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Old Aug 28, 2011, 05:09 PM
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So Dennis, how's the stab pull-pull design coming? That is something I really would like to see!

I finally got back to the build after a couple week's hiatus. Frankly, my enthusiasm had waned a bit due to the delay in receiving the bellcrank I needed.... that's my excuse anyway! But the crank arrived Friday, and I got some work done this weekend. The Left wing is about 70% framed up, and I've been pondering over the mods I'll have to make in order for the bellcrank to work. Shouldn't be too difficult, just need to be careful to measure twice and cut once!
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Old Sep 11, 2011, 04:23 PM
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Got all 4 wing panels off the board today, and laid them out on the floor. It's starting to look like something that might fly one day! Ordered the Kimbrough couplers for the flaps, and next major step will be to sort out and put together the fin with the bellcrank inside it.

Are any of my fellow Southwind builders making any progress?
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Old Sep 13, 2011, 12:37 PM
Dennis Keith
Dana Point, CA
Joined Nov 2006
26 Posts
My build is currently stalled for a couple of reasons. Firstly, it looks as if we will be getting a large project on board and I have been involved in much of the preparatory work. Secondly, the more I thought about the pull-pull approach for the horizontal stab, the more it looked sorta like a Rube Goldberg concept. I didn't want to put a pulley or turn post back in the fin without access and by the time I sketched out the whole thing it looked too complicated. Currently I plan to go back to the original design
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Old Oct 01, 2011, 04:15 PM
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It's been a little while, and some progress has been made. The brass tubes for the wing joiner is installed, and the inner bays all boxed in. I went with a larger diameter brass tube than comes in the kit, 11/32". After reaming out the holes in the ribs, using a larger diameter tube, and extending the tube all the way to the outboard end of the 2nd bay, I discovered the end result of these changes was a slightly shallower dihedral angle. I hope it doesn't affect turning performance too much, but I think it will be allright. After installing the brass tubes, the 1/8 ply fwd shear webs were installed. Then, the cavities above and below the tubes were filled with an epoxy/West Systems filler, as shown in the picture. This is an important step, otherwise all the load on the joiner is transferred to the ribs and then to the spar. Filling the gap evenly distributes the load over a much wider area, preventing damage to, or failure of the ribs. Finally, the aft shear webs are installed.

The next step will be to clean up any glue drips, sand a small chamfer on the shear webs along the tops and bottoms, and wrap with kevlar tow.
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Old Nov 13, 2011, 03:44 PM
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Wow, over a month since my last post. Have not had much time to work on the SW, but have made a little progress. Got the joiner boxes wrapped with kevlar tow, and the center and tip panels joined. Did the left one first, not terribly concerned with the angle as long as it was close. It turned out quite nicely, and now have the right wing joined and epoxy curing. I took great care to make sure the tip angle on the right is exacty the same as the left. The plans call for a 1/16 ply joiner glued to the aft side of the spar for the joint, but that didn't seem like enough, so I added a 1/32 joiner to the fwd side of the spar as well. Seems pretty solid.
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Old Nov 19, 2011, 01:47 PM
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Still working slowly, but this is the 2nd weekend in a row I've been able to lay my hands on her.... starting to look like something that might fly one day.....
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Old Dec 01, 2011, 05:27 PM
Dennis Keith
Dana Point, CA
Joined Nov 2006
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On the third try, here is the setup for the elevator control linkage. It will be a pull pull with a horizontal ss wire in bushings about 1.5" aft of the control horn. I will use spider wire with the down line going to the control horn, looping there, held with a dab of silicone, continuing on to the turn shaft and then returning to the other side of the control arm. Both the bellcrank pivot wire and the control line turn wire go through bushings and will be finished flush. I will leave a flush hatch in the bottom so that opening the hatch and removal of the pins will allow the mechanism to be removed.

I have a couple of questions. The widths of the formers on the plans don't appear to match the top view dimensions. I don't mind making the fuse narrower but am not sure if that is the way to go.

Dennis
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Old Mar 25, 2012, 02:00 AM
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South Wind Plan's

OK where can I get them, it's about that time.
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Old Mar 25, 2012, 08:21 AM
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Quote:
Originally Posted by prodjx View Post
OK where can I get them, it's about that time.
Check your PM inbox
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Old May 12, 2012, 10:23 AM
Dennis Keith
Dana Point, CA
Joined Nov 2006
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Still plodding along as time allows. The fuselage is framed up with the sides and formers, the horizontal stab is done and I am still fiddling with the control linkages for it. While I wanted to create a pull pull for it, I haven't been able to build something that I feel comfortable with and am on version 4 now. I may just give up and use a bellcrank with a carbon rod connection. The wing rib templates have been made and all of the ribs fabricated. I am getting ready to laminate a rectangular tapered carbon fibre piece to a 1/8 X 3/8 balsa strip to make the spars and I am puzzling about the small bend at W5 - in particular, how best to make the break without losing the strength of the spars. One other question, since I am working on the spars - would using balsa ply (1/16 + 1/16) with the grain on the diagonals for the shear webs make sense or am I simply complicating things for little or no gain?

Dennis
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Old May 12, 2012, 12:26 PM
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That little jog at w-5 concerned me too.... I just used a piece of 1/4 ply between the upper and lower spar caps running from w-4 to w-6, made sure everything fit real snugly, and epoxied it together. It's so far out on the wing that the bend load out there is minimal, so unless you're planning on full-pedal winch launches, you should be fine....

In other news, I managed, by sheer luck, to get my mitts on another Max Mills kit..... called the Westwind.

We just bought a house and will be moving in a couple of weeks so everything is on hold for now. Once I get my building area all set up, and wrap up the Quasoar I've been building, I'll dust off the Southwind and get back to finishing her.
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Old May 12, 2012, 12:32 PM
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Just noticed the question about the spar webs. I used full-width vertical grain balsa. 1/16 on the diag is a ton of work for little gain. Again, think about how you intend to launch this thing. In the end, it is still a woodie, so full blown pedal to the metal launches are probably not a good idea, so there's no need to try to build to that standard.
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Old Jun 03, 2012, 09:56 AM
Dennis Keith
Dana Point, CA
Joined Nov 2006
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The wing tips are almost completed and I've started on the center panels. I'm puzzled about the flaps. As I read the plans, the servos are mounted on a piece of pine on the floor of that bay. This means that the access would almost have to be from the top of the wing. The few wing mounted servos that I have seen have the access hatch on the bottom of the wing. How did you mount the servos?

The other question is about the hinging of the flaps. The plans show the hinge line on the top surface with relief cut into the leading edge of the flap. This allows full 90 degree deflection upwards but a limited travel downwards. It also puts the surface gap on the bottom in a higher pressure area. Would it be better to hinge on the bottom and use a smaller bevel on the top of the flap? i.e. limited reflex but full downwards movement.

Dennis
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Old Jun 03, 2012, 08:13 PM
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Quote:
Originally Posted by DennisKeith View Post
The wing tips are almost completed and I've started on the center panels. I'm puzzled about the flaps. As I read the plans, the servos are mounted on a piece of pine on the floor of that bay. This means that the access would almost have to be from the top of the wing. The few wing mounted servos that I have seen have the access hatch on the bottom of the wing. How did you mount the servos?

The other question is about the hinging of the flaps. The plans show the hinge line on the top surface with relief cut into the leading edge of the flap. This allows full 90 degree deflection upwards but a limited travel downwards. It also puts the surface gap on the bottom in a higher pressure area. Would it be better to hinge on the bottom and use a smaller bevel on the top of the flap? i.e. limited reflex but full downwards movement.

Dennis

Yes, exactly that!

As for servo mounting, just do it however you feel is best. Remember, lots has changed WRT radio equipment since the Southwind was designed. I was kicking around the idea of using an RDS system.


In other news, did I mention I somehow, miraculously, picked up another Max Mills kit? This one is called the Westwind. Don't know anything about it, it's still in the box, and we've just moved, so I won't be playing with my hobbies for a bit, but there will be a new thread on it when i get started.

Edit...silly me, I see I did mention the Westwind, just a few posts back.... I must be really tired from moving!
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Old Jun 09, 2012, 12:43 PM
Dennis Keith
Dana Point, CA
Joined Nov 2006
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I noticed that the plans called for a 9/32 OD tube and that you upped to 11/32 OD. What size and type of rod are you using? I have seen posts about Dixie Pins but only found lengths of 6" on their site. Is carbon a good idea? I am beginning to worry about weight. Any suggestions or sources for wing connecting rods and tubes would be great.

Thanks

Dennis
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