Adding a hook to a fiberglass fuse?

[wingbeat]

I've recently acquired a used F3B ship for flying slop, a Valenta Models Storm. Flying weight is a beefy 100 ounces, ws 126". http://www.soaringusa.com/products/product.htm?product_id=16157&category_id=259

I'm interested in adding a hook so that I can also launch it at the field to try some thermal flying.

From the layout of the servo tray already (permanently) installed in the nose and the way the wings are joined it would be difficult to install a hook plate from the inside. I'm concerned about the strength of the fuse, as the fuse was cracked and repaired close to the cg prior to my buying the plane.

Any tips, links, pics of doing a sturdy install of a launch hook? I'm afraid to put a hook in without distributing the stress over a larger area... even with the previous repair this is an F3B plane, and the fuse oughta be built strong enough, right? Links to sources for a good adjustable launch hook also appreciated.

thanks

[glidagida]

Hi Wingbeat

That's one Heavy dude.

For the tow hook it looks as though you should be able to access the cg position through the rear of the hatch, but as you say the servo plate is already installed [the Soaring USA site does not show the tray installed.] I sell the Dural F3J hook by Hot Avia here in Australia <www.rc-sailplane.com.au> and I know Mark Miller of Istmus Models sells them in the USA.
<www.isthmusmodels.com>

The advantage of this hook is that the hook is Dural and has a plate both internally and externally it is very light but sufficiently large to spread the load even over a damaged area.

But the neat thing is that the inner plate should fit into a standard servo cut out and with some 'encouragment' with a satay stick and a bit of gum it should be possible to position it over the holes/screws from the outer hook and plate. You can make the hook adjustable by elongating the screw holes. Look at the Isthmus 'Soprano' construction article on Mark's site for pics on how to do it.

Regards
David [Aeroplane] Leigh
Radio Control Sailplane Australia

[kkw]

That is one ugly hook David :D I use these in my models. Adjustable and very strong.

[slozuke]

Hey KKW, where did you get that hook? What's the name of it, who makes it?
C'mon, details, details!

[wingbeat]

Thanks for the info on the hooks.

KKW- source?

glidagida- I think you're right... I played "Operation" as a kid. I should be able to persuade the inner plate to line up. As long as I don't need any fuse reinforcement- that's the part that concerns me. But it's made for F3B, so I guess I'll fire away!

No doubt I'll want something lighter though... lol.

[eye_rc_soar]

Hey KKW, where did you get that hook? What's the name of it, who makes it?
C'mon, details, details!

Barry Kennedy sells them. They are not on his web site http://www.kennedycomposites.com, but he has them. I am using them in my F3B and F3J planes.

don

[kkw]

I got a few from http://www.aircraft-world.com but it seems they are out of stock. They are a good hook in my opinion.

[Mark Miller]

The two other nice features of the CNC hook David and I sell is that it is infinately adjustable. With the other hook mentioned you have to bond in the inner plate and once there you only have the adjustment range built in. If you are working with an unknown design you may need to move it more.

The second thing is that the plate that is inside on the CNC hook is one side is curved for round fuselages and the other side is flat for box type fuselages. I have not found anything it will not work well in. I find that the clamping pressure is enough to hold it in place.

Mark Miller
Isthmus Models