CTDavies

Today I want to show you a bit how our Albatros C.I kit is being developed. The drawings are pretty much complete now and we (that's Abufletcher, Frank Sopwith and me) are throwing some ideas around and testing some components. Abu will build the prototype model, like he did so wonderfully on our Snipe (and you've probably all seen his excellent [link=http://www.rcuniverse.com/forum/m_6738262/tm.htm]scratch built propeller[/link]), Frank is again the CAD Operator extrodinaire, Flight Line Engineer, and Test Pilot all in one and I'm the one bossing everyone around
The unique thing about many german WW-1 aeroplanes is the box like wooden fuselage built up around formers and sheeted with plywood. The Albatros C.I is no different. It was developed from the popular B.I and used throughout the war as a reconnaissance, bomber and training aeroplane. It was very popular and built in large numbers.
We're trying to incorporate a scale fuselage structure as Abu wants to detail his cockpits later, and I'm sure many others will want go this way as well.

CTDavies

So far I only know about one Albatros C.I flying model kit and that was done by David Boddington's Sport And Scale company back in the late seventies early eighties. I believe it is still available.
As mentioned earlier we want to do ours with scale fuselage structure so the super detailers amongst you all have a good basis to work from. This is where our problems start. We've seen many good scale models with ply fuselages, but they were built around a stick framed fuse box which I don't like because, the ply sheeting needs to be part of the structure as opposed to building 'a structure over a structure'. Not an easy task. Here's what I've come up with. I was going to email the following images to Abu but thought I could just as well show them to you all, and at the same time start a mini thread about designing/constructing scale german biplane. This won't be a fully fledged online build but more a losely done, occasionally updated thread just to show you the ideas we've come up with.
But back to the fuselage: I made a lot of fuselage formers as the were on the full size, keeping dimensions to a minimum to keep them as scale as possible. The basic fuselage structure was built up using two parallel rails that run along the lower front fuse. You can see that everything includes notches for interlocking parts that makes construction so much easier.

CTDavies

We want to use an [link=http://www.rcvengines.com/rcv91cd.htm]RCV .91 four stroke[/link] engine on this one mounted on its side. The cylinder head is quite short and after a lot of discussing and head scratching we decided to try it this way. The width of the fuselage increases much quicker than the height does, so we think a small portion of the cylinder head poking out of the side would be less conspicuous than a larger portion trying to act as a front Mercedes cylinder. So that little piece of structure you can see in the middle picture in my previous post is the engine bearer assembly, specially designed for the RCV. 91. With the plans and kit specially designed for this engine, this of course limits the choice for all modellers, so it would be nice to hear some comments here.
Now the basic structure is done I can add the fuselage floor and sides. The sides will be made of 0.8mm (1/32" ) ply with 1.5 (1/16" ) doublers, the floor probably 0.8mm ply. A fuselage building jig will obviously be essential here as the loads induced on the frail structure need to be evenly distributed to prevent twisting or even breakage. More later.

CTDavies

Designing a kit in a computer only reveals so much. It is very important to actually hold a sample of the major components in your hands to get of feel of how everything is turning out. This fuse structure is built using 1/8" birch ply only and weighs just under 500 gramms, which is about 17 ounces. Our target weight will be 7kg which is 15.4lbs for a 82" wing span model, so we don't want to go crazy adding unnecessary weight so early on, so I'll definately be adding lightening holes in some places, and I might even change the birch ply cockpit floors to lite ply ones, although birch ply has a much smoother surface.

abufletcher

Am I dreaming? After all the discussion, it almost seems weird to see the actual pieces sitting there on my screen! It sure looks impressive and looks to be another classic CD design! And as they say, "well begun is half done."

Guess I'll need to finish up the Snipe so I can get on with this one!

CTDavies

Good morning Abu, glad you like it. Feel free to add comments, remarks and critisisms of all sorts, although you should know it by now
Thanks to forum member Stan Borkowski a canadian from Poland I can add some cockpit shots from the B.II and C.I survivors in the Krakau Museum, Poland.

abufletcher

I guess this is all I can contribute at the moment. []

spad

Watching with (great) interest - that machine has such character[8D]

keep it coming

Rick

caribefoto

My Feedback: (2)

Sorta like an old vaudeville strip tease routine, now she's fiddling with the snap on her bra. Can't wait to see what's next! (dirty old man metaphor)

abufletcher

You know, Chris, I think your designs get more and more sophisticated with each new kit! Obviously, designing those serious 2- and 4-engine WWI models has rubbed off on your WWI designs. I think you're on your way to a whole new level of "sport scale" with this kit. I can hardly wait to start building!

CrateCruncher

My Feedback: (1)

I love this airplane and I like this scale for a big two-seat reconnaissance craft. Have you considered the RCV-90SP with in-line horizontal cylinder? It might solve the engine fit problem. Either way I might suggest a more conventional firewall/engine mount design allowing the most flexibility for the power unit. It seems everyone I know convert the kits that have maple rails piercing the firewall. I'll be watching and anticipating your updates.
Mike.

abufletcher

I think getting sufficient airflow over the RCV-90SP would be a problem on the Albatros. Plus the odd way of starting those engines (like starting a heli) would be a hassle on a scale model. I do agree, however, that it would be wise to build in some flexibility in terms of engine choice. In the end through, there really isn't any perfect solution so it'll be a matter of different folks preferring different (4-)strokes. I personally like the side-mounted and originally suggested this to Chris. That way we get at least one clean side view -- and a full dummy engine. No one looks at the right side of a model anyway, right?

R101

You could always go electric ?

abufletcher

Gorgeous model R101! Can you tell us a bit more about it? Chris suggested electric almost a year ago when we first started talking about it but I convinced him to start off with a messy, noisy, glow version first. I'd be curious to know, however, what it would cost to go electric on a model this size. For someone who doesn't have anything for electric what would be the cost for a motor, controller, lipos, lipo-compatible charger, etc.

R101

OK - here is what I used in my C1, but as there is such a wide choice for electric power these days, prices vary quite a lot.

Axi 5320/34, Hacker 75 opto ESC, 18x7 APCe prop, 8S LiPo

Power is more than enough and a short, poor quality (sorry), video can be seen here -
http://www.youtube.com/watch?v=sET9n1zpKHM

abufletcher

Hmm...18 inch prop, you say? That sounds good. [sm=omg_smile.gif] But then a quick price check for the components you list put it well over $500 and I'd still need a proper charger for the Lipos. I think I'm going to have to stick with IC engines until price compells me to go electric.

What are the stats on your model. Is this the Bonnington design or a scratch-build? One-sixth scale always looks so huge in the shop and so small at the field! But it's come to be my preferred scale.

R101

yep

FlyerInOKC

My Feedback: (6)

How much is this kit going to cost?

FlyerInOKC

My Feedback: (6)

In dollars or Euros

CTDavies

We don't know yet, FlyerInOKC, as we haven't even done a wood count yet .
But on with the show. Here is the latest development: probably doesn't look much different to most of you than what I previously posted, but actually we have completely redesigned the whole fuselage. Initially we wanted to skin the fuselage with 1.5mm (1/16) ply wood but after playing around with our mockup we realized that that is way too stiff and heavy, so we're shooting for 0.8mm (1/32) now, which meant we had to rework each and every former plus cockpit floors etc. Hope I don't have to do that again in the near future. Also we moved the two rails further inwards and changed the engine bearing module.

CTDavies

The engine bearers now include two large 1.5mm plywood flanges to reduce vibrations as our RCV .90 will be mounzted sideways. You can also see that we have included lightening holes on the two large rails as well as on some of the formers.
The cockpit floors are 3mm (1/8) ply sheets, which I'm not too pleased with as they are fairly heavy, but the surface is really smooth, but I'm thinking of using lite ply skinned with 0.4mm (1/64) ply sheets instead to keep the weight down.

CTDavies

Also at this stage we were able to test fit the elevator and rudder servos which will be mounted ahead of the cockpit infront of the rudder bar area. You can tell by the pictures here that nothing has been glued yet.

CTDavies

Tonight I also did the skin around the turret out of 0.8mm ply just to see if the notches in the formers are at the correct location. The formers are now closed at the top but need to be opened once the ply sheeting has been applied. If you look carefully you can also see the notches for the pilots cockpit cutout in the previous pictures. I'm planning on using an 8oz tank for this one, but must admit I haven't even checked the manual yet to see what the engine manufacturer recommends. As I mentioned earlier, inpite of having a large boxy fuselage the available space for the radio equipment etc is surprisingly limited. This goes along nicely with Allan's rant on model airplane tanks over at his Pup thread, as I have been using these Slec tanks for nearly 20 years now, and I have, as they say, never looked back .
Look at the tabs under the fuselage rails. You can see by the groove at their roots that they can easily be snapped away once the fuselage has been built later, but having them in place greatly improves handling the model while it is being built. The interlocking parts eliminate the need to build the model over the plans, once the first former is glued to one of the rails at a right angle, everything else is self aligning.
Next I want to get an RCV engine to check the exhaust routing etc. and in the mean time I'll start the rear fuselage with the empenage an tail skid.

TFF

Will you make the firewall universal or are you going to make it only side mount? From the pictures it looks very well thought out in the design, and i can just about see it chugging around the sky. I like it.

abufletcher

Already, I'm licking my lips in anticipation! How is the construction of the rear of the fuse going to work out?