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Oct 20, 2014, 07:39 PM
treefinder
springer's Avatar
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OK, finally time to start posting. I have had a few days of rainy, windy and mostly cold weather that started the build season in earnest! As I worked through the build and kept changing things, it got harder and harder to keep track, so I started making changes in the sketchup file to get it right. So, Be aware that the files showing on first page won't be perfect. Most of the changes involve structure for the tricycle gear; if one does tail dragger, they probably will work ok.

I found a gear kit I got from Banggood.com that included a bent aluminum main gear, steerable wire nose gear (which I won't use, too heavy), 3 wheels and a bunch of misc hardware parts. I think it was $10 for the whole set. Seems about the right size for OSK. Of course here I go varying from the original intent of a wire gearset....

These pics show the work done so far on Fuselage:
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Oct 20, 2014, 07:55 PM
treefinder
springer's Avatar
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I finished gluing and sanding the wing. One of my FB's (macdaddy) found a type of very open ribbon used for stuffing in gift bags that works well as control surface hinging. I used it on the elevator and ailerons. I put down a coat of polycrylic, laid the ribbon on and laid down more poly. after several coats, It looks like it belongs there. a bit fragile to trim around, but seems durable enough. Unfortunately there is no label on it, but i'll post a pic.

The wing is KFM4 as in plans, with a LE spar of 1/4 wood glued into a groove sanded on middle layer of foam. The spar is steam bent to provide a bit of dihedral.The airfoil is cut and sanded into the fwd portion top and bottom. I added a short of steam bent piece of tongue depressor to TE top surface to protect from rubber bands. You can see the ailerons left not cut out while the ribbon is applied and cured. I trimmed them out last. The wing feels stiff enough with just the LE spar, and should be even better with tape and the center cockpit/canopy installed, so i'll not add any spar at step.

For the tail, I used the packing tape over/under method of making the hinge. Looking at the parts in full size, I am thinking I may seriously consider the mod that Mark made to extend the rudder. I will have to cut away most of the tip of fuse to clear the elevator swing, so may as well make it rudder. I also think it's a bit small, and may extend it aft which will provide more "meat" for that mod. more to come on that.

The H stab and elevator uses a piece of (happens to be oak, a bit overkill, but available) wood 1/16"x1/4" glued to aft edge as a stiffener. Seems adequate, so I'll not double the thickness at this point, though I really like the durability when I have done that in the past. The hinge is ribbon/polycrylic, and I glued a piece of wire bent to open 'U' shape to reinforce the elevator at center.
Last edited by springer; Oct 20, 2014 at 09:21 PM.
Oct 22, 2014, 06:39 AM
Registered User
caveeagle's Avatar
I likne how your subframe and fuse top/bottom went together before putting the sides on. (I did not think of that). I agree with reducing or eliminating the nose taper. This design has a really long tail, so adding space in the front should only help.

I also like how you fitted the battery.

Your alum gear mount looks much simpler. I am interested to see how durable my wire gear turns out to be.

Weather has been windy and nasty here in Chicagoland lately. Hope to get a good calm day shortly for a maiden flight.
Oct 22, 2014, 08:55 AM
treefinder
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My guess is the wire will be better, as you can bend it back in place when bent, wheras if i twist the aluminum gear it will never come right, but it was sitting there saying "use me!" So i did. The battery is still an issue, i'm going through the same esc/batt wiring conundrum as you. But we'll figure it out! I need about an inch extra on batt wires of esc to get my fingers around the connector if esc lays flat in fuse bottom. I need to glue bottom on and cut hatch in top to finalize that aspect. I did get nose gear and ailerons set up last night, stll need ele/rudder wires. Winds supposed to be down tomorrow morn,so i may getcin a first flight too.
Oct 22, 2014, 06:14 PM
treefinder
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Thread OP
Scrambled to get gear invfor a first flight and took her out this pm. Wind 5-8mph. Did not try a glide test, but tried ROG. She cut he grass for five feet or so with no interest in climbing. Moved to a more bare spot. This time she pulled up fast, stalled and doinked. Hmmm, longer run to build flight speed. . . power up leaves ground and immediately rolls hard left into ground. After fourcor so of these (while trying ele, no le, etc) i noticed i had cracked the fuse at h stab and tail was offset. Not sure if that was cause or not. Regardless this may be one of the tougher onesheeters to get flying....
Oct 22, 2014, 10:05 PM
Marty Petri Sr.
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Quote:
Originally Posted by caveeagle
It was a slow weekend for model building...
Referencing Post #22

On the topic of plastic washers, I save all the prop adapter rings that come with plastic props, usually I find what I need for either a screw or dowel in my junk drawer of prop adapters.

just a thought ........

Once again Springer, you astound me. Nice work.

Marty
Last edited by mbpetri; Oct 22, 2014 at 10:11 PM.
Oct 23, 2014, 12:57 PM
treefinder
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Thread OP

mea culpa!


Lessee, what's the first thing we are all supposed to do when we take a plane out to fly, right after we connect the battery? Particularly when we first fly a particular plane? Eh?

That would be check all controls for correct operation and throw direction!

This morning, after our ORG (old retired guys) breakfast, i headed for the field with my kestrel, hoping the tall grass would be more gentle than my new short grass while i sorted her out. Plug in pack, the thought comes "check all the throws again". "Already did that, but ok, one more time...." D'oh! Ailerons reversed! After a bit of reprogramming, i still carried her out to the grass for a hand launch. Power up to half, gentle push; she flys straight and true out of my hand! Ten minutes later she glides to a perfect landing. I even flared correctly. I had wrung her out: loops, rolls, snap roll, inverted, fast, slow, high low 3" off the deck. Second pack ROG from grass, no prob; more fun and games til she hit LVC out at end of field (why don't i pay attention to performance drop?!)

Mark, i think you will like yours. I never had an original Goldberg version, but from what I hear about them, i think this one will be as good.
Oct 23, 2014, 01:02 PM
treefinder
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Thread OP
I should add, the only concern i had was when i did an outside loop, the wing flattened out all dihedral, maybe a bit anhedral. Didn't notice it bending the other way on inside loops. I am not really concerned, though, as i have several flexible wing planes that haven't snapped in any maneuvers i can do.
Oct 23, 2014, 07:27 PM
Registered User
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Did you make any major changes from your first couple flights? I thought you had something wrong leading to the "doink"..??

I won't be back in town until Sunday. Hopefully, I will have time for a test flight>

Need to work on a conopy too.

Quote:
I should add, the only concern i had was when i did an outside loop, the wing flattened out all dihedral, maybe a bit anhedral. ....
I put a dowel support at mid wing as well. Only around 10" or so, but I think its pretty stiff.
Last edited by caveeagle; Oct 23, 2014 at 08:48 PM.
Oct 23, 2014, 09:51 PM
treefinder
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The "something wrong" leading to the "doink" was ailerons reversed! Yep, it's time to add the canopy and some color! I added some vid from today to first post.
Oct 24, 2014, 08:30 AM
Ken's CAD Models
dz1sfb's Avatar
Nice work guys!

Ken
Oct 25, 2014, 10:47 AM
treefinder
springer's Avatar
Thread OP
Got serious with packing tape last night, finishing this morning. I wanted to fly her in new livery, but even though this morning was calm, it's more than breezy at mid day, so have to wait a bit to get flight vid. I pondered the color, and looking around the "hanger", noted that by far most of my planes are red or red/white/blue, so something different seemed indicated. Not quite enough green for a true John Deere version, but seems appropriate for the "farm"! I found a canopy I'd shrunk for a previous plane that seemed right, so adapted it to it's new home.
Oct 25, 2014, 12:41 PM
Registered User
caveeagle's Avatar
Very Nice!! Love the color scheme! Canopy looks great on there.

I am still a litter perplexed as to how you found room for the top battery hatch in that front compartment. I am still not 100% resolved with my arrangement, and need to finalize when I get home tommorow.
Oct 27, 2014, 12:52 PM
Registered User
caveeagle's Avatar
Any noticable difference flying with packing tape? I really like the look, but tend to build a little heavy anyway and was reluctent to add weight.

Any video flying in yellow?
Oct 27, 2014, 01:44 PM
treefinder
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Thread OP
Quote:
Originally Posted by caveeagle
Very Nice!! Love the color scheme! Canopy looks great on there.

I am still a litter perplexed as to how you found room for the top battery hatch in that front compartment. I am still not 100% resolved with my arrangement, and need to finalize when I get home tommorow.
I ended up cutting the center portion of the four former/doublers at wing LE below the servo tray. Cut away enough to slide the 1300 mah pack through, leaving the "sides" as structure. Cut away the forward two first, but needed more room, so cut the aft two. Since we are doing tri gear, they aren't really needed. If you have your fuse bottom glued on, it may be easier to cut through it to open up the pocket and reglue the skin.


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