09 for Sig Shoestring?

I have been flying a Sig Shoesting (the all sheet balsa profile) with an Enya .15 III using a bulky but very quiet aftermarket muffler and a couple oz of lead on the tail to compensate. Ended up 19 oz with 150 squares of wing area. I am using this as a trainer/sport flier - not for racing.

I have been thinking of swapping in a Tee Dee or Medallion 09. This engine without a muffler would likely allow most or all of the lead in tail to be removed and lighten things up considerably overall.

But would the 09 have enough power? Despite the small wing area this is still a beefy airframe. Has anyone used a C*x 09 in the Shoestring (or Sig Buster) and how did it work out?

Thanks,

Darryl
MAAC 41841

I am betting that the Cox 09 will have plenty of power. The Shoestring really isn't much bigger in wing area than the little Sig 1/2 a Skyray. I agree it is a bit heavier tho'.

I would think the Cox .09 would have the power of some .15's so it should pull things around real well.

We've used Medallion 09's interchangeably, practically, with Fox 15X's, and the power is similar. TeeDee 09's are a lot more powerful. Jim Thomerson's Streak Jr. with one of those needed 55' of 012's to slow down to a practical lap speed compared to the 52's he started out with.

So in spite of any conception about the relative weight of the two Sig all-balsa mini-Goodyear kits, I'd say a Medallion 09 is PLENTY of power, and a TeeDee 09 is an excess of same!

.

Kiwi

Yep. The Medallion is fine, the TD is probably way overkill for this small a wing area. Remember this is a profile, with a realtively thin wing section- not a lot of drag there.

Jake

Darryl,
If you are going to fly without a muffler, why not remove the one on your Enya .15 and rebalance first?
If you go for the Cox, parts for the TD are more plentiful if you need them.
Good luck either way.

Hi George,

Yes, your question begs the obvious. The reason I use the muffler is simply because the local RC club where I sometimes fly has a rule that mufflers are mandatory on engines .15 and larger. As far as the actual noise level, the TD 09 really screams but from bench running the Enya unmuffled, I think it is louder than the TD. The guys at the club don't seem to mind the TD whine. But the Enya without a muffler running rich 2 cycle has a raspy quality that some might find obnoxious.

Thanks for your responses guys.

WORKS PERFICT My son built one with this set up.

Norvel 15 unmuffled.

Hang on!

I had one before and flew it with a Med.09, worked fine as a trainer. here is my new one that I just finished with my son. Painted with rustoleum, and the wing was 'glassed with 1/4oz fiberglass cloth and EZ Lam epoxy. haven't weighed it yet, feels kinda hefty but should be pretty durable.