Since I'm hacking away on this wing I decided to change the flap actuation from the original bottom drive to top drive. I did this in an attempt to lower drag. This decision was based a lot on the write up by Martin Hepperle.
Top drives keep a lot of the linkage inside the wing
https://www.mh-aerotools.de/airfoils/index.htm
See Aerodynamics and then Drag of Aileron & Flap Linkages
I'd like to ask which way do you set up your linkage? I know that the DS guys set up there flap linkages to be "locked" while in profile to minimize the load on the servo gear train at high speeds.
I've got my flap linkage set up so that the linkage is locked with the flaps fully down. This was done to try to save the flap servo gear during landings. The concern I have is that any gear slop I have is now showing up with the flap in profile. This hasn't shown up as a problem as the top speed at the bottom of the split "S" start is probably less than 100 mph.
I know the ultimate solution is to use servos with tighter gear trains, such as the MKS or KST.
https://alofthobbies.com/mks-hv6110-mini-servo.html
https://alofthobbies.com/kst-x08h-servo-2-8kg-38-oz-in-09-sec-8-grams-wide-voltage.html
But for the price of one of the above mentioned servos I can fit the wing with 4 of these economy KS Servos.
https://alofthobbies.com/jx-pdi-0902mg-servo-19kg-264-oz-in-10sec-94-grams.html
I've been using the HV version (PDI-0903MG) and these have been working well in this ship for about 2 hours of high speed flight.
At one time I was involved in trying to keep youths involved in this hobby. This often meant helping them with repairs and basic construction methods. I remember one insightful youth say to me; "It's not that you don't make mistakes, It is that you know how to fix your mistakes". That realization that we make mistakes during the repair process went a long way towards that youth becoming a great modeler.
I've seen far too many models abandoned because there were mistakes made during the repair attempt.
As a form of encouragement I'll detail the two mistakes I've made during this repair. The first I've already covered in detail and that was the failure to realize that stiff structures (carbon spars) fail at three points as a result of impact damage. This cost me about twice as much carbon as would otherwise have been needed (read added weight to my repair).
The second mistake was the sloppy use of CA glue, and the subsequent soaking with acetone!
During the initial piecing together of the wing with CA glue, I folded over the aileron to use it as a splint. This was great as it defined a straight trailing edge upon which I used as a datum to piece together the wing. The mistake I made was not placing a release layer between the aileron and the top wing. Yep you guessed it, I had glued the aileron to the top of the wing! Now as the structural foam was imperious to CA glue I thought, wrongly, it was safe to use acetone. In a panic I soaked the glued area between the aileron and the top of the wing, giving it time to soak into the joint to loosen the CA. Much to my horror I noticed the wing tip distorting as the structural foam was dissolving. I shook off the acetone and with my fingers and pry bars lifted the aileron off the top of the wing. You can see the extent of the damage as the block sanding clearly shows the low spots. I got lucky in that after the acetone dried the structural foam remained stiff. To repair this damage I will have to use a bit of glazing putty and a lot of block sanding.