and it has plenty of power. I would imageine the 70 four stroke should work well. It does not take much to get it off the water as long as you don't hold too much up elevator. Just hold the nose up a bit to get it moving through the water then back off on the elevator and let it transistion to planin then flying off the water.

Overall, it's a very enjoyable plane to fly with no significant vices. It does tend to change pitch a little bit when applying throttle but that is pretty typical of the pylon mounted engine. It's reasonably aerobatic but is very gentle and predictable in all flight regimes.

Ed_Moorman

My Feedback: (1)

I have a Sea Monster with a Magnum .70 4-stroke in it. Plenty of power. Will not stay on the water very long-mine doesn't. Goes vertical for a good distance, but solwly runs out. I am running a Master Airscrew 12-8. I think a 13 inch prop will just barely clear, but it was so close I didn't want to try it. I was running a 12-6 3-blade on my Saito, but it revved a lot. A 12-8 APC would undoubtedly be better, but I didn't have one. The all-up weight with the Mag .70 is 6# 14 oz.

I am using a JR 8103 with an FMA FM receiver and Hitech servos. Nothing fancy because it might get wet and ruined. I do highly recommend Corrosion-X to be sprayed on all your electronic components.

My first one had a Saito .72 in it, but I managed to dunk it in a bayou (brackish water), trashed the engine bearings and tore up the wing. I bought a replacement wing and installed the Mag .70. Excellent flying plane. Big, thick, symmetrical airfoil-good on insides or outsides. Has a little adverse roll coupling in knife edge, probably due to the tip floats acting like a small amount of anhedral. Good take offs and landings. Good for touch-and-gos.

Other than the hardware-clevices, pushrods-I thought it was an excellent kit. I replace 99% of the ARF hardware as a matter of course. The forward fuselage bottom is fiberglass. The T-tail is glued on and bolted on with metal angle brackets. Mine built on CG without any nose weight. There is no nose compartment, by the way. The pylon has a fiberglass center with ply laminated on the outside. Some of mine started to delaminate, but I epoxied it back on and haven't seem this again. The pylon does not seem to be as flexible as a buddy's Mariner pylon.

I don't see white planes in a cloudy sky very well, so I added red-yellow-blue diagonal stripes for more visibility.

You will need a special cradle to hold the thing upright. With the engine mounted high, it tends to tip over easily before the wing is attached.

Personally, I like the arrangement of the Sea Cruiser better with the engine pod mounted to the wing. The pylon is wider and doesn't flex. The sponsons on stub wings don't seem to affect the roll coupling like tip floats. These are minor things that most fliers won't even notice. I would definitely buy another one, which I may do and try the sponsons. I would recommend it to anyone.

magyarbacsi

Thanx for the info Ed. You answered many questions I had sent to the co. I was wondering how strong is the pylon with the Magnum 70 on it. The motor is a bit bigger than the opening and will have to hog it out a bit. Was wondering if that would weaken the mount. What type of fuel do you run in the Magnum. I have the Omega Cool power, 10 % nitro and blend of syn/cast lubricant but the jug does not say what % is lubricant.

Re the prop, I think my brochure sates 13-5. what is the size of the 3 blade you are using?

The Seamaster with an OS 46 is about to be launched, if it does not rain Sunday

Ed_Moorman

My Feedback: (1)

I am using Omega 10% which is 17% oil, 30%/70% castor/synthetic. Here is the Morgan fuels page where they give the percentages. I have been running this fuel, and sometimes the 15% in the winter, for years.
[link=http://www.morganfuel.com/modelfuel.htm]Omega Fuel[/link]

I ran a Master Airscrew 12-6 on the Saito .72 I had on the Monster, but it revved up a lot. I thought it was really too much for a 4-stroke so I tended to keep the power down. For the Mag .70, I am running a Master Airscrew 12-8, which sounds good in the air. I have also tried a MA 12-8 3-blade, but this seemed too much for the Saito to comfortably run.

I had to grind out the pylon mount area. If I did another one, I would lop off the mount legs, install a firewall with some metal angle brackets and use a Great Planes adjustable mount.

A buddy and I have several sea planes and the Monster is my favorite to fly. Sceond is a Fazer on floats.

One more thing, watch out for any of the tanks that come in ARFs. The plugs tend to come out after a while. I switch the rubber plug out with a DuBro replacement kit or a Sullivan, and I glue them in with Zap-A-Dap-A-Goo.

moocowfish

HI there
i have a sea monster and are in the middle of converting it to electric, with 2 Kyosho 600 on the wing getting rid of the pod all together, ill let you know how it goes if you are interested.
I have no pictures at this stage.
cheers
Rob

Ed_Moorman

My Feedback: (1)

A twin Monster! You must post pictures and let us know how it flies. Are you running regular 600s or brushless. (I am clueless on electrics). After you get it sorted out, post your whole setup.

phil1

I like the Seamonster almost as well as the Seamaster ARF- the Seamaster has a flat bottom hull so rides in the water better and doesn't tend to oscillate in bank during rough water takeoffs - but it's easilly controllable with aileron - just bring the power up till aileron control is reached then go to full power.
In flight -the Seamaster is again the slight winner especially in slow and point rolls - and it tracks easier in large vertical maneuvers.
These are only minor differences but seem consistent -we have had 32 Seamasters at our lake

bob27s

My Feedback: (19)

another Sea Monster. Jett 46 up top.

magyarbacsi

Ed
In the process of breaking in the Magnum 70 4 stroke to put on the Seamonster. I'm using the left over engine pod from the Mariner to mount the Magnum. That Magnum has a lot of torque and really moves the pod around. The Seamonster pod look even weaker and wonder if the vibration is what caused yours to delaminate. In retrospect, would you change the pod, reenforce it or build a different mount similar to the Mariner's.

Ed_Moorman

My Feedback: (1)

My buddy has a Mariner and his pod is more flexible than mine. To tell you the truth, none of the pods I have seen have been very stiff. The other planes flew OK so I figured mine would, too.

I have had 3 engines on mine so I glued on some 1/8 ply in the mount area. I also had some slight delamination, but fixed that with 30-minute epoxy.

If I did another, I would cut the mounting legs off and add a firewall and use a radial mount.

The only stiff pod I have seen is the Sea Cruiser type which is wing mounted between 2 ply ribs with a slot for the main spars. Here's a picture of the Cruiser.

The other thing you could do is to make a new ply pod mount, but make it a couple of inches wider and cut into the leading edge of the wing.

moocowfish

HI remember me?
i have converted a Sea Monster to twin electric, running 2 mag mayhems 600, brushed, with 12x8 props, well...................
i flew it off land the other day at my local club, which doesnt have a lake, and it flew great, plenty of power and it just went up like a gas plane, flew around for a while, it was quite steady in the air. Maybe because of the extra weight involved in electric, well anyway i flew it around for a while untill on of the motors gear came loose, so i landed it with one motor. All in all a successful first flight.
this weekend i am going to a friends property near on the lake so i get to try it in the water...yeah.
Sorry there are no pictures but they will be coming soon, one way or the other.
all the best.
Bob

moocowfish

The twin Seamonster flew, here are some pics that my lovely wife took, i only got one flight in as it grew too windy.
till next time.
bob