Mud Duck Aviation Forums

I just got my plans for the Agri Duck. I ordered on Sunday had them on Wednesday. Now that's service, thanks Greg!! Hopefully I can get started this weekend if my brother still has a good supply of coro. We are planning on building several of these. Here is our gameplan:

WINGS:   Built out of 2mm. The bottom wing skin will be traced from the plans with a top skin
         glued to it. Ribs will be made from 3/4" foam with light ply added where needed.The spar
         height will be determine by the highest point of the rib. Next the spar and ribs will be
         slotted to fit each other and then everything glued to the bottom skin. Ailerons will be
         made from 4mm to prevent flexing of control surface.

FUSE:    The fuse hopefully will be made from 2mm also. The plans will be drawn on the coro then
         gluing tabs will be added to both side pieces. 3/4"foam will be used for bulkheads with
         light ply where needed. Yardstics or lath will be used along the top and bottom of the
         side pieces for added strength. The canopy will be framed so that a foam Agri Duck pilot
         can be used.

TAIL:    Tail will be made from 4mm doubled to give an 8mm surface for added strength.

LANDING GEAR: Landing gear will probably be as per plan with optional skis or floats. We live in Chicago IL.

Decorating: I am kind of leaning towards this for the Mad Duck:


     

If anyone has some better ideas I would love to hear back from you.

Cool Scheme, I'm looking forward to it!

My Warbird Duck will have a sibling...


The rest of the images:
http://www.mudduckaviation.com/Pages/Warbird%20Duck%20Gallery.htm

Greg

I wish I had seen that first, it would have saved me a lot of searching. Thanks looks great!!

I just want to offer a suggestion about your build.  You mention you want to use a flat bottom wing; This is fine if you want a faster and more maneuverable Duck, but you will miss out on some of the real exciting aspects of lazy flying with the undercambered wing which is one of the Duck's trademark characteristics.  Since the design is so simple, building a spare set of wings is cheap, fast, and easy; I recommend building a "stock" pair of wings to experience both worlds! It only takes a pin and a servo lead to swap the wings to enjoy it either way at the field... Just a thought

You also mentioned the contruction method for the flat bottom wing design.  If I am picturing it correctly, it sounds a little overbuilt, I don't see the need for a spar unless you really want to push the G's.  From the plans you can see how little material and simple the wing is for foamboard construction, corroplast would be only more rigid. I would just modify the wing by eliminating the D-tube portion and use the bottom skin to lock in the ribs. This would require to address the aileron area with either the addition of an aileron that is a cross section of the wing (rather than flat), or cutting the bottom skin at the inboard aileron cutout and shortening the cord of it so it can be glued down to the top skin right at the leading edge of the aileron cutout.  This would result in a light and very strong wing as well.

The mod that I just explained was something I was going to draw up and test with the use of rare earth magnets (or screw-on if the magnets can't handle it) to be a "removeable" bottom skin for Duck owners to use depending on the type of flying they felt like doing that day (lazy vs. spirited)  The Original Mud Duck Convertable Wing*.  For your case, you can do the same or just apply the principle but make it a permanent part.

Hey Greg, The flat bottom wing has several advantages from a build standpoint. I can simply fold the top skin over the spar and glue to the trailing edge and have a wing in minutes. This technique also allows me to sandwich in coroplast ailerons. I will definitely take a look at doing the standard duck wing also so that we can do a fair comparison between the two materials. Thanks for all of the good advice.