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Jul 21, 2019, 10:44 PM
c/f
c/f
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when I decided to migrate to Graupner over FASST 4 years ago I did some unconventional things .

In an EPP foam wing I mounted the reciever on top of a ESC and routed the antennas in between the 3 motor leads, and did range test flying, even with parkfly rx the only way I could get it to say rx strength was to hold TX around the corner of a building while keeping an eye on model Line of sight
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Jul 26, 2019, 08:26 AM
Registered User

Receiver Temperature warning


Hi,

I'm just setting up a new plane with the following components:
  • S1019.AIR.LOSE GR-18AIR 9CH Airplane and Helicopter (FBL) Flight Controller
  • S3041 Brushless Control + T 80A HV ESC - BEC Telemetry
  • S8437 HoTT Alpha GPS and Vario Module
  • mz-32 Radio

Everything works perfectly except when the motor is running the Receiver Temperature telemetry readout starts jumping all over the place, often going to above 100 degC and causing multiple voice warning messages. Revving the motor for 30 seconds or so causes anything from 5 to 8 warning conditions. As soon as the motor stops running the receiver temperature reading drops back to a steady, presumably true value.

Any ideas what's going on and how to stop this? I am reluctant to disable the voice warning messages....
Jul 26, 2019, 09:14 AM
'n boer maak 'n plan
yufasa's Avatar
Nice setup there. I have not run into this issue with receiver temps and I have it enabled on all my planes. Do you have a lot of vibration (prop out of balance a bit etc) ?
If I must guess I would venture it is receiver related.
Jul 26, 2019, 10:13 AM
Registered User
The setup is installed in a Hangar 9 Ultra Stick 30cc. I've set it up as electric running with 12S, so vibration is not significant. The issue starts even at very low RPM with no prop on the motor. I'm tidying up the install now and routing the servo and power wires. Will test again once done and post a video. I'm convinced the readings are erroneous, the receiver does not even feel warm to the touch.
Jul 26, 2019, 10:43 AM
Registered User
Here is a link to a video showing the issue:

Receiver temperature issue
Jul 26, 2019, 01:01 PM
Graupner USA's Avatar
Thread OP
This is odd, at least I have never seen this before.

Maybe you should give our service line a call to figure this one out.
Jul 26, 2019, 01:24 PM
Registered User
Quote:
Originally Posted by BritinUS
Here is a link to a video showing the issue:

Receiver temperature issue
Obviously there are many possibilities, here are some thoughts/possibilities and how I would approach it:

1. Question, / Check:
It is not possible to see how you actually wired the Receiver & ESC. Check that first, if you have not done so already.

Did you connect the GPS and the ESC via a y-cable to Ch9?

The ESC has a 3 pin cable which needs to be connected to Ch 1 for throttle control. (In your case there are 2 BEC cables, 1 master and 1 slave.) Then there should be a single pin cable (orange wire) which is for the telemetry which connects to CH9. Also make sure that CH9 in the receiver firmware is set to Sensor, so you get telemetry.

2. In case all your wiring is OK, I would go back to basics / process of elimination:
- Disconnect the ESC, GPS from the receiver.
- Use a standard battery to power the receiver and check the temp (use a heat source i.e. hairdryer to slightly increase the RX temperature

Do Not connect the ESC BEC and a battery at the same time!

3. If that works, disconnect the battery, reconnect the ESC BEC 3 pin master connector to Ch 1 and the slave BEC - try that.

4. If that works, connect just the ESC telemetry cable (1 wire) to the receiver, check again.

5. Finally reconnect the GPS as well and check again.

Hope this helps.
Last edited by yrag; Jul 26, 2019 at 01:52 PM.
Jul 26, 2019, 02:02 PM
Registered User
Quote:
Originally Posted by BritinUS
Here is a link to a video showing the issue:

Receiver temperature issue
Additional question/clarification:
What is the device on the right hand side of the fuselage, another BEC?
Jul 26, 2019, 05:19 PM
Registered User
Thanks for the speedy feedback guys.

The device on the right is a Castle Creations BEC 2.0. I have removed the central power wire from the ESC servo connector. GPS and ESC are connected to Ch9 via a Y cable. Ch9 is set to sensor in the firmware. Since all wiring is okay I'm about to go back to basics as per point 2. Will report back...
Jul 26, 2019, 06:05 PM
Registered User
Culprit found.

I conducted the following fault finding suggested by "yrag"
  1. Removed Y connector and plugged single wire ESC telemetry into Ch 9, still powered by Castle BEC. No change.
  2. Removed Castle BEC, reconnected center power wire to ESC in Ch1 to use ESC BEC. Receiver temp readings now stable.
  3. Reconnected GPS using a Y cable into Ch9. Receiver temp readings stil stable.

Looks like for some reason it does not like the Castle Creations BEC -it's powered from the main 12S battery that powers the ESC. This should not cause a problem should it? The only reason I'm using the Castle BEC is because it's rated at 9 amps continuous current, whereas the "3041 Brushless Control + T 80A HV ESC - BEC Telemetry" is just 5 amps continuous. I'll fly the plane tomorrow using the BEC onboard the ESC. I'll experiment afterwards whether using a separate battery for the Castle BEC solves the problem.
Jul 26, 2019, 06:53 PM
Registered User
Quote:
Originally Posted by BritinUS
Culprit found.

I conducted the following fault finding suggested by "yrag"
  1. Removed Y connector and plugged single wire ESC telemetry into Ch 9, still powered by Castle BEC. No change.
  2. Removed Castle BEC, reconnected center power wire to ESC in Ch1 to use ESC BEC. Receiver temp readings now stable.
  3. Reconnected GPS using a Y cable into Ch9. Receiver temp readings stil stable.

Looks like for some reason it does not like the Castle Creations BEC -it's powered from the main 12S battery that powers the ESC. This should not cause a problem should it? The only reason I'm using the Castle BEC is because it's rated at 9 amps continuous current, whereas the "3041 Brushless Control + T 80A HV ESC - BEC Telemetry" is just 5 amps continuous. I'll fly the plane tomorrow using the BEC onboard the ESC. I'll experiment afterwards whether using a separate battery for the Castle BEC solves the problem.
Thanks for the update and glad to hear that you found the cause. It is an interesting situation/problem. I am curious and checked the Castle Creations BEC information and found that the default Voltage setting is 5.25 Volt.

The default Voltage setting for ESC BEC is 5.6 Volt.

It shouldn’t really be relevant, since you have remove the red wire from the ESC 3 pin connector and not using the ESC BEC.

The following is just a thought/theory and might not make a difference. However, I would be interested if you are willing/able to check it out.
When using the Castle Creations BEC, the receiver will have a supply voltage of 5.25 Volt. The receiver will receive the ESC telemetry data which might have a signal amplitude of 5.6 Volt. I am not certain about the amplitude, since I have not measured it yet.

In any case, if you own the castle link so you can change the default settings, would you mind changing the Castle Creations BEC Voltage to 5.75 Volt (changes are only possible in 0.25 Volt increments) and see if it will eliminate the problem?
Jul 26, 2019, 07:07 PM
Registered User
Hi Yrag,

Great conversation. I have the Castle Creations BEC set to 8.0 volts and the Graupner ESC BEC set to 7.4 volts (I run HV servos). You can see in the last photo on the Tx display that the Rx voltage is 7.3 volts on the telemetry. On the uploaded video you can see the Rx voltage is 7.8 volts on the telemetry.

Happy to try any other suggestions you might have to get to the bottom of the external BEC issue.

Many thanks for all your help.

Martin
Jul 27, 2019, 12:22 AM
Registered User
Thanks Martin, that answers that question.
It is time to find the source. I watched the video a few more times and the rapid/erratic fluctuations point to interference, noise and/or voltage fluctuations.

As you mentioned already, time to play when you have some time.
Here are some ideas, which you probably have already on the list.

- Run it with a separate battery instead of the Castle BEC.

- Reconnect the Castle BEC and disconnect all the telemetry (ESC, GPS) from the receiver in order to eliminate it as the source.

- Use only the 2 wire cable from the Castle BEC for power to eliminate the possibility that the signal wire from the Castle BEC is the source.

- This one might be a pain to test unless you have another Castle BEC. Use a separate supply battery for the Castle BEC to check wether the interference is coming from the Battery/ESC when the motor is activated.

Looking forward to hear what you find, this is an interesting one.
Last edited by yrag; Jul 27, 2019 at 08:15 AM.
Jul 29, 2019, 12:44 PM
Registered User

Temp Sensor for twin cylinder engine


I there a way to setup temperature sensors to read temps on each cylinder of a twin gas engine? I’m considering an EME 70 twin for my next project and would like to have read outs for the individual cylinders. Also, is the General Engine Module required to use the sensors?
Jul 29, 2019, 01:20 PM
Registered User
Quote:
Originally Posted by Trottterjt1
I there a way to setup temperature sensors to read temps on each cylinder of a twin gas engine? I’m considering an EME 70 twin for my next project and would like to have read outs for the individual cylinders. Also, is the General Engine Module required to use the sensors?
That is a Yes and another Yes.
As you probably saw, the module has input for 2 temperature sensors.
Buy 2 temperature sensors for the range you need.

You might also consider an Opto RPM sensor which connects to your ignition.
https://www.graupnerusa.com/Telemetr...621.html#tab-1

The GeneralEngineModule is a nice setup. It adds quite some flexibility, particularly if combined with the new MZ32/MZ16. The module has 2 analog voltage inputs as well. I designed/developed a pressure sensor with an analog output voltage. That way I can monitor the air pressure for retracts/brakes (i.e. automatically deploy retracts if the pressure gets low due to a leak)
Last edited by yrag; Jul 29, 2019 at 02:21 PM.


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