4 Metre Glider Scratch Build

[TooJung2Die]

I got to see a 4 meter glider fly at our club's July Fun Fly. An AVA Pro sailplane. OMG that's a long wing. It is rudder-elevator control with spoilers, no ailerons like your 4M. Flying in a light breeze several hundred feet up it seemed to hang motionless.
The pilot said the hardest thing about flying a 4M is landing it. Even with spoilers deployed it doesn't want to return to the earth.

 

[Jackson T]

I got to see a 4 meter glider fly at our club's July Fun Fly. An AVA Pro sailplane. OMG that's a long wing. It is rudder-elevator control with spoilers, no ailerons like your 4M. Flying in a light breeze several hundred feet up it seemed to hang motionless.
The pilot said the hardest thing about flying a 4M is landing it. Even with spoilers deployed it doesn't want to return to the earth.

That is one cool glider! Yeah, 4 meters is pretty long . Did you find out how heavy it is by any chance? How well does it turn without ailerons? My plane won't have nearly as good a glide slope, and I fly in a large farm paddock, so I should be able to get it back to terra firma. Thanks for sharing this!

 

[TooJung2Die]

Did you find out how heavy it is by any chance? How well does it turn without ailerons?

The website Kennedy Composites AVA says 48 ounces. It does not turn quick. He compared it to turning a barge on the Mississippi. Give it some rudder then wait, wait some more, it turns. I only brought it up because I didn't understand how long 4M was until I saw it.

 

[Wildthing]

I got to see a 4 meter glider fly at our club's July Fun Fly. An AVA Pro sailplane. OMG that's a long wing. It is rudder-elevator control with spoilers, no ailerons like your 4M. Flying in a light breeze several hundred feet up it seemed to hang motionless.
The pilot said the hardest thing about flying a 4M is landing it. Even with spoilers deployed it doesn't want to return to the earth.

That's a lot of wing

 

[Jackson T]

The website Kennedy Composites AVA says 48 ounces. It does not turn quick. He compared it to turning a barge on the Mississippi. Give it some rudder then wait, wait some more, it turns. I only brought it up because I didn't understand how long 4M was until I saw it.

48 ounces, that's way lighter than mine's going to be!

 

[TooJung2Die]

48 ounces, that's way lighter than mine's going to be!

That's way lighter than my 1.8 meter Apollo. You aren't spending thousand$ and building with carbon fiber.

 

[Jackson T]

That's way lighter than my 1.8 meter Apollo. You aren't spending thousand$ and building with carbon fiber.

How heavy is you Apollo? Does it still "float" alright?

 

[TooJung2Die]

The Apollo weighs 56 ounces with battery. I wouldn't say it's a floater but it can ride a thermal or two. If you read the AVA glider description it has room for adding ballast. On breezy days you want more weight to keep the airspeed up and penetrate the wind. Looking at your construction I think your wing load will be nice and light.

 

[Jackson T]

The Apollo weighs 56 ounces with battery. I wouldn't say it's a floater but it can ride a thermal or two. If you read the AVA glider description it has room for adding ballast. On breezy days you want more weight to keep the airspeed up and penetrate the wind. Looking at your construction I think your wing load will be nice and light.

Thanks. My estimated flying weight is 70-90 oz, which would put my wing loading in between your Apollo's and the AVA Pro, so I guess I'll get the best of both worlds! My fuselage is way overkill, so if I ever wanted ballast it shouldn't be a problem.

 

[Jackson T]

Got heaps of work done! I sheeted the topside of two panels, did the shear webbing on 4 panels, and made the dihedral joints. the plywood's for strength, the balsa for sanding down to a snug fit, and the foamboard is for spacing. I'm thinking of maybe not sheeting the underside of the panel's in the first and second pic. They are the second outermost panels, and I'm out of 1/16th inch balsa, and I don't feel like forking out another $10 to sheet the undersides. That far away from the center I shouldn't need it, should I?

 

[Jackson T]

Made two more plywood dihedral joint thingy's and test fitted yesterday.

Here's a shot of the wing minus the 140cm (55 inch) center section.

Next up is gluing these panels together (they're only dry-fitted), then I'll make the wing joiners after that.

 

[OliverW]

It looks BEAUTIFUL

 

[Jackson T]

I glued two panels together yesterday! I was totally freaking out that I would mess it up, but it worked out ok. It used about 5 grams of epoxy, but I mixed up almost 30 grams . At least now I know how much to mix for the next joint. Hopefully I'll glue a joint each day for the next 4 days. Will a stanley knife cut the excess off? I sure hope so!

I'm not doing the neatest job, am I?

 

[Joker 53150]

The less epoxy used, the better off you are. As long as there is enough to bond the panels. You may want to cover the exposed edges of the ribs with painters tape or similar to help avoid getting extra on them, as that will be very hard to finish sand later on. Remove excess before it cures when possible as once it cures it's super hard.

 

[Jackson T]

The less epoxy used, the better off you are. As long as there is enough to bond the panels. You may want to cover the exposed edges of the ribs with painters tape or similar to help avoid getting extra on them, as that will be very hard to finish sand later on. Remove excess before it cures when possible as once it cures it's super hard.

Thanks for the advice, will do. Will normal sticky tape work instead of painters tape? I tried to remove most of the excess epoxy before it cured, but I think some seeped out after I left it. Any tips to removing cured epoxy?

 

[Joker 53150]

My best tip is to remove excess epoxy as early as possible. Once it cures, it’ll fight you. A lot.

 

[rockyboy]

I find a sharp chisel and steady hand (along with tape to protect other surfaces) works OK

 

[Wildthing]

Dremmel tool with a cutting wheel and grind it off.

 

[Jackson T]

They are all really good ideas!
@Joker 53150, will do
@rockyboy, my dad's a carpenter, so I should be able to borrow a nice sharp chisel and give that a go. Thanks!
@Wildthing, good idea, I just need a dremmel now

 

[Jackson T]

I've glued up the other joint on that same panel, now it's time to start the other side! I realized that if I use my 30 minute epoxy for the other two dihedral joints, I won't have enough left for the carbon fiber tow later. I don't exactly feel like buying another $20 worth of epoxy, so I'm going to use PVA glue for the dihedral joints on the other panel. I'll get some pics up later when my dad comes home from work (I use his phone camera).