Flap trailing-edge forming

[cfsanford]

I hit the backorder wall on wing assembly and have moved on to the flaps. Everything is deburred and primed and flap substructure riveted. I’m ready
(I thought) to rivet the skins. A couple of early posts implied that skin edges were pre - bent to their final shape, and at least one on-line YouTube video proceeds through flap assembly without any mention of a brake or bending the flap upper skin trailing edge. There is no mention of skin bending in the General Notes for FL-15500 assembly (KAI page 36-04). However, page 36-24 of the KAI notes “Complete all trailing-edge forming …” just before the step of applying Fuel Tank Sealant and attaching the upper skin with it’s trailing edge. When I did a dry run attaching the skins to the substructure with clecos, it looks to me like the trailing edge of the upper skin definitely needs additional bending before final assembly and riveting. I’ve attached a photo of the upper skin as it shipped and a photo of the upper and lower skins attached to the substructure. Am I correct in proceeding with additional bending with my home-made brake per Section 5 General Information (page 05-09)? Any additional guidance? Thanks!

 

[Alphalpha]

I hit the backorder wall on wing assembly and have moved on to the flaps. Everything is deburred and primed and flap substructure riveted. I’m ready
(I thought) to rivet the skins. A couple of early posts implied that skin edges were pre - bent to their final shape, and at least one on-line YouTube video proceeds through flap assembly without any mention of a brake or bending the flap upper skin trailing edge. There is no mention of skin bending in the General Notes for FL-15500 assembly (KAI page 36-04). However, page 36-24 of the KAI notes “Complete all trailing-edge forming …” just before the step of applying Fuel Tank Sealant and attaching the upper skin with it’s trailing edge. When I did a dry run attaching the skins to the substructure with clecos, it looks to me like the trailing edge of the upper skin definitely needs additional bending before final assembly and riveting. I’ve attached a photo of the upper skin as it shipped and a photo of the upper and lower skins attached to the substructure. Am I correct in proceeding with additional bending with my home-made brake per Section 5 General Information (page 05-09)? Any additional guidance? Thanks! View attachment 113005View attachment 113006

Yes, the pucker needs to be taken out by reducing the trailing edge radius. With the flap being that long I suspect it is going to be a multi person job working to keep the brake straight and even. I also think getting that upper skin on, tucked in on the front and wrapped around the back and clecoed in place while not smearing the Proseal everywhere is going to be interesting.

 

[bigmikeh24]

I toured the factory when I picked up my kit in December. I chatted with the prototype guys that were in the process of building a -15 wing. They mentioned that you had to bend the flap trailing edge. They were using the 1x stock that the spar crates were made out of for their brake to make the bends.

 

[TShort]

I clecoed mine up before prosealing but didn't notice the bulge as above ... I was able to get it close after assembly but I agree, the TE will need bent before final riveting. I will address this on the second flap for sure.

With 2 people getting the skin in place with the bead of proseal wasn't terrible. I'm not sure it will be as easy after the TE has been closed some.

 

[rocketman1988]

I clecoed mine up before prosealing but didn't notice the bulge as above ... I was able to get it close after assembly but I agree, the TE will need bent before final riveting. I will address this on the second flap for sure.

With 2 people getting the skin in place with the bead of proseal wasn't terrible. I'm not sure it will be as easy after the TE has been closed some.

How much pro seal did you mix up for one flap?

 

[cfsanford]

How much pro seal did you mix up for one flap?

I made a cardboard template of the bend angle I thought was needed, then used my home brake ( two 2”x8x6’ hinged with no gap ) to bend the trailing edge. Worked slowly sliding the very long flap skin up and down the brake (abour 1 hour) and ended up with decent result, good final angle. Mixed 27.5 grams of tank sealant and barely had enough for the bead. I’ll mix a little more for the other flap. Got the top piece on withot much mess. My wife helped me hold out the bent top trailing edge as I slid the top piece up to the leading edge, attached 3 clecos at the top then released the bottom trailing edge over the lower trailing edge. The overhanging trailing edge seated on the sealant bead perfectly. I’ve been riveting with LP 4-3 ‘s all afternoon. Gratifying to see it come together. I really like this kit!

 

[MCA]

I used 2x6x8 with beveled ends to bed the trailing edge. It definitely needs bending on a brake. If doing again I’d buy 10 ft long boards and walk up and down it w 2 people. That trailing edge is one tough sucker. I sent Marc at Vans a note saying they should really bend this trailing edge fully. There’s no reason it has to be open to the degree that it is.

30 grams of sealer, 33 total. Just about right for each flap.

On a related note, I used about six pieces of duct tape to hold the VGs wrapped roughly close around to the top skin before Cleco-ing .

 

[catmandu]

If doing again I’d buy 10 ft long boards and walk up and down it w 2 people.

Lucy, you gots some 'splaining to do: flap on a flat floor, ten feet of wood on top just inboard of the trailing edge that you walk on, or what?

 

[MCA]

Lucy, you gots some 'splaining to do: flap on a flat floor, ten feet of wood on top just inboard of the trailing edge that you walk on, or what?

Yep.