2m glider

[danskis]

I've only ironed on laminating film but I believe all the iron on films work well on foam.

 

[Piotrsko]

Gotta use a covering that has lower temp glues and shrink capable. Generally ones that say safe for foam. Monokote isnt

 

[hello183]

The fuselage is really narrow, and I don't think I can fit the double arms on the servos for pull-pull. But I think I could fix the problem by mounting the servos inline, with one of them being slightly higher than the other so the lines don't touch each other. But this will make the rails more complicated, and I will need to design those into the formers too.

 

[hello183]

So I have finished drawing the fuselage formers, and am choosing the airfoil now.

I am thinking of three choices: the Sa7035(top), S3025(bottom), and the ag35(middle). All of these seem good for sailplanes. My problem is that I would like the airfoil to sit inside the top half of the fuselage (marked by that curved line down the middle). To do that, the airfoil needs less camber, to be closer to a symmetrical airfoil. So I am thinking of trying the Rg-15. What other airfoils are closer to symmetrical and good for gliders?

Also, I am considering making the battery hatch a canopy to give the top a better look

 

[Piotrsko]

Nasa series 0008?
The further back on the airfoil that the high point is, the more sensitive that airfoil is to CG placement along with increasingly nasty stalls. That's a rule of thumb, but....
No one has convinced me yet that at our sizes one airfoil is hugely superior across all flight regimen. You could make your chosen airfoil arbitrarily flat bottom which is effectively just a change in camber.

The solution for fuselage placement is to have just only the spars go through the fuselage or make a couple of ribs that are flat where the wing attaches to the fuselage

 

[hello183]

I made more progress with the plans, and I included a half-canopy, which makes the fuselage look better. This two-piece wing idea is hard to visualize, so I looked at some models that also do this, like the Fillon champion.
When I figure that out, I'll move to designing the rest of the wing and the control surfaces. I may do single pull on the rudder and pull-pull on the elevator.

 

[hello183]

I just started working on some of the formers. I'm planning on using 1/8 square longerons and 1/16 sheeting. School's over so I'm hoping to get more done. I will incorporate things like servo rails in some of them but that's for later.

 

[hello183]

so now I am working on some of the top sheeting (the fuselage is built upside down) and cutting the notches for some of the formers. Right now the fuse is more delicate than I'd like it to be, but when I sheet the entire thing, it will be durable enough.

I'm also going to use an aluminum tube for the boom, cause I don't have the tools for cutting carbon.

 

[quorneng]

Have you considered a glass fibre fishing pole for the boom? You can get multi section 6ft ones pretty cheap. The fact they are slightly tapered is good as it matches the bending loads.

This boom actually uses two sections of a 3 section pole but permanently glued together.

 

[hello183]

for two of the formers I want to use 3/32 plywood, but it's expensive. I'm probably going to do it by laminating 3 1/32 sheets of basswood together. Hopefully it'll be strong enough.
I'll probably make the firewall out of 1/8 plywood, since I'm considering using a motor anyway. I may make a motor and a nose block and make it so they can both mount onto the firewall so I can switch them.

 

[hello183]

Now I cut the firewall and cut the bottom notches

I finished cutting out the top sheeting (I didn't do the front because that's where the hatch/canopy is). It fits well. Some of the formers are slightly slanted cause the notches are wrong so I'll straighten them.

 

[hello183]

So I am just making some more formers, and it's kind of just more of the same thing. I also added the sticks that hold the servo rails. Has anybody had good experience with Superphatic glue? I've been using it like superglue but it doesn't seep into the wood like it says on the bottle. The bonds were weak so I used normal wood glue again. Is it not meant to be used that way?

Before I assemble this I will steam the longerons so it doesn't put forces in the fuselage all the time

 

[danskis]

The plans and balsa parts all look good....congrats!!

 

[Piotrsko]

Back in the day when that style of glue came out, we used to joke that when you crashed you just shook the parts out of the covering and rebuilt the plane. Aka: Bag of balsa.

No you don't need to use plywood if you aren't going to screw attach things to it. Hardwood has better properties for retaining screws. Balsa ply works fine if you use nuts and washers.

 

[hello183]

I laminated 1/16 and 1/32 basswood to make a 3/32 former. I may make all the plywood parts this way because it is way easier to cut than normal plywood

next I need to put some holes in it for the servo lines to pass through. I also steam bended the longerons and glued on the top sheeting.

 

[Piotrsko]

Congrats you made 2ply plywood. Other than using pressure and less glue that's the process. Basswood should be able to hold screws if that matters.

 

[hello183]

There's been a bit of a delay, because I have been sick and not really in the mood to do anything. But I got the boom today, it's cf because I couldn't find an aluminum boom, but I heard you can cut it with a dremel, so I should be fine. I also cut the servo rails and the former that the boom mounts into.

it's really rough. My tools for cutting plywood aren't very good, but I'll clean it up.

 

[hello183]

Now that all the formers are done, I needed to cut holes in the balsa formers towards the back that the boom passes through. I just finished that, and I'll be able to finish the fuselage soon.

If I ever redid this fuselage, I'd make it wider. The last former is basically the size of a nut.

 

[Piotrsko]

Two comments: it will tend to fracture at the cut

Need to sand/scuff it to get glue to stick to it better

Looks good, keep doing what you're doing.

 

[quorneng]

Looks good but do wear a mask cutting CF (or glass fibre) with a Dremel. The minute fibre particles created do your lungs no good long term.