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Old Jul 12, 2004, 04:29 PM
Trying to defy gravity...
jimsky's Avatar
USA, NY, East Northport
Joined Dec 2003
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Those plan do have "ruler markings" on them. I downloaded and printed them. I got a printer error, "original is sized larger than sheet". I over rode the error, (they are multiple sheets, with redundancy on each sheet) and printed them. When I check the six inch scale size, it was perfect...6 inches. Worked for me.

Jimsky
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Old Jul 13, 2004, 11:43 AM
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Joined Jul 2004
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Carbon Rod

Jimsky,

Thanks for the info on printing scaled plans. I realized I had to load the files in Photoshop and print instead of just printing from the browser. Once they were being printed in Photoshop, I got the oversize message, but they printed out at full scall.

I do have another question, being new at foam building. Someone talked about installing a carbon rod wing spar to stiffen up the wing. This was not in the plans. What diameter and length should be used. Were can I purchase a carbon rod? I heard someone suggest purchasing an arrow shift, but that would be bigger in diameter than the wing material. Should the rod go through the fuselage, wing tip to wing tip, and not be cut?
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Old Jul 13, 2004, 12:03 PM
Trying to defy gravity...
jimsky's Avatar
USA, NY, East Northport
Joined Dec 2003
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The carbon wing spar is shown in the photo in the original thread, as well as my photos. I've purchased my carbon rods at:

http://www.airdyn.com/

I think an arrow shaft is over kill, size and weight wise. I just used a carbon rod I had, I didn't measure it, I'd guess it was like 0.080" or some thing close. I ran a single rod, just about from wing tip to wing tip. I installed it after the build was complete, I just pushed it through the Universal Fuselage. I used hot glue at the wing tips, mid way and at where the rod punctured the fuse to hold it in place. Pretty stiff wing, minimal weight.

Jimsky
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Old Jul 14, 2004, 09:10 PM
gpw
“There’s no place like Foam”
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United States, LA, New Orleans
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even a Bamboo skewer will work as a spar ...long one 12" +
Lucky... it is pretty clean so the DD should work fine , you really need to ask Gbond about that since he's got so much more experience and knowledge....
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Last edited by gpw; Jul 14, 2004 at 09:13 PM.
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Old Jul 15, 2004, 07:55 PM
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Joined Jul 2004
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Foam Beginner

I have cut all of the pieces out of Bluecor. Do I remove the plastic sheeting on each side of the Bluecor? I have read some of the other threads, and they talk about removing the thin sheeting from each side. Is removing the plastic a good thing? One would think the plasic gives the foam additional support, but would make it hard to paint.
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Old Jul 15, 2004, 08:23 PM
Crash Master
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Indianapolis, IN
Joined Sep 2001
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You are correct, leave it on. I gives at least double the strength of the foam with the film removed.

I do usually take the time to sand the edges a little round, and seal them with some polycrylic...
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Old Jul 15, 2004, 08:42 PM
gpw
“There’s no place like Foam”
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and the skin can easily be airbrushed with Wal-Mart craft acrylics ...I only take the skin off when I'm going for maximum lightness...and for some reason , always on the UF ... that's why I can't wait to get some new colored Hippofoam UFs without the skin... The UF without the skin weighs less than an ounce...
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Old Jul 15, 2004, 09:27 PM
Trying to defy gravity...
jimsky's Avatar
USA, NY, East Northport
Joined Dec 2003
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Good point. I rounded all the LE's of the wing and stabilizers. It's pretty easy to do before assembly. I used a sharp Exacto knife and cut a 45 degree on either side. Then rounded it all off with sandpaper. Actually I rounded the edges of the fuse while I was at it. I never thought about coating the open foam. What you you use and how do you apply it?

Jimsky
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Old Jul 15, 2004, 09:37 PM
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Indianapolis, IN
Joined Sep 2001
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I just use a cheap foam brush and Minwax Polycrylic... (Water Based Polyurethane) It kind of protects the edges of the skin, so it doesn't peel away at the edge as easily.
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Old Jul 17, 2004, 09:11 AM
gpw
“There’s no place like Foam”
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United States, LA, New Orleans
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Gosh!!! You guys make me feel bad!!!! I don't do ZIP to the edges , other than Pinching the le of the surfaces thinner .... but never rounded or glued .... it seems too permanent and interferes with my philosophy of "expendable airplanes"....

........ Templates , Trace, Cut , Hot-Glue , Fly!!!!!!!!!!........Viking Funeral .....( Actually the radios are stolen and they gather dust in my studio , till I can find a good home for them.... most of the time)
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Old Jul 19, 2004, 12:36 PM
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Finding COG

I want to thank everyone for their help so far. This is my first plan I have built and all of the suggestions have been a great help. The plane is looking good, but I applied too much Gorilla glue to the wings. However, it should still fly.

I do have a question about the COG. From what I have read in the other forums, you add weight to the front or tail until you get the glide pattern you are looking for. Then you locate the point of balance where the plane is level and this is the COG. You do not have the engine or battery installed while trying to determine the COG. How about the servos? What about the elevons? How do you align the elevons?

What has been the average COG for the Arado?
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Old Jul 20, 2004, 08:01 AM
gpw
“There’s no place like Foam”
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United States, LA, New Orleans
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Imagine if you will....

The plane EMPTY of all eqpt. ....a little clay on the nose , a large backyard, calm weather.......now toss the plane level into the "wind" , if any ..... when best glide is achieved, by adding or removing clay , make a mark on the wing atthat CG location .... the actual flying CG will probably be slightly forward of this mark (towards the nose of the plane)...It helps to make the elevons, or all control surfaces neutral......
Most of the time , I build the glider version first(no control surfaces cut or hinged,yet) , toss it around in the yard till I get bored and then make the Radio version .... FUN!!! OK????
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Old Jul 27, 2004, 11:08 AM
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Mounting Equipment

Being new to R/C, where do I mount the servos? Over the COG or more towards the front of the plane?

Also, if I don't use lipos, what size battery should one use for the J250. Since it requires so many amps, I assume we are not talking AAA or AA. More like 2/3. Correct?
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Old Jul 27, 2004, 12:48 PM
Trying to defy gravity...
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USA, NY, East Northport
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Well I love the suggestion GPW provided about glide testing. I didn't do it on the Arado, but I did do it on the Nutta and Pibros that followed. I just used a short lengths of a bamboo skewer and a little blue painters tape to lock all the control surfaces at the neutral position. Put a bit more blue tape down to protect the foam and push on some modeling clay to get the CG "somewhere correct". Go outside any play glider, add/remove or move clay to get best glide. Put plane on CG fixture and spot the CG with a Sharpie. I love it. Thanks for that tip!

Personally I put the servos in my Arado way up front. I had no problem getting the plane to balance out with my Etec 2S1P 1200maH pack. I can't really comment on batteries aside from lipos, I've never used anything else. I'm sure GPW can provide some suggestions.

Jimsky
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Old Jul 27, 2004, 01:06 PM
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Salt Lake City
Joined Jul 2003
323 Posts
gpw
I am still flying my Arado and love it every day. I have seen you using the APC gray props with prop saver. How do you secure the prop? I have done it with GWS props/nut in the hole/rubber bands! The nut does not fit in the APC hole. How do you do it? As always thanks in advance for your help/fantastic designs/plans. I sure love to change my Arado from direct drive to geared If I learn the trick about prop saver for APC props.

Regards,
Saeed
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