Sky 120 LMA Trainer

[Geoff McVey]

Part LE1

This is part LE1, because the root wing rib W1 is set at an angle this part will have to be sanded to allow the front part of W1 to fit into LE1.

[Geoff McVey]

Wing Ribs W13, W14

Another dry test fit of wing ribs W13, W14 after a little more sanding was needed.

[Geoff McVey]

Wing Ribs W1 - W14

All wing ribs now glued in place, LE1 and TE1 only dry test fitted check allignment etc, only a couple of minor adjustments to make, will then glue LE1 and TE1 in place and then the top strip hardwood.

Next step is to make the wing brace to allow for the glass dihedral spar, going to build 2 wing halfs purely for ease of transport, then finally cover the top of the wing with sheet balsa.

[Nick Reeves 3055]

following this build with interest

[Geoff McVey]

following this build with interest

Enjoy.

[Geoff McVey]

Servo Tray.

Servo tray mount glued in place, this was simple and easy, a good fit.

[Geoff McVey]

Wing Brace Box Holder

Wing brace parts ready to be put together.

[Geoff McVey]

Wing Brace Box Holder

Second hardwood strip added, a good fit.

[Geoff McVey]

Wing Brace Box Holder

Wing brace box holder taped up, a good tight fit, juat a little sanding needed on both the box and the glass spar.


Wing brace box holder finished ready for sanding.

[Geoff McVey]

Wing Brace Box Holder

Wing brace box holder glued in place to the right wing, just need to remove the hardwood strip coming out of rib W1, main glass spar inserted a good fit.


A good fit, only a little sanding needed.

[Geoff McVey]

Right Wing

Right wing almost completed, ready to be skinned with 2.5mm balsa.

[Geoff McVey]

I have weighed the 12 sheets of 2.5mm balsa and have come out with the following.

31, 31, 31, 33, 36, 37, 39, 41, 41, 41, 44, 46, total weight 451 grammes, jut under 1 pound.

Bottom right wing - 31, 41, 41, total weight 113 grammes
Top right wing - 31, 37, 44, total weight 112 grammes

Bottom left wing - 31, 39, 41, total weight 111 grammes
Top left wing - 33, 36, 46, total weight 115 grammes

Only a 1 gramme difference between both wings.

[Geoff McVey]

Wing skins

Adjusting the 2.5mm sheets for skinning both wings.

[Geoff McVey]

Wing Skins

Before gluing each of the 2.5mm sheets together, only a light sanding was needed, these were then held together with masking tape, the sheets then turned over and then a thin super glue was used, turned over again and the other side done, only a light sanding is needed.

[Geoff McVey]

Wing Skins

Both wing skins ready to be glued in place tomorrow to the wing frame, small adjustments were needed to make sure that both top and bottom skins cover the wing framework.

[Geoff McVey]

Right Wing Top Skin

Right wing top skin ready and to be done first, will glue the skin to the main spar, let this dry, then curve the sheeting to the ribs and glue in place with cyno/this super glue.

[Alan Cantwell 1131]

Can I suggest here, the use of white pva glue, cover the structure with the pva, then use magazines to weigh the skin down, the mags will flex, and bend the skin to the wing, I doubt cyno will do the job as well, it will have gone off before you apply the skin, the pva will penetrate the wood, and give a much stronger bond,

[Geoff McVey]

Can I suggest here, the use of white pva glue, cover the structure with the pva, then use magazines to weigh the skin down, the mags will flex, and bend the skin to the wing, I doubt cyno will do the job as well, it will have gone off before you apply the skin, the pva will penetrate the wood, and give a much stronger bond,

Alan,

Will do what you have suggested, I have more than enough magazines, plenty of weight.

[Alan Cantwell 1131]

Bags of sand work equally well, don’t use aliphatic, the penetration is not as good as pva,

[Geoff McVey]

Free Spare Parts

Visit to IKEA this morning and once past checkout noticed this area, spare parts etc, they were all free so picked some items that I will use to build the Sky 120 with.