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Old Dec 01, 2012, 03:17 PM
Proud of Brushless Sprouts
Commander Clumsy's Avatar
Belgium, Flanders, Antwerp
Joined Feb 2007
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Originally Posted by scruffy1 View Post
my only complaint is that since google took over youtube i can't seem to see my uploads in waterfox or firefox (unless they are embedded), although ie9 seems to work

is this a conspiracy to force me to finally download chrome ?

edit : no, i'm an idiot and had to clear a stale cache file
Seems like you need some 'how to maintain my computer' lessons scruffy1, anyone over 25 and willing to teach will do.
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Old Dec 01, 2012, 06:00 PM
looking up down under
scruffy1's Avatar
Australia, NSW, Fairlight
Joined Feb 2008
1,289 Posts
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Originally Posted by Commander Clumsy View Post
Seems like you need some 'how to maintain my computer' lessons scruffy1, anyone over 25 and willing to teach will do.
as a bespoke builder and avid overclocker since the early days of socket a / 462, the hardware side is never the issue

in my enthusiasm to tweak the software, i am sometimes a bit too "bleeding edge" for my own capabilities, and i always presume the worst in providers when it fails to work as i thought it should, before i finally realise my own errors

even so, i manage to maintain around a dozen working machines networked at home without any formal training, so occasionally things go wrong

so, did you like the aeroplane, or what ?
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Old Dec 02, 2012, 07:40 AM
Proud of Brushless Sprouts
Commander Clumsy's Avatar
Belgium, Flanders, Antwerp
Joined Feb 2007
317 Posts
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Originally Posted by scruffy1 View Post
as a bespoke builder and avid overclocker since the early days of socket a / 462, the hardware side is never the issue

in my enthusiasm to tweak the software, i am sometimes a bit too "bleeding edge" for my own capabilities, and i always presume the worst in providers when it fails to work as i thought it should, before i finally realise my own errors

even so, i manage to maintain around a dozen working machines networked at home without any formal training, so occasionally things go wrong

so, did you like the aeroplane, or what ?
LOL, your conspiracy theory kind of tricked me into thinking that you were an inexperienced user.
I stand very, very corrected.

And yes, I like your aeroplane, I've been admiring it since page one.
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Old Dec 02, 2012, 04:20 PM
looking up down under
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Australia, NSW, Fairlight
Joined Feb 2008
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Originally Posted by Commander Clumsy View Post
And yes, I like your aeroplane, I've been admiring it since page one.
lash out for one for christmas; you know you deserve one

from my experiences, you won't be disappointed

edit : 2 batteries' worth this evening in almost calm, and no ballast - beautiful ! lots of down elevator at "neutral", but no vices
this aircraft is a really fine machine for a gentle outing, or going a bit silly if the urge strikes
highly recommended for anyone who can control a full house trainer and wants to move onto something that is both responsive and forgiving
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Last edited by scruffy1; Dec 03, 2012 at 02:58 AM.
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Old Dec 03, 2012, 11:13 AM
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Joined Aug 2005
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Originally Posted by scruffy1 View Post
lots of down elevator at "neutral",
Did you check the decalage before installing the horizontal stabilizer? I'm looking at buying/building one of these (a soft spot for biplanes) and am curious. Are you referring to "down elevator" as physically down elevator, like right stick forward?
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Old Dec 03, 2012, 05:54 PM
looking up down under
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Australia, NSW, Fairlight
Joined Feb 2008
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Originally Posted by t.edwards View Post
Did you check the decalage before installing the horizontal stabilizer? I'm looking at buying/building one of these (a soft spot for biplanes) and am curious. Are you referring to "down elevator" as physically down elevator, like right stick forward?
nah, left stick forward if i was doing it manually (i fly mode 1 like most australians seem to do)

but it was adjusted in trim, and yes, there is a significant "down" in the trim

the picture demonstrates the amount required when flying level at low throttle, and it still climbs under increased power, which is pretty standard from my limited experience with conventional layouts (unless you have significant downthrust)

the decalage seems to be a few degrees positive on the upper wing, as set by the cabane struts and baldachin supplied, which have notches pre-cut to define it

the cg is hard to figure but seems to be around 45mm from the l.e. of the lower wing (dropping a perpendicular from the top wing, where i can actually get it to balance); the plans state "20mm from the leading edge", so i expect if i obliged then the down trim would be unnecessary

however, despite the "unusual" elevator setting, which i am sure could be easily compensated for by adding ballast or using a larger lipo, the flight characteristics seem very lovely and the rearward cg makes for very responsive controls which isn't a bad thing in my opinion

of all my squadron (more details here) this is the current favourite because it has more capability than my skills can use presently, and is thus a good learning tool

i loved the spitfire, but the size and weight were a little bit brave for the circumstances where i can easily walk for a brief session, as it was much faster and potentially more lethal

if you like biplanes i don't think you could do wrong with this one

presuming you are in u.s.a., feel free to use this link to buy one if that's soon, because they'll give me credit for the referral and i can buy even more toys

hope that info helps
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Old Dec 04, 2012, 04:32 AM
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Australia, QLD, Mountain Creek
Joined May 2012
151 Posts
Hi Scruff...
I am still tweaking and tuning, when i get a chance between work and winds and other planes..
Im getting there, still very tail heavy but your tip about the elevator down trim is interesting and worth a try. I am flying with two 1000mah batteries and i think we are getting close.
https://www.google.com.au/url?sa=t&r...jWYcnWi7gkF2bg
This is the sort of attitude my Pitts like. Bum down head up
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Old Dec 04, 2012, 05:14 AM
looking up down under
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Australia, NSW, Fairlight
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Originally Posted by Xmod View Post
This is the sort of attitude my Pitts like. Bum down head up
if you check my 2nd video you can see that mine seems to track nice and level

even at low throttle it just putters around the sky very directly

down trim is your friend if the nose points up too much - i am surprised how far back my cg is without any detriment to good behaviour
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Old Dec 06, 2012, 09:16 PM
looking up down under
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Australia, NSW, Fairlight
Joined Feb 2008
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destructive testing results

well, it's pretty tough

i taught myself that it is inappropriate to try and perfect knife-edge flying close to the ground, and more so if you choose to apply the wrong rudder input

bounced rather impressively, and sprung the fuselage stringers and ripped the nose a bit

the good news is that 5 minute epoxy has done a fine job of repairing the splits, and i went a little further and epoxied the joint where the lower wing joined the fuselage - this confirms my suggestion to use epoxy for the cabane struts, as the cyanoacrylate is simply too brittle to allow impact loads across a join, rather tearing the bond

looks as good as new, and hopefully i can control my destructive urges next time out
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Last edited by scruffy1; Dec 07, 2012 at 07:34 AM. Reason: speeling eror
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Old Dec 06, 2012, 10:50 PM
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Originally Posted by scruffy1 View Post
i am surprised how far back my cg is without any detriment to good behaviour
Is it really "that far back"? Isn't "rule of thumb" on a bi-plane to consider the wing chord to be the distance from the most leading edge to the most trailing edge (like it was a mono-plane) and take ~30% of that to be the starting point for cg? Don't know where that would fall in this case.
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Old Dec 07, 2012, 07:32 AM
looking up down under
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Australia, NSW, Fairlight
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Originally Posted by t.edwards View Post
Is it really "that far back"? Isn't "rule of thumb" on a bi-plane to consider the wing chord to be the distance from the most leading edge to the most trailing edge (like it was a mono-plane) and take ~30% of that to be the starting point for cg? Don't know where that would fall in this case.
on your suggestion above, the cg is at 44% if the front of the (swept) top wing and the rear of the (unswept) bottom wing are considered the edges of the chord

so yep, it is "far back" based on standard layout
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Old Dec 07, 2012, 07:59 AM
Canadian Bacon
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Kingston, Canada
Joined Jun 2004
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On my planes of this type, I set the CG by setting the elev trim to fly level at cruising speed or half throttle, then flipping it inverted. It should neither climb or dive, still fly level. I then set the motor thrustline so it stays level at full throttle setting. This works for me. Of course there are other methods that work equally well.

Gord.
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Old Dec 07, 2012, 07:39 PM
looking up down under
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Australia, NSW, Fairlight
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Originally Posted by flypaper 2 View Post
On my planes of this type, I set the CG by setting the elev trim to fly level at cruising speed or half throttle, then flipping it inverted. It should neither climb or dive, still fly level. I then set the motor thrustline so it stays level at full throttle setting. This works for me. Of course there are other methods that work equally well.

Gord.
i fail to see how you can have it both ways

even if you fly a perfectly symmetrical airfoil at zero / zero for thrust line and incidence (with the wing on the thrust line), you still need to trim it upright and inverted

and altering the thrust line to allow for throttle when upright will immediately destroy your inverted trim

i think like full size you are obliged to trim down for increased thrust to overcome the natural increased tendency to climb, and whilst this can be dialled in on mixing with r/c, you can't get it to work inverted without switching the trim

again, it can be programmed no doubt, but not as a single adjust to do both orientations

if you have some magic tricks then share away... but i quite like having to fly the various settings manually - it's the fun of being a pilot rather than driving a drone
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Old Dec 07, 2012, 08:09 PM
Canadian Bacon
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Look at it this way. We're talking about symetrical or semi symetrical airfoils. On a fairly nose heavy plane, you'll need a fair amount of up trim to keep the nose up and if you flip it inverted, with that much up trim, the nose will drop quite abruply. As you move the CG back and retrim it, it will take less and less up trim, to the point where it will climb when you flip it inverted. This is the point where you went one step beyond. Now move the CG ahead just enough where it carries in level flight whether upright or inverted. This is all done at cruising speed or half throttle. Now crank it on to full throttle. It should maintain the same level flight. If it climbs, put in a bit more downthrust. The opposite if the nose drops. This is how all of my aerobatic planes are trimmed. As I said, it may not work for everybody.

Gord.
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Old Dec 07, 2012, 10:07 PM
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Originally Posted by flypaper 2 View Post
Now crank it on to full throttle. It should maintain the same level flight. If it climbs, put in a bit more downthrust. The opposite if the nose drops. This is how all of my aerobatic planes are trimmed. As I said, it may not work for everybody.
once you invert with downthrust you are effectively flying with upthrust

balancing the trim for upright flying to allow for more throttle by using downthrust will have an impact on the inverted trim; and thus once inverted you will be obliged to play with elevator

i can understand that with a non-symmetrical airfoil that may work inverted at a particular throttle setting, but not across any large speed range without compensation on the elevator

"it may not work for everybody" suggest that aerodynamics shows favouritism, but i don't think it has any such anthropomorphic qualities
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