FW- 190 400 series

[dirk gently]

If so, you must really love building airplanes.

[David Lewis]

My advice is one aileron servo to save weight. The ailerons could be actuated with a torque tube*. I also have found a good idea to 1. make the ailerons larger than scale and connect the flaps to the aileron servo, and 2. make sure the ailerons have differential throw (goes up a lot farther than it goes down) via correct aileron bellcrank design. The downward deflection should be small because it creates a lot of adverse yaw (drag) with little increase in lift coefficient at low Re.

I haven't worked out a rule of thumb for aileron area at this small scale. I just make them nice and big, and hope for the best.

* The strength-to-weight ratio of a torque tube is proportional to the square of diameter. Wall should be just thick enough to prevent local buckling.

[davidchoate]

I figured that out, and have learned also about the aileron settings of less deflection on the one that goes down. Thats why I was going to use 2 digital servos. I have the torque tubes in the wing, and I did increase the aileron area about 20% more area than scale. I should have gone more, but I just want the thing to Fly. I dont know if there is a rule of thumb on aileron area when down scaling. Like there is with the stabilizer.

[davidchoate]

No. It was not Her. I told Her before not to make Me choose between Planes or Her because I will choose Planes. She Has a Son, and He's on My side anyway with the Planes. Thanks. I think I did good on My 1st laminating try. and I am astounded at how strong and light it is. I may have to use this method on a Guillpow kit. It's easy to do. Just need a tracing of the shape and make a jig.

[davidchoate]

I want to try these micro retracts someday

[davidchoate]

lon next two weekends. want to get the servos and ailerons hooked up

[David Lewis]

In the context of electric motors, BL stands for brushless.

[Bill Gaylord]

I installed those MPI retracts in my last build here. Intricate job, but they work well.
With the low cost of 3-4gm servos versus the $25 we used to pay, the individual servo setup is the most straightforward, although the single servo can be made lighter, with thin gauge music wire and harnessing. Use a cable and standard 22ga servo wire, and the weight savings is lost. On torque tubes/rods, I used something like .047"wire on my first FW190 and the Spitfire, as well another model similar sized. They feel sloppy to the hand, but given the small amount of force needed in the air for a model this size, I noticed no difference between them and a direct linkage setup, as they flew well. As always, keep it simple. I've seen people go to great lengths to create torque tube setups versus a simple wire setup, which doesn't have reliability issues either. You can easily create differential also, by simply connecting the linkage points on the servo horn at less than 180 degrees offset, connected toward the wing TE side of the servo horn. The round horns work well for this. You can always set a "X" horn at 45 degrees offset, but that may create more differential than desired. FWIW, the FW190 doesn't seem to have issues with needing aileron differential, given the ideal proportions. Higher aspect ratio jobs can be an issue though.

[davidchoate]

Thanks Dave and Bill. Bill, I have Copied Your methods a lot. You have given Me freely Your practical experience on these challenging conversions, and David Lewis has shown Me (with frustration at My asking the same questions I'm sure)The formulas and physics to where I can now get a design/RC conversion into the ballpark of what must be proportioned, changed,etc as scale and purpose changes. And more importantly, WHY. Bill. Are You referring to Sullivan Gold n Cable? And if possible can You post pictures of the setup. I,m not quite ready for retracts. but I know who to ask when I am . I like the MPi stuff. Eflite has electric micro retracts, but they are $75. MPi was like $2.00. I also am becoming very curious about VPP setup, and why it it not more widely used. It is mechanically simple, and not very costly. I got one to Experiment with. It seems to Me (espescially since My newest area of study has been prop size, pitch, and understanding pitch speed and its effects. I am starting to begin to understand why I failed at My earlier attempts at power RC conversion. I really started backwards. These small GUILLOWS Planes designed for multipurpose stuff around 1935 technology ! It's as challenging as starting from scratch. I shoulda started with larger around 1 metre or 1/2A(not sure what that stands for) Kits that either include the motor prop combo, or tell You what will work best. I do not regret it, and if nothing else, I do know 1st hands on what a poorly, or wrongly calculated Plane will do for the short time it is in the air. I am even gaining confidence in My piloting. I am Flying My trainer in intermediate mode, and if calm day, on expert. It gets addictive. I want More. And I I now find Flying an enjoyable event, and not another disaster. I wonder if its like this for all of Us? Or if I'm just the kind who has to learn through failure. I mean extremely embarassing failures.

[davidchoate]

Oh, I am a fan of Pat Tritles designs for beginner pilots. Very light, floating, but simple and straight forward to build.

[Bill Gaylord]

Hello Dave,

There's a build thread here of my 190 with the retracts done about a year ago, that has all the detail pictures. I'm not sure where I mentioned the Gold Cable, but a few thoughts on it: I've found substitutes which seem to be about the same, such as a Sig cable that's cheaper, although you have to find sheathing. I've found various plastic sheathings/tubings at the LHS that I've used for sheathing, that are even lighter than the Dubro type sheathing included in the Gold Cable kits, and are cheaper. I've also become a fan of .020" music wire, where a bit of pre-shaping can reduce the friction with single servo aileron setups, and is lighter than stranded cable and cheaper. Of course with 3-4gm servos, it's easy to use 1 servo per aileron, and not much heavier than a single servo setup, with something like 26ga wire, versus the heavy, standard 22ga. I initially got into the single servo setups, since the few 3-4gm servos available were $25-$30! Much cheaper now.

As for learning the hard way, it's probably the best way. People with real ambition always start off a bit ahead of themselves. My first Guillows FW190 came around like a boomerang and almost hit me! Of course I tried to fly it with rudder control also. In the long run, I managed to fly my second build which I still have with rudder/elev control, and eventually added ailerons and flies quite well. Always worth all the experiences in the end. Many of the people at places like RCG will say to start off with a simple trainer and easy conversion. I'm one of the few people who appreciates people who start off with big ambitions, since I did it the same way, trying to convert these kits and eventually succeeding. BTW, most of those people who constantly recommend to people that they should "build a simple trainer" have never done anything really impressive IMO.

[davidchoate]

tHANKS. i WILL LOOK FOR yOUR 190 THREAD.

[davidchoate]

I got the wing warp out.

[davidchoate]

I finally got the wing and ailerons ready to cover. I used the torque tube type set-up. I used .047 wire, and as Mr. Parker said it seems a little "mushy", but the movement of the control surfaces seems sufficient. I dunno. I think I may not be ready for this type of Plane. I am not ready to get an accurate AUW to figure out the wing loading, sstall speed, and etc., but I know its going to have to go faster than the trainers I have flown. I will post some photos later.

[davidchoate]

I finally got the wing and ailerons ready to cover. I used the torque tube type set-up. I used .047 wire, and as Mr. Parker said it seems a little "mushy", but the movement of the control surfaces seems sufficient. I dunno. I think I may not be ready for this type of Plane. I am not ready to get an accurate AUW to figure out the wing loading, sstall speed, and etc., but I know its going to have to go faster than the trainers I have flown. I will post some photos later.