Tech One Mercury (NP) or Breeze (HK)
Tech One Hobby Mercury Trainer Kit from Nitroplanes.
I just received this trainer kit.
I was looking for a sturdy taildragger where I could mount bigger wheels so I could land and take off on moderate height grass.
This one arrived very well packaged, double carton and excellent styro inside, securely holding the parts. No damage observed.
Added on 9/26/2013
This model with a new wing with a center spar running between the two halves is now sold by HK as the "Breeze":
Reserved for listing mod's
1) 2 layers of WBPU to protect foam and very fragile decals.
2) used the WBPU to put some .75oz fiberglass on the wing tips and fuse bottom.
3) reversed one flap servo to preserve the stock pocket orientation.
4) Cut out foam in rear to make more room for RX.
5) Installed plywood floor above ESC to have a stable platform for Guardian stabilizer while moving it forward to make room for spaghetti.
6) Replaced wheels with bigger dia for grass.
7) CAUTION!!! Firewall sits loose and wiggles in grove, makes motor rattle. Glue firewall solidly into its groove before testing or flying.
8) Inserted 1/8" shim under trailing edge of main wing to reduce decalage resulting in a less strong pull-up during dive test. CORRECTION: This was the wrong move. Better to fly with a 1600 mAh battery.
9) CAUTION!!! Make wing halves into a single wing with ducktape to prevent breaking the sparboxes.
10)Infiltrate gorilla glue between landing gear fixation and fuse after it works loose.
11) Landing gear bends too easily. Installed a heavier guage landing gear from the HK Bixler.:http://www.hobbyking.com/hobbyking/s...h=bixler%20lan
-good quality foam
-well reinforced wing, little flex
-flap option with pre-cut servo locations. Both servos point outwards, so either recut and flip one location or use a servo reverser. Will they never learn? For the same money...
-hardware: pushrods,quicklinks,control surface horns of a bridge like type,6x4 2b prop,tail wheel,4 motor fastening screws,rubber bands and a Y servo lead.
Feels compact and strong compared to the Skysurfer (of which I have built four kits)
-most decoration is transfer decals. The packaging styro holds the parts so well that it rips off the decal colors. not repairable!! They put some sheet protection on the wing tips but not for the wing middle nor for the fuse.
Looks like it can handle some rough landings
been looking at this plane to do up as a night flyer. let us all know it flies
I am interested as I want to try it for fpv... Checks all boxes, cargo box looks cramped though
Finished the wings. Decided to use these servo's:
Bought two 3-packs for $18.00. Six in all for Ail, Flap, Rud, and Elev.
Decided to reverse one flap servo to maintain the orientation of the stock cut-out. It is tricky soldering!
The other solutions are a servo reverser or cut a new pocket and flip the servo.
The control surface horns of a novel form to me, attach easily and look solid.
Nice touch is the wider channel space provided to bury the extension connector leading away from the aileron servo. Of course the leads on my servo's are just a bit too short so I had to cut a bit of foam.
I glued on some servo covers which I had, just because it looks better. But the the double servo arm protection looks a bit funny.
The .75oz glass on the tips is almost invisible.
The spar runs 2/3 of the lenght of the wing, making it quite rigid. The two wing halves connect together with a square dowel (CF?) sliding into the wing spars.
I decided not to glue the wing halves.
I will post pics later.
Motor and Wiring
I used this motor which I had:
It is a 2826 with more than 300W and weighs 50g. All for $11.00!!!
I intend to mount a MAS 6x4 3 blade prop or a 6x5.5 2 blade and I expect around 25A draw.
The motor screws in perfectly. I added no thrust correction. Will fly it first to see if needed.
Getting the 3 wires through the narrow tunnel is a PITA. I made a 30A ESC with extra long 3 leads and fed those in from the front of the tunnel. Then connected the 3 motor leads, checked rotation sense and then pulled the leads with the ESC back forwards. Once it is inplace it is clean, but it takes some doing.
The Guardian is stuck upside down against the roof above the ESC with the USB port accessible from the front.
The receiver with most of the wiring goes in the back. Still have to find a safe position for the antenna.
Also in the front a 5A UBEC that feeds off the 3S balance plug.
And to top it all a 2200mAh in the nose.
Ventilation/cooling may be an issue.
I would gladly have seen an extra inch of width on this model. Give me the SkySurfer's cargo bay anytime!
dang it really is cramped in there!, i have some 1550 11.1v's, should be better.
looks good though, keep the pics coming!
I guess the CG will tell what size battery to use.
To gain some space in the rear under-wing compartment, I cut away some foam to lodge the Rx upside down in the back. It frees up a lot of space for spaghetti from stabilizer, Ail and Flap Y-leads.
Some tape holds the Rx and antenna in place, easy to remove.
Need bigger wheels
I only have a grass field varying from fairway to short rough.
I happened to have some 3" blue Fokker triplane wheels from Tower.
They are quite light and fit well in dia as well as in color.
The landing gear attachment is always a delicate problem. This one looks fairly solid, we will have to suck it and see.
I am still studying the option of a bigger tailwheel. Stock for the time being.
Edit: I mis-remembered. These are Nieuport wheels not Fokker. see:
One more Deck
At first I attached the stabilizer upside down with velcro to the ceiling of the middle compartment.
This does not work very well because velcro does not hold well to foam and the spaghetti in the back moves the stabilizer too easily.
So I combined the moving of the Rx to the back cut-out with the installation of a light plywood floor above the ESC, carefulli lined up to horizontal and CA'ed to the foam walls.
The floor stops about 1" short of the rear wall to let trough some airflow from around the ESC and to leave room for Rx plugs, which sits upside down.
The stabilizer now sits right side up and the USB port is more accessible.
It is now effectively a "three decker"!!!
I wanted to maiden this Mercury yesterday before the storm hits.
Total weight w/o battery 635g. Because there was very little wind during maiden, I chose a 3S 1800mAh 40C to get the CG to the rear of the recommended range @ 65mm.
Static test 25A draw with a 6x5.5 2blade prop and 30A ESC. The RC_Timer 2826 2200Kv delivered 295 Watts. I like a bit of reserve!
With that battery it should be good for 4.5 mins @ full power.
Takes off at 1/2 power w/o flaps. Rock steady. Needed virtually no trimming. Gains on the stabilizer were set too high for ailerons, causing wing rocking.
When making rudder only turns, it loses altitude and gains speed, then climbs again when level. It does not do that with an aileron turn.
No ballooning when extending flaps! Remarkable!
On final with flaps, it flies like a SlowStick.
This is going to be fun!
During maiden the motor had a pronounced rattling sound even with a well balanced propeller. At first I was suspecting the motor fixation screws but then I noticed that the whole firewall was moving inside its grove. I squirted CA all around the grove so now there is no more wiggle room. We'll see at the next flight.
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