EVERY MANUFACTURER IS ADVERTIZIZING CCPM – WHY? BECAUSE IT WORKS SO WELL.

Yup, almost every RC heli ad you see now a days talks about their helicopter having CCPM. Is it a gimmick, a new marketing buzz word like 3D (don’t get me started on that one)?

I am glad to say no – it is a huge benefit – it simplifies life for you, makes your servos happy, and makes your helicopter fly better.

Before I get ahead of myself, I better explain what CCPM stands for and what it does... the benefits will then become obvious. It is an acronym that stands for... Cyclic-Collective-Pitch-Mixing. This feature is only found on RC helicopters with collective pitch (as the name suggests), it doesn’t apply to fixed pitch helicopters.

I should mention that you will sometimes see CCPM referred to as electronic (eCCPM) or mechanical (mCCPM) mixing. While this is essentially correct I feel it adds too much confusion. Seeing that true CCPM is only produced electronically, that is how it will be referred to in this discussion.

MECHANICAL MIXING

Until CCPM came around, we only called our mixing method mechanical. A way to control pitch function and cyclic function by means of a complex series of linkages and levers. Most systems consisted of mixing the collective pitch servo movements with the left/right cyclic servo and the fore/aft cyclic servo movements to the swash plate.

This does make setup a bit more difficult and because of all the linkages and levers, there is always a bit of slop or play. This can be minimized on high end helis by using ball bearings on all these levers in stead of simple bushings, but of course that adds to cost and weight.

This method of pitch control does put a lot of strain on the pitch servo. It not only has to move the entire swash pate up and down to change the pitch angle of the main rotor blades, it has to overcome all the friction associated with all the linkages.

Mechanical mixing does have a few advantages, such as no swash plate variation issues and because the servos are usually mounted in a servo tray and not in the frame, they are exposed to less vibration.

These are minimal benefits seeing that todays servos are much tougher and there are ways to almost eliminate swash plate variations either mechanically or electronically.

ELECTRONIC MIXING

Cyclic-collective-pitch-mixing is only possible because of advances in computerized RC radio technology. The mixing functions are all done electronically within the RC radio and the servos move accordingly.

Now two, three, or sometimes four servos can be hooked directly to the swash plate with out any complex mixing linkages. This of course simplifies the helicopter, reduces the number of parts, weight, and cost. There is less slop in the system and this provides very precise control of your helicopter.

The problem of excessive strain on the pitch servo is also gone. Not just because the linkages are gone, but also because the work load is now spread over two or more servos.