Gremlin Goes Full Throttle when Arming

[Cullen Chong]

Please help.
I am having a problem with all four motors going to full speed when I arm the quad.

I have a Gremlin with an R-XSR FrSky receiver. Everything is configured in Betaflight. All transmitter outputs are varified on the Betaflight receiver tab. I have calibrated the esc's in BLHeli Suite. I use AUX 1 to arm the quad.

When i Arm the quad my throttle is at 1000ms. Its in angle mode. When armed moving any of the stcks has no affect on the motor speed. Picking the quad up and moving also has no affect on motor speeds.

Its almost as if something is driving all 4 motors to full speed when Armed.

Does anyone have any suggestions?
Thansk
Cullen

 

[mountaindewdude76]

I'm still not very familiar with the FrSky rx's but you might try this.

On your transmitter, lower the throttle trim all the way down, as far down as it will go. In Betaflight (or whatever you are using), set your Min Throttle to 1000, Min Command to 1000, Max Throttle to 2000. Go into the Receiver Tab and make sure that it shows Min Throttle at 1000 and Max Throttle at 2000. Then try to calibrate your esc's again.

I hope this helps!

 

[Cullen Chong]

Yes I'm using Betaflight. Thanks, I'll give it a try.
You got me thinking.... it's kind of weird that there isn't a transmitter calibration tab in Betaflight. Or is there?
I guess i can also recalibrate my sticks right from the radio too.

 

[PsyBorg]

Messing with trims on the radio for a quad is not a good idea. All trims should be centered. Any trimming that gets done is done on the flight controller. I like that the Taranis has a feature you can disable trims all together and I use that when I set up my quads.

Radios have stick calibrations to let the software know how far the electrical measurement range and center is.

Two things I would check is make sure you don't have throttle or any other channels reversed on the radio. Next make sure you are using the correct protocol for the firmware that is flashed on the esc's. Trying to run Dshot on esc's flashed to non Dshot protocols does funky things. The last time I flashed esc's on my Gremlin any firmware that was XX.5 was specific to Multishot and that is what they came flashed with from the vendors. That was a year ago so they may have a different version shipped on them by now. Make sure what protocol you are using matches whats flashed on the esc's

 

[ElectriSean]

The transmitter is calibrated using the receiver tab in Betaflight, and adjusting the subtrim on the radio so that the sticks center at 1500 and adjusting servo travel to get the sticks to 1000 at minimum and 2000 at maximum. The regular trims should be left at center and never touched.

If you are using any of the DSHOT ESC protocols, the ESC's don't need to be calibrated. If you're using Oneshot or Multishot they should be calibrated using the motors tab in Betaflight.

 

[ElectriSean]

@PsyBorg Beat me by 2 seconds lol

 

[PsyBorg]

TAG!!!

 

[Cullen Chong]

I am using the Emax bullet series 6A ESC's. https://store.flitetest.com/emax-bullet-series-6a-esc/ The description says they support DSHOT so I'll give it a try. Thanks
Cullen

 

[PsyBorg]

Setting it to Dshot won't help if they are flashed to one of the *.shots. You need to check what version they are flashed to OR reflash them to what ever protocal you want to use.

Now. that said. Multishot is faster then Dshot 300 which is the limit that those esc's can work with. That's what I run on my Gremlin.

 

[Cullen Chong]

How can I tell what i have flashed on the esc’s?

 

[ElectriSean]

How can I tell what i have flashed on the esc’s?

Connect with BLHeli configurator, remove props, plug in battery and hit the read setup button.

https://github.com/blheli-configurator/blheli-configurator/releases

 

[cranialrectosis]

+1 remove props.

 

[PsyBorg]

Any progress on this one yet? figured Id bump it back to the front so it doesnt get lost in the shuffle.

 

[Cullen Chong]

Whew…. This week had its ups and downs. I was totally stumped. I couldn’t figure out why I had no control of the throttle. The only thing that I can figure is that it was an old version of Betaflight with a newer FC. So I just started over by installing the newest Betaflight 3.3 and reflashed the FC. I set it up with DSHOT600 and the latest BLHeli 16.7. So everything was going great. I armed the quad and the motors went to idle speed and I had throttle control. So I'm thinking this is it. I’m ready to rock. So I screw down the top plate and a few other thing and I go to test it and S.O.B one of the motors isn’t spinning. What the Heck!. I did some troubleshooting. Swapped out the ESC, no luck. I swapped out the motor, no luck. I tested the to see if I still had power to the ESC, yup. No grounded signal problem. So i figured that something screwed up the signal to that motor. What I ended up doing was learning how to remap the Motor 4 signal to the LED pad and resolders the signal wire. It worked!!!! Wooo Hoooo!!! I got three packs in. This thing is so much fun. Thank you to each and every one of you who helped me troubleshoot it and gave great suggestions. You guys are what make this hobby awesome! I so appreciate your help and I learned so much.
Mahalo,
Cullen

 

[PsyBorg]

Interesting this flys on Dshot600. Last I read up on it all Dshot 300 was max it could handle processor wise.

Great you slogged thru it and got it in the air mate. Enjoy as they are a blast to rip around.