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[afb]

Anybody else experiencing this problem?

I've just bought a further three R6M receivers which came with addendum sheets advising of a revised failsafe function. This seems to be aimed at aircraft/helicopters and is factory set such that in the no-signal condition it sets the throttle to "lowest position" (measures at 0.90mSec for all my three new units) My two earlier R6Ms set the failsafe to whatever the throttle position was at switch-on - thereby rendering them suitable for model boats if switched on with throttle at centre stick position. After some experimentation, in the absence of any sensible documentation or relevant forum post in various groups that I can find, I am unable to achieve a 1.5mSec failsafe condition with the new receivers, but I'm guessing I'm not supposed to be able to do so!

My new receivers are coded 201105 (presumably date of manufacture) whereas the old ones are 201003 and I have just checked the latter out again to confirm they work exactly as I remembered.

I can see how the new receiver is attractive to fliers, for whom this system is intended, but hardly a delight for model boaters!

The new receiver asserts the 0.9mSec fail-safe throttle condition immediately at switch-on until it has 'booted up' and then asserts the pulsewidth appropriate to the stick position. The remaining channels on the new receiver assert a nominal 1.5mSec signal until boot up is completed and they follow the sticks.

In a no-signal condition, the non-throttle channels on the original receiver briefly asserts a 1.5msec signal and then go quiet whereas the new receiver continues to assert the last joystick position.

Thus it seems boats fitted with the new receiver have the potential to go into full forward, or worse still, full reverse in a loss of signal condition, and depending on what your ESC considers to be an "in range" signal to "arm" it, a short burst of full speed at switch on until the receiver has booted up.   

Fortunately I make my own ESCs and can program my way round this by restricting the valid signal signal range from 1mSec to 2mSec, thereby bypassing the 0.90mSec condition. As they need to see neutral (1.5mSec) before arming the potential switch-on problem was never a problem for me anyway.

So I thought I ought to alert the community to the problem, and sincerely hope I'm not causing unneccessary alarm - but if you have a new R6M receiver please check your system in a loss of signal condition.

[cuppa]

I have found this very thing with the two spare receivers I have just bought.

The way I got around the problem was to switch the transmitter to mode 1 for throttle and then plug the ESC into the channel that corresponded to the new channel assigned as controlled by the left hand stick's vertical movement.

[unbuiltnautilus]

The same way I cured the problem on a Tamiya King Tiger tank, turn on and £750 worth of tank shot across the workbench backwards. Re-assigning the set to mode one results in the gun barrel depressing only, much safer

[John Mk2]

And cheaper 

[afb]

That's a great workaround guys - thanks for sharing it with me. Typical that I made an involved modification to my ESCs when a much simpler solution was staring me in the face!

[afb]

Hang on - perhaps I was a bit hasty in saying you had a solution guys. Sure enough it moves the nasty kick at switch-on to an unused or less dangerous channel, but in a loss of signal condition the revised throttle channel (vertical left stick now controls channel 3 instead of channel 1) just freezes at the setting you were on when signal was lost, so a boat on eg 1/4 throttle will just keep going - that's not a fail-safe to my way of thinking - though it's safer (or should I say "less dangerous") than full astern!

A conventional fail-safe module interposed in the throttle lead is no help here as the channel output continues to be active with a signal within acceptable limits of normal operation.

OR  . . . .  have I yet again missed something? . . .. after all, rabbits *do* have very small brains!

[richald]

I don't use Planet RC stuff,  but there is a similar problem with the
Radiolink stuff I have in my boats, the solution I use may work . . .

Sequence is to start with everything switched off then . . .

1) Switch transmitter on.
2) Wiggle lefthand (throttle) stick up and down.
3) Finally switch receiver on.

On the radiolink T4EU the default at start up, is to set the throttle channel to its minimum
setting which on a boat equates to full reverse, and it sometimes confuses the speed controller
if it is the type that autosets at powerup.
Hope this helps...

Richard

[afb]

Richard - thanks for the suggestion - afraid it didn't work. But worth a try - I know there was an art to setting the failsafe on my Spektrum system too (don't hold the binding switch for too long), which the manual fails to tell you. I found that out either on here or at rc groups.

I shall revert to mode 2 throttle as the 0.9mSec (full reverse) failsafe signal can't be produced by my transmitter even at full stick/full trim so its easy (for me) to program my ESCs to shut down in this situation secure in the knowledge it isn't a valid user command. Quite what everyone else will do though . . . . . . ?