Pitts Python

[Tim Mackey]

[Dusty]

Right weighed the model less the Lipo's

 

3.05kg or 6.72lbs

 

So a estimated AUW of 3.5kg

 

I have installed the Rx and programmed the model into my Tx, however applying pressure to the control surfaces under load the servo hors were slipping on the gears so I have changed the horns to the original Hi-Tec ones which are not as pretty but at least they dont slip! Rather find this out now than in the air

 

I am not 100% certain on the clevisis for the Ail/Ail pushrod, I was thinking of using ball links instead?

 

Have a nice day!

[Dusty]

mmm interesting, if this link works here you can see the AUW on a 5s setup with Hyperion motor if you download the flight report (in German but I you can see the data specs.

[Sheldon Holy]

Hmm... I dont usually use ball linkas but i put 'usually' in itallics as i use them on larger aerobatic models (like this). This model is big, but not so big that having ball links is neccesary or strength, but instead for accuracy. Get the setup right, and the word 'play' will be running as fast as possible. Hey, if a job is worth doing, it's worth doing properly!

 

Sheldon

[Dusty]

Sheldon,

 

Evening to you! We did mention earlier in the thread if the model was possible of 3d/free style? The play must come from the TX sticks not the linkages, the ball links will be a better fit and precise control movement? Am I being picky? If I was to fly like a Sopwith Camel I would be ok with the current "play" but I have other things on my mind with this

[Dusty]

Morning all,

 

I have done some testing this morning!

 

3 blade 16x8:

 

1163W

 

50.99A

 

22.71V

 

2 blade 16x8 wooden prop:

 

881.7W

 

37.81A

 

23.16V

 

Looks the 3 blade is the better choice, however I am porky at 3871g (8.53Lbs) Flying weight!

 

Thus if I used the 3 blade I will only be getting approx 136W per lb... I was hoping for more! I could prop up but I dont want to push the motor over 70A.

 

I suppose I could use lighter packs?

[Tim Mackey]

Allowing for the lower efficiency of the 3 blader versus the 2 blader, I would wonder whether you will see any great difference in flying performance - despite the lower watts.

However, all the bipes I have flown ( and all have crashed so they aint my fav steed ) needed plenty of power - due no doubt to the high drag.

Lighter packs will come at the price of lower C and may not hold up voltage as well under load - those you are using now are doing very well, quite a bit higher than the "norm" of  21V, although of course @ 5000mahr they are only working at 10C or less.

I think I would use the 16 x 10 two blader you mentioned earlier for first flight, and see how she handles?

[Dusty]

Thanks Tim,

 

Maybe a 16x10 will be better? I was using a 16x8 for testing..

 

Yes I did think that lowering the Mah on 6s would obvioulsy have less V. I was think of 5s but there is only a 60g difference in weight. Just reading reviews of this motor it seems happy at these figures, anything higher and it starts to chuck magnets, I guess its most efficient in this area of power. The Lipos were freshly charged so I expected the V to be a tad higher... I guess flying it is the real test, it certainly feels like it wants to fly so no doubt it will!

 

P.s Tim last year you didnt have much luck with bipes and other aircraft varients  

 

Not meant to bring back any memories!

[David Ashby - Moderator]

 

 

P.s Tim last year you didnt have much luck with bipes and other aircraft varients  

 

Not meant to bring back any memories!

 

 LOL, brave man Dusty

I'd fly her and see, you may be pleasantly suprised

[David Ashby - Moderator]

....like my E-flite Pitts, the wing profile is quite slim so perhaps not quite as draggy as you'd normally expect for a bipe?

 

 

 

 

 

[Tim Mackey]

Not just last year guys.... I remember my frst bipe - an impulse buy from a trip to Mike's models in Birmingham ( my local at the time ) when young Mark Leavesly persuaded me what a great model this huge ( well it was in 1those days ) lovely pitts special would be for me. Hanging up from the cieling, resplendant and complete with ST3000 engine and muffler, she did indeed look fantastic.

That Sunday it drew quite a crowd around the pits, and under the watchful eye of all my clubmates, I fired her up and tore off across the WMAC strip.

Approx 20 seconds of wildly undulating roller coaster style "flying" later, the bucking bronco made a rather huge hole into the turf.

COG was wrong they all cried - very helpful at this stage lads

Some years later I was tempted again - this time the well behaved and easy to fly "Panic" The name says it all - Nuff said .

 

Then came the Camel.....and since then I have pledged to never fly one of those silly looking biplane thingies again - I mean come on, if it really needs two wings and all those wires and struts somebody screwed up with the design

( Inserts tongue in cheek icon )

[Dusty]

Hi David,

 

Yes the wings are pretty slim on the Python. I will jusy have to fly and see how she performs. Did you ballance the Eflite Pitts on the bottom wing with the model the right way up?

[David Ashby - Moderator]

No, top wing with the model the right way up.

 

 

 

Edited By David Ashby - RCME Administrator on 13/03/2010 11:28:22

[Dusty]

Thanks David, the manual said 40mm from the leading edge of the bottom wing, I assumed Bipes were always ballanced on the Top wing?

 

Tim thats a sad story! Bit like helicopters then? Something I keep well clear of... Bipes have a uniquness compared to conventional mono-planes! I suppose with mordern techonolgy etc I assume many compaines have manufactured Bipes to be easier to fly?

[Dusty]

Took the Pitts round to a mates house this evening and he helped me ballance the model being an avid bipe flier. Whilst I was there we linked the model to a scale to see what the thrust was, it was bang on 4kg so pritty much 1:1 over a tad more over, should fly well "I hope"

[Dusty]

Managed to get some work done on the model this week! I have painted the face of prop and re ballanced! Sourced a bigger 3 blade spinner so hopefuly it arrives soon!

 

Guess I need to maiden this asap before next winter arrives!

[Sheldon Holy]

Nice! That big 3-blader looks brilliant. Now we want to see it in the air

 

Sheldon

[Dusty]

Hi Sheldon

 

Thanks! Yes she will be in the air sometime this week  I needed to bed the Mirage in and some other projects so...

 

Anyway here is a update to the nose! All my bits arrived over the weekend and now I have the cosmetic look I was wanting! Hope you like?

 

Better huh?

[Tim Mackey]

Yep... but it will fly better if you fit wings on surely?

[Dusty]

Well yes LOL.... i hope

 

I am lazy and its like doing the dishes fitting the wings! You lucky it went into the garden for Kodak moments!

 

Now go moderate naughty people or build your Hawk!!!

[Tim Mackey]

... Im gonna sulk now.

Actually, I have just two models sitting in boxes now, after my sudden burst of activity over the last few months, all outstanding mag pieces written and submitted, alienator done, rippy spit done, spacewalker done,   so apart from the garden work that is looming...I have no excuses left really

As Snow is forecast again for next week, it looks like starting on one of the two models will win...but which should I do ?

The easy peasy Extra 300 which will probabaly take under a week in total

......or......the flyfly Jepe hawk.

Decisions

Dont bother to reply, cos I know which one will get your vote!

Oh, and NO, I cant do both, I am a man and cant multitask!

[Dusty]

Tim,

 

Great minds think a like

 

I will say the Hawk for number of reasons:-

 

1. Wont take long to build once you get going! You have been there before

 

2. Review the JEPE version of the Hawk compared to the bog standard FlyFly

 

3. Review a decent EDF model that is a 90 size and affordable as much so as the other cheap edf things flying that are **** and look like toys IMO and defeat every aspect of effiency in ducting, fans etc etc etc.. I did hint David in another thread to review a JEPE fast foam... please

 

5. Do what you feel is going to be the most enjoyable (catch 22 there hey)

 

6. If you choose the other please send me your Hawk and I will build it for you

 

7. Sorry forum for going way off topic but I followed the footsteps of mods LOL!

 

Hope you enjoy the snow  enough of that!

 

 

[Dusty]

Maiden complete she flies

 

Snuck to the field whilst no one was about to avoid any embrassment incase it went peep tong! After 10mins of rigging she was ready to go!

 

Very stable, 5 clicks of trim down so I need to adjust the c og slightly forward! As I kind of expected the 3 blade didnt give enough "punch"  IMO so I will try fly with a 2 blade. Rolling circles were effortless, rolls crisp, hammerheads nice and the rudder is very sensitive. Even in the wind she handled well and has a nice presance all round. Now I know she flies and handles well I will play abit more and get some vid/pics in the near future!

 

Landing is abit like a warbird, blips of power to bring her in...

 

Never flown a bipe before so it was a new exprience! Kind of like them except the rigging part

[Matt Halton]

Congrats Dusty!

 

Glad it all went well, shame about the prop,it looked great. Bipes are excellent, no flaps to worry about, landings are completely controllable with speed and descent with a bit of power as you found, I'm a biplane lover too!

 

Enjoy her mate, and I'd love to see a video.

 

Matt

[Dusty]

Thanks Matt,

 

Well the 3 blade prop can still be used for lazy Sunday flying or sedate flying probably be adequate for the average flier, I am just being greedy as I wanted the 3 blade and the thrust...

 

Hope the Buc is feeling better!