Frank Skilbeck

Myron what's wrong with your Optic 6 and Futaba sets. I have a couple of sets of fleet gear a 7 channel PCM set but the Tx battery has failed and a 6 channel XP/FM set that i don't use any more as i like the programming flexibility of modern radio's and being able to have several models in the memory. CS if you like the programming on your FF7 that would sway my decision that way, as you will be familiar with the programming (and I have a DX6i !) 

Scott, I've been flying for many years and we used to use 600 mah 4.8v Rx batteries without much problems , admittedly on 35 mhz. I've got 3 spekky set ups 1 6200 and 2 6100's all running off a 3s lipo and ESC standard BEC set up, the 6200 uses 4 servo's and I've not had any problems, these are all 5v BEC's I have another 4s lipo powered 6 servo plane on 35 mhz (Multiplex IPD) with an ESC with a built in SBEC again no problems and I've monitored the temp of the ESC which is in fuselage in flight with my e-logger and there is only a moderate temp rise after a 8-9 min flight (see below) so it's not being stressed. I don't think a 5v is a problem here unless there is another connection problem. This is also taken from the Spektrum web page "With all radio installations it is vital the onboard power system provides adequate power of 4.5 volts or more without interruption to the receiver even when the system is fully loaded (servos at maximum flight loads). This becomes especially critical with giant scale models that utilize multiple high torque/ high current servos. Inadequate power systems that are unable to provide the necessary minimum voltage to the receiver during flight loads have become the number one cause of in flight failures. Some of the power system components that affect the ability to properly deliver adequate power include: the selected receiver battery pack (number of cells, capacity, cell type, state of charge), switch harness, battery leads, regulator (if used), power bus (if used). While Spektrum’s receivers’ minimum operational voltage is 3.5 volts, it is highly recommended the system be tested per the guidelines below to a minimum acceptable voltage of 4.8 volts during ground testing. This will provide head room to compensate for battery discharging or if the actual flight loads are greater than the ground test loads." So brown out doesn't occur until 3.5v also if Shaun had the latest Rx firmware the reconnect time is pretty quick in the event of an intermittent loss of power.

The fact that the motor when to the fail safe setting points to the Rx going to failsafe, this could be due to i) Interference (but being 2.4 I'm surprised it lasted for 8-10 seconds) ii) a component failure on the input side of the Rx iii) a power supply issue, I'm guessing that if the ESC saw no output from the RX it would shut the motor off. or a  iii) TX fault Hope your investigations show something tangible.

Looks good, I saw your DHC Beaver picture in your gallery, if this flies as well as that you are in for a treat. They really are nice models aren't they.

Shaun I ran some tests using my E-logger and a temp sensor on the ESC when in flight on my E Flite Beaver where the ESC sits behind the bulkhead, the temp went up when running at part throttle and down when running at full throttle. But it only went from 26 DegC to 34 DegC. I also have a Fantom in which the ESC, battery and Rx are all enclosed (in the foam fus) with no airflow over them. When I land after a fairly spirited flight the battery is pretty warm but I've not had any RX problems (6100) in this set up. It could be that you do have a faulty component on the Rx (or just a bad connection) which causes it to cut out when it gets too warm, or alternativelly the UBEC cut out through getting too warm. Hope your tests show something amiss, if just for POM.

For dual Ailerons you are (or should be) using aileron and flap channels (basically flapperons), so you need to reverse Flap in the reverse list (page 26). You then get the full adjustments on each servo and can set the flap switch to drop or raise the ailerons to work as flaps or spoilers if you wish. Probably best to set this to 0% for the first few flights or keep your finger away from the flap switch. I've set up my YAK 54E with dual servo's (6200 Rx) and had no problems, not tried using them as spoilers/flaps yet.

James when you program the throw on the servo on the TX it does it for the position the rate switch is in, flicking the switch and you can reset the throw for that position.

Shaun Don't know if it helps, but I've had several flights this weekend with my Dx6i and 6200 and 6100 Rx's in several diffent models, some Balsa and some Foam and never a glitch, I hadn't done anything special with respect to Rx mounting, just used some velcro to attach it to the side on the fus (inside) near the ESC and battery. The 6100 also worked really well in my Alfa Mig 15 EDF which is very Rx sensitive on 35 mhz, so I can't see it's anything you've done related to the above and i'd suspect a bad connection somewhere. 

I have an e-sky 6 channel Rx which i got from Al's Hobbies for around £10, I've used it in a couple of electric planes and it's been very good, has a long aerial though which I routed out the back of the plane.

I think the message here is as Timbo and Marck both point out, make sure your battery pack can deliver the amps with out losing too many Volts. Some of the cheaper high capacity mah AA cells that are appearing and havge been made into Rx packs seem to have more internal resistance than others and when asked to provide a high load the voltage can dip. If you have a 6 servo plane, or are using high power digital servo's than you should check that the Rx battery (and switch harness etc) are upto the job, also make sure you have a charger that can handle the batteries you are using. 

The servo can't talk to the RX, are you checking the throw rate with the dual rate switch in the same position. I.e. did you inadvertently flick the dual rate switch on that channel from 80% to 100%. My Dx6i seems OK but I've only had it for 4 weeks or so. 

If it's a DX6i they have a setting for US or EU in the programming, not sure about the DX7.

My measurements were on a pro-peak charger so not sure how accurate it was but all batteries were tested on the same. Rob I note you said your cells were 2600's, are these the newer instant packs?. Maybe I was just unlucky and got some from a bad batch, but in a low ma application they would be fine and would give almost 2400 mah. But it does show that it's worth checking your batteries for peace of mind, how many fliers just buy packs, stick them on their Radio set supplied wall charger and leave it at that. PS Rob tests done in Gloucestershire, now I know summer has not been briliant but it's not that cold

I have a reward mounted motor on an ESTES canard plane and extended the motor wires by about 5 inches, I didn't twist them or do anything fancy. Note downhole pumps in oil wells (over 8,000 ft) use the cables set paralled as there isn't room to twist them, not ideal. But at our lengths I don't think it will make any difference.

I've been using Lipo's for over two years now without any problems, but at the Cosford show at the weekend I invested in a Lipo sack just for added protection. Incidentily whilst most chargers will check for the number of lipo cells, they will only do this if set to charge lipo's, if you had been charging say a NimH Rx battery and then went to a Lipo you might fool the charger and it would work as a Nimh charger. I know this works as I used it to put a bit of charge back into set of Lipo's I had discharged too much and the Lipo setting wouldn't recognise them. I only did this until I'd put 200 mah back in and then charged them as lipo's. So it is possible to inadvertently set the wrong cell type. 

Timbo, the VP cells have been like this from new, if you do a test on them discharging at say 500 ma then they will give over 2200 mah, I don't think they are goosed just not upto delivering large amps. I first noticed it when I put the 4 cell pack in a 7 servo plane to set it up and the onboard battery checker was going into the red when I deployed the flaps (on the ground ) so that's when I did the check. But I think the issue here is don't be fooled by the mah hour rating of the cells as they may not deliver the amps when required. You were cheating and using Sanyo cells

I posted these results on another site of some  VP 2400 mah AA 4 & 5 cellNimH RX packs vs a 4 cell 4/5's sub C Sanyo 1650 mah NiCd and a 5 cell 4/5's sub C EnrichPower 2200 mah NimH. I ran a series of tests on them using the discharge function on my cycler to measure the performance. Results are as follows             VP 4 cell        Sanyo 4 cell         VP 5 cell          Enrich 5 Cell Amps       Volts               Volts                Volts                Volts 0.2          5.48                5.32                 6.8                   6.77 0.4          5.3                  5.22                 6.62                 6.67 0.6          5.1                  5.12                 6.45                 6.57 0.8          4.92                5.05                 6.21                 6.45 1.0          4.71                4.95                 5.58                 6.13 1.5          4.1                 4.57                  5.48                 5.62 2.0          3.63                4.33                 5.1                   5.62 3.0          2.65                3.92                 4.4                   5.2 Note the VP cells were fresh off the charger, the Sanyo cells had been used briefly earlier in the day and the enrich cells had been charged the previous day. Note at 3 maps my cycler basically shut the VP cells off after a couple of ma had been discharged and went into pause before starting the charge cycle. 3 Amps is a lot, but if you are running a 6 servo set up they recommend that you use at least a SBEC on an ESC rated to 3amp continuous, so the same recommendation should go for regular RX packs. So if you are running smallish planes (say 40 size and below) with 4/5 servo's then NimH AA's should be fine but for bigger models and more servo's you might want to go up a battery size, (note size not mah), as these have less internal resistance and can deliver more amps.

Excellent stuff, would be good to see some more motor/ESC tests showing the combinations. My measurements of lower cost motors and ESC's (just Watts vs prop rpm on a given prop) tend to show what you've found that the efficiencies are fairly comparable. But I did agree the construction of the AXI motor's does appear better and this should give a longer life, but then again if a £15 motor (32 size) lasts a few seasons it's probably good value.

I have just finished and test flown an E-Flite DHC Beaver with a Turnigy TR42-50A 700 KV motor, bags of grunt.

Hobbycity if you don't mind buying from Hong Kong, I bought a Turnigy motor and its very good and excellent value.