RE: Cold Duck - Build
 

I forgot to mention that there are rumors that the guy that deigned the Cold Duck used the actual wing template plus 1/16" to draw the fuselage wing opening on the plans so that the fuselage would fit the wing perfectly.

RE: Cold Duck - Build
 

I installed the plywood servo mounts and servos. I positioned them well back in the fuselage because the RJL K.61 engine is a little heaver than my old Veco 61.

On this installation I laid out the servo screw holes on the mounts before installing them in the fuselage. I then mounted the two outside servos on the mounts and then installed the assembly in the fuselage. I used a scrap piece of ½” thick balsa under the servos to hold them while the epoxy setup on the mounts.

By accident the wing mount bolt hole provides perfect access to the outside back corner screws of the outside servos.

RE: Cold Duck - Build
 

I usually use fiberglass pushrods with the requisite hardware to attach the Kwik link wire but at $10 for the rods and ends I decided that I would investigate a lower cost solution. I’ve use square balsa pushrods but they must be pretty large to have any strength and were bulky to work with. I’ve also used ¼” hard wood dowels and they are very strong but I didn’t like they way they worked with the Kwik link attached to the side of the dowel.

I decided to revisit the hardwood dowel idea but find a better way to attach the Kwik link wire. I wanted the pushrod ends to look like the fiberglass pushrods with the Kwik link attached to the center of the rod end.

My solution is a ¼ hardwood dowel (four feet for $.24) that I drilled a 1” long hole in the end. The hole is slightly larger than the wire but is a snug fit to provide a good mechanical connection. For drilling this type of hole I use my variable speed Dremel Moto-Tool on low speed. The key is getting the hole started in the exact center of the dowel and then I slowly rotate the dowel as I drill to make sure the hole is centered for the full 1”. I then sanded 1” of the end of the Kwik link wire with 60 grit sandpaper and made a bunch of dwells and ridges along the sanded area using the cutting edge of wire cutters.

I worked 30 minute epoxy down into the dowel hole with a small wire so it would soak into wood. I put a little epoxy all over the end of the Kwik link and worked it all the way down into the dowel bleeding the air out of the hole by twisting the rod.

The pushrod looks pretty nice and didn’t take much more time than installing the ends on fiberglass rods.

After making the two pushrods for the Cold Duck I made a third one for destructive testing. I let the epoxy setup over night and then started working with the test rod. First I bent a ¼” hook on the end of the Kwik link and hung a five pound weight on the end and it held fine. I the tried my ten pound bench vice (see image below). I figured if it easily held ten pounds without the Kwik link pulling out it should work pretty well.

Next I tried the destructive test by hooking the hooked end of the Kwik link around the edge of a ceiling beam in my shop. I grabbed the dowel with pliers and put my weight on it expecting the wire to pull out but all that happened is that the wire hook unbent. This is a pretty long winded description but I wanted to make it clear that it looks like it will be a good solution.

RE: Cold Duck - Build
 

I've done the 1/4' wood dowel, but instead of drilling a hole in the end of the dowel, i've drilled it through the side of dowel. Bent the wire 90 degrees, inserted it in to the hole. Wrapped the wire around the dowel with thread and covered it with expoy. My only change now would be to replace the normal thread with kevlar thread. www.hookhack.com/threads.html . The kevlar thread is pretty inexpensive.

RE: Cold Duck - Build
 

I’ve done that too with dowel and balsa pushrods but I wanted the wire to be centered like it is with a fiberglass rod.

RE: Cold Duck - Build
 

i think so too!:D, i was flying my G-trick 90,then i next week, switched to the cosmos and it felt very fast(and unforgiving),had to go about 5 landing attempts so safely land.

RE: Cold Duck - Build
 

After giving the pushrod idea a little more thought I added a taper to the front end of the dowel end by putting the dowel in a pencil sharpener after drilling the hole. Because I’d already glued the back end I tapered the end of the dowel with a file and sandpaper.

RE: Cold Duck - Build
 

I installed the nose gear to test fit the steering arm clearance and operation. It looks good but is way too simple! I probably should have gone with retracts but it is too late now. I completed shaping the lower part of the rudder and completed the lower rudder hinge installation using a small Robart unit to make room for the rudder control arm.

I need shape the wing tips and do the overall sanding and then I’m ready for the Monokote work.

Decided this would be a good time to tape the stabs on and take more pictures to show the overall look.

RE: Cold Duck - Build
 

Hey 8178, what's happened with the build?

RE: Cold Duck - Build
 

I stopped working on it for awhile. After seeing it fully built I’m very disappointed that I didn’t install tri-gear retracts. I don’t know what I was thinking but it was a big mistake on my part and I’m analyzing my options. It is going to look pretty dorky flying around with its gear hanging out!

RE: Cold Duck - Build
 

I received some inspiration in the mail today. I found a classic Macs flow through muffler on ebay for the RJL K.61. Not a big demand for them so the biding turned out well! Got to move ahead on this build ASAP and do the next one with retracts!

RE: Cold Duck - Build
 

8178, you can donate this Cold Duck to me since it will be too dorky for you to fly without retracts. I've never even owned a plane with them, so it will suit me just fine. ;^P

RE: Cold Duck - Build
 

Started the MonoKote work today! This is one of my favorite parts of a build because of the dramatic change adding color makes. I’m a fan of MonoKote because it is very light, durable, easy to apply and gives the best painted “like” look of all the film coverings. The shinny color really shows off the nice thin 15% tip airfoil.

RE: Cold Duck - Build
 

You do a nice job on the wing tips with the monokote. Do you use a separate piece first? You must have bought a good stock of orange. Are you going to lusterkote the fuselage orange again too?

RE: Cold Duck - Build
 

Thanks jpurcha! I had to use orange so it would look like the original Cold Duck! I’m going to work out an updated white and black color scheme for the fuselage side.

Some additional info on the covering steps. Four pieces of MonoKote were used to cover the complete 62” wing, using all but about 6” of a 6’ MonoKote roll. Because the wing is tapered the four MonoKote pieces were cut about 13 ¼” wide at the root end and about 12 ½” at the tip end. Cutting the taper lets me flip the remaining equal part around for the other side of the wing. I need at least I” of extra MonoKote at the leading and trailing edge to work with and more at tip. No extra is needed at the root because it is cut to fit before application making sure the cut makes the MonoKote line up at the tip. I cover the bottom side of the wing panel first and then the top. The bottom piece overlaps the center line of the wing by about 1/8” and the top piece over laps the center line and the edge of bottom piece. On the leading edge I wrap the top piece down around the leading edge about ¼” so the seam can not be easily seen and keeps the MonoKote edge facing the direction of air flow.

It is hard to explain how to do the wing tips. You almost need to see it done to understand the process. As the panel piece is pulled tight and being tacked down at the root, leading edge and trailing edge, I lightly tack along the tip on the wing surface. By “tack” I mean touch the MonoKote lightly with the MonoKote iron in a few spots so the MonoKote barely sticks to the balsa so it can be moved easly. After the MonoKote is well attached around the wing I start the pulling of the wing tip. I pull and stretch the MonoKote using the heat from my MonoKote iron but I do not let it attach to the wing until the shape will fit around the section without wrinkles. I work it around the tip a little bit at a time. You need to be careful not to pull too hard and tear the MonoKote or push dents in the balsa with your fingers.

I only use a MonoKote Iron and a few new single edge razor blades to do all my MonoKote work. It takes two new blades to do a wing and they need to be very sharp to be able to control the cutting. I trim the top piece edges along the loose side of the glue line and then tack the edge down. At the wing tip I trim on the glue line, very gently scoring only the top piece and then pull the trimmed piece off along the line.

The fuselage will be covered with MonoKote too because it is all balsa. It is a very fun curvy shape to cover!

I used MonoKote paint on the Kwik Fli III and Tiporare fuselages because they were fiberglass. I prefer the fiberglass fuselages over balsa because of their longevity of service, trueness, light weight, strength, extra inside space, resistance to denting like balsa does, etc.

View of the wing with the bottom covering on showing the wing tip.

RE: Cold Duck - Build
 

More images showing how I work the MonoKote around the wing tip and the finished wing. It took about four hours to complete the application of the MonoKote on the wing.

RE: Cold Duck - Build
 

Merry Christmas, can't wait to see the finished build.

RE: Cold Duck - Build
 

Yet again, you amaze. That looks like you dipped the tip in a can of thick orange paint. I thought one had to use silk to get smooth curves like that.

RE: Cold Duck - Build
 

Both ailerons are MonoKoted and ready to have the hinges glued in with epoxy.

RE: Cold Duck - Build
 

Working on the tail MonoKote.

RE: Cold Duck - Build
 

The stab is done!

RE: Cold Duck - Build
 

Coming along very nice, really want to see videos of her maiden

RE: Cold Duck - Build
 

Thanks for the nice comments guys!

The tail is done!

RE: Cold Duck - Build
 

Going to totally "Money-Kote" this plane. No paint this time.

RE: Cold Duck - Build
 

That Orage Monokote sure looks good. Good luck with the Duck. Just started looking though the RCM Plans Guide. Alot of cool oldies in there.

Smooth Fying and Good Luck.
Mad Man Marko