Albatros C.I from 3seabees - RC Groups
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Apr 25, 2017, 11:39 AM
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GringoTuerto's Avatar
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Albatros C.I from 3seabees


Hi all, I thought I would share some of the latest project, FYI. I bought a 3seabees Albatros C.I last fall, and am just getting around to completing it (1/5 scale, 102” span). The plane comes very fully assembled, covered and with linkages installed. But it is still taking me a huge amount of time to finish it, mainly because I had the stupid idea of animating the observer/gunner, so that a second person with a second transmitter could control something (no flying skill needed….I could hand it to any visitor at our field, including children).

The turret/gun can move in both directions (i.e. rotation and elevation). The elevation is controlled by the gunner standing, which is how the original gunners fought (i.e., it would make no sense to have the gun pointing down with the observer still seated, because he would be significantly out of line with the gun). There is a sound system from Model Sounds Inc, and a high-power orange LED on the tip of the parabellum, synced to the gun sound.

A fourth channel controlled by the non-pilot-transmitter will control a bomb rack (still TBD how and where I will put that).

But this rotating observer’s seat sits squarely on the path between the servos and the empennage, so I have to re-route the elevator and rudder linkages. Still in progress.

I have a Hacker C50-14XL geared inrunner, which I will run on 10S x 5000mAh. Mounting this in the pointy nose will be a challenge. It does fit, but there is no room for a typical “X” motor mount on the front.

The vertical stab/rudder is relatively small, so it may be a little squirrely in the air. I could not easily add aileron differential because the ailerons have a complete closed-loop pull-pull system including both ailerons. So…will need to turn with rudder to prevent adverse yaw.

It will be a fun plane to have at the field, and be able to involve visitors with no flying experience. The wood finish is nice and the plane looks great. Unfortunately, 3seabees is effectively out of business, although they are still selling off some inventory.
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Apr 26, 2017, 10:37 AM
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Very nice project! I too have a 3SeaBees Bristol Brisfit that I need to get together. It has a rear gunner position also so I am very interested in what you are doing with yours.
May 01, 2017, 02:35 PM
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GringoTuerto's Avatar
Quote:
Originally Posted by spitfire1999
Very nice project! I too have a 3SeaBees Bristol Brisfit that I need to get together. It has a rear gunner position also so I am very interested in what you are doing with yours.
Well, I do have some advice about “animated rear gunner” after having done this.

1. I chose to mount the entire assembly on a servo. Picture for example a drink cup with a hole in the center bottom, and the servo shaft screw fits through that hole. I used a large 4-arm servo arm to secure to the bottom of the “cup.” So the whole cup rotates with the servo. I made sides of the cup slightly smaller than the hole in the fuse, so that it does not touch the fuse. Well, the disadvantage of this (in retrospect) is that any bump experienced by the fuselage exerts quite a bit of torque on that single point (the screw into the servo drive shaft). It is TBD if this will cause any servo problem. But even if it doesn’t, the whole cup vibrates around when I move the fuse, which looks a bit funny.

I plan to counteract this with some side springs…it is easier to take a picture than to try to describe. I will post when I get there.

It might be better to have the top of the “cup” hanging from the top of the fuse, rather than sitting on the bottom. Picture a lazy-susan type ball bearing ring, empty in the center. For example, here is a 12-in one which is way too big, but just to give the idea:

https://www.amazon.com/Heavy-Duty-Al...GJT/ref=sr_1_6

I looked for a while for this, but didn’t find anything that was light enough and the right size. I would recommend this method, if you can find or make a suitable ball bearing ring.

2. If you choose to mount the whole thing on top of a servo like I did, then note that you need to get the servo mounted directly in the center of the cockpit hole and perfectly flat with the top of the fuse. My points of advice here:

A. Measure along the floor of the fuse, to get your center point. For example, check where the cockpit hole (on top of the fuse) starts relative to some bulkhead; then measure this same distance from this same bulkhead along the bottom of the fuse. Do NOT attempt to use a perfectly vertical line down from the rim of the hole on the top of the fuse down to the bottom of the fuse. You will never get it perfectly vertical, and millimeters matter here.

B. If the floor of the fuse is not parallel to the top fo the fuse, then you have to angle the servo. For this, I propped the entire fuse so that the cockpit top was level (using a level). Then I measured the from the bottom of the fuse to the table surface (which was level also), at the start and end of the cockpit, points about 6 inches apart. Now I had a good indication of the floor slope. I ended up using the arc-tangent of this to set my table saw (which has an accurate angle gauge). But equally, you could just take a 6-in or wider board and replicate the same triangle on it, and cut across the board to establish the rail angle. It is important to use a wide board, so that your measures are accurate. In other words, it is inaccurate to measure an small angle with two closely-spaced points. You need two measures spaced by 6 inches or more to get a good read on the angle.

(And this is a little subtle, but note that when you take the measures in (A), you have to scale them to correct for the angle (B)).

I’ll post more photos shortly. I am working on this plane at least a day every weekend, so although it is slow going, it shouldn’t languish indefinitely
Jun 24, 2017, 04:58 PM
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GringoTuerto's Avatar
Got the wings on this finally. It is huge! 103 inches.
Jun 24, 2017, 05:51 PM
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Nice! Can't wait to hear a flight report.
Aug 11, 2017, 12:42 PM
Canvas Falcons Forever
Stachel's Avatar
Looking forward to seeing it fly! Saw this on Youtube, these are 1/6 models by David Boddington.
https://youtu.be/iC9zSQdke2A?list=PL...d23YE2TdIvgmCd
Aug 11, 2017, 03:57 PM
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GringoTuerto's Avatar
I did fly it a couple weeks ago, but posted the pics in a different thread:

https://www.rcgroups.com/forums/show...ostcount=16032

I have collected some video, and intend to edit it into a watchable video when I have some time.

Also, shortly before my maiden flight, I found this video on a defunct forum in Spain, and I think this is the same model. See video in 5th message down in this thread:

http://www.rcmodelistas.es/foro/aero...15-t56-75.html
Sep 21, 2017, 11:50 AM
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GringoTuerto's Avatar
I finally did put a video up on Youtube. I posted it in another thread, but here is the link to that thread:

https://www.rcgroups.com/forums/show...ostcount=16225
Sep 21, 2017, 02:04 PM
Registered User
Great Video! Thank you for posting and congratulations on an excellent job! 3SeaBees/K&W models can definitely be a handful.


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