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Old Jan 06, 2013, 11:28 PM
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Wingman26's Avatar
Oklahoma
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Center of gravity calculators:

http://adamone.rchomepage.com/cg_calc.htm

http://www.geistware.com/rcmodeling/cg_super_calc.htm

http://www.starcadplans.net/index.ph...alculator.html
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Old Jan 07, 2013, 07:43 AM
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Hey Smittyplugs Just try balancing it between 25% and 30% from the leading edge, to be completely honest the above links I have found to be really tricky, unless of course you are a Doctor of Physics or a rocket scientist, for example, just click on number 2 and look at those equations honestly, how many guys here really understand that stuff?
I must confess trial and error balancing on two fingers and a few Lipo moves to and fro have always worked for me, let´s keep it simple.
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Old Jan 07, 2013, 10:15 AM
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United States, FL, Palm Beach
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Originally Posted by Buggyboat View Post
To answer Jetcommander's question, here is how I did it. Hope it is strong enough. I hinged the cowl and will replace the rubberband with magnets when I come up with some.
Another successful method I've seen and been meaning to use is to glue an antenna tube across a joint, cut the tube on the joint, and put a length of paperclip or other bendy metal pin through it. I believe this is lighter than magnets and as secure as the glue used to bond the parts.
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Old Jan 07, 2013, 03:41 PM
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United States, CA, San Rafael
Joined Mar 2012
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My latest build. 60" ws slope/hotliner inspired armin wing with 2-ply box fuse. Don't know the weight yet. I hope my horizontal stabilizer is wide enough (12"). Well try to maiden with 200w 1200kv spinning 9x6 on 3s.

I tried to take photos of the construction process and should be able to post a build log soon.
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Old Jan 07, 2013, 05:15 PM
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Thanks Viper522. I am not sure I am following. Do you have a photo or sketch?
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Old Jan 07, 2013, 07:02 PM
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Australia, SA, Old Noarlunga
Joined Mar 2012
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Originally Posted by Proper Job View Post
Ed,
You guys in the States seem to have ultra cheap prices of things like $ Tree Foam Board, Packing Tape and general hardware.
I recall that the price of DTF has been stated in this thread as US$1 per sheet (20”x30”) – hope my recollection is correct!
I have to pay seven (7) times your price at A$14 per sheet of 1000x800x5mm Foamboard (39.3”x31.5”) at the local RIOT Craft store.

Your prices of everything seems to be very low compared with those here in Australia.
Ed asked us all to publish details of any good sources of building material found , so others can benefit, so here goes:
At least I can now report a bit of good news for the Aussie readers/builders this side of the Pacific, I have found some Coloured Packing Tape at KMart (our equivalent of your Wal-Mart maybe). The brand is “OfficeOne” and at A$5 for a pack of 6(six) 50metre (54yds) rolls, undoubtedly seems to be a red-hot bargain!. I bought 2 packs for a couple of Axon type projects I’m about to start. I can’t give the URL link as I haven’t found a website.

BTW, how much do you guys pay for Bob Smiths C.A ? We pay A$7 for a 1/2oz bottle at the LHS. Although I just got 2 bottles of Gold from HK but not much cheaper though.
Hope this is useful
Geoff

Reckon, it would be great to start a new thread for OZ equivalents.

Regarding the dollar tree foam, I far as i have read Depron is the closest to Dollar Tree Foam and better quality. It would cost $10 for the same size sheet and can be ordered online and free delivery for orders over $100. At my club several guys buy a bulk order box and split it up...
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Old Jan 08, 2013, 07:49 AM
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United States, FL, Palm Beach
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Originally Posted by Buggyboat View Post
Thanks Viper522. I am not sure I am following. Do you have a photo or sketch?
Sure, here. Just glue the tubing across the joint and cut it at the joint. Then put a straightened paper clip or something else through it.
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Old Jan 08, 2013, 10:59 AM
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United States, NY, New York
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Originally Posted by Averan View Post
My latest build. 60" ws slope/hotliner inspired armin wing with 2-ply box fuse. Don't know the weight yet. I hope my horizontal stabilizer is wide enough (12"). Well try to maiden with 200w 1200kv spinning 9x6 on 3s.

I tried to take photos of the construction process and should be able to post a build log soon.
Looks awesome
I saw your other video on youtube, where you flew this plank on at the beach... it's just plain awesome!

I maidened mine, but I didn't like how it behaved, either too much dowthrust on the motor or too much weight.
I got me some carbon arrows and spars and will build a slow stick style fuselage since all I care about is portability.
Also the way you rounded off the wing is a great idea, sometimes I had problems with orientation because there is barely any sweep and at a distance my plane looked just like a black bar heh.
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Old Jan 08, 2013, 11:05 AM
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United States, CA, San Rafael
Joined Mar 2012
131 Posts
Sorry to hear that. I was going to mention that with the tailless wing you don't need any down thrust.

You may have noticed the black tape I have on mine that gives me visual cues to orient the plane from far away. The rounded wing tips are more for stability than visibility as you can't really make them out from afar.

Did you experiment by moving the cg? Correct cg with a bit of up trim reflex should get you flying.
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Old Jan 08, 2013, 12:45 PM
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Originally Posted by Averan View Post
Sorry to hear that. I was going to mention that with the tailless wing you don't need any down thrust.

You may have noticed the black tape I have on mine that gives me visual cues to orient the plane from far away. The rounded wing tips are more for stability than visibility as you can't really make them out from afar.

Did you experiment by moving the cg? Correct cg with a bit of up trim reflex should get you flying.
oh i flew, i just didn't like the way it handled Felt unpredictable and sluggish and im used to super easy flying from my BajiWing.
On next one i'll just use mixing to counteract pitch variations between low and full throttle, angling the motor doesn't seem to be worth it
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Old Jan 08, 2013, 12:50 PM
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United States, CA, San Rafael
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interesting....I have not noticed much variation in pitch with throttle. there is some slight variation that i simply trim out, especially when i'm switching between sloping/thermalling and mostly powered flight. getting the motor angle right should really help otherwise your compensations will increase drag and reduce speed and efficiency.
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Old Jan 08, 2013, 01:03 PM
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United States, NY, New York
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Originally Posted by Averan View Post
interesting....I have not noticed much variation in pitch with throttle. there is some slight variation that i simply trim out, especially when i'm switching between sloping/thermalling and mostly powered flight. getting the motor angle right should really help otherwise your compensations will increase drag and reduce speed and efficiency.
I measured it and my angle seems to be too steep, plus it's rather heavy and wasn't fully trimmed out. I've learned a few things while building this one, so next one should fly as well as yours (hopefully lol)
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Old Jan 08, 2013, 01:14 PM
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United States, CA, San Rafael
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for reference, I only had one washer on the top two motor mount bolts. that is very little down angle and is probably why I needed some reflex up. when I rebuild that tailless fuse I'll try zero angle and see if it works out better.
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Old Jan 08, 2013, 05:47 PM
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Asheville,NC
Joined Jun 2002
828 Posts
Noob Tube Throws

I wonder how much [inches] I should set all the surfaces on this Noob Tube

to start off with ??.....................te
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Old Jan 08, 2013, 06:18 PM
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manahawkin NJ
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Will side fins on my wing help with flight as in keeping it steady or will it make it harder to bank???

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