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Old May 30, 2011, 09:28 AM
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Athens, Greece
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Hi Tamas,

That is an interesting thought that the fuselages are common.

They are the same in appearance and the length seems to be exactly the same.

If that is the case, and the hole pattern is the same then possibly I will buy a Fascination wing for my Grafas.

The chord of the center panel is 260mm and the holes are 197mm from the leading edge to the center of the 5mm hole. The distance between the holes (center to center) is 33mm.

I wonder how the 3600mm wings span works on the same fuselage that is supplied with a 3070mm span model. That is obviously part of the reason that the GRAFAS has fantastic directional stability at very high speeds as well.

Let me know what the result is.

mike
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Old May 30, 2011, 11:54 AM
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Jerez Frontera (Spain)
Joined Nov 2004
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I`ve just finished mine last week. A recheck and I`ll try to maiden next weekend.

I had put a Kontronic Fun 500 with gearbox 5,2:1 and Aeronaut 16x10. I`m going to use a 3S-2600 MAh Lipo. Mine has the same colours as yours except the rudder that is white.

I haven`t weighted it fully assembled, but I think it will be simillar to yours.

Cheers.
Josť L.G.
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Old May 30, 2011, 03:40 PM
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Athens, Greece
Joined Apr 2010
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Josť
That is a huge motor for this little glider.

We are using that particular motor (KIRA 500 w/reduction gearbox) in a 3kg, 4000mm full molded XPLORER and it climbs like crazy.

My GRAFAS weighs 1900gr (flying weight) and I am using the same prop size as you are on the AXI motor and it climbs vertically (44Ampís with a 3s Li-Po)

mike
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Old May 30, 2011, 04:24 PM
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We are currently building a Grafas, and found this thread very useful. Thank You!

I'm a little perplexed as to how the little plastic exit tubes for the pull/pull cables are supposed to look - Can anyone clarify how this is generally done?

Thanks,

- Eli
http://rcflyers.mirafiori.com
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Old May 30, 2011, 04:42 PM
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Hungary Hajduszoboszlo
Joined Jul 2008
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Yep!!!

I measured the same
I can finish mine Fascination, in the next month. So after I will try out also.
Its should be a very interesting comparison, a glider with 3,07m and ~2kg and 3.6m with 3kg.

Thank you
Tamas
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Old May 30, 2011, 06:55 PM
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Another important item - I use a JR 9303 Radio, and I was planning to use a 7 channel RX. Should I be thinking about setting this up in Sailplane mode, or set it up as an airplane and set up flight modes for different wing mixes?

I am trying to slog through the JR Sailplane manual, and any real-world advice would be appreciated!

Best,

- Eli
http://rcflyers.mirafiori.com
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Old May 31, 2011, 09:41 AM
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Eli the rudder cable system is very easy to install, it just needs a bit of care.
The rudder must be installed with the two control horns glued in place. Install the rudder servo on the supplied mount in the fuselage under the wing. Measure the distance from the rudder servo arm to the wing saddle of the fuselage and transfer this measurement to the outside of the fuselage making a pencil mark.

Now place a long rule from this mark to the rudder control horn and mark another pencil line where the cable exit guides will be glued. (both sides) Mine are 35mm long and start 65mm from the balsa rudder post that you glued in place. I used a 3mm drill in a Dremel tool making a series of holes close to each other on the pencil line and then with a small file smoothed it out.

Glue the two plastic guides in the slots laying them as flat as possible along the fuselage. I pushed the two ends of the supplied cable into the plastic exit guides (one each side) until they reached the servo. Next assemble the two threaded brass ends and the links, the links must be screwed half way allowing adjustment both ways. Attach these to the outermost ends of the servo arm and take up the slack towards the rudder. Remember to cross the cables over so that the right side rudder horn cable will correspond to the left servo arm hole and the same for the other side. I use wooden mixing sticks clamped to both sides of the rudder and the fin thereby fixing the rudder in the neutral position. Using the transmitter make sure that the servo arm is as perpendicular to the rudder as possible. Now with slight tension to the cables see at which point they are at the hole in the rudder control horns and cut them with about 30 -40 mm longer.

Thread the small brass tubes on to the cables and pass the cables through the holes in the control horns and loop them back again now through the brass tubes. Pull the free ends of the cables with slight pressure until you have taken up the slack and see that the tube is about 6mm from the horn. Then using plierís squeeze the tube until it is firmly on the cable. Do the same to the other side and you are done.

You do not have to have the cables very tight as there will be no slop in the pull - pull closed loop system. Make the necessary adjustments with the links to ensure that you are completely neutral at mid rudder stick.


mike
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Old May 31, 2011, 09:43 AM
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Jerez Frontera (Spain)
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Quote:
Originally Posted by mikmerl View Post
Josť
That is a huge motor for this little glider.

We are using that particular motor (KIRA 500 w/reduction gearbox) in a 3kg, 4000mm full molded XPLORER and it climbs like crazy.

My GRAFAS weighs 1900gr (flying weight) and I am using the same prop size as you are on the AXI motor and it climbs vertically (44Ampís with a 3s Li-Po)

mike
Hi Mike.

This motor was a redundant one I have at home. I`ve been using the same configuration with a 10 cell (Nixx) pack. I checked in Motocalc and appears a good combination. My motor-gearbox weights about 300 grams (If I remember well), so my batt. will be less weighty. I am going to run in a 3S Lipo, not 4S.

Hope to maiden this weekend. I`ll report as soon as posible.
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Old Jun 06, 2011, 01:59 AM
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Jerez Frontera (Spain)
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Hi.
I maidened yesterday. All went well.

Really, at full power it climbs at 90 degrees. So,in the following flys only used 50 percent or less power.
In the crow I forgot mixing the elevator, so it pitched a lot (Thanks I tried very hight.

I didn`t check the power with a wattmeter, but with a 2600 bat (Charged at 90 percent) I managed 8-9 climbs in each sesion (at the end the batt. was at 15-20 percent).

I`m very satisfied with the perfomance of the model. Next weekend I`ll try to adjust the crow (really I landed without use of any braking).

On landing I lost sight of the plane. Probably I'll add some color or reflectan tape.

Find included a few pics of the day.

Cheers.
Josť L.G.
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Old Jun 10, 2011, 09:58 AM
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Grafas

I took couple of pictures for our web site.

Zb
Esprit Model

http://www.espritmodel.com/index.asp...D&ProdID=13821
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Old Jun 13, 2011, 10:22 PM
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Successful Maiden flight!

So, Maiden this last Saturday!

I was a little nervous, but it took off with such authority and grace that I gained confidence quickly. I was surprised by fast it was for a minute, until I slapped my forehead and remembered the 5 degree flap setting.

I cruised around for abut 15 minutes, I felt like I had the CG too far forward (better than the other way), so I brought it in. The recommended 60 deg landing flaps _really_ slow it down.

I moved the CG back by installing a 4.3oz CountourHD 1080 on the belly, and went back up for a second flight that lasted 44:10 before I hit LVC and felt ready to come down. The video was beautiful (post soon), and I could not be happier.

On Sunday I flew it twice more, learning how to manipulate the flaps, and dialing in some settings. I set a rudder auto-correction, and took all the expo out (it felt strange to me with expo in the ailerons). I used the three position switch on my 9303 for the three flap modes.

I landed after 55 minutes, because I was ready for lunch

I have considered moving the throttle to one of the sliders so I could use the left stick for flap control. Is that typical for powered sailplanes?

Future work items include a better aileron servo plug (Mike ditched the Mutiplex plugs in the wings, I did too because they are way too hard to plug in). I have JR extensions sort of hanging in the wings and it's not right.

Also, I think I'm drawing too much current, but that's going to take some more research to completely figure out. I'm keeping it below 60% throttle in order to avoid hitting LVC at 3.0v per cell. Some have suggested that I turn off current limiting - I need to send it up with the Eagletree before making any more decisions.

Build album: http://isaac509.smugmug.com/RC-airpl...delscz-Grafas/

This is a brilliant airplane, and I would like to keep this thread alive for future builders. Special thanks to Mike and everyone else for a great build thread, and also for staying with us newbies.

Cheers,

- Eli
http://rcflyers.mirafiori.com
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Old Jun 14, 2011, 06:39 AM
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USA, CT, Stamford
Joined Jun 2006
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Originally Posted by isaac509 View Post
So, Maiden this last Saturday!

I was a little nervous, but it took off with such authority and grace that I gained confidence quickly. I was surprised by fast it was for a minute, until I slapped my forehead and remembered the 5 degree flap setting.

I cruised around for abut 15 minutes, I felt like I had the CG too far forward (better than the other way), so I brought it in. The recommended 60 deg landing flaps _really_ slow it down.

I moved the CG back by installing a 4.3oz CountourHD 1080 on the belly, and went back up for a second flight that lasted 44:10 before I hit LVC and felt ready to come down. The video was beautiful (post soon), and I could not be happier.

On Sunday I flew it twice more, learning how to manipulate the flaps, and dialing in some settings. I set a rudder auto-correction, and took all the expo out (it felt strange to me with expo in the ailerons). I used the three position switch on my 9303 for the three flap modes.

I landed after 55 minutes, because I was ready for lunch

I have considered moving the throttle to one of the sliders so I could use the left stick for flap control. Is that typical for powered sailplanes?

Future work items include a better aileron servo plug (Mike ditched the Mutiplex plugs in the wings, I did too because they are way too hard to plug in). I have JR extensions sort of hanging in the wings and it's not right.

Also, I think I'm drawing too much current, but that's going to take some more research to completely figure out. I'm keeping it below 60% throttle in order to avoid hitting LVC at 3.0v per cell. Some have suggested that I turn off current limiting - I need to send it up with the Eagletree before making any more decisions.

Build album: http://isaac509.smugmug.com/RC-airpl...delscz-Grafas/

This is a brilliant airplane, and I would like to keep this thread alive for future builders. Special thanks to Mike and everyone else for a great build thread, and also for staying with us newbies.

Cheers,

- Eli
http://rcflyers.mirafiori.com
Every time I see one of these I wonder about the torsional rigidity of the wing given the lack of D-box and the round spar. Has this ever been an issue?

Louis
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Old Jun 14, 2011, 06:50 AM
USA: LakeGeorge, New York
USA
Joined May 2010
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Just asking, :-) but on the EspritModels website, it say's the plane is very much fully built?

just add servos and RC gear?

how true is this?
Post #40
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Old Jun 14, 2011, 10:17 AM
AMA7224 LSF1832
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Originally Posted by rclab1 View Post
Just asking, :-) but on the EspritModels website, it say's the plane is very much fully built?

just add servos and RC gear?

how true is this?
Post #40
I have the sister to her, the Top Model Avia and the "kit" is the same. Look here once in my blog and you can see the plane as it comes out of the box. Some assembly is required but it's easy going.

http://www.rcgroups.com/forums/showthread.php?t=1199728
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Old Jun 14, 2011, 10:31 AM
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Originally Posted by isaac509 View Post



I have considered moving the throttle to one of the sliders so I could use the left stick for flap control. Is that typical for powered sailplanes?



Also, I think I'm drawing too much current, but that's going to take some more research to completely figure out. I'm keeping it below 60% throttle in order to avoid hitting LVC at 3.0v per cell. Some have suggested that I turn off current limiting - I need to send it up with the Eagletree before making any more decisions.


I have all my sailplanes setup with the throttle on the gear switch that gives two speeds, off and on, and the flaps on the "throttle" stick. I put the watts in the wires at full tilt until the altitude limiter shuts down the motor at 200 metres. They are setup for ALES competition, but I run on the AL switch all the time as it gives consistant launch heights to work with.

For comparison my Avia, the sister ship to the Grafas, is running a PJS/CZ Hotline1300 and it's pulling 375 watts on a 2100 maH 40C 3S. This gives me 5 or 6 climbs at the above mentioned full power before I need to change it out. You need to check your setup with a watt meter as you indicated, you might have too much prop for you power plant.
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