4 Metre Glider Scratch Build

[Jackson T]

Finished sanding the centre wing piece! It was 256 grams before sanding, and now it's 233 grams. Going off a rough density estimate of 160kg/m3, I would have sanded and shaved off with my stanley knife almost 144cm3 of balsa!

On to the next panel.

After I finish the sanding, I'll have a little photo session all assembled in its bare bones. After that I'll probably do the carbon fibre tow.

 

[Jackson T]

Finished the left-hand panel!

I won't be gluing a piece of balsa to the wing tip to make it nice and smooth because I'm going to make winglets for it. They will be removable, so if they negatively affect the flight performance I can go back to plain tips, and also so I can try different winglet designs.

 

[Jackson T]

Finished sanding the last wing piece.

The cat loves my plane

Time to start thinking about the carbon fibre. Should I sand the wing really smooth for the carbon, or will it glue better if I leave it a bit rough?

 

[rockyboy]

Finished sanding the last wing piece. View attachment 140371
The cat loves my plane View attachment 140372
Time to start thinking about the carbon fibre. Should I sand the wing really smooth for the carbon, or will it glue better if I leave it a bit rough?

Yep - that's big!

I always apply the fiberglass before final sanding - as long as the surface is in the right shape, should be good to go.

 

[Jackson T]

Yep - that's big!

I always apply the fiberglass before final sanding - as long as the surface is in the right shape, should be good to go.

Is that because it's a waste of time to sand it twice, or because the epoxy glues better to un-sanded balsa?

 

[bracesport]

@Jackson T - looking awesome my friend - big enough for the cat to ride on?

 

[Jackson T]

@Jackson T - looking awesome my friend - big enough for the cat to ride on?

Yeah, probably! My sister breeds rabbits, I should try and design a rabbit parachute for an FT Guinea, and I'll have my own Special Services squad

 

[rockyboy]

Is that because it's a waste of time to sand it twice, or because the epoxy glues better to un-sanded balsa?

Don't think there is any specific benefit - just lazy!

 

[Jackson T]

Don't think there is any specific benefit - just lazy!

What do you recommend I do for best results?

 

[Jackson T]

Just did the carbon tow layup! <fingers crossed>

 

[Jackson T]

Top successful, underside in progress. I'll hopefully get some photos up tomorrow.

 

[Jackson T]

Finished the carbon! It came out at 254 grams, so the carbon weighed 21 grams. Much less than I was expecting! I was freaking out for the top layup cause I haven't done this before, but on the bottom I relaxed... a little too much. It was messy, it almost set before I got it on the wing, and a bunch of other stuff that was a bit dodgy, but it worked out.

 

[Jackson T]

My servos, spinner, and folding prop arrived yesterday!

I also got some clear 3mm ID tubing from Bunnings as pushrod guides.

We had some electricians install lighting in our shed, but it seems that one of them must have dropped a screw driver or something...

How should I repair the sheet? I have no idea. I'm just glad it isn't in the centre of the sheet where it would experience really high loads.

 

[Joker 53150]

Be careful with vinyl tube for a pushrod guide. It can be a little "sticky" and you may have issues with it binding. Another option would be small pieces of balsa glued to the structure of the fuselage to support the pushrod, although if the pushrod is very thin and flexible it would need a lot of support.

Fixing the broken sheet won't be too hard - it'll be more annoying than difficult. Use a straight-edge and cut with the grain on both sides of the break, far enough to reach the ribs. I normally cut the sheet just far enough so that it can rest on top of the ribs on either side of the break as it makes gluing the patch in a lot easier. I recently did a thread on fixing a wing on a Funtana 90 and did a similar patch to the sheeting, you may want to take a look as a reference, it might help.

 

[Jackson T]

Started the covering!

 

[Jackson T]

I forgot to mention earlier, I decided to add some sheeting to the rudder as it felt a little bit weak.

 

[bracesport]

@Jackson T - looking good - I feel a maiden coming before Christmas - was there anything tricky with the covering?

 

[Jackson T]

@Jackson T - looking good - I feel a maiden coming before Christmas - was there anything tricky with the covering?

Thanks! Yeah, I'll hopefully maiden it within the next month. The covering was pretty easy going for the h and v stab, but I did some work on the wings just now, and they're pretty tricky. It's the first time I've used more than one colour covering film on the same surface, and it's pretty difficult (at least for me) to line everything up. I'll try and get some pics up tomorrow morning.

 

[Jackson T]

Covered the first wing piece! It took me more than 4 hours . It weighed 204 grams before covering, and now it weighs 249 grams, so 45 grams worth of covering film. It was pretty difficult to line up the solid red covering with the rear of the spars, but I think it turned out alright.

 

[bracesport]

@Jackson T - you did a sterling job - well done!