Chris Dowsett

Thanks Gonzo.   The RCMF post suggests a method of using crow but retaining throttle on an electric glider. I doubt this will cure the cumulative elevator trim problem. In fact it could make it a lot more serious.   It took me 40 flights to realise the problem - an unintended tailslide on approach and a broken fuselage!   The only way of avoiding the problem is to treat normal, crow, start ofs and speed ofs as completely seperate flight phases which is not easy with so many flick switches and always to check the crow elevator trim offset on full crow at preflight.    

Only just found this thread. Sorry could have helped with FF9 crowing as I have been using it for a long time. Thought I had better update you all with a problem you may not have encountered yet.   Crow, or butterfly, operates with SW-A and 'throttle' stick movements. I set the stick position at which crow begins to operate as 80%. The trouble starts if you adjust elevator trim. Crow is not supposed to be active with the stick further forward than 80% but the elevator trim part of crow is.   As a pre-flight check I put crow full on and check the elevator moves down about - 3 degrees. It's adjustable from the crow menu or the elevator trim buttons. Think about that for a moment. What if you are flying normally and decide to add a bit of up trim but SW-A is ON. There is no normal elevator trim response because the "throttle stick" says no crow. The natural pilot action is to try more up trim.   The next action could be slam crow on DON'T! The cumulative up trim will been crowed in.    

I have been flying a Phase 6 for some years now and had a great deal of fun from it.  Go for the PRO.   Mine does not have flaps and I wish it  did.  It's not a floater so you will need to keep the speed up.

67   IC and Slope Aerobatics   From about 8 built many Keil Kraft Flying Scale. FW190 was best flier. Took years to get from flights of a few seconds to ones of a few minutes.  An Aeromodeller Plans Service A1 Aiglet glider did the trick.Edited By Chris Dowsett on 09/03/2010 21:00:27

Can't go wrong with a Fossy

Timbo means an old fashioned voltmeter.  It will not take much current when you connect it across the battery so there needs to be load resistor as well.  Same function as the powermate but you have to work things out for yourself. 

When you do the low power range check try to find out whether the failsafe action you would get is what you are expecting.   You will need to walk out of range and then walk back into range.  That should trigger a loss of signal failsafe.  You could try running a test with a 3 cell RX pack that should make it easier to trigger a battery failsafe (3.5v - not sure what that would be on your RX meter).  Good luck.  Any response from Ripmax?

Since you have had a crash Trevor,  it is just possible that you have stripped gears on both throttle and aileron servos.  If you suspect any servo after a crash it is good practice to check the gears or replace the servo. Have you tried the lower power range test?  This should show up any failsafe/recovery problems  As you have 2 servos suspect on the same stick and you have already changed the TX the most likely suspect is the new TX.  Ripmax will probably ask to see it.

You are just jealous Myron.

If anyone wants to worry about "overheating" the technical term is "thermal shutdown".   Try these keywords in Google and see what you get.  There will be the usual brand knocking. The solution for us (any 2.4GHz) flier is to make sure things do not get too hot.  If you leave your aircraft sitting on the tarmac in hot sun between flights you are really tempting providence.  My solution will be to stick a temperature indicator label on top of the RX.   I will probably start with one that turns  black at 58degC.   If it never goes black there will not have been a thermal shutdown.  If it does then I will do something about. All modern digital chips should have some form of thermal shutdown so they are protected from excessively hard treatment.  Ideally going into failsafe and quickly coming back online when they cool down.  I know Futaba's chip has thermal shutdown.  That is a good thing.  Just how well it works I have not a clue!

 Hi Timbo I will quote Idris.  "...the point I am trying to make is that there is no actual design fault with the RX.  The fact is no modern day digital electronics like to work at excessively high temperatures... " It is to do with something called Moore's law, how much electronics you can economically squeeze on a chip.  2.4GHz differs from 35MHz more is squeezed on a chip.  It is doing more work and probably running hotter. Idris has also listed "good practice" which is of general nature. Kelvin has not highlighted a Futaba RX problem but has drawn our attention to a potential problem for 2.4GHz in general.  I will do some simple tests of my own and report back when I get a chance.

Same temperatures here in Spain.  No problems though but then I am being cautious. If anybody is worried about overheating it should be an easy matter to check out. The original caution by the way comes from Idris Francis and was recently published on www.aaccmac.org .  Idris is a well respected old time UK R/C manufacturer who used to test fly all gear before he shipped it. He has done some good research on what happens when the 606 receiver is deliberately overheated (with a heat gun). Idris comprehensively answers "So what do we do to combat this problem?".  Personally I think the first step, if we are flying reliably,  is to check how hot things are getting up there.  If there is enough interest something can be done about it -  there should be enough 2.4GHz fliers around now!  It is not Futaba limited.

This is getting to be a habit!

Depends on the make of cell and the rate of charge.  The only way you can tell is to check the specification on the web and assume C/10 charge rate.  The GP200AFHR, for example, will stand a C/10 charge rate for 1 year. 

Flight:  Here are a couple of typical results from my flight log for the Harmony with telemetry data.  Thursday 17th July  Raja(mountain) 14km/h forecast.  Evening flights in marginal conditions with wind falling off. H83   Height Max 112ft Min  -15'    Battery voltage Max 5.1volts Min 4.9volts Flight duration 5mins Friday 18th July Beach 32Km/h forecast. H86   Height Max 132ft Min  -15'    Battery voltage Max 5.1volts Min 4.7volts Flight duration 21 mins Excellent test flight with a loop and 180deg turn on  a crosswind approach to avoid the new beach bar.  Battery Management:  The old NiMh 4.8V  flight pack is supporting the 2.4GHz RX and telemetry without problem.   The telemetry gives a verbal warning in flight every 0.1v change.  Once the voltage drops to 4.4v I switch off the telemetry (it no longer works properly).   The Futaba avionics is safe down to 3.5v with analogue servos.  Design:  I am used to PCM on 35MHz it allows setting up failsafe on all channels hence crow braking. Both my Futaba receivers have failsafe on channel 3 only.  Works fine if you have a throttle! Battery Management: I have run some ground tests with my all carbon Sword.   With a dead cell - presumably where the 3.5 volts failsafe comes from on the Futaba RX.   The Sword has 3 digital servos (and 3 analogues).  As the telemetry is not specified below 4.4volts it's a lot to ask of it.   The servo buzz already amplified by the hollow wings is heard load and clear over the telemetry which produces very strange results.  This is nothing directly to do with Futaba but I do wonder at the wisdom of a fixed 3.5v failsafe.