bassman2914

I'm also using 3S. All you need to do is get a slightly faster motor to compensate or use a bigger prop. I'm using the TGY AerodriveXp SK Series 35-42 1000Kv / 605w motor with either a 12x6, 13x6 or 13x8 prop depending on flight characteristics. I will upgrade to 4S once i can afford a good charger and several batteries.

daveopam

My Feedback: (9)

The motor I have is a Extreme Flight 8412? I think is the #. I have all the equipment in a EF 48" Yak 54. It is a fine sport flyer but the 3D is lacking. My charger will work on a 4C, i am just to cheap to not use the $160 worth of 3C I have.

David

exeter_acres

My Feedback: (2)

The plane is really designed around a 4S setup... the 3S will fly it, but not to the level it is designed

daveopam

My Feedback: (9)

I figured that. Looks like I can get a 4cell for about $65. Maybe this spring I will get one.

david

bassman2914

$65!! What size? At hobbyking you can get a 2450mah 4s for $25. That torque 2814(same numbers, different order) motor was definately made for 4s because of its slower speed. If this is the extreme flight yak 48" than yes they said 3s or 4s but with that motor you're only going to get serious performance with 4s. If you really want to keep your 3s batteries than i suggest looking at a 1000kv + motor rated at least 500-600 watts. mine is 605w and 1000kv because i didn't want to go up to 4s yet but that'll be when i got more cash lying around. Options-go 4s, get faster motor, larger prop or a combination of the last two or all three(extreme power!!)

daveopam

My Feedback: (9)

Thanks Bassman. It doesn't help that I know squat about all this elec stuff. I will check out the 4 cell stuff at the site you suggested. My motor is the 2814T. I bought it, plane and all, from the LHS. I just told him to get me everything I needed. I had no idea if it was right or wrong anyway. The speed control is a 45A so i think it will handle the extra battery power. i guess I need to go down on prop also. What size should I be using on the 3 and 4 cell packs?

David

bassman2914

If you are going to use those 3cell packs I'd reccomend a 13x6.5(that came straight from the website). On that motor that'll give you the most power. If you do go 4cell than just use a 12x6 and the performance will be great. I decided that instead of buying a new charger compatible with 4cell I'm going to put two 2450mah 30c 2cell lipos in series because I just want that extra power for $5 more per battery. Along with that I'm getting a 700watt motor that'll give me 2700grams of thrust. I did this because HobbyKing had mine in backorder and I just couldn't wait and this was the only other motor that seems to have enough power(infact it has more). Besides, torque 2814 for $80 or this turnigy motor for $25. Along with a 60A turnigy speed controller.

bassman2914

I'm also running low on cash so i brought it from $500 without the tx+rx to just over 400 with all radio equipment and batteries.

daveopam

My Feedback: (9)

MAN, does this arf go together fast. I spent 3.5 hours on it yesterday. All I have left to do is put the pushrods on and program the radio. Maybe 1.5 hours total. Can't wait to get it on the air. Comparing it to the EF Yak 54 I pulled the gear out of. It has a lot more carbon fibre. Plus the motor mount box is shorter. the Yak had the motor inside the box. This one has the motor in front of the box. The AUW should be quit a bit less.
Did anybody build the air delectors on thier motor mount box?

David

bassman2914

I put those air deflector things on because I think it's going to need them because of the high powered motor i'm putting on it. I haven't tested it yet though it'll be flying in a week or two once all my parts come in.

daveopam

My Feedback: (9)

I think I am going to try mine with out them. There is going to be a lot of air going through the cowl as it is. With the 3" square hole cut on the bottom of the fuse it should flow fairly well.

David

bassman2914

Not too related but was wandering if there is anyway to make the plane scream when you fly it right. I've seen vids of this where when at the right speed it literally screams and I wanted to know if you can intentionally do that and if it's bad for it. I have one plane where I know it's the prop that does it but I heard that a very small gap between control surfaces will do it too.

daveopam

My Feedback: (9)

Most of the time I would say it's the prop or motor. Having a gap in a control surface is asking for flutter. If there is noise coming from that area the plane will not be with you very long.

David

bassman2914

I figured that it wasn't very good for the plane. And I certainly wasn't going to intentionally leave a gap but that prop only did it that one time. It must of been just the right temp because it's not doing it any more. I know this guy with a 33% that does that and he hasn't fixed it yet soo he obviously doesn't think it's too bad for it. Can't wait to get this plane finished!!

daveopam

My Feedback: (9)

Could be the tips of the prop are going super sonic. I had a SS 90 that ran a ST90 and a 14x6 prop. In a dive the prop tips would go super sonic and really start making noise. I wonder if this is what you are hearing?

David

bassman2914

It makes sense that that could be it because when i switched to a bigger prop, which obviously ran slower, there was no more noise coming from it. When i flew it in the cold maybe it couldn't go supersonic because the air is thicker causeing the prop to go slower and make more thrust so no more noise. I like the noise though!

cpreinfalk

For the tips of a 14 inch prop to reach super sonic speeds, you would have to do over 700 thousand RPMs at about 120mph speed of the airplane. Also, if those prop tips would reach super sonic speed, the prop would disintegrate. I don't think super sonic speed have anything to do with that noise.

bassman2914

I think you should check your math because i got that a 14" prop would only have to go 18,000 rpm which is easily doable and at 250,000 rpm the whole blade would be super sonic so i don't know where you got the 700,000 from. Still, my plane is not getting those speeds and even if it were, there would be a pop from the tips breaking the sound barrier and from them ripping to shreds and no more noise from then on except for the thump of your plane hitting the ground or a scream from shrapnal hitting someone. You're right about it not going supersonic but not completely, unless my math is also wrong.anyone else want to check??

cpreinfalk

I calculated again. I first got the per minute / per second thing mixed up. :-) Yes, for a 14 inch prop's tips to travel at the speed of sound, it would have to spin at around 18000 rpm. Which is not gonna happen. Even to approach that speed (not considering the fact that the prop would disintegrate), there is no motor and no ESC that would fit any model plane that would take the amps that the motor would pull at those rpms.

fmidgett

duplicate post...

fmidgett

Happy New Year all! It's clear today in NC, but well below freezing so no flying for me. I thought I'd share a few flashback flights. I've been promising this for a while...RJ Gritter's full dock flight from last summer that was the centerpiece of our EXP summer vacation film. A great flight from dock takeoff to splash landing. You can hear the natural ambient sounds including our discussion of who was going to catch it since I was filming from the roof. Plus...I found another flight of the 2m Vanquish that I had never posted on FlightPass. This is AJ flying the 2 meter Vanquish on the Sunny Sunday of the Atlanta Huckfest. Plus...Both films are on the HPP VIP page. Use your VIP link or signup here if you aren't yet a HPP VIP:

http://higherplaneproductions.com/rcuvipsignup.html

The original EXP film that released this summer is on the Higher Plane home page: http://higherplaneproductions.com

daveopam

My Feedback: (9)

OK, so I am wrong about them going super sonic. Not a surprise, but there is a noise that came from the prop when this plane was in a dive and the prop reached a certain RPM. Maybe not super sonic but it did get a growl to it that made us think it was reaching the speed of sound. Maybe someone can tell me what the sound was from? Was the prop deflecting at this certain speed and RPM?

david

cpreinfalk

No idea. However, I found out that the prop is making a kinda cool noise when you do a hover, cut the throttle somewhat, let the plane go backwards, hit full throttle and watch the plane still go backwards (because the prop doesn't get clean air to bite into; there's a term for that which I can't recall).

daveopam

My Feedback: (9)

I thought that was cavitation. Once again though, I could be wrong :-)


David

cpreinfalk

I think that's right!