Jump to content

A mysterious XP2 ESC issue


Recommended Posts

Hello, 

 

For no apparent reason, the 40A Overlander XP2 in one of my models is behaving very oddly. 

 

Sometimes, it will "stick" at full throttle when in the air, but when on the ground, it works absolutely fine. 

 

When it does this, there is no indication of interference as all other controls are unaffected. On landing (after waiting for the battery to die) the ESC is functioning normally, as it was during pre flight checks.

 

I have just moved club, so I considered something "in the air" but it seems unlikely, although there is a big RAF "Golf Ball" not too many miles away. 

 

Any ideas? 

 

 

Link to comment
Share on other sites

What is the ventilation like to the ESC? Could it be overheating causing the issue? Whatever the cause, I would be inclined to replace it, especially if the BEC is powering your RX and servos; it's not worth risking a model over. Retire it to the bench for testing!

Edited by MattyB
Link to comment
Share on other sites

14 hours ago, Matt Carlton said:

Ventilation is decent, but could possibly be improved. That is a potential cause, but its a 40A ESC running at about 17A, so it shouldn't be getting too hot. But, for the sake of £20, I might retire it for duty in a boat or something. 


Does it spend a long time at the same level of partial (low) throttle, as it might in (say) a vintage model? That can actually generate more heat than running it a full as the FETS are doing more work switching with (potentially) less ventilation. It does very much dep d on the use case and install though.

Link to comment
Share on other sites

Agreed retirement is the best option but there are a couple of things you could investigate:

 

1) Have someone check the Transmitter channel outputs (if that monitoring function is available on your TX) of that model in flight to verify that the throttle is working correctly at all times on that model memory setup. It is just possible that the problem is that the TX is sending a full throttle command & the ESC is just obeying that.

 

2) Recalibrate the throttle range settings of the ESC.

  • Like 3
Link to comment
Share on other sites

2 minutes ago, Simon Chaddock said:

Matt C

A bit puzzled by your comment "after waiting for the battery to die".

I would hope you are not taking the battery down to the ESC's LVC (Low Voltage Cut off) on a regular basis.    

 

Agreed, LVC is a last ditch effort to protect the battery, but you shouldbe coming down well before you hit it on a normal flight (when you land look for between 3.6-3.7V/cell resting voltage, at that level you won't do any long term damage to your packs through over-discharge).

Link to comment
Share on other sites

4 hours ago, Simon Chaddock said:

Matt

A bit puzzled by your comment "after waiting for the battery to die".

I would hope you are not taking the battery down to the ESC's LVC (Low Voltage Cut off) on a regular basis.    

 

The throttle was stuck at 100% so rather than stuff it in at full speed, I flew it around until the rpm dropped off sufficiently to land without damage and be able to retrieve the model safely without the prop turning at full rpm. It was the safest option all things considered. This was not my routine, it was just the best I could do with the situation at hand. 

 

Afterwards, I balanced the pack and put it into a storage charge as soon as I could. It's only 3S 1600 and capacity of each cell is still fine, I think these smaller capacity 2S and 3S packs are possibly more forgiving but obviously it isn't something I want to repeat. 

 

I did think about the tx signal issue, but that would have shown up on the ground checks, so I don't think it's that. The model is somewhat racey, so spends most of the flight flat out. I will hoink it out and replace it anyway before I fly it again. 

Edited by Matt Carlton
  • Like 3
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...