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Old Jun 13, 2012, 10:39 PM
1:1 scale is fun!
ECBoehm's Avatar
United States, NJ, Midland Park
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Thanks Bruce. I'm covering it now and will weigh it when finished...fingers crossed.
These are the logos on going to add to it:
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Old Jun 14, 2012, 09:06 PM
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Senior Moment Alert!

Sorry all, the largest JA is indeed the SKY CHIEF! If I get the sides joined this weekend I will post a few bare bones photos. It has a wing that looks a lot like Lanzo's Puss Moth, Curtiss Robin shaped tail feathers and a radial engine cowl. Bob Holman only has the plan posted, no photos.
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Old Jun 15, 2012, 11:46 PM
1:1 scale is fun!
ECBoehm's Avatar
United States, NJ, Midland Park
Joined Feb 2009
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Quote:
Originally Posted by BMatthews View Post
Pat, that's a great job on your Navy inspired JA. And the Army coloured version by your buddy is pretty slick too.

EC, at the size of the Bluebird you'd be surprised at how heavy it can be and still thermal well. Anything on the low side of 5'ish oz RTF will make it thermal fodder in a hurry. The bare bones are looking great.
Well I feel a little bit better about it then. I have the airframe covered and I turned some balsa wheels. So far without prop and rubber I'm at 2.9 ounces, so I'll be close.
What do suggest for rubber size and length? I'm using a 12" carved balsa prop.
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Old Jun 17, 2012, 12:04 PM
1:1 scale is fun!
ECBoehm's Avatar
United States, NJ, Midland Park
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Glides almost FLAT! Came in at 3.2 ounces without rubber.
I'm very happy so far. Taking her out for a first flight tomorrow. I'm still trying to sort out the DT. I also need to determine rubber size.
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Old Jul 13, 2012, 02:53 PM
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Last weekend I dusted off my Jimmy Allen Parasol -- still flies great. I had more fun flying her than I have had in a long time! Also fun not to fly rc for a change.
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Old Jul 13, 2012, 07:40 PM
1:1 scale is fun!
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Nice Pat! I'm with you on the RC comment. There is a time and a place those but these simple Free Flight models are fun!
Eric
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Old Jul 15, 2012, 09:10 AM
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Eric

Tell us more about the final weight of the Bluebird. I am getting the itch to build another JA.
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Old Jul 15, 2012, 10:24 AM
1:1 scale is fun!
ECBoehm's Avatar
United States, NJ, Midland Park
Joined Feb 2009
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The Bluebird flew right of the board, to use the cliché. Originally she was 3.2 oz (without rubber) and I was using an old 11” diameter craved balsa prop off of another airplane. After a few test glides to determine wing location, the first real flight was 250 winds from a hand launch. This showed some amazing potential. In regards to the wing mount, I used the method shown on the original plan, using wire saddles and rubber bands around the fuselage. So it’s easy to slide back and forth as needed.
The second flight was 500 winds and off the card table….This showed that I need more down thrust so I shimmed the nose block. I should point out that I had like 2 degrees down built in to the nose block already, so it really needs it to tame the initial thrust.
The third flight was the same winds and ROG again….wow! This thing has some potential. I didn’t have a watch on it but seemed like maybe a minute.
So I was going to go about 800 winds for the next test flight and POW. Guess who did not bring a blast tube. The damage was really not that bad, tissue on both sides and only 3 uprights. During the repair I added some support to the area the wing mounts to. There were no uprights in the area the wing liked best. I also carved a 12” prop as per the original plan. This new prop may be better or not, we’ll see. The thing is coming in at 3.4oz without rubber. I forgot to weigh the prop before mounting it and I don’t want to cut the shaft to do it now so I hope the extra weight is in that little bit of structure I added as it’s near the CG. If the prop is the heavier element of the additional weight I may need to slide the wing forward…making that extra structure rather worthless. Glides in the back yard are dead flat. My local SAM chapter is meeting tomorrow (Monday) morning but since I’m the kid of the group (at 53!) I still have to go to the salt mines, so my next test session is in the future. I have to convince these guys to go flying on a Saturday! It’s about an hour drive to get to our flying site and I also don’t like going alone.
Anyway, I’ll post results here after my next opportunity to fly. Oh, that red and Yellow BA Parasol of mine flies nice as well. The last time I went out with the boys I had high time for the day at close to 2 minutes. The wind was kicking up and lift was scarce so I think it will do better.
Eric
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Old Jul 15, 2012, 10:57 AM
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Eric

What rubber motors are you using in the Blue Bird and the Parasol and do you have an idea of what % the rubber is of the flying weight?
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Old Jul 15, 2012, 05:20 PM
1:1 scale is fun!
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United States, NJ, Midland Park
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No, I'm still experimenting with that...it's always been a part of the science that I never really understood. I had 4 loops of 1/4" that was just about 4" longer than peg to prop hook. I'm looking for suggestions, what would you start with?
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Old Jul 15, 2012, 05:27 PM
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Eric

I usually use long motors about 2 to 3 times the distance between the peg and prop and then folded into a 4 standed motor--then I braid them such that they are about as long as the distance between the prop hook and the peg. Currently I use 3/16 by 12 feet of rubber in 2 loops (4 strands) braided in my Jimmy Allen Parasol with a 9 inch prop. That gives me about 23% rubber in the overall flying weight.

I think I will try a 1/4 in rubber motors with a 10 inch prop next to see if I can get a steeper climb.
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Old Sep 03, 2012, 12:29 PM
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B A Parasol

OK, I've drooled over Pat's Parasol all I can without trying one myself! I started one yesterday. I cut the ribs, and stripped the 3/32 sticks needed for the wing, and glued all of those into a pretty straight structure. I did, however, increase both spars to 1/8". Building shouldn't be a big deal, but building light enough and the ins and outs of powering with rubber? I'm still learning all that I can.

EC, from what you said in post one, I know you have a thing for these. I think that my interest borders on obsession - at least for the larger ones. I've gotta try my hand at one or two of these! Pat, (or anybody else for that matter) if there is ANYTHING you can think of that I should know, please, do tell. By the way, what kind of finished weight should I be looking for??

Happy windin' guys!
David
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Old Sep 03, 2012, 01:59 PM
1:1 scale is fun!
ECBoehm's Avatar
United States, NJ, Midland Park
Joined Feb 2009
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My Parasol (the red and yellow one in post #3) is 2.3oz with 2 loops of 3/16" rubber. I have only flown it in relatively dead air but have had some nice flights over a minute and a half pretty consistently. I hope to find that elusive thermal someday!
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Old Sep 03, 2012, 03:05 PM
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I'm striving for one that can get lost in a thermal. I'll cry later, but what a thrill that would have to be! Maybe I can hit a weight close to yours, EC. I hope so.

What worries me even more than weight is a suitably bent prop shaft, rubber band attachment (both ends) and braiding, trimming, thrust angles, and even winding. All of the above is stuff you guys do without thinking about it, I know, but I'm just plain "green" and it's like learning a foreign language to me. R/C? yes, rubber? not really. The best experience I have is 45 years ago with a Sleek Streak from the toy rack at the local five and dime.

Right now I'm viewing every video on YouTube I can find. Some of those are really helpful. This is one aspect of the hobby I really want to learn.

Thanks EC!
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Old Sep 03, 2012, 04:27 PM
1:1 scale is fun!
ECBoehm's Avatar
United States, NJ, Midland Park
Joined Feb 2009
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Ha ha...You think it's easy? I struggle with every flight as I fly RC as well. These are way more challenging for certain. I'm still fighting the prop shaft battle with my Bluebird. It's capable of so much more. I have to break down and buy some of those nifty hooks, Just build it it straight and the trim flights will be a snap.
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