Hi tom, see post #19 page one (elevator servos)

OK i missed that post thanks. Pull pull on elevator would be pretty complicated as the elevators are split and you would need a pull pull to each elev. I think the system they have is pretty good, there isn't much slop in it.

I used pull pull evevator on another model, were i was concerned more with throw rod (flex) slop.
due to the length of the fuselage & tail of plane.
It takes awhile to set up because you have to run two "up" elev. cables to one side of servo, and two "down" elev. cables to
the other side.
Adjustments for split elevators is made by threading in or out at clevis attachment.
On this model i didnt want to add two servos to the tail section,as it was already slightly tail heavy.
It takes alot more cable but the plus side is there is no slop, and the resulting control on elevator and rudder is fantastic!

Ive heard from those that have completed building this kit that the plane ended up tail heavy.
I assumed it was due to the rear mounted rudder servo.
My thought was to move the rudder servo forward to help with balance. By adding duel servos to the tail i would replace that weight x2
Alfredbmor is using a 4 stroker engine so his plane may end up balancing fairly close.

Before I started the modification on this model I started to think on how could I improve this kit, (even that by its self is a really good one), firstly I thought that the aileron servos was an imperative mod, because of the computer radio benefits, then I thought that the elevators could have a more precise movement splitting in two, placing them on the fuse sides and using mini servos, taking advance of the today’s technologies, Now you can have the same or more amount of power from this miniservos than the standard servos that are recommended for this particular plane. When I finished the building of the entire frame I was able to balance the plane placing the servos, batteries, engine, tank, etc. in the place that they should be, then I found that the rudder servo at the tail could make this plane tail heavy so I thought immediately on placing this servo inside with a nice pull pull system (Dubro 4-40). After those changes the plane balanced right at the spar of the wing. (Yes I am using a four stroke Saito 91 that helped me a lot for balancing)

The throttle servo could be a miniservo attached on the fuse wall in the cavity of the tank, this could take a little more effort to accomplish but there is enough room inside this plane to take advantage from, then you could install the pull pull system for elevators.

Tom I hope the picture is clear enough to respond the question you did before about the crossed cables on the pull pull system, I believe that this way it works better than straight cables.

Alfredbmor:
I wanted to add that the set up in my post #53 was just a way of servo placement which worked well for that plane,and could possibly be used for the cap provided you relocate throttle servo. Not to take away from your idea.
I also had already built in the guide tubes for the elevator throw rods.

Your rear mounted servo idea is a great! one. It is used frequently on giant scale planes because of the advantage of short linkages.
Im still debating which technique to use.
Im using an O.S. 46 fx engine so i guess if i do dry run balance check same as you did, that will probably let me know which will work better.

I cant wait to see your wing covering!

Yeah, i set up my pull pull with the cables crossed and it does work better than not crossed. The elevator i kept stock, it seems to be ok and i wanted to keep the lines clean and not have servos on the outside. I will probably do the torque rods for aileron, i have planes with dual servos and never use mixes or anything. I am trying to keep the weight centered around CG then it will stop better in rolls and snaps. My ailerons are gonna be at least 2" built up, the strip ones are useless near stall speed.

BTW this is my second CAP the first one got a bit wrecked when it tip stalled on landing (after getting heavier from previous minor repairs), so this time around i'm paying a bit more attention to weight savings.

some more pics of engine/muffler/fuel tank mods. I should have some insane performance if the plane gets in under 5lbs with webra 50 and ultrathrust pipe.

First off, nice engine!
Is that muffler going to fit inside the cowl? I checked the stock muffler for my O.S. 46 fx , and it would work with a small amount of carving to the lower fire wall. but it will also need a good sized hole in the cowl for the front of the muffler. bummer
I may just go with a pitts style muffler.

yeah it will fit, a stock muffler that you have probably won't though as they have more height. The exhaust will come out behind the landing gear and air outlets will be the lightening holes around the LG area.

Tom:
Your mods are great and for sure you are taking a lot of care about weight, you must tell me more about the 2" ailerons, are you using 2" aileron stock?
Yesterday I started with the wing covering, but I think that I should stop until I get more information about these ailerons.
Thanks.

Tom: I believe that you should use some material like aluminium to help disipate the heat from the muffler area, Is it going to be an enclosed area or an open area?

It will be open, the cooling air will go through there, i may put some aluminum tape or similar on it though, it cant hurt.

My last CAP i built 2" wide ailerons, they are built up similar to the tail surfaces. You have to move the trailing edge in order to keep overall chord on the wing the same which is a bit of work (not sure if its worth it if you have built the wing already). You could use aileron stock i guess but the built up is not hard to make.

And almost done my building table, so i can soon start the wing.

Thanks Tom, that is one more thing to think about, I like the way you are building it and your mods, besides you have the previous experience flying the same plane.
Your table is great and is claiming for you to use it, so go ahead and build the wings. I will keep track of your wings building, seems to me that I am learning a lot.

Yeah thanks, i'll get started this weekend and get some pics of the ailerons to post here. One more thing, on my old wing, i glassed the centre section especially near the bolt holes since it seemed weak so that might be a good idea to do.

Hi all
Well i followed Alfredbmor's lead and before comitting to servo placement, checked the cg with the engine, tank, and servos in place.
And to my surprise at a cg of 3 & 7/8 from leading edge, it balanced with the battery at mid cockpit and thats with the rudder servo in tail location,and one elevator servo in cockpit, throttle servo in recommeded location.
If tail heavy i was planning on mounting the battery on top of the tank inspection cover plate.

Im not sure why some have had it come out tail heavy
The instructions mention if using a O.S 46 fx engine,
which is exactly what im using, to place the battery in front of the fuel tank. That was not needed on mine??

I am not sure about it since this is the first Cap that I am building, maybe Tom could help us on this, I understand that this is the second Cap that he is building.

Since the beginning I thought that my Cap could be nose heavy because of the engine that I am using but I have some facts that I want to share with you:

In my set up I used 2 Hitec servos HS225BB weighting .95oz each = 1.9 oz total at the tail for the elevator purpose, instead of the regular servo for rudder that weights around 1.5 oz
I am using a Saito engine .91 size that weights 19.6 oz plus muffler, instead the surpass 70 recommended which weights: 20.5 oz plus muffler.
According to the plans, In the surpass installation the battery goes a little back of the wings, in my set up the battery should be installed near the CG.
My rudder and throttle servos are regular size and the ailerons are miniservos.

Some numbers to think about:
Counting the total servos weight and engine weight that I am using, in theory I have 26.4 oz plus muffler
The stock GP set up using the Surpass 70 size and four regular servos is: 26.5 oz plus muffler

With my set up I am saving the weight of a fraction of the elevator push rods and aileron torque rods, so finally I can have better performance using more servos (6) and a higher engine with less weight than the stock set up. (4 strokes related)

The Os 46 fx should be around 17 oz and that is why GP consider on the plans that the battery location should be in the front of the tank tray, but when you add the aileron servos I think that the battery should also moved a little backwards.

I'd like to know your thoughts.

Thanks.
Alfred.

I guess the CG could depend on the weight of wood used in the tail, it can make quite a difference. My first one was a bit tail heavy, if yours balances right on though then thats great.
I really dislike the batt location if front of the tank, you really want the tank as close to the engine as possible. Just mount the battery wherever needed to balance the plane properly.

alfredbmor, RVman
I want to thank you both for your help.
When i first opened the box of this kit , i was a little unsure about putting all the balsa sticks together in the right place.[X(]

But i was inpressed with Great Planes's instruction manual, and the help you both have given me has sealed the deal! I Thank You

Since the balance was good where all the servos were, Im going to go ahead and put the rudder servo in the tail.
On the elevater servo im still going to use pull pull cable, because i really enjoyed the precision it gave me on another model.

I have my ultracote now, so its all systems go on the covering. Im starting today with the yellow base color.

You are very welcome rugerv45; Great Planes are great planes to build; I have only good experiences with them but remember kits does not assemble by its self so you have a bunch of merits for doing exactly what you are doing, building a kit is a big chance to have nice experiences to share, just imagine how, with your hands, a bunch of wood turns into a flying machine, and believe me, the first time you watch it flying, is, WOW, hard to forget and you want to talk about it all the time to anyone. I have built eight kits till now and I still have this feeling and I like it.
Congratulations and keep posting.
I started the wing covering and I will post some photos as soon as I take them.
I am very interested on the wings that Tom is about to build, especially on the larger ailerons I can not give this step back and I will stay with the current configuration but I must learn this anyway.
Thanks.
Alfred.

There is another thread were a guy that goes by Gumhead, buit this kit pretty close to stock, with the exception of duel aileron
servos. He claimed to have a fast roll rate with the stock ailerons. I guess we will see for our selfs later on.

Heres my progress on the covering, and a pic of the instrument panel, unpainted.

I strengthened the landing gear with a piece of ply over the top of the 1/4 in. brace, almost forgot to do that before covering!

I played around with ms paint and come up with some trim scheme ideas.

The stock roll rate is ok at speed, i enlarged the ailerons for better low speed handling. Im confused looking at the stablilizer, it looks like the elevator balances are glued onto the stab?[&:] The covering looks great, yellow and black is easy to see for sure.

I finished the wing panels, next steps are to join them and build in the centre section. I should have some pics up by the end of today. I moved the TE up an inch to accomodate the larger ailerons.

Here is the mostly finished wing, it sure goes together quickly the second time. Weight is 14.6 oz including servo which is pretty good. Should be 1 lb when covered and totally finished which is 5 oz lighter than my old wing. The larger ailerons are actually lighter than stock. With the torque rods i have about 45-50 degrees of throw. I also took out about 1/2 the dihedral.
That table barely fit down there, had about 1/4" clearance through the doors, but its awesome to work on, nice and flat and level.

Tom:
Great job on the ailerons, did you tapered following the airfoil? Did you assembled the wing as per the plans and cut the trailing edge or shortened the ribs before assembling?

Rugerv45 I like the number 3 design.

Here are some of the most representative photos of my wing covering process.

Thanks.
Alfred.