Setting up ECCPM
Index
1) Introduction
2) Notes
3) Procedure Order.
4) Mechanical Swashplate Diagram.
5) Tx Channel Matching to Swashplate Servos.
6) Movement Range & Direction
7) Swashplate Levelling Adjustment
8) Final Test Flying and Fine Trim Adjustment
1) Introduction
Trying to find definitive corroboration information on this subject is patchy - the best I have seen, so far, is on the Internet as videos (www.helifreak.com).
2) Notes
The current smaller Electric Helicopters now expect a decent Tx to support ECCPM.
This deals with 120 degree swashplate setup only. 140 degree involves using Tx mixers.
3) Procedure Order
1) Check and set connecting rods to suggested factory sizes by Manufacturer.
2) Check lh / rh / elevator servos are connected correctly to the swashplate.
3) Check that the servos are correctly plugged into the correct Rx channels.
4) Check Tx is set up for 120 degree swashplate. Manufacturer's instructions should be followed here. However if no guidance is given start with +70/+70/+70. (see "Movement Direction" if the pitch direction is wrong)
5) When swashplate is moving uniformly up and down, set middle of stick movement to 0 degrees.
6) Check and adjust swashplate to be level both in the roll and elevator axis.
7) Check swashplate is also level at both full positive and negative pitch positions.
8) Check swashplate is level in all modes.
8) Assuming 3D setup - Check mid stick = 0 degrees and maximum / minimum pitch values with pitch gauge. If too high reduce on Tx pitch curve.
9) Adjust sub trim / fine trim settings after test flight.
4) Mechanical Swashplate Diagram
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This setup example is from a Hitec / Futaba Tx and a Hitec / Futaba Rx. Use the Helicopter Manufacturer's Construction Manual to ascertain if the swashplate layout is different to the above.
5) Tx Channel Matching to Swashplate Servos.
Servos have to be the correct torque for the size of the Helicopter (30/50/70&90) and the three Cyclic servos should be matched.
.30 size torque = Collective 3.0kg 0.25sec Cyclic 3.0kg 0.25sec Throttle 2.0kg 0.25sec Tail 2.0kg 0.11sec
.50 size torque = Collective 5.0kg 0.25sec Cyclic 3.0kg 0.25sec Throttle 2.0kg 0.25sec Tail 2.0kg 0.11sec
.60 size torque = Collective 6.0kg 0.25sec Cyclic 4.0kg 0.25sec Throttle 2.0kg 0.25sec Tail 2.5kg 0.11sec
.70 & .90size torque = Collective 6.5kg 0.25sec Cyclic 5.0kg 0.25sec Throttle 2.0kg 0.25sec Tail 2.5kg 0.11sec
Make sure that the channels are connected to the correct servos prior to switch on, otherwise switched on the servos will move in opposite directions, and possibly bend connecting rods.
On an Electric Helicopter, I find it easier to set up using a 4.8V Rx battery connected and the ESC/channel 3 disconnected so there is no chance of accidents. The throttle direction can be checked last.
6) Movement Range & Direction
The + or - denotes the direction the swashplate moves (up or down)
The value % + 70 (to 0) denotes the movement range for each servo.
Assuming +70/+70/+70 settings, if the Tx stick is at full positive pitch and swashplate moves the front of the main blades down (negative pitch), then change the values to -70/-70/-70 which will reverse the movement.
Note that if there is any binding at extremes then the movement range should be reduced.
7) Swashplate Levelling Adjustment
Servo arms should be at 90degrees to the Connectors mechanically when the swashplate is level.
Tx Trims should be set to zero.
Initially, use connectors for adjustments only.
Sub Trims ideally should be zero, but very small amounts can be used if servos / arms do not center.
Use ATV to fine adjust swashplate levelling.
Check ATV settings in each flying mode.
Re-check for binding at cyclic exremes in each mode.
8) Final Test Flying and Fine Trim Adjustment
Set up using fine trims on Tx , then add trim settings to Connector lengths until trims can be set to zero.
If a lot of fine trim has to be used, then adjust Sub Trims so that fine trims return to zero.
Re-check for binding at cyclic extremes.
This is time-consuming but worth it.
Finally, fine trims are used to finalise or compensate for flying conditions.