410onefor

I've been thinking about this project for a while and I finally decided to give it a go. I live in an area where restrictions are high especially gas engines. Soo, I've decided to build a seamaster half the size of a forty. This project is no comparison to the albatross being built in another forum but I figured it would be a good first scratch build. I could go out and buy the new seawind ep but where's the challenge in that. The build is aprox 40% complete and no major hick ups so far.

MinnFlyer

My Feedback: (4)

Sounds great, I've thought about doing exactly that many times

Good Luck, and keep us posted on the progress!

Pics?

410onefor

So here's a few pics so far. I've made a change to the wing design. I opted for a flat bottom wing to achieve better slow flying characteristics. I haven't built a rudder yet although that won't be an issue. Any advise is always appreciated but I don't have any specific questions at this time.

ronwc

My Feedback: (404)

ACE used to make a 1/2 size Seamaster (kind of) - here is a pic of the kit - Puddle Master - I built and flew one in the early 90's, kept this kit to convert to glow at some point -

410onefor

Right on, thanks for the pic. The puddle master is quite a bit bigger than my little project with some differences compared to the seamaster. The fuse looks exactly like the forty but no T-tail, the wing floats are different and the wing profile is definitely more of a flat bottom.

My wing span on the build ended up 32" where as the P.M. is 48". Projected weight should also be about half of the puddle master hopefully no more than 20 oz. I'm going to try the T-tail design hopefully help it to ROW. Things are moving along pretty quick and should be covering by next week.

Turbobeaver

What size engine are you planning on using on this plane?At 36",that is putting you into a .15 size engine category roughly.Any larger engine than that and you may as well just built one of these.

http://www.rcmmagazine.com/store/sto...2eDIP8aZ84X6x4


At a 48' wingspan,it is being powered by a .19-.25 size engine.A .20 and a .25 size engine are almost identical in size and weight so you got me curious as to what your planning to use for power if not a .15..

410onefor

This things going to be electric. I have no experience with the electrics but I figured why not go for it. So I bought three micro servos, brushless motor, esc and a couple of batterys. I just tried the motor earlier this evening and power is not going to be an issue! This also happens to be the first prop that bit me! Very minor scrape but instantly gained respect for the little motor. The prop is only held on by an o-ring but they can still do some damage.

I'm almost done building except for a few odds and ends but should be covering this weekend. So far I'm just under a pound without covering. After running the engine I felt the need to beef up the wing a little but I should still be under my projected 20oz. The fuse turned out to be real solid once I sheeted the bottom yet still very light. I'm looking forward to getting its feet wet and see how she floats. I'm going to be pissed if this thing doesn't come up on step but won't know for sure 'til I try. Once I get to that stage I might have to pick some brains.

Anybody have any idea how much weight would be packed on by coating the fuse in epoxy diluted with a bit of rubbing alcohol? An oz at the most maybe? I don't think light weight covering is going to be water tight but I could be wrong. And will the covering stick to epoxy? Might just have to paint it.

I'm also wondering about esc and battery temps. They'll both be in the fuse but there's little to no air circulation in there. I might have to ask the electric gurus that one. And if these do heat up, how do I waterproof them? Can't really wrap them in balloons then either.

I should be able to download some pics tomorrow.

John C

If you want to use epoxy on the fuselage, my practice is to use say 5 cc of each epoxy component and add 10 cc acetone and mix with an acid brush. I use the disposable 1 oz. mixing cups. Then I use the brush to apply the thinned epoxy. I did a set of HOB floats this afternoon and am waiting for the epox to finish curing. I find the acetone mixes better than alcohol, and evaporates better to allow the epoxy to cure, although curing does take longer than straight epoxy. I was using 6-minute epoxy today.

Once cured, I'll sand fairly smooth and put on a second coat of the same mixture. Finish sand and it's ready for paint. You can get a really smooth base for your paint this way.

John C

410onefor

Thanks for the tip. I never thought about using acetone as a thinner. I ended up covering the fuse with monokote today and it worked quite well. I'm using micafilm for the rest of the plane.

So I didn't do a very good job on researching the electric accessories for this little project since everything I bought, ESC, motor, and battery clearly mentions to keep away from water! Anyway, I'm aware of the hazards and I've chosen to continue. Fuse is covered along with both stabs and rudder. Main wing, wing floats, alerons and elevator left and she'll be ready for final assembly. Pictures soon!

410onefor

Well Here's a pic of the progress. Company on the weekend has been hard on productivity but still making some headway. So far it looks like it will be under a pound. Wing floats are almost done.

410onefor

If this is a repeat post I apologize. I wasn't sure if the first on went thru.

The mini maidened today! Well on land anyway. I'm still working on the wing floats and I have to seal the wing seat before I head to the lake. Everything went well but the cg needs to be moved up. Barely any throttle is enough to keep it airborne. I've already added 1/4 oz. to the nose because everything is moved up as far as is practical. Might have to add up to 1/2 oz. I figure to get the cg where I want it.

C-124 Flt Engr

For what it's worth,
Ken Willard designed a ''Seamaster II'' for .25 engines in the mid 80's & published it a couple of years after his original ''Seamaster'' in M.A.N.