Some good things some bad things some miscalculations
First the good things - I've started to add some color to the Polaris and thats working out fairly well so far. Lots more to do. The colored packing tape sticks well. A pass over by a med hot covering iron helps a lot. I still need to paint a lot of the blue foam with white which Im not looking forward to.
My cowling ended up looking pretty cool I think. Its tilted down a bit more than I wanted but it will do for now.
Now the not so good.
Ive been playing with various options for an air scoop in the front. I haven't come up with anything I like so Im just going to do something and live with it for a while - until Im inspired
I did some checking and decided where the two packs would need to go to balance properly and cut a new hatch in.
Thats when I got a good look at my speed controller Holly cow! The heat shrink is melted badly and the foam it was sitting on is also melted
Good golly molly I must be pulling waaaaay more amps than I expected. That got me to wondering how that could be so I went back and re ran the numbers through MotoCalc.
I must have pushed the wrong buttons the first time I ran the numbers or entered something way off because now Im seeing predicted amp values up near 80 amps! With no cooling air flow no wonder things got hot!
On looking closer I noticed that the efficiency numbers are down close to 50%! Thats why the motor is running so hot.
Obviously I need to prop down a lot until I can get a motor with a lower kV. I am running this setup waaaay over proped.
I should be able to get better performance on fewer watts by running the motor in a more efficient range. I definately need the ugly air scoop
Ive made some good progress on the changes. I came up with a new idea for the air intake - its part of the new hatch. Looks a lot better than my other idea.
Im also getting some more color on it. I have some Coast Guard markings I'll be adding as well when its a little further along.
Its about ready to test fly with the 2P battery setup and a much smaller prop. The motor I want isnt in stock at medusa yet so I'll have to wait on the new power plant for a while. Im still waiting and a new spinner which will help the looks too.
That water bird looks great Larry. I love the scoop, but you're going to have make sure you keep it right side up on the water. Colored tape is cheating, but it sure looks good. Do you Corrosion-X your electronics? I haven't made much progress on mine, but I got the shop cleaned up (the center at least) and my build table is flat empty so the Polaris wing will be on the table tomorrow. I have spent far too much time finishing the small parts. If I keep at it I'll have it ready for final assembly and paint.
Towards the bottom of the page is a package deal where you get 6 rolls for $9.45 plus $6.50 shipping. Comes to $16 for 6 rolls which isnt bad. You get to choose any colors you want too which is great. I got 1 roll of white, 2 red and 3 black.
The white doesnt cover very well at all unless its going over a white base so keep that in mind. The red covers fairly well but not 100%. You can see the lap lines. The black covers almost anything. So its important to plan your application so the darkest colors go on last.
I run a covering iron set to medium heat over the tape after its applied and that seems to make it stick better and smooths out some of the wrinkles.
Larry - I use CorrosionX on everything except the servos. I dunk the motor, rx, BEC, esc, servo leads, power conectors, etc.
Dont do the servos. The CorrosionX will kill about 1 out of 3 from my experience.
I dont worry about being upside down in the water and things getting wet.
I have deliberately run a rx, esc, servos and motors while they were completely under water with no issues after they were treated with CorrosionX.
When I fly my Capricorns on the water, the controller is under the wing and gets splashed all the time. I have had the Capricorn up-side down in the water for 20 minutes waiting for a breeze to blow it right side up again. The motor, controller and rx are under water the whole time. As soon as it gets right side up - Im flying again. I dont even wait to dry anything out. Its not necessary.
The stuff is truely amazing. The TV commercial they used to run showed them watching a TV treated with CorrosionX while it was on the bottom of a swimming pool!!
A few people have reported loosing esc's when they went into the water even after being treated with CorrosionX. I have never had any issues after many dozens of dunkings with several different controllers.
I can only assume they didnt get the stuff into every nook and cranny under the heat shrink.
The other possibility is they didnt shut off the throttle soon enough after the plane went into the water. The amp draw of a prop in the water is at least 20 times more than in the air. Its just like stopping the prop from turning and going to full throttle.
So if you dont shut down soon enough after hitting the water, your going to burn something up for sure.
I have occasionally had an untreated servo go nuts when it filled up with water but they have always been ok after drying out. More often than not its no problem.
Im hoping I wont get much if any splashing into the cooling inlet but I'll have to wait and see once I get it on the water.
The only problem that would cause would be a weight and balance issue if enough water did get inside.
I dont really have any choice anyway. With a 1000+ watt power system you have to cool it some way or you'll get melt down like I did on the maiden flights!