RTF

I had to make a trip to the hobby shop again to get more hinges. I used more than I usually do on the flaps and elevators. I dipped the knuckles in liquid vaseline and used pliars to insert them into the slots so I wouldn't get slippery stuff all over the hinge with my hands.I used the Quick Grip glue and it proved messy as the tiny tubes were a problem to handle. Epoxy or other glues in a syringe would have been easier. While the glue was curing I installed the motor and ESC and timer. After that I installed a flight battery and checked the balance and leadout position. On the plans for the wing the balance point is 6 3/4 inches up from the trailing edge and, I don't know how it happened but that's where it balanced. The RTF weight is 62.5 ounces. I have the leadouts set at 3/16" to the foot nose down which is where I set all my maiden voyage planes. How far behind the c/g? I don't know and I don't care, this is rocket science compared to trying to set that. I'm going to wait for the first flight until after the El Dorado contest this weekend. That will give the glue plenty of time to cure and give the park crew time to mow the field.

I've heard about the new Monokote.

I bought two rolls at the hobby shop on Saturday and got to use it today Monday. The first thing is the plastic/chemical odor is a lot stronger and not the same as it was. Also the material felt thinner. Using dial calipers I got .002 on the new stuff and .003 on the older Monokote thickness. For what it's worth the new stuff should be lighter. I have figured that covering a wing will ad 2 ounces with the older stuff. As I was sticking the covering down around the edges it didn't stick as well as the older stuff. I raised the heat and then remembered using another brand that needed a longer time for the adhesive to cure so I let it sit a bit before shrinking. It did shrink as well as the old stuff. I used a heat gun on the open bay wing and stab/elev and the iron on the solid flaps. One new thing I tried is to spray some 3M glue on the wing where the landing gear blocks are. It should as a lot of adhesion to the covering there. I'll put a strip of packing tape over the area as well. Compound curves, the wing tips, are a pain in my existence. I put a strip of covering on the tips so I wouldn't have to stretch the covering too much. I picked that trick up from the Fancherized Twister article of long ago. All in all it took 3 1/2 hours to cover the wing, stab, elevators and flaps. Now it's time to glue in the hinges and install the control surfaces. That will take another day then assemble all the flight stuff and bench trim it before the maiden flight. That's looking like next week some time as there is a contest this weekend. Should the plane be deemed worthy I will slop some paint on it.

Fitting the covering.

The directions that come with the Monokote have always said to cover the wing with four pieces of material. That makes an overlap joint at the leading edge which will loosen from repeated wipeings to remove exhaust residue. Being of the lazy but intelligent side of the Rose family I got rid of the leading edge joint. I now cover all my wings and flight control surfaces with one piece of covering that wraps around the leading edges coming together at the trailing edges. It takes a bit of patience and masking tape and a dry erase marker.
  I start by making sure the width of the covering, generally 26 inches, is enough to wrap the wing at the root. On this wing I need 23 inches so I'm good to proceed. Measure the span of one wing panel and  ad a few inches. The sweep of the leading edge will cause the covering at the tip to fold back and if you didn't leave enough you will have a bare spot at the tip. Make it 3 inches extra. Roll off 33 inches from the roll and cut the piece off. This wing is 30 inches per panel so I cut 33 inches on the second panel. The first was very close to not being long enough. Trim off one of the clear selvedge edges. Lay the covering on the wing, align the trimmed selvedge edge with the trailing edge and tape it in place. Turn the plane over and pull the covering snug against the leading edge and lay it against the fuselage. Mark where it needs to be trimmed along the fuselage and the trailing edge. Cut the trailing edge first then the fuselage side as the excess will be used to cover the flaps. Lay the covering over the wing to see if it needs any more trimming before sticking it down. If not you are ready to iron the covering down.

Spice injector for hinges.

At most grocery stores you can find a syringe and needle for inje4cting any meats with spices or whatever. The needle is scary big. I found that with a bit of modification the system can be used to inject your favorite glue into hinge pockets.
   First  cut the point off the needle and using an Exacto No. 11 blade tip flatten the needle around the blade so it leaves a flat point with an even opening. Now that opening will fit into the hinge pocket. I have found that carpenters glue, epoxy and this Quick Grip glue works very well in the syringe and holds the hinges in place.
  I ordered some Quick Grip from Amazon as I couldn't find it in stores anymore in the 2 ounce tube. I got a bunch of tiny tubes and each has the pointy end when cut off fits into the needle so You can inject glue into the hinge pocket with having to clean up the syringe barrel. The needle will fit over the end of an Ambroid tube too.

Fillets and first weigh in.

I taped off the fillet areas and mixed up a batch of Super-Fil. I had enough to do the wing and stab but the stab wasn't installed so I just did the wing.  After a few hours I set the plane on the glass table and leveled it and installed the stab. By then the wing fillets were firming up so I mixed another batch and slopped it on the stab.
  Out of curiosity more than anything I got out the scale and weighed all the components of the plane plus the motor and battery stuff. 55 ounces without covering and paint. That will probably ad another 4 ounces total.

ARF. (almost ready for fillets)

As ones flying skills improve there is less damage to repair and some planes will last long enough to be in need of a new finish. I have found that when stripping old monokote from a wing it usually is under the fillets. This makes a mess of the fillets and the balsa causing a lot more work than it needs to be. I learned the hard way that using a strip of monokote around the edges and putting the fillets over the edge of the strip it becomes permanent to the plane. Any subsequent covering removal and replacement becomes a lot easier, if the plane lasts that long.
  I need to be careful of the gaps where the flaps meet the inboard and outboard stationary flaps. To get the gaps as tight as possible I can only put one layer of covering in the gap ends on the flaps and stationary flaps. That should produce a nice close fitting gap that doesn't interfere with the movement of the flaps. (In my case it's more like a Henny Youngman joke"Take my gap, please")

 

Startring the assembly process.

I aligned the wing and fuselage and glued them together. I knew that the flaps would need a cut out for the push rod to pass with down control. I angle cut both flap big ends and, with the mark I made on the fuselage sides on the chord line, glued the stationary parts to the fuselage sides. This makes it easier to set the controls.

Fuselage and push rod.

I was out of glues and threaded couplers. I made up the push rod sans the elevator end. A trip to the hobby shop for the parts and it's ready for installation.
  I added some balsa to the nose to fair in the spinner and slopped on a coat of  Poly-Crylic yesterday. I gave up the idea of fiberglass and will just thin some spot putty and paint that on and sand it down. Probably take a few coats to get it somewhat smooth. Monokote on the open bay structures with Rustoleum 2X for trim colors.

Waiting time.

While I was waiting for the glue to dry on the fuselage sides I installed the control horn on the elevators. I drilled a hole with a piece of sharpened brass tube and glued in a piece of hard wood dowel that was drilled to accept the 4-40 bolt. I'll use a lock nut when it's ready for flight. The nylon piece is from Du-Bro and the clevis hooks into it. Adjustability is almost infinite. You can shorten of lengthen the horn .001 increments if you wish. I usually go for a turn which is .025. Most of the time I glue in a square of 1/4 ply instead of the dowel but these elevators are thicker than normal.

More on the fuselage.

I usually sheet the entire fuselage with 1/64 ply for any of my engines. This being electric I only ran the ply 24 inches from the rear. The motor/battery box is 5/16 wider than the fuselage on both sides so filling that with 5/16 laminated balsa sheets back to the ply should do the trick. The second side is drying now and should be ready for more work tomorrow. The ply may be a bit heavier than balsa but it only takes one coat to seal it and then a coat of primer and colors. I believe it is lighter in the long run and a lot less work to get it smooth.

  I checked the wing and stab incidence yesterday and it's all set.

Building the fuselage.

When I started this project I planned on using an engine. So I built a engine crutch first. Then I drew the outline on the balsa I planned to use for the fuselage front end. I had already marked the thrust line and the wing chord line. I used the chord line to lay out the crutch by mistake. I've done this more than once. When I figured that out I drew the crutch on the thrust line where it should be. Then I couldn't find an engine I figured would be powerful enough and cheap enough at the same time. It occurred to me that electric would be the logical choice and after conferring with experts I got what I needed from Brodak. I already had the Conversion Kit "D" for the motor. After building the motor mount I started to use the chord line again to draw the cut lines. After some re measuring I think I finally got it in the right place. That is why there is  lots of lines on the nose and why there are marks denoting the right place to cut and different colors. I'm going to check it again before going to the band saw. The open back half will be sheeted with 1/64 ply and the front will be covered with layers of balsa to blend in the motor box.
  I put the wing and stab in place to check the fits and measure hinge to hinge. I found a mistake there and put in an extra piece to close up the stab opening. I'll check the wing/stab incidence to see if I have enough room to adjust the stab if necessary.

Flap horn installation.

I install the flaps onto the wing with the hinges and then center the horn on the flaps using the wing centerline. I draw a line around the horn wire and cut that part away. Then I take a piece of brass or aluminum tube and cut off two pieces that will go over the wire legs that stick into the flaps. I plug the end with a bit of tape to keep epoxy out. Then I lay a strip of 1/16 balsa into each cutout to help center the horn wire. I lay the horn into the slots and shim the flaps out a bit for horn clearance with the straight edge. Then using 5 min. epoxy I slop some in each cutout covering the tube/horn assembly but not so much as you don't want  the epoxy to contact the horn wires. Then another strip of balsa over the slots. When the epoxy cures sand the balsa down to the flap surface. I used 1/64 ply as reinforcement on top and bottom of the horn wire/tube.
  This makes flap installation so much easier. The flaps can be added any time in the finishing process. And they can be removed if need be. Gluing them up on a very flat surface assures that they are in alignment.
  If you like to taper your flaps sand them down after installing the flap horn in this case.

Wing tips.

After three hours of carving, sanding and trial fitting I got the wing tips glued onto the wing.The biggest problem I had was fitting the tip weight box. I carved as much as I dared out of the right tip so the box would be inside the tip but I couldn't get it done. I had to cut about 3/16 out of the tip rib so the box would let the tip fit flush to the wing. The Makita grinder and rotary rasp makes short work of hollowing anything.
  When I tack glued the tips to the wing for sanding to match the wing ribs I wrapped some tape on the sanding block so it wouldn't dig into the cap strips. I put a black guide line on the cap strips so I could tell when the sanding was close enough.
  The leadout guide didn't give me too much trouble and I epoxied it into the left tip.

Landing gear and bell carnk.

The landing gear torque leg is quite long. Rather than use a long piece of wood I elected to use brass tube and a short piece of wood. I got the idea from plans by Don Hutchinson and from the ARF Strega landing gear set ups. The tube won't cause any drag on the leadout if it should make contact. I positioned the bellcrank according to the plans and found a piece of wire .105 dia. Metric probably but plenty strong. I drilled a threaded connector to fit and soldered it to the outside end for the clevis. I used wheel collars and fuel tube to keep the bell crank in place.
  After that I installed the bottom leading edge and center sheeting. Cap strips next and wing tips.

Ordered parts.

I added a piece of center sheeting and the leading edge sheeting on the top of the wing. I have to wait for it to dry before taking the wing out of the jig. I can't go much further as the red things are in the way of the bottom sheeting and spars. The bell crank is ready to install and I had ordered the wrong flap control horn, which is my usual M. O. I figured the upright had to move 3/4 to the left. I put it in the vise and leveled the horn with a line level. My trusty Bernz-O-Matic heated the braze and i slid the item to where it should be and added more braze to hold it. I filled the top hole with braze and re drilled it 1/16 as I want to use a clevis. I have some ply wood parts from the Legacy kit as I used fuselage mounted gear on it so I have all the parts needed to make wing mounted gear on this build.
  I called Brodak and ordered the motor and stuff so that will keep the fuselage on the table until that arrives.

Flaps.

I made the hinge pockets on the flaps the same way I did for the wing trailing edge. I cut the flaps 3/4 short on the leading edge so the 3/4 strip with the hinge pockets would make them the right size when glued on.

One piece wing trailing edge.

I marked the location of the hinge pockets on both halves of the trailing edge and sanded the pocket into each half of the trailing edge. Then, using a straight edge, I aligned the halves and pinned them and opened up the pieces for glue. Pushing the parts against the straight edge I pushed them together. Then I marked the rib locations and made notches for them on the band saw. I had to taper the assembly from 3/8 at the front to 1/4 at the trailing edge using rods and a razor plane. After that I installed the trailing edge on the ribs and secured it in place ready for glue. The trailing edge sheeting will cover the assembly adding strength. I plan to install shear webs on the trailing edge sheeting and between the spars for a "D" tube structure.

The wing.

The wing is taking shape. As usual I didn't place the jig rod holes to my best advantage. The bottom spar can't be installed until the wing is removed from the jig. I have to get a sheet of 3/16 balsa for the trailing edge. It will be full length and laminated together to make it 3/8 x 1/2 with rib notches cut in and the hinge pockets sanded in to get them perfectly centered.

Brodak to the rescue.

The laser cut Legacy ribs came in today. I poked the rod holes in each one and had to tape the cutouts in place.  I've been using the Adjusto-Jig for 30 years or more. I've found the fastest way to set the red things for the proper rib spacing is to measure the spacing on the plans and subtract the width of one of the red things, in this case 3/8". Then I cut pieces of corrugated cardboard to that dimension, in this case 2 1/8 minus 3/8 equals 1 3/4". Then I set the center rib spacing on each side and using the cardboard pieces place one between each of the red things. Making sure the cardboard is touching the pipe and not riding up into the red thing. A measurement makes sure it's right.
  The 45 degree bias balsa sandwich is curing and I'll use that to beef up the nose. Probably use a piece of lite ply over it on the outboard side.
 I included a picture of Nomads one and two so you can see what I'm doing. I have a third one the same size and a larger one with the Pattern Master wing. LA .46 power on the three and .52 or .60 on the bigger one.