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Thanks Jim I'm glad you enjoy them. I enjoy posting them and it helps keep me motivated.
Yeah Michael, #1, #2 and #3
Yeah Michael, #1, #2 and #3
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Yes much fun to watch these builds...brings back memories of when I built a Graupner sailplane back in the late 70's. I think it was a Cirrus also, memory is fading with the more gray hairs I get
thanks for posting the series...love to see all three in the circling of the same thermal!
MattLast edited by hello82; 04-15-2017, 11:35 AM.Comment
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Flight report of Cirrus #1: Just to recap, Cirrus #1 is a rudder, elevator, ailerons and spoilers ship. I decreased dihedral from 6 to 3 degrees and set it up for tow only.
We finally got things to come together for some Aerotowing today but I was the only tow pilot. So I asked a fellow club member to maiden the Cirrus for me. He reported very little effort to maintain position while on tow. However, the slim profile and all white finish made it a challenge to see at altitude and with the cloudy sky. After release he had to add a little aileron and rudder trim and then put it through it's paces. It was surprisingly fast and maybe a little nose heavy. It had good aileron authority but wouldn't even come close to doing a roll. Banks and turns were smooth and precise with no bad habits. It responded good to some lift on the second flight and was a pleasure to fly. Everyone commented on how great it looked in the air and I had to agree. The only way I could be happier is if I actually get to fly it myself. Either someone is going to have to man up and fly the tow plane or I'll put a hook on it and winch it.
Oh I know if there aren't pictures it didn't really happen. Sorry I'll make sure we get pics or some video next time out.Comment
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I finally got to fly Cirrus #1. All I can say is wow! It really is a joy to fly. The ailerons have good authority as well as the spoilers, most landings require only half stick at most. I added a tow hook and found the position on the plans is way too far forward. I moved it back to just in front of the CG and started getting decent launches. We finally got some video. See the link below.
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Very nice flight and a 100 feet each circuit... WOW! It's a 'keeper'!!!Comment
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Thanks Michael, yeah that was a boomer. The funny thing is, we didn't have a way to view the footage at the field. It wasn't until I got home and saw that big patch of plowed earth in the video that I realized what produced that big thermal. It was undoubtedly generating lots of them but we weren't searching in that direction. Next time I'll know where to look!!!
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That's what is called a 'Blue Thermal' if I have terminology correct. It sure was a 'boomer'! What kind of camera do you have on board?Comment
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Hey Michael, it's a RunCam HD. Since I started using a vario I've noticed that in most good thermals I get about 50 ft per circle and that one was 100 ft. per circle. It happened so fast, all of a sudden I was at 800 ft and starting to have trouble seeing the plane. I bailed out and still continued to climb before finally hitting the sink. It was an awesome flight.
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Art
great to see your cirri complete and flying. Regarding spoilers, I'm not gluing mine in ! Here are two pictures. I've made light-weight cedar boxes. These Hobby King spoilers come with two holes in the bottom so you can see the aligned holes through the wood. Also no servo required. I'll use socket head cap bolts
with blind nuts that bite into the wood (and I'll glue them as well).
This way I can remove the spoilers without destroying the whole thing. The box will be glued in. I'm running all my servo wires under the front section planking. Now I may regret this, but if I need to replace anything, I'll just cut the wires and resolder (there would be no hope of pulling anything through).
As for visibility, here is my cirrus with deep red stick on solar film tips (on the bungee and heading past the moon). Makes it very visible and I think looks pretty nice too (perhaps not to the purist). This is the two channel version, the other wings (spoilers and ailerons) still on the bench, but at last proceeding again after lots of staring and thinking... With just rudder it's pretty sluggish. I almost came to grief with a fence a few weeks back. Slow speed for landing, full right rudder, but it just kept on heading for the fence....
cheers
Neil
Attached FilesLast edited by neilk; 06-27-2017, 01:10 PM.Comment
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Art
I do have a question on the ailerons (again...). Did you cut the ribs off in situ or before you glued them in ? I can think of reasons to do both ways !
thanks
NeilComment
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Hi Neil, I like the red wing tips. Are they removable? Someone told me there is a removable film that would be ideal for that purpose.
I trimmed the ribs to fit as I glued them in.
You will like having ailerons, you should consider reducing the dihedral to 3 deg. if you haven't already. I love the way mine handles especially circling in a thermal.
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Art
it's just solar trim. So stick on over the solar film. It should peel off pretty easily if i want. I only did the undersides of the wings...
They help a lot with finding it!
As for the dihedral, I thought I'd see how it goes first at 6 degrees. If crap, then I'd need to make shims to fit against the root rib (god
knows how, I don't have any useful tools!) and make new wing rods. I made new wing rods for my extant wings (some how I lost
them over the 40 years it was in storage) and it was tedious as I had to grind down the spring steel to the right diameter (stuck
it in a drill press and used a file and abrasive paper).
cheers
NeilComment
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Yes... that trim scheme looks very nice!Comment
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HI Art
yikes the minutiae of making ailerons.... So, your auxiliary trailing edge spar (abutting the aileron) is 3mm thick.
So that's not a lot for hinging. Did you use CA hinges and quite a lot of them to be sure they are hanging on into the 3mm thick spar ?
I assume you rounded the aileron (where it joins the spar) and centre hinged ? This is good because it means I don't
have to make a perfect cut when I attempt to taper the aileron (I Just have a knife...)
The spar intersects the tops of the ribs at a constant height because it's angled forwards. However, the height of the ribs
(at spar intersection point) varies from about to about 12.5 mm (at rib 82) to 8mm (at rib 92) because of the washout and aileron
taper, Did you taper the spar before gluing ? That would be much easier, except for the likelihood of the rib heights being slightly different
from prediction (at least, that's likely for me) and also the advantage of sitting the spar on the building board when
gluing. Trimming it after would be a bit tricky since the wing would need to be turned over and secured gently
somehow for sanding.
cheers
NeilComment
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Hey Neil, I first tried to use packing tape for hinges but warping in the ailerons caused them to let go over time. So I used the Ultracote covering for hinges and the hinge is on top. I have had no further trouble with them. I sanded the spar after lifting the wing off the bench in the normal way using masking tape to protect the ribs.
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finally returning to this after a dismally cold winter, broken heating and being ill for 5 weeks after a month in Europe ! All good now. So today I finally tackled the ailerons in earnest, instead of just looking at them and pondering. made very good progress (at least that's what I think
at the moment !).
I'm planning to round the aileron a little and centre hinge with CA hinges (a lot of them I think...)
Do you have some video of your aileron-cirrus flying ?Last edited by neilk; 10-01-2017, 08:44 AM.Comment
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oh my that's sooo high Art ! Did you use the spoilers to get out of the big thermal (i.e. were they effective) or only for landing ? I'm adding spoilers primarily to get out of thermals I can't seem to fly out of....
The tow hook on mine (just the standard 2 ch config at present) is fine where the plans say it should be for bungee launches. Was it the additions of heavier wings (with some modest CoG change I guess) that impacted this or was it an issue in the original configuration on this plane ?
The 3-degree dihedral looks great. Yesterday I visited a friend and we (well, he) made 3 degree to feather shims that I will be able to
slide over the wing rods to accomodate the smaller dihedral (I am not attempting to build this into the wing root - I'm likely to get that all wrong !)
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Very pleased with my first wing ailerons.... I have centre hinged them with CA hinges and rounded the abutting wood. Art, how much throw do you reckon is sufficient for the ailerons ? I have about 30 degrees at this point (I've never had a plane with ailerons so really i have no idea !).
So that I remember what I did when I get to the L wing, I made a simple web page with the details. I imagine the method is very similar to Art's but different in detail (different hinging for example).
http://www.users.on.net/~nkilleen/Mo.../ailerons.html
You'll need Firefox (e.g.) for the images to rotate correctly (Safari is too old and stupid...)
cheers
NeilLast edited by neilk; 10-08-2017, 01:15 AM.Comment
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