Albatros CIII 57 - AerodromeRC · A semi scale adaptation of the Albatros CIII , this model is designed to be easy to build and exciting to fly

Albatros CIII 57”

Copyright© 2007 M.K. Bengtson All Rights Reserved Rev 07/11

Albatros CIII 57”

R/C Scale Model Instructions

CONTACT INFORMATION Designed by M.K. Bengtson Prototype by Frank Jaerschky

Manufactured and Distributed by:

Bengtson Company e‐mail: [email protected]

www.aerodromerc.com

Albatros CIII 57” Page 1


Albatros CIII Thank you for purchasing the 57” Albatros CIII model for electric flight.

THE MODEL

Finished Model by Frank Jaerschky

A semi scale adaptation of the Albatros CIII , this model is designed to be easy to build and exciting to fly. This manual is a distillation of Frank’s comments in building the prototype.

POWER SET UP The model is powered by the AXI 2826/10 direct drive brushless outrunner and an APC 13x8E prop. Battery power pack is a 3S2p 5000 maH Lipoly.

SPECIFICATIONS More than 320 laser cut parts

Scale: 1/8 Channels: R/E/A/T Wingspan: 57ʺ Wing Area: 887 sq in Prop: 15x7 APC Weight: ~AUW 62 oz Power System: AXI 2820 brushless Wheels: Balsa & plywood, Neoprene foam tires Airfoil Type: Scale Cowl: N/A Spinner: N/A Decals: on website

BUILDING THE MODEL Before Starting A note about the photos: The photos were taken of a prototype and the parts supplied may look slightly

different from them. However, the concepts illustrated are the same.

WINGS

Wing Construction I am commencing with the lower right panel. I really like the way wing construction has been thought out. The wing is built around 2, 1/8ʺ o.d. carbon fiber tubes, and either a 1/4 carbon fiber tube or 1/4ʺ birch dowel for the leading edge. I would have liked to have used CF for the leading edge, but cost swayed me towards the dowel instead. Besides, I had to buy a bunch of servos today. And the airfoil is a scale undercambered airfoil. Looks great!

The ribs to which the interplane struts are fastened are unique. They are built up of two 1/16 ply ribs on the outside, with a 1/32ʺ ply rib in the center. The center rib has ʺUʺ shaped cut outs that are the same shape as Dubro metal landing gear straps. The hole in one end of each strap must be drilled out to 1/8ʺ. The 3 ribs are joined together with the Landing Gear straps in the ʺUʺ cut‐outs, (the pre‐cut ʺUʺ ensures the strap is at the proper angle) and the 1/8ʺ hole lines up with the laser cut holes in the ribs. When the wing is assembled, the 1/8ʺ carbon fiber tube slides through the rib and the landing gear strap, making an incredibly strong strut mount.

The rest of the wing builds up easily. The trailing edge is 1/32ʺ ply. Just slide on the ribs, double check they are in correct position, and apply thin CA.



I have started the upper wings. Both main spars are 1/8ʺ carbon tube, transitioning to 5/32ʺ brass tube 7ʺ inwards from the root rib. The brass tubes will slide over a 1/8ʺ music wire joiner at the cabane struts. It looks complicated at first, but studying the plans and the photos of the actual aircraft makes it fairly straight forward, and oh, so scale! The ribs are merely slid over the spars to their correct location. Once everything is checked and aligned, and rechecked again, a few drops of thin CA secures the ribs to the spars. The interplane strut attachment points in the lower wings are straightforward, as they coincide with a wing rib location. However, this is not so with the upper wing. A very clever method was devised for the upper wing strut attachments. The landing gear straps are held by a sandwich of 3 sub ribs that are tied into the spar. Of course, you canʹt permanently glue in the landing gear strap attachment points when the wing is on the board, as they would not be able to sit in their proper locations. So first an outer sub‐rib is slid on, then the landing gear straps, and then another outer sub‐rib.

NO glue is used on this assembly at this time. Once the wing is completed and off the board, a the 1/32ʺ ply centre sub rib with the cut outs that ensure proper alignment of the landing gear straps is slid in between the outer sub‐ribs and over top of the CF spars, and then the assembly is glued into place. The C.III had ailerons on the top wing only, so that makes a scale version a bit easier. The original design calls for an HS‐55 in each wing panel with a pushrod to the aileron. The servo leads run through pre‐cut holes in the ribs. A very easy, simple, and effective set up.

I tried scale aileron cables. The aileron servos will reside inside the fuselage. Cables will run out through tubes in the lower wing, exit the lower wing near the outer rear interplane strut, and then up to the ailerons. This is such a gorgeous airplane, that I really feel the scale cables will be the icing on the cake.



Top Wing Construction Detail Lower Wing Construction Detail

Scalloping is pre‐set by the top and bottom ply trailing edge parts supplied.

Aileron Construction Detail The upper right wing is now complete. The scale aileron modification has been made, and it will work out very well. Iʹm using a piece of 1/8ʺ carbon tube for the aileron horn that projects forward from the aileron. I might try a 1/8ʺ dowel because it will look more scale, but it would also not be as stiff.

The aileron cables run from inside the fuselage out through the lower wings and then exit the lower wing near the rear outer interplane strut. One cable goes to the front of the 1/8ʺ horn that projects forward from the aileron, and the other goes to an attachment point on the bottom of the aileron behind the hinge line. The ailerons will be top hinged, and thereʹs lots of room for up and down travel. I imagine Iʹll be using quite a bit of differential, so up will be more important than down, anyway.

FUSELAGE CONSTRUCTION Each fuselage side is laminated from 5 pieces of 1/16ʺ balsa, forming a side that is 3/16ʺ at itʹs thickest point. The designer has been very clever here! The joints are such that they donʹt overlap, ensuring maximum strength. Slots are cut in the sides for the various formers.

The first step is to remove and identify all the fuse side parts. I canʹt stress enough how important it is to familiarise yourself with the plans and the parts to ensure you build a left and right half, with the proper orientation of all the parts! The parts are well marked, and the plans are very clear, so take your time and everything goes very smoothly.

You must first join the front and rear halves of both the middle and outer fuselage sides. I use Ambroid balsa cement for this, as it sands better than most glues. The



final finish on the fuselage on the prototype will be natural wood, so I did not want to use CA on this joint, as I am planning on using wood stain to achieve the dark colour. Stain will not work on a CA joint, leaving a very tell tale light line. Ambroid takes a while to dry, and for best results, requires the ʺDouble gluing techniqueʺ. First spread a light coat on each surface to be joined, let dry, then apply more glue and join the parts.

I laminated the three layers together using Z‐Poxy finishing and laminating resin. Using a plastic spreader, I spread a very thin coat of epoxy on the sides, aligned everything just so, and then piled weight on top until the epoxy cured. Using a plastic spreader, you can get the glue on very thin, and it adds almost no weight. I didnʹt want to use CA because I wanted time to align things, and I was worried that aliphatic would cause warps. I did not put any glue between the layers at the nose, because there is quite a sharp bend at the front. I think if the 3 layers were solidly glued together, it would be very difficult to bend them later. Thatʹs one reason the sides were designed like this, the grain of the middle layers runs perpendicular, making the bending easier. Once I join the sides, Iʹll add glue between the layers and bend them to shape. Once the glue dries, the bend will be permanent.

In the photo, I have pinned down a side and have started to add the longerons, stab mount doublers, and vertical reinforcements. (I got a little ahead of myself and installed a former when I should have waited.) The lines on the inside are something I do for every model. I draw a series of parallel lines 1/2ʺ apart on the inside of the fuselage. When the fuselage is assembled, it makes aligning things like servo rails, etc, a breeze.

The fuselage sides are joined together. It just seemed that with the shape of this fuselage, it was best to start at the rear and then work forward. Take your time, as this will decide whether you come out with a square fuselage.

The nose takes a very sharp bend, but the fuse sides are designed so that the bend happens quite easily.



There is a tab on the fin that fits into a pre‐cut slot at the back of the fuselage. The plan calls for foam or wood adjacent to the fin to form the rounded aft turtle deck. I made a ʺChannelʺ for the fin to fit into by using a piece of 1/16ʺ balsa alongside the base of the fin that runs from the aft most former to the tail of the airplane. I then used 1/16 sheet to sheet the rear portion. I have also installed short lengths of 1/8ʺ o.d. nylon pushrod housing to act as guides for the control cables, which exit in the scale locations.

You can see 4 holes in the aft turtledeck where the cables exit. The foremost holes are for the upper elevator cables, the after‐most holes are for the rudder. The lower elevator cables exit at the sides of the fuselage under the stab. Itʹs important to spend time getting everything lined up at the back, especially the control cable runs. I was fooling around with the markings for this bird. I made a full size pattern and printed it out. The markings will be hand painted, but I can at least use the full size pattern to make it a bit easier. At least itʹs all black and white. And NO LOZENGE!

The nose is a bit tricky because it comes to almost a point at the front where the prop shaft exits the nose. The only way I could get access to the mounting screws (and also ensure air flow through the Axiʹs ventilation slots) was to make some holes in the balsa nose. Once itʹs all painted up, it wonʹt look so obvious. The Axi 2826/10 mounts easily up front.



Hereʹs a look at the servo layout. Iʹm using Hitec HS‐225BBs for the rudder and elevator. I want to use ball bearing servos, as I think they are a bit better for larger aircraft when using pull‐pull cables. In the pictures of the radio bay, the front of the aircraft is to the right. The HS‐225s sit near the bottom of the radio compartment, close to the cockpit floors. The middle 225 is for the rudder. I think I will probably use a rocker‐arm set up for the elevator cables further aft in the airplane. The servo will be connected to the rocker arm with a pushrod, and the cables will go from the rocker arm to the elevators. This will make sure the cable geometry is symmetrical to the elevators.

By the way, installing the servo rails so that they are square and level with each other was a total breeze because of those parallel lines I drew on the inside of the fuselage sides. Try it on your next build, you wonʹt regret it!



The ailerons required a bit of a different approach. Iʹm using Hitec HS‐85BBs, again because I want a ball bearing servo in this pull‐pull set up. The HS‐85s are located so that the servo arm lines up with where the aileron cables enter the fuselage. Things get a bit complicated here, so bear with me. The servo arm will be permanently attached to one set of aileron cables. Remember, the wings stay connected together as right and left hand assemblies. So the wings slide on to the music wire joiners, and the servo arm goes through a hole in the fuselage side (not visible when the wing is attached) and is then attached to the servo. To take up any slack in the cables, the servos are on mounts that allow them to slide sideways, so that I can always ensure the correct tension on the cables. The servo mounts are a core of 1/8ʺ spruce faced with 1/32 ply on the top and bottom to provide a hard surface. I used my Dremel to cut the slots. 2‐56 socket cap screws hold the servos down. I soldered 2‐56 nuts to square pieces of thin brass stock, and they go on the underside of the servo mounts. A few turns of a ball driver locks the servos into place.

I want to stress that this method of aileron actuation is entirely my own doing. The method as designed is straightforward and not complicated. I felt that this was a good idea to demonstrate the level of ʺScalenessʺ it was possible to go to with this airplane.

Iʹve done some work on the cabanes. The cabanes are an inverted ʺVʺ shape, terminating in ring terminals soldered at the ends. A short piece of soft copper tubing slid over the 1/8ʺ music wire joiner rods acts as a spacer to keep the wings the proper distance apart. The C.IIIʹs upper wings did not completely touch at the root, and the model correctly reflects this. If you look at some photos, you can see that there is a thin metal fairing that goes on top of the wings, and I will probably make that out of some thin aluminum lithoplate. The joiner rods will be soldered to the cabanes, so it will just be a matter of sliding the wings on to the rods. To keep them from sliding off the rods, there are two ʺhardpointsʺ on the bottom of each wing near the root with a 4‐40 blind nut installed. Iʹll use some kevlar thread or braided thin wire with ring terminals at the ends, and bolt each end into the blind nuts.

Iʹve switched over to installing the cabane struts. They plug into brass tubes set into basswood mounts in the



fuselage. I should have shown the struts before installing into the tubes, but forgot to take pictures. They are basically an ʺLʺ shape, but have more than a 90 degree bend so that the ends of the struts meet at the fuselage center line, and there is a ring terminal soldered to each strut end. I use JB‐Weld metal epoxy to glue the cabane ends into the tubes. I use the long cure JB Weld, so I have lots of time to make sure I have the angles right. Iʹve also started to do a bit of work on the dummy motor. Hereʹs a series of pictures describing how I aligned the cabanes and top wing joiner rods. The wing joiner rods are 1/8ʺ music wire, with a slight bend in the middle to set the dihedral angle. There is a short piece of brass tubing (about 1/2ʺ long) right in the middle of each joiner, at the ʺVʺ. It fits over the V with a bit of persuasion. The joiner rods are then slipped through the ends of the cabanes, and another small 3/32ʺ piece of music wire with ring terminals that connect the fore and aft cabanes. The parts are then soldered together. Iʹve been scratching my head for a while trying to figure out the best way to make sure everything is properly aligned. It looks kind of weird, but hey, it worked!



First, I made a high precision plum‐bob from a piece of kite sting and an old wheel collar. I put a nail in the rafters above the workbench, and put my plumb‐bob there. I jacked up the rear end of the fuselage until the top ends of the cabanes were level, and checked that with my Robart Incidence Meter. I then aligned the front cabane assembly directly underneath my plumb‐bob. I then measured the length of the joiner rods, and put two more nails in the rafters on either side of the plumb‐bob nail, the same distance apart as the length of the joiners. I then slipped the joiner rod into place, and tied a piece of kite string to each end of the joiner rod, securing it with a small drop of CA. I then tightened each piece of string so that the ends of the joiner rod were the same distance up from the workbench, and used clamps on the strings up at the nails. Using the clamps allowed me to tighten and loosen the strings as necessary to until I got the joiner rod in the right position. I measured from the tip of each joiner rod to the centre of the very back of the fuselage to make sure the rods were square to the fuselage. Once everything was in position, checked, checked, and re‐checked, I soldered all the bits together. After the solder had cooled, I untied



the strings, slid the fuselage forward until the aft cabanes were under the plumb bob, and the repeated the above steps. Everything lined up perfectly! A bit of sandpaper took off the CA residue at the tips of the joiner rods, and the wings slid right on with no problem at all. I think this speaks volumes about the designer’s use of CAD to draw the airplane. Keep in mind this is a prototype, and it fit together perfectly, first time. Follow the plans, and all will go well! This may seem like a lot of work, but once I hit on the idea, I had both front and rear cabanes done in less than an hour. Itʹs obviously important to get this step right, to make sure the wing incidence is proper. Another advantage of this sting method is that the tension of the strings automatically rotates the joiner rod into position so that the ʺVʺ shape of the joiner is correctly aligned, with the tips of the rod being raised as high above the middle ʺVʺ as possible. This ensure proper dihedral, and also that the wings will slip easily on to the joiners. I have the fuselage stained and clear coated with 3 coats of Water Based Polyurethane. Total weight of the finish is 0.56oz (16g). I think thatʹs pretty good for the size of model. The nose looks brutal at this point, but fear not, it will wind up looking just fine. I used ʺPlaidʺ brand antiquing medium for the stain, ʺDownhome Brownʺ colour. 2 coats did a decent job. Just paint it on, let it sit for 3 minutes, then take a paper towel and wipe everything off. You can adjust the darkness by adding another coat of stain. I stopped here, as it seemed to match my documentation.

The clear finish is gloss water based polyurethane. I was thinking of using satin, but I figure in time, the gloss will wear off. My guess is the originals left the factory in some sort of gloss varnish, but the gloss probably faded quickly. Iʹll do the nose using .75 oz glass cloth and epoxy finishing resin. That part was aluminium sheeting on the original, so I think that will simulate it fine, when sanded and painted. For the nose, I masked off the portion that is metal sheeting on the full size aircraft. Then I carefully applied 0.75 oz glass cloth with epoxy finishing resin. I sanded it smooth, then applied a layer of glaze and spot putty, and then sanded that down. Thatʹs the stage itʹs at in the photo. The theory here is that by leaving the masking tape in place and applying the putty over the tape and then sanding it down, there will be a raised panel appearance once the tape is pulled off. The next step is a coat or two of white sandable auto primer.

I peeled the tape off, and am quite happy with the way it turned out. The white primer has been applied and sanded. I spent a few minutes with a syringe and white glue applying some fake rivets. This is one of those little things that make people “Oohhh” and “Ahhh” when itʹs done, because for some reason, many modellers donʹt bother with them. For the sake of 10 minutes with a syringe and some white glue, itʹs well worth doing!



To fill the weave, I re‐applied masking tape along the new ʺPanelʺ. I sanded down the high spots on the fiberglass with 120 grit sandpaper. Then I applied a thin coat of glaze and spot putty (From the auto body store), and made sure I rubbed it into the fiberglass. Then I sanded everything down again, this time with 220 grit paper. By now, the weave is pretty much filled. I then sprayed on white automotive primer, and sanded again. Then another coat of primer and more sanding, this time finishing with 400 grit sandpaper. I did the rivets using a 10CC syringe with a needle, but with the sharp end cut off. (My wife is a nurse. Itʹs amazing what modelling uses I can find for medical supplies!). I used a white glue called ʺWeldbondʺ for the rivets. Itʹs has pretty good consistency right out of the bottle, but if it is too thick, you can thin it with a little water. As far as the size of the rivets, experiment on some cardboard until you get something you like. You may need to try different syringes and glues until you hit on the right combination that works for you. The rivets arenʹt super scale, but a little surface detail goes a long way in making a convincing looking model, especially in the larger sizes.

This is the process of painting the crocodile and dragon on the fuselage sides. I scanned the image from the Windsock Datafile into my computer, and cropped the image until I had the part that I wanted. I then compared the model to the documentation, and came up with the size I needed my artwork to be.

I then made a mirror image of the scan. Using a freeware program called ʺTileprintʺ, I was able to enlarge and print the image. I printed it on to the paper backing of a clear plastic material that is intended to protect the covers of paperback books, or to go over maps. It sells at the local stationary store for $1.50 for a 14ʺ X 5Ft roll. Using a sharp blade, I will cut out the crocodile, and then stick the the negative mask on fuselage. Then Iʹll spray on a coat or two of white paint. The black parts I will paint in later by hand, so that will be a challenge!



Iʹve taped the mask down shiny side up to a piece of glass on top of the work bench. A fresh scalpel blade and a few minutes work makes a negative mask, which will be attached to the fuselage and then the white paint sprayed on.

The masking worked out very well indeed. The paint I used is actually Krylon ʺFusionʺ the stuff that is meant to paint plastic. It covered the dark brown finish of the fuselage in 4 light, misting coats. Wet coats greatly increase the chances that some paint will run under the mask, so light, misty coats are best. The big brown space in the middle of the dragon will also be white. I did it in sections, as it was easier to apply the crocodile masks that way. Iʹll fill in the big white section later today, and then the rest is up to my rock steady hand. I may need some beverages to relax me, first! Hereʹs the white paint all complete. By the way, the green stripe you see near the tail is a piece of masking tape I applied to the fuselage before I started any of the finishing. Thatʹs where the horizontal stab glues on, and I wanted to make sure there was no stain or paint there to ensure a good wood to wood glue joint.

Sometimes, it just all works out..... I am very happy with the results. I used a small brush and Tamiya semi‐gloss black acrylic to paint the dragon and crocodile. I followed the documentation to the best of my ability, but donʹt go counting lines and crocodile scales, Iʹm afraid you may notice some inaccuracies! Still, good enough for me! The crosses are black enamel, airbrushed on using stencils made from that clear plastic book cover stuff.

I completed the large belly hatch. Itʹs made of 1/32ʺ ply, and I used magnets to hold it in place. The piece of ply I used had a natural warp in it, so I cut a piece out to use as a hatch that naturally followed the curve of the fuselage. 4 magnets hold the hatch on. They are circled in the first picture. The magnets furthest forward are recessed by about 1/8ʺ. On the hatch, I glued on 2 nuts that correspond with the magnets up front. The nuts sit in the recesses and make contact with the magnets.



They other 2 magnets are about set into mounts I made from 1/8ʺ lite ply. They magnets are recessed by about 1/16ʺ or so from being flush with the fuselage sides. I glued small pieces of metal from a cut up tin can to the hatch with silicone. I put a dab of silicone on each piece of metal and then put the metal pieces in place on the magnets. Then I put the hatch on, made sure it was in the right position, and taped it down last night. This morning the silicone has cured, and I removed the hatch. The magnets hold it on securely. Because the curve of the hatch is sharper than the curve of the fuselage, the very rear of the hatch stays tightly pressed against the ply cross piece that has the 4 holes in it

By the way, the 4 holes in the bottom of the fuselage are scale and included in the kit. The real aircraft had a bomb bay for 4 bombs to fit vertically into. The two middle holes are larger than the outer holes. Makes a great natural cooling air outlet!

Hereʹs the rear gunner/observerʹs position. The full size aircraft had a plywood cone around the observer, with the gun mount fastened to it. I guess the whole mount and cone rotated to allow the observer to swing the gun, hopefully not shooting his own tail off.



The cone is made of thin cardboard from a manila folder, and painted with craft acrylic, and then a coat of polyurethane to seal it. I glued it in with ʺWeldbondʺ white glue in syringe. Because of the thin edge, I place the cone in position and then ran a bead of glue around the base of the cone on the inside. When dry, the glue will be invisible, and I can touch up with paint if necessary.

Next is the landing gear fairings. I still need to think of a way to try and make the attachment point at the fuselage semi‐scale looking. I think probably pieces of pained thin card stock will do the trick. The kit provides fairings made from 3 laminations of 1/16 ply. I used only 2 laminations, and then sanded them down until they were the 3/32ʺ thick, same as the undercarriage wire. I then used thick CA to glue them onto the wire. I first sanded the wires, and then cleaned them with acetone prior to gluing. I then filled the small gap caused by the wire being round and the fairing being flat with glaze and spot putty, and sanded everything smooth.



The fuselage fairings were pretty simple, too. The ʺPlateʺ on the side of the fuselage is just card stock from a manila folder. I put a drop of glue in each corner to simulate a rivet. It doesnʹt show up too well in the photos, but it will after some weathering. The round part of the fairing is epoxy and micro balloons. I used a high concentration of micro balloons for easy sanding and light weight. Sanding proved almost totally unnecessary, because I shaped the fillets with a wet finger tip before the epoxy cured. Just remember to clean your finger with a paper towel and some alcohol prior to the next wetting!!!! The whole shebang was then painted with 2 coats of Testorʹs Model Master flat Gull Grey FS36440.

TAIL SURFACES

Hereʹs the horizontal stab and elevators. Nothing too difficult, glue and pin the parts down over the plans. I use aliphatic glue; I just like having a bit more time to position the parts, and I like the way it sands. The parts are laser cut from 3/16 sheet, and fit perfectly. A few pieces of 3/16 square form the cross pieces. There was enough of a ʺBorderʺ around the 3/16 laser cut sheets that I was able to strip off 3/16ʺ sq strips with my balsa stripper! The fin and rudder are also constructed from laser cut 3/16ʺ balsa and some 3/16ʺ balsa sticks. Once again, there was enough wood around the edges of the cut parts on the 3/16ʹ sheet to strip off some square piece.

Horizontal Stabilizer Laid Out On Plans



LANDING GEAR For the landing gear, I used the same method that has proven itself on my DH2 and Fokker D.VII. The spreader bar is 1/8ʺ spruce, with a lamination of 1/32ʺ ply as well, for some added strength. The spreader bar is bound to the landing gear struts with strong, 100% nylon thread, and then soaked with thin CA. <<LEGS1.JPG>> I drilled a series of small holes through the spreader bar either side of the landing gear strut joint to allow the needle and thread to go through. I tried something different where the front and read struts meet. Instead of wrapping with wire and soldering, I joined them together with a short piece of brass tube, and then silver soldered them together. I think in theory wire wrapping makes a stronger joint, but this seems plenty strong, and itʹs sleeker and looks better, too.

The 1/8ʺ axle is then bound to the top of the spreader bar. The first binding is inset 3/4ʺ from the end of the spreader bar. This allows the part of the axle outside of the binding to flex upwards a bit, making a bit of a shock absorbing gear. You can set the amount of flex by where you place that first binding. Further away from the end = more flex. Careful not to go too far inwards, as the axle is also free to flex fore and aft in this set up. I also put one more binding in the center of the spreader bar, just to make sure the axle isnʹt going anywhere.

The wheels are the designer’s standard built up from discs of balsa and ply, and the tires are a soft, round rubber material. Iʹll solder a washer to the axle to retain the wheels, and then the hubs will be covered with a cardboard cone.



Laser cut landing gear strut fairings are included, and thatʹs the next step.



Iʹve been scratching my head over the tail skid for a while. I made the pyramid shaped skid support struts from thin music wire a while ago, but I was lost as to how to attach the skid. Finally, I decided to use some thin brass stock to make a support. I nibbled a bit of the stock out using a Dremel and a cut off wheel. The bite allows the stock to be folded over the apex of the pyramid. Itʹs then soldered on. The skid is shaped from spruce stock, stained and sealed with water based Polyurethane. Itʹs slipped in to the bracket, and a small hole drilled through the brackets and the skid. Then I inserted a small piece of music wire to retain the skid, and secured the pin with some thin CA. The front of the skid is supported with 3 wraps of strong nylon thread. The thread goes from one front strut at the fuselage to the skid, wraps around, and then over to the other front strut. The thread has a slight bungee action,

and gives a bit of suspension. Itʹs really strong, and I canʹt break 1 strand of it, let alone three. All in all, I think it came out looking quite a bit like the full size, and it has some shock absorption, too. Iʹm happy with it.

DUMMY MOTOR the dummy exhaust stack. The stack is supplied as 3 laser cut laminations. As you can see, itʹs a tricky piece. You will need a few minutes with some sandpaper to get all the edges rounded.

Once I had it shaped, I was wondering how I would fill the wood grain. I hate supposedly metal parts where the wood grain is clearly visible. I was thinking of glassing, but wasnʹt looking forward to all the sanding, weave filling, sanding, priming, etc. So I thought ‐ ʺWhy not Polyspanʺ!



So for those who are not yet convinced of the merits of Polyspan, I easily covered this exhaust manifold with Polyspan. A few coats of dope and it will be ready for a rust coloured finish. Lots of stuff hangs out in the breeze on the C.III, including the radiator. The radiator is furnished as a balsa frame in two halves that you sandwich some screen material between. The radiator supports are laser cut 1/8ʺ lite ply. To fill the wood grain, I used a coat of epoxy finishing resin, and then sanded it down. On the radiator itself, I followed with a thin coat of Glaze & Spot putty. Once it was dry, I sanded most of it off.

The radiator supports are attached to the forward cabane struts. Simply gluing them to the music wire was not an option. I drilled a small hole in the end of each leg on the radiator supports. Then I sanded the paint off the cabanes, and tack glued each support to the cabane with thick CA. Then I used a needle and nylon thread and bound each support leg to the cabane. After soaking with thin CA, itʹs rock solid.

Once everything was dry, I repainted everything. I still need to make some radiator hoses from and to the engine block. There was a thread on E‐Zone on a radiator on a Pietenpol that was absolutely stunning. The screen that I used doesnʹt come anywhere near that, but it does the job.



Note the dummy fuel tank between the upper wing roots



is also in place. Itʹs furnished as 3 pieces of balsa that are laminated together and carved/sanded to shape. Fill the grain, sand and paint. Right back at it with the radiator feed and return pipes. Looking at photos of the original, it appears that they were pipes and not hoses. I made the tubes from 1/8ʺod soft brass tube that I had lying around from my glow power days. Itʹs used for making fuel tank fittings, and is very soft and easy to bend. The tubes sit in 1/8ʺ holes I drilled in the radiator and engine case. They are secured with thick CA that has formed a fillet around the fitting, which looks convincingly like a soldered joint when painted over. I painted a small ring of black on the upper radiator pipe to look like some sort of rubber fitting or seal. I was going to paint the pipes, but I like the way the brass looks. It will age naturally and take on a nice used look. The pipes also add a lot of strength to the radiator assembly.

Hereʹs that crazy exhaust stack. It was painted with reddish brown dope. I hollowed out the end with a small bit in the Dremel. After painting, I used my airbrush and some flat black paint and added some ʺSootʺ weathering around the exit. Looks the part!

The model has to have hatches and louvers. The model looks naked without them. They donʹt take long to make. I used thin aluminium lithoplate for the hatches and louvers. The aluminium is easy to cut, file, and shape. The ʺHingesʺ on the front of the hatches are just short lengths cut from a pin, and glued in place with thin CA. The drop of thin CA that comes out of the bottle is way too big, so just manoeuvre the pin piece into place, and then soak up the excess glue with the tip of a paper towel. The other bumps on the panels simulate the retaining screws, and are just small drops of thick CA applied with a toothpick. The panels are painted and glued on to the fuselage with thick CA. The louvers are simply filed and bent into shape, painted, and attached carefully with thick CA.



This was probably my least favourite part of the build ‐ the 8 interplane struts. Each strut is a lamination of 2 outer pieces of 1/16ʺ ply with a center 1/32ʺ piece. They go together great ‐ but they are a pain to sand, even starting with 40 grit paper. Oh well, if it were easy, even Cricketers could do it. So each strut was sanded so that it had nice round edges. 2 coats of nitrate dope, and then painted. I wanted a bit of the wood grain to show through, and the effect is perfect, although you probably canʹt tell from the photo.

COVERING

Covering has started! I was going to use my usual silk span and dope, but the designer and others convinced me to give Polyspan a try. My initial impression is ‐ Iʹm glad they convinced me! I donʹt really know what Polyspan is made of, but it is stronger than silkspan, and just as light, probably even lighter than the medium to heavy weight silkspan. It is ironed on to the framework after applying a coat of Sig ʺStix‐itʺ covering adhesive to the framework. I found it irons on very easily, and shrinks very well with heat. 3 coats of thinned nitrate dope are then brushed on to fill the weave, and then it is painted. I will be using dope for the final finish.



The covering of the bottom of the undercambered wing turned out to be totally anti‐climatic. The Poly span went on easily, and stuck tight. When covering an undercambered airfoil, it is important that the covering be stuck down tightly to each rib. When you start ironing, do not iron the outside edges first! You must start ironing at each rib, from where the undercamber is the deepest. Work slowly along each rib, from the centre point towards the trailing edge. Do this for each rib. Then start again at the centre point, and work towards leading edge. Do the same for the wing tip. Do this until the covering is ironed down to each rib. Only then attach the covering to the outside edges of the wing panel.

I shrunk the covering with a heat gun. Polyspan shrinks great with a heat gun. You can fine tune the temperature and shrinkage by how far you hold the gun from the material. I was careful no to apply too much heat, for fear that the Stix‐it would soften and the covering would pull away from the ribs as it shrunk. There was no sign of that happening at all. So ready for paint, the covering has added 11g, or .39oz. The colour dope will obviously add a bit more weight. With a bit of fancy math, that works out to 1.14oz/sq yd. (3.6g/sq ft.) For aileron cable attachment points, I used the eye end of some small fish hooks. I cut off the hook end, put a 90 degree bend in it, and then inserted it through a small

hole I drilled in the bottom of the aileron. Itʹs secured with a drop of thick CA and accelerator. The small block of balsa in the aileron also supports the 1/8ʺ CF tube that will form the front of the aileron horn. I made up some graphics using a scanned picture of the Albatros logo, and then used Wordperfect with the ʺCentury Schoolbookʺ font. The font matches my documentation very, very closely. Iʹll print it out on clear decal paper and apply it to the finished fin.

Decal outlines for this model are available on www.aerodromerc.com/decals in Adobe Acrobat pdf format for printing on decal paper. Contact paper used for kitchen shelf lining makes excellent decals. Print out the decal on paper, glue with a glue stick to the paper backing on the shelf paper, cut the decal out with an Exacto knife or micro scissors. Peel off the paper and adhere to your model. Use black material for the crosses and white for the backgrounds.

WHEELS Gluing the ply sides on the balsa core makes the basis for the wheels. Use the brass hub for alignment. Epoxy the hubs in place and add a sufficient amount of epoxy around the base of the hub to reinforce the connection of the hub to the ply. Plywood reinforcing hubs are provided that are to slip over the brass tubing as shown. Next, CA glue the neoprene cording together to from a “tire”. Use thin CA sparingly as the CA bonds very aggressively to the rubber. Press the CA wetted ends together for an instant bond. The best way to align the ends is to glue them while they are in place on the wheel. Then attach the tires to the wheels and CA in place. A thin bead of CA around the rim makes for a secure tire. Paper cones are cut out. Use a ball point pen to score each line on the back to make an impression of “spokes” It is



helpful to do this operation on a paper tablet so that the pen makes a good crease. Fold the paper along the crease lines to exaggerate the raised lines. One of the sections forming a wedge is cut out. Make cuts to the center of the circle along a pair of the spokes. Close the paper cut‐out to form a cone and tape the joint inside the cone. The inside cones may now be attached to the wheels. The outside cones may be attached at this point if wheel collars are to be used. Alternatively, after installing the wheels on the landing gear, a washer may be soldered to hold the wheel in place and then the cone is attached. This method makes a very nice scale appearance.

INSTALLING THE RADIO CONTROL GEAR

Servo Bay

The servos are all in place, as are the control cables to the elevators and rudder. The elevator and rudder servos are the larger ones deep in the fuselage, and the aileron servos are the one near the wing roots. For control cables, Iʹm using Spiderwire Original Braid 30lb test fishing line. This stuff is super tough, and doesnʹt stretch, not even a little. The only thing I donʹt like is the colour ‐ moss green! I think for the aileron cables Iʹll use thin braided cable that they use for stringing beads. It is nice as well, and looks very scale. But it does stretch a bit. This wonʹt be a problem for the ailerons, due to my sliding servo tray design. Iʹll be tightening the cables each time I put the wings on, so stretching over time wonʹt matter

Hereʹs a picture of all the gear installed. The Castle Creations Phoenix45 is at the top of the picture, attached to the fuselage side with Velcro. The receiver is wrapped in foam and green masking tape, and can be seen deep in the fuselage. The Apogee 3S2P 4160mah pack can be seen at the right of the photo. There is a piece of light ply at the front of the battery that holds it down, and then the back edge of the battery is secured with Velcro. Iʹll probably rig up some sort of a strap to make extra sure the battery doesnʹt budge in flight. The receiver antenna exits out of one of the bomb bay holes, and will trail aft along the fuselage. Those bomb bays sure make good cooling air exit holes!

ASSEMBLY

Wing Mounting/Aligning Bolts on Wing Panels

The lower wings are retained to the fuselage by an 8‐32 nylon bolt. The bolt doesnʹt carry any load; the 1/8ʺ music wire wing rods do that. The bolts keep the wing root tight against the fuselage and prevent the wing from sliding outwards. The wing root rib has a small block of basswood on the inside tapped out to accept the bolt. The bolt is easily accessible from below with a standard screwdriver, so field assembly is easy.



Wing Attachment Construction Detail

Dubro landing gear straps are used to serve as attachment points and are epoxied into the ply ribs as described earlier.

Fitting Tail Surfaces The horizontal stabilizer is in two halves and has tabs that fit into slots in the side of the fuselage. Insert the two halves, and dry fit the elevator using CA hinges. The elevator serves as an alignment tool so that the horizontal stab can be CA glued in place. The vertical stabilizer also fits into a slot in the top of the fuselage formed in F7.

Pushrods

Fitting the Rigging Wires The fittings are made of thin brass sheet stock, and measure about 1/2ʺ long and 3/16ʺwide. I drilled a 1/16ʺ hole in one end, and a 5/64ʺ hole in the other to clear the 2‐56 mounting bolts. Trouble is, 5/64ʺ is a shade too small, and the next drill size, 3/32ʺ, would be way too big. So each 5/64ʺ hole had to be opened up a bit with a needle file.



All the struts line up perfectly, so it was ʺsimplyʺ a matter of mounting the required number of fittings on each strut with a 2‐56 nut and bolt. It seemed like it took darn near forever. I was going cross‐eyed by the end of it. The fittings are not scale. I simply tried to make something that looked like it could be scale.

Once the rigging is added, I think the effect will be quite convincing.. Iʹve finished rigging the right wing assembly. For rigging, I used heavy duty 100% nylon thread. It is super strong, and has a bit of stretch to it, so you can get a real nice ʺTwangʺ when itʹs all tight. I used crimps made from 1/16ʺ OD aluminium tubing, cut to about 3/32ʺ in length. After the crimps are squished down, I apply a drop of thin CA to make sure there is no slipping.

For the aileron cables, I used ʺSoftflexʺ beading wire. It is coated with some sort of plastic and runs smoothly through the guide tubes.

The wings slide off in pairs. The upper and lower halves stay permanently attached. They halves slide on to the wing rods. The lower wings are retained to the fuselage by a small bolt, and the upper wings are kept together with a small bolt on strap.



Hereʹs the airplane broken down for transport.

Hereʹs how the airplane goes together.

First, the wings are slid on to the upper joiner rods on top of the cabanes. (The lower wing rods are secured into the lower wings). Then the wing is slid on to the rods until the lower rods are close to the fuselage. Make sure the lower rods are aligned with the tube mounts in the fuse, and then continue sliding the wings on until there is just enough room to allow the servo arm to be passed through the hole in the fuse side.

An 8‐32 nylon bolt is then inserted from inside the fuselage, and it grabs hold of the wing root and pulls it tight against the fuse.

The servo arms are then placed on to the servo output shaft. The servo is then slid towards the centre of the fuselage on its sliding mount tightening the aileron cables, and then the servo mounting bolts are tightened with a 2‐56 ball driver. Then the servo arm screw is installed and tightened. Straps keep the two upper wing halves from sliding apart. To secure the straps it will simply be a matter of tightening 2, 4‐40 bolts. There are blind nuts built into the bottom of the top wings, near the wing roots. Keep in mind that the scale aileron set up is not stock. The kit as designed has a servo in each wing, so it would simply be a matter of plugging the servo leads in to some extensions. The Windsock Datafiles “Albatros C.III “publication has details on placement and markings. Available at http://www.byrdaviationbooks.com/

Battery Hatch Detail

Balancing the Model Balance the model at the point shown. It is best to position the battery to do this operation.

FLYING The model should ROG on grass, pavement or hard surfaces. The model may require coordinated turns using



both ailerons and rudder control. This is due to adverse yaw. Halving the aileron down throw may reduce this tendency. One solution is rotating the control arm of the aileron servo forward about 20 degrees.

Finished Model Here are some excerpts of Frankʹs maiden flights.

It was a beautiful evening. The wind was very light, and what little there was was up and down the runway. Air temp was about 65F (18C). I slowly advanced the throttle. I did not notice any tendency to veer left or right. I probably unconsciously added a bit of rudder, and it was enough to keep her pointed straight. By the time I had reached half throttle, she leaped into the air. I added some down trim and a click of right aileron, and then settled down to enjoy the flight.

And enjoyable it was!! This airplane is a real winner. It flies beautifully. It was absolutely rock solid and stable in the air. The controls responded very crisply. The ailerons are very effective. I have quite a bit of differential mixed in, with hardly any down movement and about 9/16ʺ up. The elevators are effective too, and they have about 9/16ʺ up and down. The rudder has as much throw as I could give it, and it seems to work well. Almost the entire flight was spent between 1/4 ‐ 1/3 throttle. I briefly experimented with 3/4 throttle and pulled the nose up, and it climbed out at about 60 degrees with no hesitation. Motocalc was bang on in its predictions. I really like the sound it makes in the air. You can hear the air rushing over the wires. After about 10 minutes of enjoyable cruising with figure eight turns and the odd fly‐by to admire her, it was time to land. I set up on final and eased the throttle back to just above idle. She was rock solid on approach, and exhibited very good slow speed flight. It just settled in and all I had to do was flare at the right moment, and that was that. It was an airplane!!!! I flew her again this morning. There was just a bit more wind today, and I was interested to see how she would handle it. There was a bit of a crosswind, and the first thing I noticed on take off was that I needed to get on the rudder hard and early to prevent weather‐vaning. Nothing horrible, and the rudder throw was easily sufficient to straighten things out. Slow speed flight is real slow! She nearly hovers in a bit of wind. The stall is predictable and when it happens it is not a surprise. It does tend to drop a wing first. But you would need to work on getting her slow enough to stall. You would certainly not be in danger of reaching that low a speed in normal flight and landing. I tried a loop today, and with all that power itʹs no surprise that loops are no problem at all. I havenʹt tried a roll. I doubt either manoeuvre was typical of the C.III ! Landings are really a sight to behold. With itʹs ability to fly at such slow speeds, it is important that the airplane be flown until it comes to a complete stop on the runway. So keeping the wings level and using the throttle are important. I did a few landings, and the last one was into the wind. Ground roll out was all of 4 ft. It seems to like to



land on the mains first and then have the tail settle afterwards. She shows no tendency to nose over at all, which is a real blessing in a WW1 model, especially with all that detail up front! I flew for about 15 minutes. I removed the battery just after landing, and it was only room temperature. “

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Documents

Albatros CIII 57 - AerodromeRC · A semi scale adaptation of the Albatros CIII , this model is designed to be easy to build and exciting to fly