I think if you need the Speedo so light as to require a pull string mod, you would be better off flying that DLG instead. In bigger lift conditions where you might reach speeds that would induce flutter, lack of weight would not be an issue at that point, instead you'd be trying to figure out ways to add it back in like...

The Frankenspeedo


-Jonathan

Well
I will say something interesting. I fly Spirit with pull-string for elevator and rudder with line- rubber sistem, Also I add one rubber plus on the elevator too because I put to thin wire in the elevator.
Also I fly Hyper from Arthobby with line and rubber sistem (You can use wire on place of rudder.
Also I had E-Hawk 1500-electric sailplane. Again line- wire sistem. It work perfect. I lost that sailplane but line-wire sistem was not a reason.
Competiton DLG are with line-wire system. I think moust of them. I have one competiton DLG and it has pull-line sistem
Before-I made Free fly sailplane F1A for competition and there is rule-beware of extra weight. Because my goal is marginal lift weak condition on my slope hill hot air bubbles too it is nature to made lighter saiplane. But If You have healthy wind on Your slope that is not a big deal . But I like less weight on the tail.
I really love my sailplane and when I start to fly it I work on it step by step which thing I can do better to got better performance. My goal is tune sailplane maximum good. When You make some steps You will feel benifit If You looking it.
PS
My Spirit has all history. Today is lighest as possible. I made resurection of it when pull out those massive commands in the tail. Lots of weight I pull out from the nose. It is bigginer ship but I made it better. Plus made zero zero incidence tail and wing and now is so nice flyer..
best
boris

My Speedo has a 6 oz. duck decoy anchor taped to the belly for ballast probably 90% of the time. I see no reason to be too picky about the weight. I do usually fly in stronger wind, but my slightly heavier than average Speedo without the ballast will just barely stay up in a 3 mph breeze on a hill that does not produce spectacular lift.

Anyone out there using a hi start or bungee to get their Speodo Pro Mark II in the air? How's it working? Hook mounted at CG? Any issues mounting hook? I'm still building mine and would like to try bungee.
Thanks,
Bill

It's funny, I've been toying around with the idea as well, and I reckon an ordinary catapult / slingshot would probably do it! You would need the hook to be as far forward as possible for any type of bungee / catapult launch..

Chris

Talk about a wrist rocket, haha!

Originally Posted by war64

Anyone out there using a hi start or bungee to get their Speodo Pro Mark II in the air? How's it working? Hook mounted at CG? Any issues mounting hook? I'm still building mine and would like to try bungee.
Thanks,
Bill

There are a few videos around of people bungie launching the Speedo, probably in one of the older Speedo threads. It looks like they launch well. I have no personal experience, though.

Originally Posted by Gwalch

Make sure you glue in those little bits of carbon in the wing bolt holes.. it's amazing how much movement the wing gets from those if they are not secure.
I glued one on one wing and the other on the other wing so that I could still get the wings apart.

Here is how I did mine.

I taped the top of the wing where the bushing go, inserted the bushing and then squirted Titebond II into the gaps. I let that sit for about 7 hours and then used a rat tail file to spin and then push the bushing out before the glue fully dried. I might have to do this twice due to shrinkage, but I think this will help some.

Thanks for the tip.

Frank

Originally Posted by war64

Anyone out there using a hi start or bungee to get their Speodo Pro Mark II in the air? How's it working? Hook mounted at CG? Any issues mounting hook? I'm still building mine and would like to try bungee.
Thanks,
Bill

I found it. You'll find quite a bit of info in this area of this thread. http://www.rcgroups.com/forums/showp...postcount=1405 Search that thread for "launch" to find more.

Here's a video linked to from that thread.

Speedo Bungee (4 min 42 sec)

A couple weeks ago I saw a Speedo at my hill that did not have a front wing mount screw. Instead the wing slotted in underneath an overhang on the fuselage (not the canopy). Is this an older version, or a newer one?

Originally Posted by war64

Anyone out there using a hi start or bungee to get their Speodo Pro Mark II in the air? How's it working? Hook mounted at CG? Any issues mounting hook? I'm still building mine and would like to try bungee.
Thanks,
Bill

Hook placement depends on what sort of launch you want.

If you want a flat out fast launch then put the hook in front of the leading edge.
If you want a high start then go back.

Originally Posted by Gwalch

Hook placement depends on what sort of launch you want.

If you want a flat out fast launch then put the hook in front of the leading edge.
If you want a high start then go back.

But, what must be read together with that, is the choice of equipment: a bungee (rubber only, or rubber plus short safety string) is used for the flat launch / hook forward; a hi-start (rubber with long string) is used for a "high start" with hook back. Two completely different scenarios.

Chris

Originally Posted by bjaffee

A couple weeks ago I saw a Speedo at my hill that did not have a front wing mount screw. Instead the wing slotted in underneath an overhang on the fuselage (not the canopy). Is this an older version, or a newer one?

That's the original Mk I. The "overhang" contains a wedge that fits into a notch at the front of the wing. The wedge forces the wing halves apart on excessive impact. It works quite well to protect the wings.

Thanks Chris,
I bought an up start from Tower Hobbies. It has 25 ft of rubber tubing and 300 ft of nylon twine. So i guess I need to place the hook farther back. At the CG? Mid wing?
Thanks again,
Bill

Bill sorry I'm out of my depth there - never done a hi start, only bungee launches. I'm sure someone will answer that, if not, post a question in the "Thermal" or "Sailplane Talk" sections...

Chris