Creating Wing Flaps

With a fair bit of time of not being able to go flying due to my wheels in the Garage again for a fuel leak I thought I would have a go at making flaps into a spare smashed up ME 109 wing.  The ME 109 needs to come in fairly fast but takes the whole length of the our runway to stop or even at St Georges Field at Ferndown a while ago as Jon found out.

Anyway going in "blind" and thinking if I *uck up I still have the original wing.  I followed the line of the trailing edge of the wing then I drew a line and sliced down through with a craft knife.  I now have two bits with open edges.  These will be closed in using strips of balsa. See image.  As the "flaps are hollow I need to put some balsa into the centre area for the control arms to screw into.  I used pieces of left over hard balsa aileron strips to achieve this.
Being flaps the hinge line will have to be angled for at least 50 degrees, allowing in practice 45 deg of down flap.  I set my sander to max tilt angle which was about 50 degrees and sanded the leading edge of the flaps.  Checked the angle with a angle device and hand sanded any irregularities.  Now I can glue on a balsa strip to close of the flap forward edges. See images.

I now have to close off the back edge of the wing. Placing the "flaps" against the wing where they will go I measured how thick a strip of balsa would be needed to bring the flaps back to somewhere near back in alignment and also allowing for sanding a 50 deg angle downwards so when the flap is up the there is no gap and when it's down it can pivot at least 45 degrees if need be.

Getting this right took a lot of pondering, scribbling on bits of paper, scratching head and thinking, " Fairly easy job to add flaps and realising it ain't that simple."  Also why would any manufacturer make a warbird with NO FLAPS.  Well back in around 2014 VQ models did and this ME109 was imported by CML

As you can see the wing is in a bit of a state.  Mind you when the wing was made it looks like the factory used any spare bits of balsa whereever they could.

So I have ripped out landing gear plate and random holes and dents.  I found I needed 1/4 balsa strip to close off the back edge of the wing which will allow at a "guess" enough to create the angle and the flaps in alignment with the trailing edges of the aileron and wing - hopefully!

Whilst the glue is setting on the strips, I now had lots of fun trying to recreate the landing gear plate. Numerous card templates and two fails. I was starting to think, "Should I give up this project and find something less aggravating to do? "

I needed a rest so after a large black strong coffee I set about repairing the wing sheeting.  I now need to make up some flap servo plates. That was fun too trying to get a reasonable fit in the wing. These were made from 2 mm ply.  I used 2 mm ply strips too for mountings that will glue between the ribs so when the servo plates are fitted they are level with the wing sheeting.

Covered the underside of the wing with what was left of a roll of light grey. I have no idea when or why I bought this colour but anyway it gets the wing partly covered.

Next stage was to cover the flaps in what light grey I had. (I have ordered another roll from MS Leeds).  For hinging I had a few options but after thinking about how each type affects how the flap operates I plumped for Kavan flat hinges.  After few dummy runs with some scrap balsa I figured the hinges need to be 5 mm down from the top edge.  Hopefully with a degree of "accuracy" when the flap is up there will be minimal gap but when the flap goes down it moves back slightly.

Dug out my slot cutter and managed to nearly slot a finger but after 30 minutes they were all done. The hardest part was slotting the solid balsa in the centre part of the flap.
Dry fitted the hings into the flaps, aligned with the wing trailing edge and pushed them fully in.  Looking good with very small gap. They drop down nicely under their own weight to about 50 degrees. Pleased with that result!

With the servos installed I could now set up the ailerons.  Made up control rods and using my Hitec servo tester set the ailerons.  However, on test movement I discovered that the servo arm is not tall enough to give full throw and hits the wing slot.  Just managed before clicking Buy Oracover Light grey I added a pack of JR/Spektrum heavy duty arms.  Luckily  model Shop Leeds were the only shop with them in stock. They are now on their way.