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Old Mar 10, 2013, 12:04 PM
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BBCC3 - Easy Built Models Ryan ST 20" - KnifeEdge51

Alright, it's about time I got this going! Progress may be slow, as I have a LOT on my plate right now, and will be movin in mid-May once I'm married (woohoo!). But I'm excited to get started!

The plan is to convert an Easy Built Ryan ST into a 4-channel micro-R/C plane. I'll be using the guts from an E-Flite UMX Beast 3D for control, and either a 2200kv or a 3000kv Park180 for power. Covering will be doped tissue, and I'm fairly certain I why color scheme to use, but not 100% sure just yet.

Seeing as how it's been about 8 years since I've done any real building, I'll likely be re-learning a few skills along the way, and asking many questions. I've never done a conversion before, let alone one of this size! But I'm sure it's gonna be a blast, and I'm really looking forward to it!

EDIT: Well not much got done in BBCC2, so I'm having another go with BBCC3. Let's see if I get anywhere this time!
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Old Mar 10, 2013, 01:39 PM
UMs & parkflyers... for now.
davidterrell80's Avatar
United States, VA, Herndon
Joined Apr 2012
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Subscribed. I had to look up the "Ryan ST." What a pretty plane.
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Old Mar 10, 2013, 06:14 PM
Proto morlock
Australia, QLD, Brisbane
Joined Mar 2008
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Sent me to google as well - nice. Proportions look good, too.

Don't be shy with pictures...
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Old Mar 10, 2013, 08:08 PM
Heads up...
RMCCOR7737's Avatar
United States, VA, Stafford
Joined Jun 2009
744 Posts
OK, now I had to google it. Here....
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Old Mar 11, 2013, 05:59 PM
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central AZ
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Alrighty. No build progress yet, but I've looked the plans over a few times. I obviously need to hinge the tail feathers, which'll be easy enough to modify them for. However, I've never build a balsa R/C model, just lots f balsa FF models. So I'm not 100% how I want to hinge the control surfaces. The two methods I'm most familiar with are either threaded hinges, or CA hinges. I'm guessing a CA hinge would be pretty easy, if I can get the slots cut straight, but where does one purchase CA hinge material? And I'm guessing you just slide it into the slot and hit it with some CA, correct?

Also, cutting ailerons will be a new experience for me, so I need to do a little reading up on that, too. The fuse should be fairly straight forward, aside from using some 1/64" or 1/32" ply as a firewall to mount the motor to, and making the cockpit decking into a removable hatch to access the battery and receiver.

Any input on any of that, feel free to comment. I've never done a conversion before, so airframe changes are all Greek to me. Looking forward to the challenges it'll present, though!
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Old Mar 11, 2013, 06:49 PM
UMs & parkflyers... for now.
davidterrell80's Avatar
United States, VA, Herndon
Joined Apr 2012
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You're right on about the CA hinges. You can also consider taped hinges. I've used the Purple Label Scotch Gift Tape and clear packing tape to good advantage, and I've used one of the surgical tapes, Blenderm, on a larger, faster model.

For small planes, I've normally used strip ailerons, driven by a single servo. The UM T-28 is a good example of such a build. Driving the ailerons out at the wingtips is possible with a torque rod--I've done it--but, getting the rod aligned after the wing was built was not easy. If I was doing it again, I might consider a aileron that functioned like a individual split flap. I've also thought about splitting the elevator into halves and driving them separately, as elevons.
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Old Mar 12, 2013, 04:43 AM
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Norfolk, England
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You might find conventional CA hinge material a bit stiff at this size, unless you use very narrow strips, but scuffed up floppy disc material works well - if you can still find some. Some sweet wrappings work well too. As long as it's flexible, can be glued and doesn't fatigue easily, pretty much anything will do. I've used the clear wrap from cigarette packets on very small models - thin, vitually invisible, VERY flexible and cheap. Just remember to hinge AFTER you've doped the surfaces. Thin plastic and dope is not a match made in heaven.

Pete
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Old Mar 13, 2013, 10:53 AM
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All good input, gentlemen. Thanks!

I'm going to use one micro servo per wing and drive each aileron individually, as most UM aircraft do. Otherwise I'd have to make a complex bell crank system and find a way to squeeze it into the already thin fuselage. Just need to figure out how to cut the ailerons out first. Should I cut all the ribs before gluing them in? Should I build the wing first, then cut them out and cap the ribs at the cuts with some 1/32" sheet?

As for hinge materials, some excellent ideas, Peter! I'm thinking grocery bag material may also work. Perhaps I'll build a few test tail feathers and try various materials to see how each works, and pick the best one for me.
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Old Mar 13, 2013, 01:00 PM
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central AZ
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I work part time in the mornings and do full time school in the evenings (25 hours a week in class, but not a ton of homework since it's a trade school). However, my back got messed up some in a pretty rough bike wreck a number of years ago, and it's been KILLING me the past week. So I called out today. No way I would have been able to do what needed to be done. I'm hoping my rest today helps relax things so I can hit work again tomorrow. We'll see what class does to me!

BUT, the good news is that I got started today! Super simple stuff, just the vertical stabilizer framed, and got the wood pieces for the rudder cut. The nice thing about this plan is that the tail feathers are designed to be hinged from the start, to aid in trimming the model in "FF mode." So I didn't have to bother with splitting them (not that doing so is difficult). I'm a touch rusty after a 4 year break from any balsa work, but she came out alright.

The fuse and wings will take a bit more thinking, in order to lay things out right inside during setup. I'll have to modify the fuse to take the motor and a battery/radio access hatch (disguised as the cockpit), but that should otherwise be straightforward. I also think I'll add a few more ribs to strengthen the wing. I MAY try to make the wing removable for transportation and storage purposes, but we'll see. That would mean quite a few more fuse mods, which I've never done before. I'll give it some thought.

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Old Mar 25, 2013, 02:58 PM
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United States, TN, Memphis
Joined Dec 2012
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There's always more balsa......and X-acto's....and CA.....and, and, and.......
I've made more scrap than airplane lately........

I'm putting the finishing touches on my entry into BBCC-2......I don't have a job, and I left school in 1974.....retired in 2010.....

Good luck with your build...I'll be watching with great interest.....

Hope you feel better

Keep your nose up in the turns

O_P
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Old Mar 25, 2013, 03:02 PM
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Hinges

Scotch Permanent Double Stick Tape works pretty good to for over/under hinges.

and if you cover over them.....they don't come loose.
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Old Mar 26, 2013, 01:37 PM
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China, Guangdong, Shenzhen
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The Ryan ST is a real beauty of a plane. good luck with this build.
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Old Mar 28, 2013, 09:18 AM
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Thanks! I think she's a real looker as well.

No progress as of late, though. Wedding plans, work, and school have been busy. The wedding's in 7 weeks, so once that's over, that side of things will calm down.

I need to get some foam meat trays from the store or something, though. The horizontal stabilizer is shown on the plans in two parts, each joined straight to the fuse. I want it to be one piece, so I don't have to bother with double the alignment issues or a lack of strength in that area. So the balsa bits the print wood shows won't work. As such, I'm going to cut a foam template, coat the edge with some candle wax or bar soap, and laminate the stabilizer. Might even do the wingtips, too, but I need to check them over again.
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Old Mar 28, 2013, 07:59 PM
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Norfolk, England
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Laminated tail outlines are definitely the way to go. Less wood, lighter and much stronger that those typical kit tails. Less inclined to warp as the covering shrinks too.

Pete
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Old Mar 28, 2013, 08:10 PM
Heads up...
RMCCOR7737's Avatar
United States, VA, Stafford
Joined Jun 2009
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Do you have any Dollar Tree stores where your at? I got a sheet of foam board there 24x36 for $1.00. My first attempts, ever, at laminating...
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