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-   -   Help on engine advice for 30% edge (http://www.rcuniverse.com/forum/giant-scale-aircraft-3d-aerobatic-110/11343503-help-engine-advice-30%25-edge.html)

raron455 12-24-2012 09:29 PM

Help on engine advice for 30% edge
 
Ibought a 30% edge 540 made by Peak, plane is nice, put together as well as my wild hare Iused to fly, it has an actual 94" wingspan I measuredon it, and Iam looking for some opinions, advice, experience on engine. The manufacturer says 50-60cc. However Ihave a great da-85 that Iam almost convinced on putting on it. Here is my logic and tell me if its off and why you believe that, experience is always the best teacher,,
A dle-55 weighs right at 3 lbs, the da-60 is stated as 3.1 lbs, the Da-85 listed at 4.3 so it is just a little over 1lb heavier than the da-60 which is what the manufacturer recommends, this is all engine weight manufactures generally never list total powerplant weight,,. Iam reinforcing the firewall, and fuselage runners, adding a piece of ply to both sides of the firewall and pinning it, also using aluminum angle to tie it all to the fuselage, (I do this stuff no matter what,, once I get a new plane, Ialways reinforce the engine box),,
The way I am thinking is this, running the da-85 with a carbon fiber spinner, and the ignition as far as it will go into the fuselage, and putting the batts in the tray with the reciever, (maybe a little further back) Ishould be able to compensate for that extra lb to get my CG where Its supposed to be,, if notI could run a little heavier tail wheel assembly to bring it where it needs to be.
Now the only thing I see that is not as the manufacturer designed is that the plane will be a little heavier, but with the CG correct the plane should fly well, just perhaps a little more wing loading, but would have way more power than It needs, which is always a good thing,,,,at least to me.Laying out theda-85 it will fit fine onthe firewall,,
We have a club memberwho flys a 30% Yak with a da-85 on his and the power is insane, thats why Ibelieve it will be fine in mine,,
I know alot of you guys have seen alot and put together you have probably seen everything,, SO let me know if you think this is a good setup for great power, or a bad Idea because Iam just about to jump into it with both feet,, thanks fellas

BarracudaHockey 12-25-2012 05:34 AM

RE: Help on engine advice for 30% edge
 
Sounds like you made up your mind

gene6029 12-25-2012 09:01 AM

RE: Help on engine advice for 30% edge
 
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I have a little experience with putting a DA-85 into a 50 cc airframe. My suggestions are to re-inforce the firewall area where it attaches to the airframe. Also I would suggest offsetting the motor to the left of centerline & bring the motor shaft back to center, or it will constantly be pulling hard left. Make sure all of your hinge points are well anchored too, and use good servos. I moved my batteries to the rear as you allready mentioned. I had to go with a 3 blade prop for on mine for safe ground clearance ( 25-12 x3). I have several years of flying on mine & it really an animal & stupid fast. Heres a few pics to help explaine the above.......Gene

raron455 12-25-2012 10:03 AM

RE: Help on engine advice for 30% edge
 
so far I have doubled up the firewall I have cut some side panels that I am going to epoxy in that run from the firewall to inside the fuselage, basically boxing the frame, I am going to pin the firewall, and then use some aluminum angle to tie the outside of the box to the fueslage wall, Hopefully that will make the box rock solid, I am using the performance aircraft wood mounts, to try and kill all the vibration I can,
I have some high torque digitals for the plane,,
the box already has the right thrust built into it, mounting it on center, are you saying scoot it to the left and shim that side up to center the engine up, so it does not pull to the left,, wouldnt it actually pull to the right with a flat mount andthat thrust built in?

gene6029 12-25-2012 01:04 PM

RE: Help on engine advice for 30% edge
 
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Mine had 3 degrees allready built into the firewall. I added another 2 degrees & it tracks straight without any added rudder.( by moveing the motor over to the left some, this allowed me to add the 2 additional dregees & that brought the prop shaft back onto the center line of the cowl) This was thru trial & error. I have built several of these planes with various size motors & the 85 required the additional right thrust to track straight on up lines with out adding rudder input. Yours may vary with different props. You could allways mix in rudder with throttle, but i prefer not to do it that way. Sounds like you are on the right track with re inforceing the front end......Gene

sensei 12-25-2012 06:27 PM

RE: Help on engine advice for 30% edge
 
You are asking for advice, so I will tell you what I think. I think you will have a better flying airplane with a lighter engine, power is never an antidote for wing loading.

Bob

raron455 12-25-2012 08:55 PM

RE: Help on engine advice for 30% edge
 
thanks and I do appreciate the advice,, I understand the wing loading will be a little higher, But I was figuring the available power would allow me to do just about anything with the plane,, I have not had too much experience with this kind of build, I know If I run a da60 or dle55 I would still be using everything else I will be using if I use the da-85, the only dis-advantage would be that extra 18-20 ounces of engine weight,, And I am just not sure if that would be enough to cause a noticable difference in the plane??
I want to make this choice right, because I only want to build it once and get it right the first time,,
I fly pretty aggressively, I wanted the bigger engine for high alpha passes, and of course hovering, and want the absolute power to pull out of it in an instant,, thats kinda why I figured the da-85 would be the beast for the job, just not too sure about that little extra weight?? and not sure if the 55 or 60 would have that much punch,, the plane is advertised as having a fly weight of 15-17 lbs.

nitro wing 12-25-2012 11:11 PM

RE: Help on engine advice for 30% edge
 
of course the 85 will overcome the few ounces mentioned, by the time you "BEEF" up other areas, it will be alot heavier than you think, and the 85 will still hover out of it easily.
All the other flying characters will greatly suffer though.

gene6029 12-26-2012 05:24 AM

RE: Help on engine advice for 30% edge
 
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I agree with the above wing loading statements. The key here is to build your plane strong & keep it light or as close to the original weight as possible. Our Extras with a stock DA-50 build, Evo 58 & DA-85 all were within a lb or so of each other. My Extra with the 85 came in just under 20 lbs wo fuel, & i kept the aluminum wing & stab tubes. Replacement CF tubes would cut that down to a low 19lb range. Your ws is larger than our 2.3 ws & if you can keep your weight at or under 20 lbs you will be happy with the way it flies. Another example, I put a DL-50 in a Dynaflite Chipmunk that was designed for a 1.20-1.40 four stroke motor. Instead of adding unusable nose weight, the 50 balanced it out perfectly & its a baby to fly. ( the key here was the finished weight was roughly the same as if i used the smaller four strokes).

BarracudaHockey 12-26-2012 05:48 AM

RE: Help on engine advice for 30% edge
 
15.8 lbs with a DA50, please let me know where you think its lacking power :D

If it were me, I'd get a DA or EME60
[youtube]http://www.youtube.com/watch?v=J8DZ-gyauXg[/youtube]

grant118 12-26-2012 07:48 AM

RE: Help on engine advice for 30% edge
 
Nice flight Andy - love it!!

gene6029 12-26-2012 08:15 AM

RE: Help on engine advice for 30% edge
 
Very impressive flying indeed, and definately not lacking for power. I think the original poster is trying to justify useing a motor he allready has. ( in this case a DA-85) If the OP keeps the finished weight near ( a lb or so ) of the intended weight with a 50cc motor the flying characteristics wont change the wing loading enough to cause any flying issues. Gasoline with oil weighs roughly 6 lbs/gal & depending on the tank size used, weight can be saved there to negate some of the gained weight. Most planes burn thru a lb or two of fuel in a flight anyway. I'd be more concerned with the longevity of the airframe than its flying characteristics.....Gene

raron455 12-26-2012 09:51 AM

RE: Help on engine advice for 30% edge
 
to be honest, i wanted this plane and ordered it, i thought a da-85 would be a beast so i bought one from a member here, once i got it on the bench and compared it with my dle-55 i realized how big it is, but looking at the weight it is just a little over a lb heavier so i was not sure if it would be an issue,,however now i am having second thoughts, thinking of selling this 85 and getting a da-60 or bme 58..

BarracudaHockey 12-26-2012 10:27 AM

RE: Help on engine advice for 30% edge
 
Having spent most of the weekend messing with an EME with someone else, if I were buying a new 60 right now, I'd be VERY tempted to give it a try.

TailDraggerRC is taking pre-orders, packing them with an RCExcel Ign kill, and CM6 plug and shipping them for 349

zacharyR 12-26-2012 11:05 AM

RE: Help on engine advice for 30% edge
 
+1 on above post...


nice flying andy indeed ~!!!![:-]

BarracudaHockey 12-26-2012 11:07 AM

RE: Help on engine advice for 30% edge
 
I wish. That's my plane but Neal flying it.

skip1320 12-26-2012 02:46 PM

RE: Help on engine advice for 30% edge
 
What peak 30% edge has 94in W/S?

raron455 12-26-2012 04:01 PM

RE: Help on engine advice for 30% edge
 
the 30% edge 540 from aerobeez which is made by peak, they say its 87 inchs but i pulled right at 94 inches from tip to tip.

husafreak 12-26-2012 06:37 PM

RE: Help on engine advice for 30% edge
 
Just my 2 cents but I don't care for really overpowered 3D planes, the motor torque and gyroscopic effects lead to some undesirable characteristics. The perfect power for me will accelerate smoothly out of a hover, too much will cause sideways yawing and weird torque effects. These effects will be there anytime you go to full throttle and screw up a lot of maneuvers. I suppose f you had all your planes set up the same you would get used to it but if you just have that one greatly overpowered plane you might not be happy with it as it will handle very differently from your other planes...

raron455 12-26-2012 06:45 PM

RE: Help on engine advice for 30% edge
 
after all I am reading I am thinking this might just be too much engine for this plane,, I can save it for another build,, its an excellent running beautiful engine,, OR I might just sell it and get a da-60 that might be the better way to go,, I like a plane that can float when off the throttle..

sensei 12-26-2012 07:19 PM

RE: Help on engine advice for 30% edge
 
A few years ago we set up several 3 to 1 thrust to weight 3D airplanes, and what we finally all came to in our assessment was it is much more difficult to manage that much thrust in torque rolls and hovers and in the cases that the weight went up as well, the airplane suffered in many other areas of the flight envelope.

Bob

straitnickel 12-26-2012 09:07 PM

RE: Help on engine advice for 30% edge
 
Under 16lbs. Less glue and hinges is what I found when I googled peak 540 just now. Thats light for 50cc, the scale percentage or wing span is a lesser concern than weight to me anyway.

gene737 12-26-2012 10:32 PM

RE: Help on engine advice for 30% edge
 
Nice plane, great flying. Both you and Neal....super job.

MTK 12-26-2012 11:01 PM

RE: Help on engine advice for 30% edge
 

Quote:

ORIGINAL: raron455

to be honest, i wanted this plane and ordered it, i thought a da-85 would be a beast so i bought one from a member here, once i got it on the bench and compared it with my dle-55 i realized how big it is, but looking at the weight it is just a little over a lb heavier so i was not sure if it would be an issue,,however now i am having second thoughts, thinking of selling this 85 and getting a da-60 or bme 58..
I have a BME58 Xtreme NIB for sale. PM me if interested

straitnickel 12-27-2012 06:37 AM

RE: Help on engine advice for 30% edge
 
If the plane weights 16lbs. A dle55 would pretty much be a beast.
just sayin.


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