griff7166

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double post

dlipton

Ack. Sorry to hear about your Invitation. That's a very nice airplane. I hope you can resuscitate it. Thanks for the advice on the Contrast. I will be flying intermediate this year, so I think I'll leave the tcan. I think I will try the higher pitch prop like you suggest.

griff7166

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What district or you or state I might see ya out there

dlipton

D7, Northern California. You?

Silver Bullet

Matt, what esc were you using?

griff7166

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I fly for jeti and I was using a mezon lite 90 . But after close inspection I found that I had a cell fail in my thunder power pack (g8 ).also I will be moving on June 1 to California the Edwards AFB area

mups53

My Feedback: (41)

Guys I have 2 Contrast's in stock both are on sale.
This is a really well made extremely light plane.
http://www.f3aunlimited.com/catalogs...contrast&cat=0
Mike

tom.laird

Hi,

I either use an APC 20.5 x 14 or a Biela carbon 21 x 14 but could not tell the difference to be honest. I fly with the canaliser fitted and do not have any wing or tail fences fitted. Batteries are approx 1" forward of the main tube and I'll use my heavier Hobby King ones if it is particularly windy. I'll move them another 1/2 forward depending on the strength of the wind.

The main wing is set to half a degree positive (leading edge up) and the stab and canaliser are as per the factory setting. I have -4% (elevator down) coupled to zero throttle for downlines. I am flying with about 1mm of up-trim all the time as I ran out of trimming time and had to start flying comps. I am flying the 2015-16 Intermediate schedule (no bunts).

Landing is a breeze with no sign of stalling. In fact trying to get it to stall into the spin on a windy day is a real challenge

I have about 0.5mm down elevator trim coupled to full rudder for both knife edges, however the weather in Scotland has been so bad this year it is impossible to finalise the KE set-up. I either have 10 - 15MPH @ 45 degrees from the North West, North East, South East or South West, and sometimes all in the same day.

I fitted 3.25" diameter wheels for landing on (wet) grass and this stops it nosing over, though I also epoxied a small piece of carbon cloth onto the chin cowl to reduce the risk of a hole appearing as a result of the nose-overs.

I have no complaints about the model except perhaps the carbon undercarriage legs could be a bit stronger. I noticed they had to be ground down by about 1/4" front & back to fit into the fuselage recess and this has probably resulted in a weaker leg. I am on my second set and think they are getting a bit soft so will take them off and inspect them this week.

best regards

Tom

pippy

Hi Tom, I fly Bj Craft models and which tend to nose over on grass so I change the undercarriage to PT models undercarriage which are less raked back and hence no nosing over. They are also slightly lighter.

tom.laird

Thanks Paul,
Could you let me know where you are getting them from please?
thanks
Tom

pippy

The website is ptmodels.cz. You can select it to be in English. You email Pavel for what you want.

tom.laird

Thanks Paul.

algis123

It will soon begin to produce new RC-Composit bip CONTRAST PRO LT

pippy

Any plans to produce an electric version with access in the top for battery?

tom.laird

Hi,
My latest mod it to epoxy a carbon strip along the inside of the battery tray outer verticals, and add a strengthening strip along the inside. I have also moved the tray towards the read to try and get the C of G further back.

Tom

sergiortiz

Hi,

I recently bought Contrast to Algirdas.

I have mount the plane with the next configuration:

• Motor: Hacker Q80-14XS.
• Prop: RS 21x14.
• Spinner: Falcon 82mm.
• ESC: Jeti SPIN 99 Pro OPTO.
• Motor mount: front mount from Rc-composit, rear mount from Wolfgang Lorenz (modified).
• Aileron and rudder servos: Futaba BLS171SV.
• Elevator servos: Futaba BLS173SV.
• Linkages: bearing ball links and clevis from F3a-unlimited.
• Radio equipment:
  • Electronic switch DPSI Micro DualBat 7.2V F3A from Emcotec, with two 2S 450mAh Lipo.
  • Spektrum AR9020 DSMX receiver + Spektrum TM1000 with voltage sensor in the main power pack batteries.
• Main power batteries: 2 x 5S Lipo 4500mAh 20C.
• Weight without main power batteries: 3907 grams.

I have flown Contrast only for 12 flights, but I think it has a good performance. It's really stable, and it makes rolls really well, even the knife mix is not completely adjusted.

I have been playing with the centre of gravity and the wing incidence. I have the cg forward and the wings at 1.3º (+/-) of positive incidence, and the plane has a stable flight, and the elevator trim is near to zero.

I decided to put the T-canalizer a 0º and the performace is good. I really don't know a lot about it, but it seems that performs well.

I need to flight more the plane to find the proper adjustment, but I think that It is a solid F3A.

I attach some photos.

mups53

My Feedback: (41)

Hi Sergio
Thanks for this nice report. You have all great equipment. RC Composit makes beautiful planes.
I have 2 in stock ready to ship if anyone would like one too.
Mike Mueller

sergiortiz

Mike, thank you for your comments.
I've just placed 22 flights,... I'm trying to find the best setup.

Matt, I've read you have the center of gravity forward,... 25% from the back edge of the wing tube. I have it more to the back,... And I have my gator incedence adjuster to the end of the displacement to put positive incidence to the wing. I can't put the wings more positive than 1.3º (+/-). Now, I need to correct some small deviation to the canopy in the uplines, and I need to change the CG to the back to gain downtrust. How do you reach this setup?

Sergi.

algis123

Hi all, my email account send bad letter with a request to help me, it's a virus, ignore.

tom.laird

Hi Sergi,
Could you let me know how your knife edges are with the 1.3 degrees of incidence please.
Are you flying with up elevator or have you trimmed it out?
Thanks
Tom

sergiortiz

Hi Tom,

With the incidence at +1.3º (it's the max I can with the incidence adjusters), I have 2% of rudder - down elevator mix at the end of the displacement of the rudder stick. I'm using the T-canalizer, so I need less rudder rate to maintain the plane in a horizontal flight in knife edge.

With the wings at +1.3º I could move the batteries forward like you can view in the photos of my previous post. But I had an small deviation to the canopy in the uplines, and then I needed to change the CG to the back to gain downtrust (trim down in the elevator). Now I have the batteries at the end of the main battery support you can see in the photo. I’m removing this trim moving the stabs with some +0.2 positive incidence,... but I need more flight to reach the 0 trim of the elevator. I have only made 30 flights,…
Incidence setup at the moment (I’m taking the motor shaft as a reference): motor (0º), wings (+1.3º), stabs (+0.2º), T-canalizer (0º),.. all them are aprox,...

What about your setup?

Sergi.

tom.laird

Hi Sergi,

I have not made any changes since my last posting but my final 2015 competition is next Saturday after which I will be looking at the overall trim again. Currently I have 1mm up elevator for normal flight with 0.5mm on zero throttle for downlines. For left rudder knife edges I have 0.5mm up and zero for right-rudder knife edges.

I am using a Biella 21 x 14 @ 70 grams as opposed to the 120 grams for an APC, and my spinner weighs 50 grams as opposed to the 28 grams for the carbon one. I will be changing the spinner later this year.

My batteries are further back than yours which was the position to counteract the pull to the canopy in a knife edge. The batteries weight 1217 grams for the pair. If I hold the model by the wing tube with the batteries in the position shown it appears to be very tail-heavy, but when I reduce the throttle for landing the nose drops a lot and I feed in 6 or 7 beeps of up elevator to help hold the nose up.

My first priority will be to check the knife edges to remove the rudder elevator mixing, and then look at the mixing out the effects of using rudder in the inverted 45 degree up flight.

My main wing is at 0.5 degree positive incidence. The canaliser and tail are at the factory setting.

You can see in the picture the rudder deflection. I need less than this to maintain a knife edge and the amount in the picture will give a nice knife edge half-loop up. I don't have the nerve to do the down section

br

Tom

sergiortiz

Hi Tom,

I have just made 34 flights,… and I’m still trimming the plane. I’m adding positive incidence to the stabs for removing the trim (down trim). I have +0.2º, but I’m going to add +0.2º more (+0.4 related to 0º motor), because I still have some down trim. That’s the same to say that the motor is -0,4º from the stabs. My knife edge mix is symmetric (2% rudder – down elevator).

Now, I’m using RS 21x14 extralight prop (around 40 grams), falcon spinner, and I’m using different batteries,…(10S 4350 – 4500mAh – 20C). But the weight is around 960 – 1050grams,… more o less.

I’m using lots of positive incidence on the wing to have a nose heavy airplane, with the idea to obtain a stable flight,… But with the current configuration I think It’s well balanced,… I don’t need too many down elevator in inverted flight,… and only a few rudder in the knife edge is needed,.. As you said it’s possible to make a knife loop without any problem.

But all this adjustments depend of the taste of the pilot,… It’s a good challenge to obtain a free knife edge mix plane,… but with my current setup it’s not possible,… Maybe I need to taste more adjustments,…

Have good flights.

Sergi.

algis123

Hi, new paint schemes.

mups53

My Feedback: (41)

Hi Algirdas
That scheme looks so nice.
If anyone in North American is interested in getting one give us a shoot.
Thanks, Mike Mueller
F3AUnlimited.com