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It is nice to be free to make whatever changes I want, which is certainly in keeping with the concept of a scale-accurate kit. In this case, the dummy clevises are simply additions to the kit, not really changes - other than making a tighter loop in the music wire. Here's a "how-to" pix.
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Allan, thanks for the visual tutorial! ((BTW, I love the look of your computer sketches.)). The thing about the Snipe is that my building skills have grown tremendously DURING the build and so has my sense of scale fidelity. I just wouldn't have thought about making a change at that stage in the game. But after all the other "scale additions" (not really "mods" I've done, this seems almost obvious in retrospect.
I did something similar on the bracing wires on the Snipe's tail. I'm already thinking about how I can do scale turnbuckles on the Albatros CI!
< Message edited by abufletcher -- 2/22/2008 7:24:00 PM >
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Abu, glad you liked it. I have a Wacom Cintique tablet monitor and can draw right on the screen (in Photoshop or any paint program). I do a pen sketch, scan it and then work over it in Photoshop.
Today I started on the wood cabane struts which sleeve over the wires. Since the subject Pup I am modeling has nice stained wood cabanes, I elected not to use the kit provided parts for this. It was easy enough to rip some pine to size with a groove for the wires. Then I cut them to rough side view and work them until the side views look good. In terms of clearances, the front hatch had no problem but the rear one interfered. Bevels on the insides of the rear struts gave enough clearance and the side views were not affected. My little boat shackles came in last night. They are a bit big, especially on the tail horns but are probably still usable. I will have to remake the rudder horn (maybe the elevator horns too) because the shackle's bolt needs a bigger hole than I can accommodate with the provided horn.
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The wood cabane struts have been shaped and stained one coat. I use the beveling method on things like this to maintain consistency and control over the forms. In the first pix, the bottom row has the primary bevels, the next row up has secondary bevels and the third row up has been sanded to a smooth airfoil cross section. Then they were put together temporarily with transfer tape* for final sanding and staining. It will take another coat to match the rear hatch color.
(* I call it 'snot' tape because it leaves a rubber cement-like film when you pull off the backing. This stuff is great for holding ribs and things like that together while you shape the stack)
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Allan, please get someone who knows more about volts and current flow than I do to explain how increased current flow in a 6 volt pack results in higher voltage drop. Maybe there's a place here on RCU where such a question can be answered by an electronic wizzard which I am not. I have had it explained to me but not being educated in the basics I cannot relate it properly to you. The way I understand it the advantages of a 6 volt pack are higher speed and torque, not longevity. Your faux clevisis and turnbuckles look great, the build is comiing along really well. Happy landings, Doc.
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Thanks, geezeraviation. I understand now about the battery pack.
After a second coat of stain, the wood cabane strut covers were ready. They came out very good and fit well, with no clearance problems to the hatches.
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Onto the landing gear. This kit has very nice drawings, including a useful "true length" view of the struts - which helps a lot in finessing the bends to match the drawings. I also set up a few blocks on the drawing to better visualize the angles and see where I needed to trim and/or adjust them before assembly.
The fuselage itself makes the best fixture for soldering and I started with the front and rear strut parts, making sure to slide on the acid etched brass fittings for flying wire attachment before soldering the strut parts together. Then I soldered the brass fittings in place (off the fuselage) and attached the little brass fittings on the fuselage for the diagonal bracing. I deviated slightly from the kit with the rear flying wire brackets because my subject Pup has dual wires both front and rear (the kit has single wires at the rear). Fortunately, the acid etch sheet has some extra fittings (probably provided for use on their Snipe model) that I could rework to use for these.
The last step for the day was to fabricate the axle guides out of 1.5mm wire. Fine copper wire was used to preassemble them for soldering.
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Worked on the axle unit today after first I taking a ride to the San Diego Aerospace Museum to take a closer look at their Pup replica's axle, along with a few other details.
I wanted a design in which the axles can be replaced down the line if necessary. The center bracket locates the two outside rods and a tab for a center brace wire's clevis. I will have to think of a way to retain the pivot pins, probably a 0-80 bolt.
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More work on the axle unit today, interrupted by electricians working in the house. I won't be able to make the bungee pins like I thought - they should be farther apart and upward from my original plan. I will have to add some little stub pieces to the primary spreader bar structure for that purpose. Today I built the swing axles and the little fittings thereon. I had misdrilled my wheels and they were wobbly so I had to redrill them and install little brass sleeve bushings in them (not really necessary except for my now-too-big holes). I will have to add the stub pins to the axle structure, then solder that unit into the landing gear struts, then add more little brass plates to cap off the stub ends and keep the bungee in place. Maybe I will start the wood parts before soldering the axle in. It would be easier to work the wood that way.
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For reference, here are some pictures of the RAAF Pup's landing gear. The white plane is the current version and the brown plane is before it was redone into the white scheme. The last shot (in gray) is the San Diego Aerospace Museum's Pup, which is a good general reference.
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The exhaust stuff arrived from England today. Chris had a good recommendation for a German company but this is from a place recommended by Abufletcher. A great thing about these newsgroups is one can not only get a source for parts, but multiple sources. They provided an adapter to transition from my Saito threads on the engine and manifold (a modified Saito pipe) to OS threads for the bendy pipe and muffler. It is a bit too long but I can live with it. I have already ground down the adapter a couple of millimeters on each end. There is enough room for a battery box for my five cell pack (2 over 3) in the space above the engine. I will need a couple of clips or something to retain everything (and lose the bailing wire). Before I solder the axle assembly to the landing gear struts, I will make and prefit the wood covers. After ripping the blanks and making grooves along one edge, I have to fit these around the wires - which is rather complicated. It seems to work best when the complicated end is sliced off and dealt with separately. Two struts are now done, fitted and beveled to approximate the airfoil sections. There will be a lot of shaping still to do after epoxying these on. The spreader bar airfoil shape will be easy compared to these.
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All Forums >> RC Airplanes >> RC Scale Aircraft >> RE: CD Scaledesigns Pup build 
RE: CD Scaledesigns Pup build - 
I've done, this seems almost obvious in retrospect. 
