PDA

View Full Version : Wading in


capn chaos
07-17-2010, 01:38 AM
131936

131937

131938

131939

131940

131941Back in early June, FREEBIRD posted on his Great Planes Electric Seawind.
Now every 4th of July my extended family get together for a reunion at Lake Murray in central SC. So the wheels (floats????) started turning (?) and decided that I needed to put a seaplane together for some lake flying. The Seawind looked great but while looking into their site, found the PBY 53" Catalina. Hmmmmmm twins...somewhere in my "skunk works things to do list" sits a twin WWII XP model that never saw combat but was nonetheless a real eye catcher.
Having never set up twin electrics thought this would be a good way to get experience with the wiring set up while diving into a seaplane for the first time also.
So the Catalina was ordered along with two 28-30-11's, 20amp ESC's, counter rotating GWS EP 80-40 three blade props and a 2700 mah 25C 3s battery all from HURC.
Work has still been hectic so did what I could over the next three weeks with only a minor detail or so to iron out when I was packing things up for the trip south.
Plenty of reviews on the plane so wont go into the build other than it was well instructed, straight forward and pretty much just as advertised. Also read some horror stories of water infiltration to wings, fuse, etc and spent extra time making sure there would not be any problems in this department. Before wings went on I did the float test in the bath tub and found the rubber drain plugs were undersized for the hole supplied in hull for drainage. Trip to true value and a couple of size corks solved the problem. REports of water entering fuse were harrowing where trim was erratic at best as water rushed from tail to nose and back. Decided not to take any chances and folded two paper towels multiple times into about a 2"x3" square and wedged them under the plywood esc mounts centered at CG location. Figured if they got soaked it would be easier to land a brick as long as the CG stayed the same.
Also picked up a tube of Dap ALEX PLUS caulk that I had used over the past fifteen years for weather proofing construction products. HAving lived on the outer banks of NC for a number of years where every third hurricane was a tracer:eek:, weather proofing was essential. The stuff stays flexible, drys clear, can be removed with a razor knife but other wise is a good adhesive. Sealed all exposed openings where water could possibly get in. In four flights, had about one thimble full of water in the fuse and that included at least one pretty ugly nose plant after a good bounce.
Overall very happy with the performance. The GWS EP 8040's didnt push the 28 30-11's very hard and Jeff's specs were pretty well spot on. 12 amps (17 max 30 secs per specs) didnt overwork much of anything and with no cooling air....thats a good thing. Performance was very much scale with extended roll out (??) some low passes and just "loitering" in general.
Glad to have the experience in twin set ups and after reading plenty of info here on separating motors and ESC at the RX throttle connection, decided to cut both red wires in the legs of Y-harness. Kept the ESC wiring in tact and still separated port and starboard wiring as necessary.
An added plus to the trip south was running into Voyager2lcats and getting a glimpse of his PT 19 dow foam build. What a cool project. Thanks for sharing that Bob

CC

gramps2361
07-17-2010, 02:08 AM
Nice Bob this is a area I would like to get into. I would like at least one float plane in the hanger not quite yet but maybe next summer I will add one.
Did you soak the electrics in corrosion x to protect them from water?

Well Bob that is a nice looking plane, and from the sounds of it you seem happy with it. May I assume this wasn't a ARM as you coined almost ready to modify, but a quality ARF.
John

capn chaos
07-17-2010, 02:19 AM
Hey Gramps (Ringo)
Yes a true ARF...no modifications for a change:Q. So out of character for me...lol.
Couldnt find corrosion x in my rush. I did get a silicone electrical (dielectric) compound that I treated all harnesses and electrical connections with as well as pushing tons of it into the heat shrink covering on the esc's...alot like packing a trailer wheel bearing (old school before "bearing buddies" were invented). Worked it in one end til it came out the other. It seems to stay as a silicone grease and doesnt cure in air like silicone sealant.
CC

gramps2361
07-17-2010, 02:27 AM
Nice when you can find a plane that doesn't need a lot of mods to get it together and flying.

Funny this is the first time reading about packing a ESC like a wheel bearing, but if it works power to you sounds like it will be water tight like a frogs butt.:cool::Q

capn chaos
07-17-2010, 02:42 AM
Nice when you can find a plane that doesn't need a lot of mods to get it together and flying.

Funny this is the first time reading about packing a ESC like a wheel bearing, but if it works power to you sounds like it will be water tight like a frogs butt.:cool::Q
Havent checked real close but I'll bet thats pretty water tight:D
I was really surprised at maiden when the PBY required 0 trim...even a blind squirrel gets a nut sometimes...musta been my turn:Q
I would like to find some "more aggressive" props, not so much for speed but these dont give much margin and have to run about 80%-90% throttle from the take off. I generally like a bit more like 50-60% then just keep advancing throttle as battery wears down. Will take some getting used to. one of the pics shows the minimal clearance of the 8" props on cockpit/cabin. Just need to find some that have alittle more punch. I could try the two blade 8x6's that came with it just to see if the amps/watts increase a bit. They look like SF props so not sure how much to gain. Could try some APC 8x6's also but they wont be counter rotating...likely not a big deal but right now there is no offset to mounts so would have to change that. Again, this was a much a venture into twins as it was seaplanes so learning curve is vertical again.
CC

gramps2361
07-17-2010, 03:42 AM
Bob I set up 2 twins both of them had o incidence and they where not counter rotating. One thing I have read here is you need to figure your watts higher with a seaplane as it takes more to get them up and in the air. You will get it figured out try his TP 8x4 prop stays with in spec's.

capn chaos
07-17-2010, 04:17 AM
Thanks, John
I might also look into a higher Kv set of motors and keep the same props. For 20 bucks a pair of emax cf2822's (1300kv) would increase amps, and power by as much as 10-15% (I think) and come closer to peak output than the 2830's (1150 kv). They would also reduce weight by one once (.5 ozs lighter each). Sounds like a win/win situation. The TP 8 x 4's could be the ticket and everyone says two blades are much better than three for performance...no argument on that one. Will try the TP 8 x 4s and see watt I end up with before ordering more motors.
CC

gramps2361
07-17-2010, 04:49 AM
I had the emax on my twin starr II EMax 2812 1600 rpm 7x4 apc prop with his 20 amp esc's, and a 30 amp 2800 mah battery WOT was 348 watts and 32 amps. this was a great setup Bob really pulled this bird along. Even could ROG as long as the grass was short no landing gear on this bird. Well those EMAX motors are cheap enough give it a shot.
John