open e hits open b

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slam
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open e hits open b

Post by slam »

last weekend drew and i flew our new design in an open b contest in west palm. we started with a clean slate for a design and came up with this funky bird.

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i spent alot of time on e-zone in the flying wings section and they were fairly helpful.

it is 60" flying wing. 670 squares, pusher configuration. 45oz rtf. drew used winglets and verticle and i used just a big verticle (we can fly the exact same design and by combat time they fly and look different).

we were using a mega 16/15/4c motor with 35a castle speed controllers. 2 common sence 2000ma 8c batteries in parrallel. got full 6 minutes at full throttle (7x5 at about 19k rpm). we radared it at right around 80mph.

the performance was good. speed is about 5mph slow, but handling was great[:D], i just have to get more time flying it to get it's true potential.

the pusher worked flawlessly, and yes, it is easy to launch with the motor running. a swift overhand toss and the prop is nowhere near me.

drew came in 3rd, right behind kirk and grasshopper, and i came in 5th behind bob (the prez).

we still have some tweaking to do before the next open b event, ssc is a no brainer (if we had any events close by), change the motor to an het 4 wind ($50) and we are done.

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slam
BenJammin
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Post by BenJammin »

That sounds great! Does 3 cells in series work or did you need to go to 4? That commonsenserc deal with two 3 cell 2000mah looks like a super deal at $42.50.

I'm not familiar with the het motor. Will it work for Open B with the right battery and prop combo? I assume it's got a smaller shaft than the mega combat motor but with a pusher config it should be fairly safe.

Keep up the great work guys!
Lee Liddle
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Post by Lee Liddle »

Yeah, give us the scoop on the Het motor. The action shots look good. I`m sure that you can get more speed out of it for a little more money (ie batteries).
Lee Liddle
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Post by Lee Liddle »

Can you give us some close ups of the wing saddle, battery mounting and motor mount areas?
slam
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Post by slam »

benjammin

we ran the two in parrallel. we have played with 4cell, but haven't got to the warm and fuzzy point yet. drew did some speed tests today and came out about 5 to 7 mph faster with 4 cells, i just don't like the costs of 4 cell. he also is trying 4 cell emoli batteries (milwalki lithium ion drill batteries). they are probably the direction we are going to go. they are fairly cheap, about $15 per cell (you have to buy milwauki batteries and take them apart). these are less powerfull than the 4cell lipos but are much tougher and you can charge them at 30c. that would mean keeping the batteries in the plane while charging.

$42.50 is a good deal for the 2000's but you can still get 10% off that. truth is the lipos are good but i'm not happy with the battery installation. i had a hard dirtnap and both batteries smooshed like an accordian. that's why we are looking at the emoli's.....that and the fast charge capability.

the het motor isn't anywhere on the web that i could find. the guys on e-zone say http://www.dynamoelectrics.com/ has them but not on the site. you have to call them. it is supposed to be a mega clone and the performance is almost identical. haven't heard of anyone spinning a 8x3 prop with one but by all accounts it should work as well as the mega, open b should be great too with the same setup as the megas. yes it has a smaller shaft, but i'm not worried with the pusher.

i have used the 16/15/4 for ssc. 17.5 to 18k before limiting throttle on a 2 1650ma common sence batteries.

slam
drewjet
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Post by drewjet »

Here is one place you can get the HET http://www.warbirds-rc.com/Store/hett-edf4w.html
slam
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Post by slam »

lee

here's a picture of the insides of the bat. it is difficult to get a decent picture. the batteries are shoved in the front of the bat. the reciever is in the back of the opening.

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here's a pic of the motor mount. it is lowes aluminum angle. i riveted it to the bat. with four bolts i can change motors, and with an adaptor i can mount the bigger motor on it. speed controller is in front of the fin.

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here's of the underside, mounted on the wing. i used coat hanger loops. on the top side i have a small carbon fiber arrow shaft spar with the coat hanger angled over it for support. on the rear of the wing i have a full length arrow shaft spar with the rear coat hanger loops over it. seems to work o.k.

Image

slam
Lee Liddle
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Post by Lee Liddle »

Cool design!! So I guess you have to take the wing off to switch batts?
Did you have any problems with the fuse wanting to rotate when you have a wing to wing hit? Thanks for the info on the Het motors. Those look like viable motors for SSC at only $50 each. Can`t wait til next year to see how prices drop. Maybe we should "suggest" a cheaper motor price limit in SSC. Say about $51. LOL
slam
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Post by slam »

i like the idea......$51 sounds right to me[:D]

taking the fuse off every round was kindof a pain but not the end of the world.

had no problem with the fuse shifting. in fact i only had 2 rubber bands holding the fuse on.

slam
BenJammin
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Post by BenJammin »

I've been avoiding R/C Groups. Seems like it just costs me money to try new things everytime I go there. Sure as heck now I'm searching Ebay for Milwaukee batteries. I had no idea they were being used.

On a side note, is that a '55 or a '56. Judging by the chrome outline I'm going to guess a 56, hard to tell without seeing the grille or tail lights. My bro has a '56 he's turning into 4wd. He's got the front suspension from a '92 light 3/4 ton chevy, the engine and trans is from a '94 caprice 9C1 and an electric shift transfer case off Ebay. His is a 4 door post sedan, not the cool hardtop like yours. The running gear is all done and most of the body work. Should be a sweet ride when he gets done.
BenJammin
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Post by BenJammin »

And another thing. 30C charge? By my calculations that's 90 amps and a 2 minute charge! HOLY WATTS BATMAN!!!
drewjet
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Post by drewjet »

If we would of used the flat bats then I think we could have made a battery acces hole in the side, but by using these smaller bats we saved about 3 ozs plus they are smaller for cleaner aerdynamics. The Emoli test today went well, however we didn't get a full test of time in on them. I think I can get a full 5 minute flight out of them but it will take some throttle management (something really hard to do in the heat of combat). I did find that by going to about 3/4 throttle that the amps went down sinifigantly, but really didn't loose much speed. We have our next open B contest in December and I hope to be better prepared for that one.
Lee Liddle
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Post by Lee Liddle »

I guess messing with the rubber bands to remove the wing is not so bad when they are not all slimy and greasy from fuel oil.
BenJammin
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Post by BenJammin »

drew, were you using 3 cell or 4 cell Emoli packs?
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o1moregil
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Post by o1moregil »

nice wing Mister Slam! looks like it can be put together fast, what airfoil are you using? what are you using for spar?
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