The paper cowl over the motor (above left) is held on by Ambroid, so after the first flight and a broken prop shaft, Stew was able to release it with acetone and replace the shaft. Now a prop saver is used. Comet Fleet showing motor installation (above center). The Sig hinge tabs on the ends of the struts are a friction fit into slots allowing the model to be assembled for fit checks. Motor and battery installation (above right) on a Comet Dime Scale Fokker D-7. Note the
prop saver on the 1mm shaft of the J-3 motor. Overall view of the Comet Dime Scale Fokker D-7 (below left). The closed hatch hides the battery. This flew much better with a radio to control the motor to run at less than full bore. Sig hinge (below center) showing the furry outer ply that can be removed. The ends of the struts (below right) are slit, a strip of Sig hinge is cyanoed in, then the end of the strut is trimmed and the hinge is trimmed into a tab.
square of velocity. So as long as you go slow, you don’t need much servo power. A few years ago, I built a Dime scale Comet fleet for rubber power with a Ceto radio and small magnetic actuator in the rudder. This was plenty enough for me to do figure 8s. Unfortunately the duration was such that I could only get one in before it sagged to the floor.
I pulled out the radio and flew it as a rub- ber freeflight. It was much happier that way. I was tempted to do it again with a Va- por system. This time I went with the wing covered on both sides and a few extra gus- sets. It turned out to be nose heavy and I had to move the receiver back one bay. It flies fine, but still not as slowly as I would like. The wing has a small chord so the area is low. A Dimer with a lower aspect ratio could be built for nearly the same weight and a lot more area.
I like the new Dimers coming from David Colllins and SkyLake
http://www.skylake
models.com/. I have built the Nieuport N-11 and Sopwith Pup, two of my all time fa- vorites, for rubber power. Needless to say they would be great as micro R/Cs. Not much needs to be changed. You do need ac- cess to the radio and battery and everything needs to be as far forward as possible. The easiest way to do this is to use a re- movable tray that has the receiver, battery and motor mounted on it. Paul Bradley has this system nicely worked out. Rare earth magnets allow you to mount it and attach to the control linkage. It would be easier to build the model with the mods for R/C to be- gin with rather than trying to retro fit it. The rubber opening on the N-11 is only 3⁄4 inch square. It needs to be full fuselage width for the tray and the magnets need to
FLYING MODELS
be moved to the cheek cowls. Enlarging the design to an 18-inch span and going to a P- 51 motor would make the job a lot easier. Converting the Pup is a bit more challeng- ing as the cowl was built integral to the front of the fuselage, but not a problem if done from scratch with a completely separate cowl like the N-11. In this case we don’t need to have the motor in the top half as we don’t have an exposed dummy motor. The receiver can be attached to the top of the fuselage. The motor on the right side and battery on the left of a slide attached to the cowl. This gets all the mass pretty far forward. The tricky part is hooking up the control linkage to the servos. It’s a bit like building a ship in a bottle. This is best done before the bottom is covered and the U/C attached. Well if you are building a biplane you are
going to have some struts. I have found Sig hinge tabs are a great solution for strut ends. Older Sig hinge material was 0.015 thick; that available now is 0.018. That’s getting to be a bit too thick for 1⁄16 struts, but that’s what I used on the Pup and N-11. Subsequently I have found I can peal off the furry outer plys to reveal a 0.010 core that is just right. A razor saw has a kerf 0.010 wide. This material is especially valu- able in reenforcing “Vee” joints. The strengthened end can be drilled to accept rigging or a pin for a cross piece like an axle or “W” strut.
I use cyano on the strut end and Ambroid where the strut plugs into a slot made with a #11 blade in the structure. That way I can remove them when the need arises. The core hinge material is perforated and takes glue well even without the furry outer plys. If you need to allow for length adjustment in a lift strut, the tab at the wing end should have
the tab run perpendicular to the tab at the other end. Since the slot in the wing is now parallel with the long axis of the strut, a slightly longer slot will allow for adjust- ment. You can use strips of Sig hinge 1⁄16 wide for hinging the tail feathers, but I pre- fer to use strips of floppy disk material which is a little less stiff.
Of course if you build a profile model the control linkage problems go away. I have done this with my Depron® Ebenezers, but it can be done with balsa and tissue as well. I have lost the name of the guy who took a Paul Bradley Profile S.E.5 and converted it to R/C, but it’s a neat job. Note that’s a 6mm motor (from a Vapor I rather imagine) not a 8.5mm P-51 motor. I found my Depron® Nieuportenezer, about this size and weight, was much happier with J-3 than a P-51 mo- tor. I also found I needed to use a prop saver, not to save the prop but to save or repair the 1mm shaft on these 6mm PKZ motors.
A profile S.E.5 from
http://www.parmodels.com Converted to R/C the receiver and battery are on the other side.
39
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68