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Old Sep 19, 2012, 02:15 AM
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Hi everyone.

First, thank you for the clarification Lincoln. Not really sure how I will do it (servo instal), but I have some ideas to kick around.

I have been looking for this video link for a bit but could not remember where I saw it. Anyway, this is a quick instructional video on how to glass with polycyclic.

http://tailwindgliders.com/Pod%20and%20Boom.htmlhttp://tailwindgliders.com/Pod%20and%20Boom.html

Interesting anyway and supposedly lighter than epoxy.

I have mostly finished the shaping of the fuse / nose. So I guess I am gonna give one way or another a shot. I am kinda leaning toward epoxy now (big reason is I have everything to do it). I guess we will see.
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Old Sep 19, 2012, 02:31 AM
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Wing and horizontal stabalizer

I really appreciate you guys taking time to read my posts and help me with this build. I know it would be so much harder to do this without RCG.

So here I go abusing the system a bit (again). In my kit it doesn't really mention any angles I should shoot for in relation to the flying surfaces and their attachment to the fuse. In the plan it says 1% on the wing. I don't really understand this, and the plan calls for the tail to be epoxied together. This is a concern to me as I am not sure of the angle of attack so I am not sure if I could correct it if it is wrong without major re-construction, and in the hope of keeping everything light I would like to try to get it right the 1st time.

I assume there are some general rules to this sort of thing, but I can't really find them. Also, I am not sure of the vocabulary so I am probably not even searching for the correct tips.

Hopefully this makes some sense. If not I am just going to throw this out there, and I assume if I am using these terms correctly it will be almost pure chance. The only things I have read about this subject is "tripping the wing" and I think Incidence?? Not really sure but maybe that will help someone deduce what I am asking about as I really have no idea.

Any help is appreciated.
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Old Sep 19, 2012, 03:21 PM
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Incidence is the difference in the angle of the wing and stabilizer around the pitch axis. Usually, the fuselage will have the correct angle, or at least the designed angle, built in. As long as you are close, you can adjust the elevator to fine tune it. However, you should be careful that the wing and tail are parallel to each other in the roll axis.

Tripping usually refers to a discontinuity like a thread or tape intended to cause turbulent flow. With some airfoils and at some airspeeds, you might get more lift or less drag using the turbulator, even though it causes some itself. Turbulent flow stays "attached" better. The theory is a real can of worms but it's probably not that big a deal either way on a Riser.

You might enjoy Martin Simons book on model aircraft aerodynamics. Come to think of it, I seem to recall there were two of them, one much simpler than the other. He explains a lot of this stuff. But you don't need to know all that much just to get a glider going!
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Old Sep 19, 2012, 03:35 PM
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Most of the time 1 to two degrees of incidence will work fine I have 2 deg. on the Crimson now.It sounds like you are on target for a light plane, so start with the plan settings, and dimensions.My Crimson came out heavy. I had to move the c/g back,it flew better but not right, then I started looking at my angle of incidence, and found that the leading edge was down.I raised it to 2 deg. I flew it and had to move the c/g just a little more forward. Now it fly's really well ,It will thermal well and responds to all controls immediately. With the spoilers deployed it just needs a little up elevator to fly it in for nice slow landing .Before it landed like the space shuttle.
I guess my point is don't sweat it to much it can be adjusted out.If you are going to add any extra weight add it to the front of the fuse.Doing a hand toss test and having the plane smash when it hits the ground sucks.I've seen it happen once to often.Got any Picks?
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Old Sep 19, 2012, 03:50 PM
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Are you measuring the incidence by the line between the furthest forward part of the l.e. to the trailing edge, or by the flat part on the bottom of the airfoil? Makes a big difference!
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Old Sep 19, 2012, 10:32 PM
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Yes it's amazing how accurate it has to be ,I started buy getting the plane in level flight attitude, horizontal stab level.The wing had -3Deg before I started.I measured from front to back.
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Old Sep 20, 2012, 01:24 AM
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Incidence

I am not really sure even how to measure that. I will need to do a bit of studying. I have not modified the angles on the plan (not intentionally). That said while sanding or assembling some pieces I am sure the angle could have been thrown off.

I guess I am going to start with the suggested 1%. I am just concerned if I use epoxy as suggested in the plans then it can not be changed. Is it a big mistake to permanently attach the tail, or is it something easily controlled be shimming the wing?
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Old Sep 20, 2012, 01:37 AM
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Progress (nose and spoilers)

I have the nose and hatch mostly shaped and getting close to ready for glass.

I have been working on a plan for the spoilers as well. I am thinking of just attaching the bottom of the servo to the wing with epoxy. Bad idea? I am also posting a picture of another idea I had which was to do sheathing under the servo and epoxy the servo to that. The last idea was to do both (epoxy to the rib and sheathing).

I thought this was ok for a few reasons.
1 hs-55 is small and probably doesn't cause a lot of stress on the structure.
2 Spoilers are not essential to control the aircraft in flight. So if it breaks it is kind of ok.

Should I make some other sort of mounting system? Also, if you think it would be ok to glue it would it be ok to use CA instead of epoxy?

As for the actual function of the spoilers I am opting for the EZ Connector method mentioned earlier in this thread.
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Old Sep 20, 2012, 02:12 AM
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Pictures

been trying to upload pictures to go with my questions, but my internet is being funny so I am done. I will give it a shot at work,
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Old Sep 20, 2012, 08:53 AM
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Quote:
Originally Posted by Fickle flier View Post
I am not really sure even how to measure that. I will need to do a bit of studying. I have not modified the angles on the plan (not intentionally). That said while sanding or assembling some pieces I am sure the angle could have been thrown off.

I guess I am going to start with the suggested 1%. I am just concerned if I use epoxy as suggested in the plans then it can not be changed. Is it a big mistake to permanently attach the tail, or is it something easily controlled be shimming the wing?
Don't get too worried about the wing incidence. Glue down the tail and make certain that it is square to the fuselage and that the vertical fin is straight and perpendicular to the horizontal. Any incidence issues can be corrected by simply shimming the main wing LE or TE.

Quote:
Originally Posted by Fickle flier View Post
I have the nose and hatch mostly shaped and getting close to ready for glass.

I have been working on a plan for the spoilers as well. I am thinking of just attaching the bottom of the servo to the wing with epoxy. Bad idea? I am also posting a picture of another idea I had which was to do sheathing under the servo and epoxy the servo to that. The last idea was to do both (epoxy to the rib and sheathing).

I thought this was ok for a few reasons.
1 hs-55 is small and probably doesn't cause a lot of stress on the structure.
2 Spoilers are not essential to control the aircraft in flight. So if it breaks it is kind of ok.

Should I make some other sort of mounting system? Also, if you think it would be ok to glue it would it be ok to use CA instead of epoxy?

As for the actual function of the spoilers I am opting for the EZ Connector method mentioned earlier in this thread.
When it comes to the spoiler servo install keep it simple. I simply took a 1/8 inch piece of balsa and made a tray on the bottom of the rib bay by setting the 1/8th inch sheet onto the lower rib cap strips. I glued it in place with wood glue. It has stayed put for 5 years. As far as mounting the servos, you might want to rethink the epoxy option. Ultimately you want the servos to be removable in case of failure. I simply wrapped my HS-55 servo in electrical tape and then glued the tape to the servo tray. That way if I ever need to remove the servo I can cut the tape and lift out the servo. I will try to post a couple of pictures this evening so you can see what I am talking about.

Wayne
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Old Sep 20, 2012, 07:16 PM
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Pictures

Here are a few pictures of what I was trying to say with the spoilers. If I glue them in after wrapping with electrical tape could I use CA or maybe go epoxy?

As you can see the nose is basically ready to glass. I am going to drop by the LHS and get some glass cloth tonight so it is happening soon.

I will take you guys' advise and just plan to shim the wing a bit if needed.

After that I will need to join the wing sections, install the control rods, electronics, and cover/fly.
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Old Sep 20, 2012, 09:35 PM
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Spoiler Servo attachment......

I haven't done this yet with servos, but they do make a double-adhesive-sided thin foam tape made for fixing servos onto fusalage walls. I have used it to mount switches into place with good results. It's about the right width for the mini-servo's you're using so that might be a good way to too. It's surprizingly good at sticking things to balsa surfaces. Epoxy would not be my first choice either due to Wayne's stated reason of possible need for removal/replacement in the future.

Incidence- My Spirit had WAY too much incidence per plans and I negative-shimmed my wing and positive-shimmed my horiz stab/elev until I had it much less but still have some. I don't know if that is a common problem/complaint with the Sig Riser, but it is with the Great Planes Spirit and it flies really nicely now. I'm doubting it's much of a problem with the Riser as a lot of people like it per plans. Wayne's on target saying that getting things straight is what counts and I agree you will be able to do whatever (if) you need to later by shimming the wing.

Otherwise, Looking Good - Paul
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Old Sep 21, 2012, 04:05 PM
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Fickle Looking good ,I went with a similar servo set up, I used goop to attach the servos.It's neat and can be removed if necessary.Thanks for the pictures ,it;s going to fly great!
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Old Sep 24, 2012, 07:49 PM
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Servo instal

I did some quick tests and I think I will be going with electrical tape wrapped around the spoiler servos and then CA them in. The bond it formed on the test was very good and still removable.
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Old Oct 03, 2012, 06:08 PM
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Glassing the nose

I glassed the nose. It took me around 5 or 6 steps. I am sure all you guys know a better way, but what I ended up doing was just to tack the glass cloth (.75 oz) on with thick CA (just a little spot). Then I would mix the epoxy and do some of the fuse. After it was mostly dry I would sand off the excess glass and epoxy. It came out well; however I have not done the final sanding so I am not sure how the top and hatch came out, but until then the rest came out better than I thought. Like I have read elsewhere the hardest part was getting ready to do it as I thought it would be more involved.

I have also figured out the spoilers. I had to trim down the control horn on the spoiler itself and move it to the extreme edge of the control surface. I will post pictures of the finished product shortly (have to finish the other side).
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