Reassemble the entire head onto the shaft, replace the “Jesus pin” and track the
blades. Note that if you do this in front of a television screen, you can see via the raster
lines that the tips cone upwards! For this reason, the plastic blades are not suitable for
regular flight. You will need wooden blades, but I would shop for a better price. For
regular flight, this is noteworthy mod #4.
Noteworthy mod #5 is a decent capacity Li-Po battery and charger. You'll have to hunt
this on eBay, but I would go for something well over 1000mAH at least. The little green
stock Ni-MH batteries need to be charged to the point of being so hot, you cannot even
hold it! I have a trick, throw it in the freezer after the charge and watch the current really
flow when run cold! Even then, you get maybe 3 minutes of sufficient power to hover it
properly and with good response. Without the power afterwards, it bounces around the
ground and just damages your chassis even more! I have not yet tried two stock
batteries in parallel.
You want a shakeless rock-stable helicopter? Read on and follow exactly:
buy (2) 4-40 1/2” long screws with matching hex nuts, also maybe some internal-tooth
lockwashers and (4) matching flat washers.
Remember I mentioned that some DF4's come with a metal head stiffener? Drill
out the (2) screw holes to accept the 4-40 screws. Take the original blade holding
screws out of the Top Plate and remove the main blades. Now, remove those (2)
plastic spacers as seen in [Top Plate] photo. Using a 1/8” drill, open the spacers
to accept the 4-40 screws. See down arrows in diagram.
Replace the spacers into rotor hub. Now secure the blades onto rotor hub from
the bottom using (2) 4-40 screws and flat washers. The hex shape at the top
represents (2) 4-40 nuts. Use either Loctite here or (2) internal tooth lockwashers
with flats against the spacers you just drilled out. Sock 'em down TIGHT! For
even more stability, you can add this and it sits on the Top Plate.
What will this do? Okay, pull both blades straight out with your hands as hard as you can.
Now turn everything on, set the heli on the floor and slowly run up the motor.
Notice what's different? No shaking or vibration if you did the mod right. Now, pick it up
and track the blades. You do this by bending them to induce either more or less pitch.
Once tracked well, try hovering. Next, you should notice it lifts off much sooner and
easier on the throttle than before. Almost like you put a bigger battery in it. You should
also note that although the trims have changed slightly (adjust them!) the whole
machine is rock-stable and easy to fly!
After you hit something, check and retighten nuts as they may loosen. It is the overall
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