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Jun 05, 2008, 08:24 PM
Slopeosapien
jonesymj's Avatar
Chara: I didn't mean anything bad by it... My enthusiasm often times gets the best of my restraint, and I don't want to speak out of turn... Glad I'm not stepping on your toes!! I know I sure appreciate everyone on this board that goes through the trouble of designing, testing, and perfecting a design, only to give it away. That kind of attitude isn't something you find all that often anymore, let alone as often as we find it here... Thanks for your designs... This is the third of your designs I've built so far (Bipie, then the Raceduck) and I'm liking them more all the time. Keep up the good work!!
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Jun 05, 2008, 11:20 PM
Registered User
got my 26" WS version about half done. maybe it's just me, but i can't find any reference to CG. anyone got a suggestion for a good starting point?
Jun 06, 2008, 12:27 AM
Slopeosapien
jonesymj's Avatar
kev0383: On my little one, it balances nice at 11 3/4" (29.8cm) from the tip of the nose... I'm not sure which size of plans you have, but that would be about 15 9/32" (38.7cm) for the 130%, 18 13/16" (47.7cm) for the 160%, and 23 1/2" (59.6cm) for the 200%. These are rough calculations, though, so make sure you do some glide testing first to fine tune it!!

So I was the only one to come out flying tonight, and it was really WAY too windy to fly, but I put both 2 cells and 2 3 cell 800mAh's through it. I used the 4.1x4.1 APC for the 3 cell... Significantly faster, but honestly not any better. It performed more like a jet, you needed to think ahead so as to not bleed too much energy and find yourself falling out of tight turns... It didn't feel as responsive or nimble as it does in it's 2 cell configuration either. But it was much faster ... I suspect that this is due to the smaller diameter prop, which would provide greater efflux speed due to higher rpm, but lower overall thrust. It also slowed the roll rate down to about 1.5 rotations/sec (high rates), from what was probably 2 or maybe 2.5 before. Obviously not the best prop for my type of flying. I'm thinking of going to a 4.5x4.1 APC for the 3 cell next time, but it's up to 7.3oz with the 3 cell as it is, and the next bigger esc I have is a clunky Assan LV-18 (solid performer, but heavy) which would bring me up to 7.6-7.7... Wing loading is getting up there little by little... I'll probably do it once or twice til something goes horribly wrong, just so I can say I HAD a 230w/lb, 18" span Mig-29 lookalike at one point in my life, but I doubt it'll be something I do consistently...

So the old adage is true: Build it light!!
Jun 06, 2008, 05:01 PM
registered foam addict
chara's Avatar
kev and others,
I've added a picture near the plans on page 1 that visualizes the approximate CG location. As jones said: glidetest does not hurt either.
cheers
chara
Jun 06, 2008, 08:54 PM
Slopeosapien
jonesymj's Avatar
My balance point (and the calculations listed above) represent a significantly more rearward CofG than Chara is recommending... As I've said before, follow Chara's instructions, and ignore me...
Jun 06, 2008, 10:37 PM
Registered User
fr4nk1yn's Avatar
Quote:
Originally Posted by chara
alternatively you can of course make yourself a trapezoid fome former (the classical way).
DOH! Why didn't I think of that?!?
Jun 07, 2008, 06:56 AM
registered foam addict
chara's Avatar
Quote:
Originally Posted by jonesymj
My balance point (and the calculations listed above) represent a significantly more rearward CofG than Chara is recommending... As I've said before, follow Chara's instructions, and ignore me...
I wouldn't say that! you have the most recent flight experience with the 29.
I'll fly her today hopefully and I will update the picture if necessary.
thanks for the hint!
chara
Jun 07, 2008, 11:26 AM
Slopeosapien
jonesymj's Avatar
Chara: I don't know why my CofG came out so much more aft than yours... I just don't want anyone having any problems... I guess everyone's got a range to work with now... Glide tests are the key, if you can make it glide, it'll fly!!

Flew mine again last night... Decided to test the vertical, so I stood it on it's tail and went WOT. Made it to (probably) 500 ft before I lost sight of it... but it came down eventually... It does glide very nicely... Must've taken 3 minutes with the power off to make it back down to reasonable altitude, and that's with me throwing a loop or 2 in on the way down...

Now I've been asked to build one for a flying buddy... This thing's catching on!!!
Jun 08, 2008, 09:55 AM
Registered User
finished my 26" version yesterday. AUW about 16 oz. with 2250 3S lipo and grayson 2212-06 combo. it's got a great glide and flies generally very well (great high alpha), but the tailerons can't overcome prop torque at higher throttle settings. had a couple of hairy moments as a result. so i brought her home and fixed up some ailerons and will report the results.
Jun 10, 2008, 12:20 PM
Slopeosapien
jonesymj's Avatar
So I'm on my 3rd H-29 now, my original (which recieved a nose job when flying {crashing!!} saturday night) a second for a flying buddy (original size, come on it's 75 cents worth of foam and a couple of hours, why not?) and I got the 130% done this weekend for myself, and wouldn't ya know it, rain and wind in the forecast for the next couple of days... That's ok, though, I still have to build a motor mount. I'm going to try pitch only thrust vectoring through the motor mount, so hopefully I'll have something built tonight and pictures up for everyone later tonight or tomorrow. Bare airframe weight of the 130% is 3.1oz, so I should have it airborne at 8.5-9.5oz... At least I hope... This one's getting the FC2805 1600Kv motor on 3 cells (1300-1600mAh), but I still have to do some wattmeter/thrust tests tonight. Hopefully I can get 120 watts out of it, decent pitch speed, and no smoke...

That's the idea, at least!!
Jun 10, 2008, 04:09 PM
registered foam addict
chara's Avatar
kev,
I inspected mine and realized that I had added 1cm or so to the taileron tips to extend them a bit (w.r.t. the plans). You can also mount them 1-2cm further apart to increase roll power and/or allow larger deflections. Did you try that out?
In any case let us know how your aileron mod works out.

jones,
I'm on my 130% version as well. I realized yesterday that when I print the parts, they are noticably smaller than 130% (maybe 124%) . Can't figure out why. When I measure them in my CAD software they have the right dimensions. But not on paper. Very strange...

Flew the small one on the weekend again and noticed that you were right about the CG, as I suspected. It was a bit more aft than I remembered. I've removed the picture on the 1st page to avoid confusion.
BTW: man I also forgot how fast this thing gets small at WOT. The 130% will be more relaxing I hope

cheers
chara
Jun 10, 2008, 04:53 PM
Slopeosapien
jonesymj's Avatar
Chara: I'm glad the CofG thing worked out. I was worried about my airframe being way off from you plans, even though I re-measured everything... <breathes sigh of relief>... And I agree, it's a speedy little bugger for only 60 watts... A buddy of mine who came out to see it fly the night I did my "Vertical super zoom climb" (his dad flies scale and sport gassers) said he'd never seen ANYTHING do something like that. Gave him an entirely new respect for electric, and he thought it was a good deal better than gas already!!!

My 130% probably won't be that relaxing, as I'm gonna end up somewhere between 225 and 250 watts per pound... . Mine came out at 24" wingspan, which would be 130% of the original 18" version... Maybe your printer settings have gone wonky on ya... I also used the plans for the increased strake size, just to see what happens. Should move the CofG ahead the slightest bit due to more forward wing area. I also boxed in the intakes infront of the prop region just to give it a bit more form. More drag too, I guess, but it looks cool!!! I used a 2mm carbon tube for the wing spar (now full span) and 1mmx3mm on the leading edges for stiffness of the wing. Hopefully that will keep things lined up on high speed passes. That coupled with the moving motor mount should give me insane manouverability (in the pitch quadrant, at least), and insane speed. That or it'll fail miserably... Oh well, it's still just one sheet of fanfold down the tubes if I do mangle it!!
Last edited by jonesymj; Jun 10, 2008 at 05:00 PM.
Jun 11, 2008, 07:09 PM
Registered User
fr4nk1yn's Avatar
Well that maiden went better that I thought it would... MUCH BETTER (:
It left my hand and it climbed out smooth and fast. I'm not sure if it's as fast as it seems or if it's the size but this is gonna be fun to tease the slimers with this weekend.

I just need to find a way to clean it up. I'd take a couple photos but I think I've built the ugliest fuselage in the history of ugly fuselages ): In mu experience paint doesn't stick well to hot glue either. Besides that it's pretty standard except the the wing tip "thingies", like a F-18, I added (:

Very responsive especially in pitch, I don't normally add expo to the elevator but I may have to and cut back on at least the down elevator.

Motor mount broke on landing and since my TX was running low I decided not to try my luck.

I made a former for the fuselage cut an angle to the top and bottom and glued it all together.
The former is 2" at the bottom 1.5" tall and the top it .75" wide.
Jun 12, 2008, 01:38 AM
Registered User

My H-29


After watching jonesymj fly his H-29 around I couldn't resist, I just had to have one. Thanks to jonesy, I now have one of my own. He built the airframe for me and then I proceeded to add all the electronics, controls, etc...As you can see from the pictures it is ready to go, so I'm hoping that the weather holds out for the next couple of days. If the maiden goes well I will post a follow up to this (who am I kidding, I'll post all the pictures if the maiden doesn't go well). Either way I can't wait to get this wonderful design of Chara's ripping up the sky.
Now more about the plane itself: I am using a 2s 550 LiPo, an assan 10 amp ESC, a FC2805 2840kv motor, 2 Hextronic HXT500 servos, and a GWS 6nII Rx. My AUW is 6.2 oz or 176g. The measurements are: ~ 18.5 inch wingspan and ~23 inch length. Fingers are crossed for the weather to hold for the maiden.
Thanks again to Chara for the awesome design and jonesy for his quick building skills!
Jun 12, 2008, 12:02 PM
Slopeosapien
jonesymj's Avatar
Nice work brother!!! And yours came out lighter than mine... Ya rotten bugger!!
I love the rounded canopy... Glad you found your markers!!! So we should have some formation flying pictures tonight... That or a really cool mid-air collision picture.

Can't wait to see it fly, Tim!!


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