griesel

Disclaimer: All the problems found so far I consider minor. This is the PNP version.
The plane was purchased for IMAC Basic practice so there will not be 3D flight information.
The part of the manual devoted to assembly is only 4 pages. This is not an Aeroworks manual
for sure. I took 4 hours but I am slow. I would like to hear if anyone makes it under 1 hour.
INSTALLING LANDING GEAR
A note says you can remove the landing gear fairings. If you can remove the fairings
then the wheel pants can go for the same reasons. However I found it necessary to add
slightly longer very small servo screws and 4-40 washers to hold on the fairing plates.
Also had to scrounge up 4 wheel collars to hold the wheels on. About less the 60 seconds
to get rid of the fairings and pants. About 30 minutes to figure out what to do and get parts.
INSTALLING WINGS
This is what should be done:
1. Turn plane upside down.
2. Insert wing tube
3. Install left wing gently pushing in until the wing bolt holes align.
4. Install left wing bolt.( I think the wing bolts are the ones where the thread goes only half way.
Do not use thread locker as it is plastic.
5. Very gently make sure the wing tube is fully in the left wing ( very important the right wing
may jamb).
6. Repeat 3,4 on right wing.
On mine there was an extra bolt for the wings and the horizontal tail. If the bolt falls out in flight
and the wing or part of the tail falls off you might or might not need the extra parts.
INSTALLING RUDDER
It kind of clicks into place. If you study it; it will be intuitive. Do not break anything as it looks
like some of the fittings are plastic.
INSTALLING HORIZONTAL TAIL ...............
Pretty much the same as the wings.
INSTALLING PUSHRODS
This is standard stuff. I am not in love with plastic clevis but went along with it.
INSTALLING THE FLIGHT BATTERY
I was inserting the small end of the velcro thru the hole then bending the small
end down the side of the battery. This is a very secure way to hold the batteries
in but takes forever to install and remove them. I am going to try placing the small
end on top of the big end without messing with the hole. Will report on this later.
CONTROL SURFACE TRAVEL
Set up everything according to the manual. Have not tried High Rate yet but after
one flight changed the aileron low rate down to 20% for the travel setting. This set up the
roll rate to about 300 - 400 degrees / second ; which should be pretty close to the real plane.
Everything else, for the low rate, was good to go.
TRIM FLIGHTS
Had to trim the elevator and ailerons a little. It was windier up high which made trimming
a little difficult.
WEIGHT and CG
I did not have any 2800mah 30C 4S batteries but did have a 2200mah 35C 4S and a
2200mah 40C 4S and a pair of 3300mah 30C 4S.
Weight with the 2200 mah batteries was 3.70 lbs. and 3.92 lbs with the 3300 mah ones.
This brackets the spec weight of 3.75 - 3.8 lbs. CG was 6.125 inches with the 2200's all the
way forwardand 6.25 inches with the 3300's an inch back (almost all the way ).
I ordered a 2650mah 40C 4S which is closer to the 309 gram BNF battery. Will report later.
VERTICAL CLIMBING
I did not verify the thrust to weight ratio of 2.0 but I am sure it is at least 1.7 with both battery
weights. This baby is going to be able to power out of a hover very well.
STALLS
With the CG forward it basically mushes forward, but sometimes it would fall off on one wing
but very very slowly. No sudden tip stalls with a forward CG.
LANDING
I would say it was easy to land fast or slow. Sometimes it would set down on one wheel
and stay there until a tiny tic of the aileron brought the other wheel down. No big deal,
but I have never had a plane that would do that.
GROUND HANDLING
Very good at the low rate rudder settings. I may increase the rudder travel a bit because I
did put it into the dirt when I misjudged a turn onto the taxi way. Paved runway at Tucson RC Club.
PROBLEM
After about a dozen hatch openings one magnet pulled out of the fuselage. Drilled three small
holes between the two existing holes; filled all 5 holes with hot glue and added a layer on top
and quickly pushed the magnet down into the goey mess and held it there while the glue solidified.
Added 4 pieces of clear tape on top of both magnets and keepers to reduce the force.
These are the strongest hatch magnets I have ever seen. Will later report how it works out.
BATTERY LIFE
I flew up to 9 minutes on the 3300's and 6 minutes on the 2200's doing one IMAC routine
and one touch and go etcetera. On four total flights I did not deplete any of the batteries.
In the shop it ran for 9.5 minutes before starting to shut down at 50% throttle with a 3300mah battery.
However cruising around only took about 40% throttle. More on this when I get a lot more than 4 flights
on it.
CAUTION
Do not get anywhere near the foam with a soldering gun or a heat gun. Bad things happen.
Do not change the connector on the speed controller without removing it from the plane.
PHOTO's
1. Top hatch - the left magnet is misplaced and attached to the hatch - right velcro tools
2. Bottom hatch - Optima 6 in nest - antenna mounted thru hatch cover - plenty of room in there.
3. On work bench - In back ground is a Bill Hempel Yak being assembled
ASSESSMENT
Quick and easy to put together and with only four flights it seems to fly very well. If you like the
T28 you are going to love the CZ Yak 54