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Motion Control Specialists
with special interest in R/C model helicopter control
CSM Ltd, PO Box 101, Glossop SK13 5ZW, England.
email: tech@csm-ltd.co.uk       Tel: +44 (0)1457 854680
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CYCLOCK

CycLock 1 CCPM manager

The real alternative to expensive in-transmitter mixing.

Eliminates RC system latency errors:

One of the most common problems with in-transmitter mixing of CCPM is that the three servos driving the swash plate receive their position information at different times so, for example when you push the collective stick one servo will receive the command to move first and, if it's a fast coreless servo may well have reached full speed before the other two servos even know they should be moving. This causes transient, unpredictable errors in the elevator and aileron when large sudden collective inputs are made. CycLock allows the RC system to transmit separate unmixed aileron, elevator and collective signals and mixes these simultaneously into all three servo command streams thus eliminating this source of errors. Also, by using two dedicated processors to handle the CCPM mixing CycLock can apply a complex mixing algorithm while keeping delays undetectably short - the mixing calculation takes less than 1ms - less time than it takes to send a single servo pulse. Also, where digital servos are being used on the swash-plate CycLock can drive these servos at digital servo frame rates - a feature that really comes into its own in electronic stabilised flybarless applications. Exploits full resolution of the RC link:

Because of the geometry errors in CCPM linkages become more apparent when large servo travels are employed it is normal for the total servo travel of the swash plate servos to be less than the standard (100% ATV) throw. Furthermore, each control (aileron, elevator, and collective) is responsible for only a small proportion of the total servo travel. Where the CCPM mixing is done in the transmitter all this adds up to a big loss in resolution with which the commands are transmitted. Lets assume you are using an RC system with a resolution of 2048 points. This 2048 points has to cover the maximum servo travel obtained with say 140% ATV set. So at 100% ATV you are already down to 1463 point resolution. At a typical CCPM servo travel of 70% you are down to 1024 points. If the collective throw only covers 50% of the CCPM servo travel you are down to 512 point resolution and for elevator and aileron the situation is probably worse. So, if you use in-transmitter CCPM mixing you can be reducing the control resolution of the best 21st century radio systems down to that of a 512 point system that went out of fashion the 1980's!

With CycLock you transmit the aileron, elevator and collective signals at maximum ATV (say 140%) and exploit the full resolution potential of the RC system. CycLock then mixes the signals and transmits the resulting servo commands at 4800 point resolution losing none of the control resolution of your radio system.

Corrects for CCPM geometry errors:

All CCPM systems suffer from interactions due to the geometry of the linkages. These errors are most apparent at large collective pitch values and give rise to aileron-to-elevator, aileron-to-collective, and elevator-to-collective interactions. CycLock has six geometry correctors that allow these errors to be offset providing greater accuracy and allowing, where advantageous, larger servo throw angles to be employed.

Electronic cyclic ring:

This has a number of advantages over a physical cyclic ring. Because it acts on the signals and not on the stick you can make adjustments to the stick feel of the transmitter with travel adjustments, rates and exponential without the worry of making a change that could over-travel the linkage. It even works for mode 1 pilots where the aileron and elevator are on separate sticks! Importantly, it works when gyros are introduced into the system for electronic cyclic stabilisation.
CycLock
RRP 39.95

Size 27 x 38 x 16mm
Weight 16g
Supplied with all leads and mounting foams. For spares and alternative length leads see Spares and Accessories

Requires a standard CSM PC interface for set-up:

LPT interface 12.95
USB adapter 24.95
Both come with all software for SL720, SL560 (Rev 4),
RevLocks 20, 30,40 and CycLock 1

Download CycLock manual 

Download CL1 PC software

Download CycLock manual in German


CycLock - the gateway to electronically stabilised flybarless operation

CycLock can work in conjunction with two SL720 gyros to provide superb electronic stabilisation at a very affordable price. Please note that you do not have to use CycLock on non-CCPM machines to go flybarless - just use the two SL720 gyros.
  • The full temperature-compensated-zero stability of SL720s gives automatic speed trim in any attitude without an expensive, fragile airspeed sensor
  • Keeps investment in flybarless operation to a minimum with both the gyros and mixer applicable in conventional models.
  • The remarkable flexibility that the PC interface of the SL720 gyro provides means it can be used for a variety of specialist applications, from camera stabilisation to wheelchairs. Here the SL720 proves its worth by being able to be set-up for cyclic operation - a very different situation to its use as a tail gyro. For more info on the use of SL720 gyros for flybarless or other applications, see our page on special uses of the SL720.
Suggested CycLock setup                      Wiring diagram for flybarless operation.

Suggested aileron gyro setup                   Suggested elevator gyro setup 

Here are photos of our attempt to modify a Raptor 50 to flybarless, using one of the cheap modification systems available. Note the orientation of the gyros for cyclic use - the elevator gyro on the side, and the aileron gyro on the front. The CycLock is down at bottom right, with a RevLock hidden in the middle. The tail gyro is not shown, but is at the rear of the machine.
CSM Cyclock & gyros
Click images for larger photos (approx 300K)
flybarless head

4 servo use:
CycLock is designed to mix 3 signals from the Rx and put out 3 signals to the servos. With four servo systems, two CycLocks are required.

Wiring diagram for 4 servo flybarless system ie two CycLocks and two SL720 gyros

Wiring diagram for 4 servo system with flybar - two Cyclocks

All our helicopter products are distributed worldwide through RC Models Distribution Ltd, and should be available from your local model shop or mail order company. To find your nearest stockist see the RC Models shops page

phone +44 (0)1457 860001 or email sales@rcmodels.org
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