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Member postings for Allan Bennett

Here is a list of all the postings Allan Bennett has made in our forums. Click on a thread name to jump to the thread.

Thread: How to log Rx data?
26/10/2020 14:04:49

Another question, please: I've just looked at the log from yesterday's flights, and it recorded correctly. It was a small quad flying ovals around a rugby field, and RSSI fluctuates rapidly and greatly, presumably as I flew to and away from myself. The data shows RSSI ranging from 106 to 49 -- is that the kind of numbers you would expect for flights less than 50m away from me? The receiver is an RXSR incorportated into FrSky's Omnibus F4 V6 flight controller, and the transmitter is Taranis 9D+2019 with v2 firmware.

Thread: Flux for soldering XT90 connectors
23/10/2020 20:32:15

One key to successful soldering is the mass of the bit, perhaps more important than the wattage of the iron. My Antex iron (50W I think) has a range of interchangeable bits from 0.1mm to 6mm, and it meets alll my needs from undercarriages through Deans Ultra connectors to sufrace-mounted components on PCBs.

I can see no advantage in a solder gun -- I had one once, but binned it.

Thread: How to log Rx data?
21/10/2020 17:41:07

Now at least I should be able to prove my next crash isn't my fault laugh

21/10/2020 17:09:46

I think I know my way around it now: Logging is turning on and off with SG, and I've also discovered that deleting sensors is not good, for it seems to corrupt the log file and all the subsequent entries for the same model.

So to summarise what I've done which seems to be working:-

I've set a global function to activate logging at 0.2 second intervals with SG^, thus logging all the time my motor is running. If I were a glider guider I guess I'd have a dedicated switch for it, rather than my throttle-cut switch.

I've discovered sensors for each model, and NOT deleted any unwanted ones.

I've deleted all my historic LOG files -- they're no use whatever, for none of them contain any RSSI or RxBt data.

Thanks each for your patience and assistance.

21/10/2020 16:41:26


For my next trick I deleted all the log files for the particular model I was using for testing, then when I ran another test all the fields were displayed when I viewed the file.  As you suggest, I won't bother deleting any sensors either after I've detected them.

So I'm going to delete all my other log files from the SD card, for they're obviously the root of the problem. Could it be becuase they were created with an previous version of OTX?

Edited By Allan Bennett on 21/10/2020 16:42:39

21/10/2020 16:32:06

OK, I've gone back to one of my models and Discovered sensors then Stopped discovery, and still no joy. In fact, it doesn't seem to be logging the sensors at all, for when I use OTX Companion to view the log I get an error message that 'The selected log file contains 2198 invalid lines out of 2271 total line' and, according to the date/time stamps, the logging I've done just now doesn't exist.

21/10/2020 15:38:30

I'm getting somewhere, but not all the way!

I've been into the Telemetry screen and Discovered new sensors, stopped discovery, then deleted the ones I didn't want, so I'm left with RSSI and RxBt.

2020-10-21 14.50.17.jpg

I've then clicked on each of the two sensors in turn, and checked that the 'Logs' tick-box is checked (it was), but after a dummy run with the model with SG turned 'on' and 'off', then viewing the log file in OTX Companion, RSSI and RxBt are still not listed as available fields.

I also tried with another model which already has a couple of temperature sensors, which have been working well for a few years sending alerts to my Tx, but still when I view its log file I see neither the temperature sensors nor RSSI and RxBt.

So, any ideas please what step it is that I'm still missing?

20/10/2020 20:06:55
Posted by MattyB on 20/10/2020 17:19:30:
Posted by Allan Bennett on 20/10/2020 17:15:26:

Yes, I'm on OTX 2.3.9 and I've got the Telemetry screen.

Its first line is 'RSSI' followed by 'Source (default)' then 'Low alarm 45' then 'Critical alarm 42' then 'Disable telemetry alarms' with a tick-box, which is currently unticked.

Next comes 'Sensors' with 'Discover new sensors', 'Add a new sensor', 'Delete all sensors', and 'Ignore instances' with a tick-box which is currently unticked.

Lastly there's 'Variometer' with 'Scource', 'Range -10 10', 'Center -0.5 0.5 Tone'

And that's it: No 'Logs' checkbox.

.......but I also have RSSI listed under the list of Sensors further down, just above "Discover new sensors":

Logging 2

It's that second entry that you need to press enter on and edit; that is where the log checkbox will be (at the very bottom of the next screen).

Edited By MattyB on 20/10/2020 17:35:51

I don't have any of those five entries. Presumably your first three are from an external sensor, but RSSI and RxBt should come direct from the receiver? Sounds like I've got to 'Discover sensors' again, as suggested by Philip.

Out of interest, I've got one model with two temperature sensors on it, and they show in its listing, but still no RSSI and RxBt. Perhaps I didn't realise the significance of those two when I added the temperature sensors several years ago.

A job for tomorrow. Thanks guys.

20/10/2020 17:15:26

Yes, I'm on OTX 2.3.9 and I've got the Telemetry screen.

Its first line is 'RSSI' followed by 'Source (default)' then 'Low alarm 45' then 'Critical alarm 42' then 'Disable telemetry alarms' with a tick-box, which is currently unticked.

Next comes 'Sensors' with 'Discover new sensors', 'Add a new sensor', 'Delete all sensors', and 'Ignore instances' with a tick-box which is currently unticked.

Lastly there's 'Variometer' with 'Scource', 'Range -10 10', 'Center -0.5 0.5 Tone'

And that's it: No 'Logs' checkbox.

BTW, if Philip is still there, I was having a senior moment! My throttle kill switch is SG on all models, so that doesn't explain my continuous logging.

20/10/2020 16:27:19

Thanks for those very prompt replies. But, am I beig a bit thick here? I can't find any Sensors menu as you show in your screenshot Matt. I'm on v2 firmware, but I've also checked my v1 Taranis and can't find a Sensors menu there either, so I've got no tick box to enable logging. I have no external sensors, so would that be why I don't have the menu item? Surely RSSI and Rx voltage don't need an external sensor to monitor them?

Philip, I've been to the Telemetry screen but there's no tick box to enable, or anything like that. There's 'Add a new sensor', etc. and, under the RSSI heading, a tick box to 'Disable telemetry alarms', which is not checked.

SG away from me enables the throttle -- oh bother, it's not SG, it's SD, so that explains why I had continuous logging!! SG is the spring-loaded switch which is always away from me by default.

20/10/2020 15:21:18

Following a disastrous crash on Sunday I realised that I could look at the log file to see if there's an obvious cause, other than pilot error.

Luckily I had enabled logging several months back, with interval set at 0.2 seconds as recommended in the thread I'd read. But when I opened the log file for my crashed model I saw only data relating to the Tx -- all the stick and switch positions, and Tx battery voltage -- but nothing about the Rx such as RSSI and Rx voltage.

For the model in question I was using an RX6R receiver and Taranis X9D + 2019 transmitter. I've enabled logging in the Special Functions screen as follows:- SG^ SD Logs 0.2, where SG is the throttle cut switch, but I'm wondering if I've even done that right, for my logs go far beyond the point where I flipped SG to enable the throttle.

Can someone help me with info about how to get more-useful data about the Rx into my logs please? All I can find online is how to create and view GPS logs, which I'm not interested in (at the moment!).

Thread: 3 way radio switch.
10/10/2020 21:19:27

It can be done, but you'd first have to investigate how the rotary knob is wired -- does it use all three terminals (slider and both ends of the resistor track), or just the slider and one end of the track. And, of course, you'd need to know its resistance.

Then you would pick resistors corresponding to the positions on the rotary that you wish to use -- the middle position doesn't necessarily have to represent the 50% position on the rotary.

Thread: One-off signwriting for models
07/10/2020 20:15:41
Posted by Andy48 on 07/10/2020 14:11:31:

You can get printer decal sheets that are white to start with not translucent. Try Amazon.

I think that's what my link was earlier in this thread. But in my experience, even white decal sheets are so thin that dark colours can show through. I paint a white patch where the decal is going to go.

06/10/2020 20:08:42

Rather than using hand-cut or machine-cut vinyl or trim, you could print your own waterslide decals using paper like this. There's also paper for use with laser printers, which may give more-solid colours. With the injet variety I give it a coat of varnish from a rattle can, and let it dry, before cutting it out, to make sure the inks don't run when I soak it in water.

Thread: Tony Nijhuis' new Vulcan
05/10/2020 20:01:25

This afternoon I found a piece of 3mm i.d. aluminium tube which, when flattened carefully, gave me a slot 4mm long. Gluing it into the inboard elevon in place of the snug-fit tube has made a world of difference. Whereas yesterday, it was obvious there was some stiffness in the system, even with the hinges unglued, today with the hinges now glued the complete elevon is completely free to move, and it can be seen that the pin is moving at least 2mm back and forth in the slot.

In my opinion it's a mod that's well worth doing.

05/10/2020 11:47:13

Thanks for all the replies. Your comment about flattened brass tube is interesting for that's an easy way to allow the pin to slide as the two elevon parts move, and would achieve what I think is necessary for correct geometry. Even though many have confirmed that the designed system works okay, I think I'll see if I can find a suitable piece of over-sized tubing which I can flatten to form a slot. If nothing else, it's got to reduce the pressure on the servos.

I originally looked at snake tubing, but its outer diameter was greater than the thickness of the trailing edge of the elevon, which is why I went for brass.

Thread: Feeling a bit unbalanced.....
05/10/2020 11:19:15
Posted by TonyS on 04/10/2020 18:04:05:

Thanks everyone for some really useful stuff.

I suspect the answer for me lies in some/all of this as I need a short term and a longer term solution.

Bit of a bummer re the imbalanced packs though..


Another longer term solution is to buy a charger that can discharge quickly. I don't know about others in the Cellpro range, but my PowerLab 8 is able to discharge at at least 10A (that's the default setting, which I don't change) down to any pre-defined voltage for storage.

For complete discharge I use the light bulb method described by others. No need for any electronics or supervision, just leave it connected to the battery for 24 hours or so outdoors. A single bulb for up to 3S, and two bulbs in series for up to 6S.

Thread: Tony Nijhuis' new Vulcan
05/10/2020 08:45:35

I've used a brass tube, which the pin is quite snug in, though at the same time it's quite free. By 'interference fit' I presume you mean that there's no slop in it? If so, I should be good to apply glue to my hinges.

04/10/2020 20:49:03

Things have been on hold for a while as I've been sorting out a heli for which I'd updated the receiver's firmware and the flight controller's firmware at the same time -- not to be recommended!

Anyway, the Vulcan is almost ready for paint topcoat, and today I've been installing the elevons. I haven't yet applied cyano to the hinges, and they seem to work fine at the moment, but I'm a little bit concerned that the pin-and-socket joining them will cause them to bind when I eliminate the play in the hinges by gluing them, because of the different centres of rotation of the two parts. Tony Nijhuis in his notes says this is not a problem in practice, but it seems to me it shouldn't work unless the socket is made into a slot.

I remember reading in this thread that some builders installed two separate servos for the elevon halves, but has anyone who did it with single servos as per plan have any problems with binding? I'm at 4lbs 6oz at the moment, so I don't really want to add the weight of two extra servos.

Thread: Help with electric setup for newbie to electric
04/10/2020 20:07:48

That ESC appears to have a big enough BEC (battery eliminator circuit -- it eliminates the need for an Rx battery) to cope with the servos you've mentioned. So just plug it into the throttle channel of your receiver and it will provide power for the receiver and attached servos. You say your Rx and servos are HV, but just check that that means they can take 8.4v. If not, the ESC can be programmed to give a lower Rx voltage I believe.

One risk of using the BEC that's built into the ESC is in the unlikely event of the ESC failing catastrophically, it might cause the BEC to fail. If you're paranoid about this, or you think the servos' current demand may be more than the ESC's BEC can handle, you can either run the Rx from a regular Rx battery pack, or use an external stand-alone BEC. In either of those cases you would need to disable the ESC's BEC by pulling its red wire from the plug, so that you don't get two different Rx power sources competing with each other.

One thing about electric flight that you may not be familiar with is the need to pick the right prop. The motor will try to turn at (Kv x voltage) rpm irrespective of what prop size is on it. If the prop is too big, requiring more power than the motor can deliver, the motor will still try until it burns itself out. A wattmeter is an indespensible tool which will tell you how many amps, watts, and volts are being used, and with it you can check that the recommended prop size is okay and, if not, try a larger (to get maximum power) or smaller (to avoid overload) oner.

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