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Dec 02, 2013, 01:55 AM
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Build Log

Phoenix K8B 3500

Hi, i have just received a Phoenix K8B and will be doing a (slow) build thread.
I will post some pics soon, but it is off to a bad start the finish is quite bad, mainly due to the burn marks of the laser cutting showing through the covering.
I intend to fit an electric motor (sacrilege i know) as any other form of getting it airborne is not practical.
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Dec 02, 2013, 02:02 AM
Rectal cancer survivor
WOW!! Talk about freaky. I did a search in "Scale Sailplanes" for anything on the Phoenix K8B 3.5 Metre wing span, and found nothing except some bits in the Seagull 3 Metre threads. I was about to start a thread asking if anyone had one and what, if any, mods were performed, or trouble areas noticed. I don't have the plane, but I am thinking about it. I will be watching closely.
Dec 02, 2013, 05:53 AM
Registered User
Just started the wings on one of these. I'm building for aerotow. Noticed the same burn marks showing through the wing's white Oracover from the laser cutting. Will follow your progress with interest.
Last edited by sleep4; Dec 02, 2013 at 06:00 AM.
Dec 02, 2013, 09:56 AM
Asher Carmichael's Avatar
If the laser marking only appears on the rib edges and it is too noticeable to accept, you might try cutting some narrow strips of vinyl sign material or covering and apply to the rib area to simulate rib stitching. While the full size may or may not have stitching on the top surface, the simulation might solve the apprearance issue with the least amount of effort.
I have successfully cut serrated-type turbulator strips for scale sailplanes on my vinyl cutter. The additional "sawtooth" edges would add additional realism. If you can draw what you want, most any sign shop should be able to cut strips for you out of thin sign vinyl. They may also be able to cut it using your covering material as well. If you strike out with your local sign guy, let me know, perhaps I can help.
Good luck
Dec 03, 2013, 01:36 AM
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I have decided to put up with the burn marks showing through the covering, now that i have looked at it a few times it does not seem as noticeable
I have ironed and heat gunned out the wrinkles and put on the stickers, the quality of the plane as a whole is reasonably good and it has some nice touches, like the fact that aside from the hinges no glue is needed as the tailplane bolts on, as do the wings obviously. There is also supplied a carriage to mount the electric motor that bolts to the fuse floor and a small section in the instructions about fitting a motor
The pilot must have gone through the wash and shrunk, so he will be replaced with a more suitably sized example
Overall i am very happy with it and when assembled it is a fantastic looking plane,
Unfortunately with the advent of Christmas i will not be buying any radio gear for a couple of weeks, so progress will cease for a while
Dec 04, 2013, 07:59 AM
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German RC network site of Phoenix K8B 3500 discussion. Model has been available there for some time now and apparently well received. Lots of interesting posts on modifications and setup. (need Google translator on your browser unless you speak German).
Last edited by sleep4; Dec 05, 2013 at 08:09 AM.
Dec 04, 2013, 10:51 AM
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Fred Sanford's Avatar
Dec 04, 2013, 12:40 PM
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I have had a look at the German thread (my computer translates)
An interesting note, i emailed Tower Hobbies to inform them of the issue with the burn marks of the laser cutting showing through the covering. They have credited my account the equivalent of 4 rolls of covering i am very happy with this outcome, the service i have had from TH has always been great!
Dec 05, 2013, 02:01 AM
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Damian Couzoff's Avatar
Originally Posted by sleep4

German RC network site of Phoenix K8B 3500 discussion. It has been available there for some time now and apparently well received. Lots of interesting posts on modifications and setup. (need Google translator on your browser unless you speak German).
YES,rc network has been very helpful for many glider builds.Highly recommended viewing.................
Dec 05, 2013, 09:04 AM
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The pink shirt? Busted!!!! Of course... everyone knows the Johnny Cash song about a 'Boy Named Sue' so I think you're safe! That's a great looking sailplane!
Dec 17, 2013, 03:56 AM
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I have Ordered the recommended Rimfire 800 kv motor from Tower Hobbies and 4 Hitec HS-311 standard servos, i have used both these products in the past and have found them to be very good. I will be using a Turnigy 60 amp controller with a castle creations seperate BEC (with the power wire disconnected between the Spd cont and the reciever) again a regular choice in most of my electrics
The tail surfaces have been hinged and bolted to the fuse and the control horns and rods fitted. The quality of these hardware parts is very average, particularly the control rods and i may well replace these with bowden cable before i fly it.
I have elected not to glue the plastic keel under the nose as it does not look very good and i can't see that it will add much protection now that the nose wheel is in place.
The cockpit floor has been removed to extricate the pilot and i am on the hunt for a better looking candidate

Jan 03, 2014, 03:38 AM
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Hope you all had a great Christmas and new year!
The motor and servos arrived this morning so the build resumes, i fitted the motor and put on the only folding prop i have which is a 10 x 7, this drew 30 amps for 475 watts.
This is about half of what i want so the next prop i will try is a 13 x 6.5, this is probably still a bit too small but it is the closest i can get in this country at the moment
Aside from the prop it will be finished tomorrow so will have the final weight with the 4 cell 5000mha batteries, if i can get away with smaller batteries i will, but i would rather have extra battery capacity than have to add lead to the nose
I also found a (slightly) better sized pilot to be entrusted with the flying duties
And just to irk the purists a little more i have added a couple of air scoops, one below the canopy where the speed controller sits and an outlet under the rear stabilizer, covered with a plastic spoon
Jan 10, 2014, 06:45 PM
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I have just completed the maiden flight the 13 x 6.5 prop arrived which took the watts up to 750 watts, exactly what i was hoping for
It was a little bit nerve wracking hand launching an 8.7 lb plane but it was not an issue, and the lateral balance is perfect so no aileron trim was needed.
However it climbed very steeply and needed lots of down elevator so i was struggling a bit at first, after a few circuits i landed ( very easy to land with no flaps or airbrakes) and checked the cog.
I put in a heavier battery and moved it forward, this helped but i suspect it still needs either more nose weight or the incidence checked.
The second flight went better and i flew for about 20 minutes
A few observations; roll rate is slow and turns are accomplished using mainly rudder. It has huge thermal potential! i caught a couple of thermals and quite frankly was astounded at how much lift it was getting
and best of all it looks so smooth and graceful in flight
Jan 10, 2014, 11:43 PM
Gasbags & Gussets
jswain's Avatar

congrats !

i'm glad to see this project work.
I would of done the same (e-power) and now can use this model's motor specs as a baseline.
thanks again, js

ps - on my electro-gliders i mix some down elevator, about 8% down trim, during throttle up to tone down the pitching under power
Jan 11, 2014, 07:36 AM
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Bear... I was wondering was your mounting bolts for the tail section long enough? The bolts I have for the horizontal stab is not long enough! Not a happy camper here! I am not a metric fan, but I guess I will have to live with it!

Congrats on your maiden flight! Mine will be strictly thermal with a tow hook up.


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