Mode One

I wasn't implying "just adding detail" was a simple process. Sometimes it is and sometimes it is much more work then that.

abufletcher

My philosophy about building a kit is that the model I end up with shouldn't be just like the model that some other builder ends up with. Building isn't like putting together a puzzle where everyone ends with the same thing. People should be able to look at the model and say: "Oh, that looks like one of Don's models." Just like mountaineers relish climbing a "new route" up an already climbed peak, I like to think of somethng new I can bring to the building of kit, even if that kit is a Flair Puppeteer that has been built over 10,000 times! The aircraft we model have been modeled again and again, over and over, often for decades (and decades). Somewhere I have a photo of two WWI German soldiers proudly displaying their model of an Albatros CI. So that's almost a century of people modeling this aircraft!!! So I ask myself: "what can I bring to this model?"

Here are a few of the ideas I'm toying with for this build (in no particular order):

1. A gun turret that turns either opposite or towards the rudder
2. A standing observer figure dropping a bomb
3. Scale hinges (and whatever that might entail)
4. A functional scale exhaust
5. A working claw brake???

abufletcher

As I've been test fitting the pieces it's slowly become clear that I'll need to do some of the things usually done later almost immediately. For example, I need to do the deep cockpit detailing before I glue together the forward fuse parts. And I'll need to stain or otherwise color the side ply skins before I glue them together. And I need to put test fit the engine before I glue together the engine compartment parts to avoid having to do any unpleasant cutting later.

So I've been experimenting with water-based and oil-based stains and and lacquers. So far only a custom mixs of two of the lacquers is giving me anything like the "fine funiture" look I'm hoping for. The water-based stains don't seem much better than thin acrylic paint.

It's time also, before I begin gluing to go back and look long and hard at my references.

allanflowers

I had trouble gluing together stained wood on my Pup. The glue didn't bond properly.
I have heard that one good route is to get stains from Proctor which don't cause this problem.
That look like an amazing model.

TFF

Pre-staining with oil can lead to gluing problems so be careful.  Because the wood was covered with a varnish and the color came mostly from the oxidation of the wood over time, you might have to stain it to get your color and thin paint it with clear laquer or dope for the "thickness" of the look.  

abufletcher

I practiced doing the chamfered joints for the ply skins. The first step is to sand the inside edges of both pieces. Then, I put tape along the edge of the joint to keep the Titebond glue off the wood so that it doesn't mess up the surface.

I tried a number of stains but none of them produced a satisfactory look to the plywood. The best result came from a mixture of darkish mahogany and yellowish "zelkova tree" varnishes. This was thinned and wiped on with a sponge. Two or three applications produces a nice tone.

abufletcher

I'm thinking hard about the engine choice, which I need to make pretty much right away. I've been planning to use one of the RCV 91CD engines primarily becasue of it's low profile which will minimize the protrusion out the right side of the model. Only about an inch of the cylinder head would be sticking out. But I need to think about how the needle valve, throttle arm, glow plug, and exhaust would work out. The glow plug is on the upper right side of the cylinder, which in a side installation would be facing upwards. It might be too close to the fuse wall to get a standard glow starter on it however. But either a glow extender or the old alligator clips trick would work. Finally, there's also the question of me being in Japan and whether I can get adequate support if I have a problemm without have to ship the engine to the other side of the world.

http://www.rcvengines.com/rcv91cd.htm

Using the RCV90CD will require a minor adjustment to the mounting beams since the propshaft center line 3.6mm above (or in this case to the right of) the bottom of the mounting flange.

An alternative engine would be the Saito 91. This is after all the Land of Saito and support close at hand. On the plus side, I wouldn't have to alter the mounting beams at all and the top mounted plug would make that starting easy. But the the cylinder head would be hanging out in the breeze quite a way, which I suppose in terms of cooling is a good thing. It would definitely mess up the look of the right side much more than the 91CD.

http://www.horizonhobby.com/Products...rodID=SAIE091S


Also under consideration is a RCV90SP which would actually fit perfectly mounted directly on the F2 firewall and it could swing a scale size prop!

http://www.rcvengines.com/rcv90sp.htm


And advice, comments, or warnings are welcome!

TFF

I would try the 90cd.  Cleaner and it will give you some experience with a new engine; I have heard the CD series is pretty problem free.  Ideally, I would get the SP, but I am a glutton for punishment when it comes to engines.

abufletcher

You're probably right. The SP would be the sexy choice, the CD the safer option. Noteworthy quote from the SP instructions:

"The 2:1 gearing on the prop means that the torque reaction forces are
double that normally expected from a conventional four stroke. The most
noticeable effect of the 2:1 gearing on the operation of a model is that the
torque pulses transmitted back to the airframe are double that normally
expected, this means the tortional oscillations applied to the airframe are
greater. This in itself does not cause any problems, but it does mean that
the construction of the fuselage around the engine mount, and between
the engine mount and the wings, must be very rigid."

"Try to avoid large hatches in the fuselage in this region, ensure all
materials used are of suitable quality and always run the model with the
wings firmly attached."


Added to this are the installation challenges. Usually people mount these so that the starting driver can be attached from above. But the dummy engine makes that impossible. So then we have Allan's side mounted access. But then I start to wonder what it would be like trying to get the starter motor in from the side ahead of the wings and with drag wires in the way. This could all be done, but I feel that at the moment it beyond my abilities to do well.

So, the RCV91CD it is.

TFF

If they had the SP in the 1.60 size range, I would have to sell the farm for my planed Camel; big prop loping with the different sound exhaust would be quite convincing.  

abufletcher

Which reminds me: Cooling the SP in the enclosed nose of the CI would be yet another added engineering challenge. In a round cowl aircraft that's much more doable. It's not impossible with the CI but it might take some very clever venting. In modeling, as in life, you need to pick your battles. This one I'll leave for another CI modeler.

GianFrancesco

GianFrancesco

abufletcher

Please, please, do!

BTW, I've accepted that I don't have the modeling skills to duplicate the delicate details of your CIII but it can at least serve as inspiration for me to try harder!

vertical grimmace

My Feedback: (1)

Abu, I woul dhighly recommend an on board glow system. I use one from Nelsons hobby but there are many available now. It is so nice to be able to turn it on and not have to attach a glow driver to these 4-strokes. I have one on my 180 Saito on my DR1 and would not be without it! There is also the benefit of a very low idle and a much decreased chance of deadsticks. One thing that sucks with these scale bipes.

abufletcher

I always think about an onboard glow but I've never used one and honestly never had any problem with any of my Saito engines other than running out of gas!

Note: Enough hemming and hawing on the engine. I've ordered the RCV91CD and it should be here in a couple of days. Now I can happily get on with things.

vertical grimmace

My Feedback: (1)

Abu, I really think you would like one. I do not have too much trouble with my Saito's either, but the main point is ease and convienience of starting. It is nice to have your plane autonamous other than fuel. This is something i really like about the gas engines. Either magneto or e-ignition, just ad fuel and go.
I am very thankful you added those pics with the engines superimposed over the plans. I have to say if I build one of these I will go with the SP. that looks like a perfect fit. The cooling would be the only issue I guess.

GianFrancesco

Don't underestimate you too much ; the job that have done on the Snipe is amazing!
For the exhaust: I must select the details from theAutocad drawings and to convert them in file pdf.

abufletcher

The parts making up the engine compartment are a fine example of just how precise CNC parts can be. The two 10x10mm hardwood beams fit so perfectly into the 10x10mm holes in formers F1 and F2 that the whole unit is perfectly squared up even without being glued. Even the corners of the holes are as sharp as can be. And this is the case with all the CNC parts that make up the forward fuselage. Everything fits precisely where and how it's supposed to with micro-millimeter precision. The old-timer in me almost feels it's wrong that I don't have to "make the parts fit" through my own handiwork.

There are two things, nevertheless, to keep the old-timer in me happy. First, because of my choice of the RCV91CD I'll need to slightly relocate the beams. The RCV has an odd design where the shaft centerline is not level with the bottom of the mounting flanges as on most other engines. So the beams actually need to be "lowered" 3.6mm to ensure that the shaft is dead center. I could have just cut down the beam width but the more prudent solution seems to be the move the beams. This should be easy enough.

Second, because of the angles in the nose area, the edges on formers F1 and F2 need to be "chamfered" ("beveled") at specific angles. While this is beyond the current ability of CNC woodcutting (as well as laser cutting), Chris has provided side views of these angles on the plan views of these formers. But it's up to the builder to shape these edges.

abufletcher

Ah, Japan! Yesterday at around 11am I phoned in my order for the RCV91CD from a shop in Osaka. This morning at a little before 9am the delivery guy opens the door to my house to announce his arrival. I dash from my bed to the door only to explain to him that the deliver was so fast I haven't yet had a chance to go to the bank to get the money for the COD shipment. So he tells me he can come back in about an hour. So I throw on my clothes and dash to the local ATM and on my way back see the delivery van still in the neighborhood, honk my horn and wave him down and we do our transaction there in the road.

And here it is! Ah, Japan!

abufletcher

Here are the views of the RCV91cd.

And in the interest of disclosure, we did find a problem with the fit of former F1 around the actual engine and Chris and I are working on a solution together. This is what is involved in prototyping a kit and why kits do need to be prototyped (AZM take note). We will be working closely together as I build in order to provide a tried and tested product for other modelers. For me this is part of the fun of working on a brand new kit.

The weight of the engine (including stock muffler) and 14x6 APC prop is 886g (31.25 oz.). So with careful building maybe I won't need much weight up front.

GianFrancesco

I hope that the details about how my exhaust is made can help; I hope too that they are understandable since I have traced them for myself.
I try to explain anyway that: the shaped tube that exit from the exhaust port of the engine (Laser90)is of steel and was made in my lathe; the"line" is made with copper plumbing tubes and albows all silver solderd together; the cylinders no. 3 and 4 are cast together with thetwo partstube; the two cylinders tubes are joned by the manifold.
The 6 scale flanges at thecylindersexhaust stubsare bolted to the corrispondent flanges in the shoehorn tubes even if only two are the functional ones!
Despite a lot of doubts about the correct dimensioning of the diameter of the tubes, the engine test run showed that all was OK; the Laser swinged freely a nylon Dynathust 15x6 prop at 8200 rpm.!

abufletcher

Thanks for posting those. All Ican say is that now I'm as impressed with your engineering skills as I am with your modeling skills!

The photo belongs shows what we're shooting for with the RCV engine installation. We still need to work out a number of interrelated issues but the relatively low profile of the RCV encourages us to keep trying. BTW, this photo itself is a wonderful illustration of the collaboration between Chris and me. He asked if I might make some 3-view photos of the engine. I did and he overlayed them onto his drawings and sent them back to me so I can use them to further experiment with a "hands-on" solution. Any mods I make to F1 will then be scanned and sent to Chris as a guide for the redesign of this part.

abufletcher

Took the engine to the field for it's first test run. It started easily and seem to run well, but 10 minutes into the first run (at fast idle) I started to hear a high chirping noise (particularly as I thottled down). This doesn't bode well.

Mein Duff

I totaly concur with your "scale philosophy" whole heartedly, for me it is ultimate in model flying and building. There is nothing more sublime and satisfying than seeing a well built replica with convincing weathering effects ( if there are any) flown in a realistic flight envelope and presented convincingly. One really has a hard time believing that it's not there real thing in the air. I have had the pleasure of working on the flight lines of the world F4C champs. Experiencing these incredible creations up close in the air is the ultimate rush ( well besides actually flying the real thing I suppose). Looking forward to seeing how your project develops and "hat's off to you!"  It's the spirit of scale building and dedication that makes this modelling niche the most fascinating. Now that we have extremely reliable engines and electronics and support forums like this, it can only get better....all we need is time and dedication to that special project to be sucessfull ...keep em comin Jungs!

abufletcher

Ja wohl, wir schaffen es schon!