Originally Posted by casor

Jorn - you should also wrap the solder joint with wire to increase the surface area of the solder joint. And you should also wash and then paint the area to prevent corrosion from the acid in the solder. Lose the elev tiller and you lose the airplane and I have had this happen.

The filler you are using sounds like 2 part auto body filler which adheres well to a clean/sanded surface - but it is heavy. Fill minor imperfections with a single part auto body glazing filler which sands more easily and then prime it all.

Once again, thanks for your input. The solder has been “wrapped” with a little piece of brass to increase the area. I’ll take care of the corrosion warning!

And I don’t mind “heavy” in this exact case - I’ll need weight up front in the cowls or cockpit anyway Besides that it is only a few grams.

By sheer coincidence when I read your posting about the rudder gap, I had just finished dealing with the same issue on mine. The rear fuse cone has molded farings, where it looked like the rudder bottom may not have clearance. The bottom of the rudder could be sanded up a bit, but I also raised the fin 1mm just to ensure there's enough leeway. Last solution would be to fill an excessively large gap between the top of the fin and the rudder, as you mentioned. Noticed that you have a similar internal tail linkage scheme also. Worth the added effort for the clean appearance.

I imagine it is more difficult to balance the larger Mosquito. With the micro, the motors are proportionally heaver than the larger scale, making balance a non issue. With the B25's similar proportions, I used soft foam to position the tiny battery just in front of the wing, as it was nose heavy with it in the planned nose location. Built that battery tray for nothing.

Can you please mention the airfoils that are used in the wing and tail

Originally Posted by srinjayk

Can you please mention the airfoils that are used in the wing and tail

The wing is "RAF-34 modified" based on this blogpost: http://wellssullivan.blogspot.dk/201...g-section.html, but for reasons described in https://www.rcgroups.com/forums/show...4&postcount=13 I ended up using RAF-38. You can follow the discussion from there.

The tail is a symmetric NACA-0012

Spent last evening painting - got the last of the camo done on the fuselage and feathers and touched up around the new windows. Looking good.

The cowls was primed with a high build filler that seemed to do the job. The surface is nice and smooth without too many bubbles and blemishes. But then I made the mistake of thinking "primer is primer is, well, primer" ... not ... unfortunately the paint started lifting as soon as I took the masking tape off

Leason learned - primer is not just primer The good things is that it should be easy to strip the paint off before priming with the dedicated primer (on top of the filler primer) and trying again. At least the cowl painting is easy and requires very little masking.

I did some spreadsheet exercises in the train today to see how the weight was distributed. I haven't measured the all-up-including-batteries weight for some time, so the spreadsheet may be a bit off - but its "in the ball range". Nose weight for balancing is not known yet.

Dear Jorn - I respectfully note that the axiom in your last post should probably be "in the ballpark" which is of American origin and which referred, at least initially, to baseball....but we all know what you meant!!
Rob

Jorn - as compared to your est on the first page, looks like you're a little over but not terribly so. As long as you have the CG right and washout in the wings you should be fine with this model
Rob

Originally Posted by casor

Dear Jorn - I respectfully note that the axiom in your last post should probably be "in the ballpark" which is of American origin and which referred, at least initially, to baseball....but we all know what you meant!!
Rob

Sorry

Originally Posted by casor

Jorn - as compared to your est on the first page, looks like you're a little over but not terribly so. As long as you have the CG right and washout in the wings you should be fine with this model
Rob

My initial estimate was based on the Chipmunk I built before - I multiplied that weight with the wing span difference factor lifted to the third: (span2 - span1) ^ 3 x weight1 ... but retrospectively I realize that I didn’t consider the fact that the Mosquito would be built with working retracts and *2* engines/nacelles - and I think that counts for most, if not all, the difference.

Unfortunately I do not have washout (neither did the original) ... but I am considering programming a tiny bit of it into the ailerons. Blaim it on this being only my second self designed scratch built scale aircraft

Back to the painting ... I tried to sand off the cowl paint, but it turned out the hardening over night made a huge difference, so I’ll just fix the small patches and leave it “as is” - it seems like it will bond okay as it is.

Yes, I see hardware usually around 50-55% of the total. Which means the scope for weight saving is confined to the 45-50% that is the airframe.

Guess you may still have to add a bit of lead to get balanced, but she should fly nicely at the AUW you are coming out at.

Alec

Jorn,
I like your idea of a little bit of aileron reflex. I think it would serve you well.
Robert

Engineers I worked with said that when they estimated time from previous smaller projects, they doubled it, and sometimes came within 15% that way. They said the extra is related to the time spent on the higher level of integration of a larger project.

The last days have been spent painting roundels and doing some work on the canopy. I am a bit surprised to see how much time it actually takes to do this kind of thing.

I'll save the fuselage roundels and markings for later.