(07-08-2013, 03:28 PM)gbanger Wrote: Hey Jason
I have had a very thourough look at all the specifications on both the Shoestring and the Sundowner. In your humble opinion which airframe do you think might have the edge and why?
Its hard to say because I've never seen a sundowner in the flesh, the shoestring I own so I can tell you about that one.
The Sundowner looks like it has a better airfoil, the shoestring's wing has a very blunt leading edge. So the shoestring is probably dragier in that respect. However the Sundowner has a bigger wing so there will be a little more drag from that. weather one offsets the other I don't know ??
The Sundownder is heavier than the shoestring according to the specs. There is allways some lee way here too. But it has a bigger wing area. Probably not enough tho' because the specs say it's 3-4 oz per sq ft heaver as far as wing loading goes.
People say the Sundowner turns better than the Pogo but it's a little slower in a straight line. Pylon races are made of turns and straights the more accuritely you can turn, the straighter your straights will be (if that makes sence) I guess what I'm trying to say is if you don't have to go wide on the straights you'll fly a shorter distance. It's no good being 10% faster if you have to fly 15% further.
I recovered my shoestring and the covering I took off, like all eflight covering, is rather heavy. I removed the pilot, he weighed nearly 2 Oz I sacked him for being over weight, lucky is wasn't a woman that would be discrimination, So there is probably similar ways to remove some weight from the Sundowner.
I think I saved nearly 2 Oz with the covering as well. All up that's a 1/4 of a pound!! It was something like that as I remember Its probably in my shoestring build thread. There were other places on the fuse where it was over engineered and some weight could be removed as well, but I didn't go there.
You need light because lightness means faster acceleration out of the turns and less drag in the turns as well.
I think there was room for improvement in the shoestring. The aileron linkages are not parrellel to the airflow this will add extra drag, It can be fixed but you have to change the way the servos mount and use a ball link on the aileron horn. I havn't done this mod but I should have, I was in a hurry.
With the shoestring you need to toughen up the fire wall a bit, it's not that strong. The airfoil could have been better and the ground handeling could have been better as well. Having said that you don't taxi any of these planes the props are close to the ground and easily damaged.
When you land you run out and pick them up rather than taxi back if you want to keep your prop nice on the tips, which helps with speed
Where you want the ground handeling is in take off, to be able to take off fast and straight and the shoestring pulls hard to the left if you give it full peg before it gets up to flying speed. I don't know what the Sundowner does, perhaps it's similar, perhaps not as bad ??
To me the Proud Bird with it's bigger wing and lighter airframe gives it a lower wing loading than the other two, It's fuse looks better areodynamically as well. The fact that it's a low wing probably does make it a little more draggy but it looks like it has a nice airfoil. I wouldn't worry about the sweep back of the wings it doesn't make much difference to the way they fly. But the other nice feature is the wider track of the wheels which makes for better handeling on the ground and should be less draggy in the air as well, having shorter struts.
If I had to choose between a Shoestring and a Sundowner I'd probably go for a Sundowner more out of curiosity than anything else. But you didn't ask me that, you want to know which is the better plane. If you base your decision on speed I think the shoestring may be better because it's lighter and smaller but to get the best out of it it needs a bit of tinkering. You can take some weight off it with out changing it's structure and you can reduce it's drag by fixing the aileron linkages So perhaps the answer is that shoestring might be able to become a better plane. If I was to buy another EF1 tho' I'm pretty sure it would be a Proud Bird or perhaps an Invictus from HK but I like the quality of work that great planes do It's pretty nice!! The other thing is that the proud bird comes in plane white so you can add your own trim and make it easy for the cage to tell who you are.
I think the airframes are pretty closely matched tho' close enough that the better pilot will win rather than the better plane.
PS the hatch on the shoestring needs some tinkering as well it's a bit of a bugger and the battery compartement is tight too. I can show you a how I set mine up so I could get the lipos in and out relitivly easily, It took some figureing out
paaatience !!
paaaaaatience 
paaaaaaatieeence 
dooooohhhh !!! 
Ef1 would be a good class to get into, there's not a lot of people flying it.
