Mud Duck Aviation Forums

It seems that most Mud Duck's require additional weight in the nose for proper CG location.  Anywhere from 8 - 18 oz.  I was wondering if anyone has tried to lengthen the nose or extend the motor mount to over come this.  I realize that the extra weight is not detrimental to its flight characteristics, but I'm from the old school and believe in building as light as possible.  If someone has done this, how far forward is required?

Next question - have ailerons been installed on the Mud Duck II.  I'll bet someone has done this and would like to see some documentation.

Thanks, Ron

Hi Ron,

Since, I have seen a couple builders stretch the nose, but usually just for electric application.  I have never seen a published/blogged explanation of what or how they did it though.  It rarely affects the flight performance enough for anyone to make the effort.  But your point is understandable. 

Instead of stretching the nose there are other alternatives which should be observed during the initial build:


*  Do not "overbuild" the tail!  This is the #1 pitfall modelers fall into when they build a Duck.  The tail seems "wobbly" during the construction phase so they anticipate it will be bad in flight and add too much stiffening/bracing (adding weight).

*  Remember the CG, and that the tail is a big lever. An ounce added to the tail needs like 4-5 ounces in the nose to compensate.

*  Place any engine or motor used, as far forward on the mount as practible.  Just because the motor-mount plate is ao large doesn't mean you have to set your engine that far back.

*  Finishing:  Painting your Duck.  If it is electric powered, use a very thin coat of paint.  If your duck will be glow/gas powered you need to be sure to seal all the edges and paint the FRONT of teh plane very well and topcoat with a fuelproof clear (like Lustercoat), but the back half of the plane only needs a light coat of paint, you do not have to fuelproof the entire plane (which will add weight to the tail).

*  Use a big heavy engine if you have the option, If it puts out the same power (or more) than a lighter one, the Duck is a good place to use it.

*  Resist the urge to add a tailwheel or heavier-duty tail skid!  A tailwheel is absolutely unnecessary and many people who add one, end up pulling it off. A heavy-duty tailskid is unnecessary as well if you carefully install the original design.  Some may argue that it isn't strong enough but myself and many other Duck builders have had no problems with the original.  Both things will add extra unnecessary weight to the tail, hence 4x more to the nose.


Ailerons

  I just realized you had an older set of plans, the new plans actually have the ailerons drawn in.  The manual you just purchased doesn't specify anything regarding the new ailerons.  I will send you the information for adding the ailerons to your older plans directly.

Greg

Thanks Greg, I'll keep all your tips in mind.  And thanks for the aileron info.

One thing I was going to modify is the throttle servo location, and put it inside.  No offence but it looks ugly sitting outside the fuse.  Any tips you can give me on this?

I have a MUD DUCK SPORT, I lowered my radio box floor to the 1/2" balsa sticks. That allowed me to run my throttle servo inside the radio box and made just about a straight run th the Super Tigre .61 I used . It seems to work out well.
                                                            mike

Thanks Mike for the tip on relocating the throttle servo by modifying the radio compartment.  My plans are the orginal Mud Duck I version.  Tonight I'll have to look and see if your tip will work.
Thanks, Ron

Hi Ron,

  I don't know if you checked your RCU post on the same subject, but I did respond there which pretty much summed up what Mike said...
 
The Sport that Mike built was from plans and is basically a scaled-down Mud Duck MkII, and the difference between the MkI and the MkII is almost entirely in the wing construction (definitely follow the MkII building manual you bought to make the changes to the wing).  So Mike's suggestion is a viable option as well.  If Mike had built from a kit, there were differences in the bulkheads and a few other things.

Greg

Hello
I have been playing with the duck for some time .I'm working on rebuilding another one. I have the old plans can you get the mod plans for cutting the rons in the wing?or do you have to get a new set of plans?

This is how I get my c/g correct   14.8 oz astro60 motor&MAT belt drive.
stefanP

Hi Kodak,

I will provide the aileron cutout info for you, just email me at mudduck@optonline to request it so I can email the info directly.  I have to still get this to Ron yet, been a busy last few days.  Also specify if you have the MkI ("Giant") or MkII version, because the older version also requires additional upgrades to prevent structural failure of the MkI wing.

Greg