Castle Mamba XL2 ESC cogging

[digitalsolo]

I have similar behavior on my Baja with an XL2 as well. I'm going to be adding a cap pack and an external BEC this weekend to see if it clears it up. It's not quite as bad as this one shows, but it's very noticeable, especially about 5-6 minutes into a run.

I will update with regard to improvement after the change.

[othello]

I should have posted my XL2 settings earlier as i'm now driving an xl2 with castle 2028 powering a much heavier Losi 5iveT without any cogging issues (and it also worked with the trackstar motor powering the car shown in the video posted above).

You may want to try these settings:

[Dr_T]

Originally Posted by othello

XL2 settings:
- Firmware 1.32 (Date 4/5/2011 -> is this the most recent one? ... castle link says yes ... i wondered about this since that's more then 2 years ago)
- Startup Power is set to low
- No punch or torque control
- lipo cut off is set to 3.3v

Originally Posted by othello

I should have posted my XL2 settings earlier as i'm now driving an xl2 with castle 2028 powering a much heavier Losi 5iveT without any cogging issues (and it also worked with the trackstar motor powering the car shown in the video posted above).

You may want to try these settings:

[snip pics]

Hi Othello, I know it's a bit of an old thread, but I thought I'd try my luck:

How do the settings you described to run successfully in the posted pics, differ from the settings that got you the cogging problems? Only difference I see in your posts would be a change of the LVC, from 3.3 to 3.5 V/cell, no? Or am I overlooking something?

Did you end up using additional caps and an external BEC? Did that reduce ESC temps and were those additions a factor in the solution to the cogging problems you think?

Thanks!

Edit:
Lizard was so kind to link me to your thread at offroad-cult and I read about your experience with a failing XL2 while using Castle Link, seemingly because there was a load (external BEC and fans) connected to the battery leads while connecting the ESC to the link. Seems your new XL2 has been running well right? So the solution would be to put a switch between any loads (fans, UBEC, other) connected to the battery leads, correct?

[othello]

What seemed to have worked was (i think) more due to the reason that i now usually make a short brake after 5 minutes into the run (which helps the ESC to cool down inbetween).

I you take a look at the following video (FG onroader with XL2 ESC) ... you will notice heavy cogging right at the end of the run when i tried to bring the car in. The esc had logged around 100°C at that point. At the beginning of the run there is absolutely no cogging. And i think i used the settings i have posted above. It really depends on different factors how bad it might cog. Can't remember i have seen the Losi 5T cog so bad after a longer run.

Yes: additional cap pack, external bec and dual 5.5mm plugs. I'm also using a 10ohm resistor when plugging the batteries to the esc (ESC is set to 8s ... not auto lipo). I think those "goodies" help the ESC to survive and work reliable. I also have installed a plug to disconnect the UBEC from the ESC when i'm retrieving data via castlelink (as it would be otherwise powered as soon as you connect castlelink to your laptop/PC).

With all this small goodies i'm now runing two XL2 esc without issues.

Would be interesting to know when the "xle50" castle car esc (12s?) will hit the shelves.

[Lizard]

Originally Posted by digitalsolo

I have similar behavior on my Baja with an XL2 as well. I'm going to be adding a cap pack and an external BEC this weekend to see if it clears it up. It's not quite as bad as this one shows, but it's very noticeable, especially about 5-6 minutes into a run.

I will update with regard to improvement after the change.

On my Mamba Monsters I could also observe cogging that looks and feels the same as the XL2 cogging, although not as bad. It seems it is connected to ESC temperature somehow. After I removed the case from my ESCs and put a bigger fan on them, the cogging was reduced significantly.


Here's what I found out about the XL2:
The two parts of the cases are glued to the PCB with thermal glue that doesn't hold on too strong. With the ESC that I got, the bottom half almost fell off on it's own and there was dirt on the thermal glue, so it wasn't really sticking anymore. I have seen the same on rcs2022's pics of an opened XL2 here on the forum, one could see dirt there also, so it must have seperated before. The plastic case around the heatsink case holds the two parts together, but it doesn't apply pressure which is needed to keep everything tightly together for good heat conductivity between the PCB and the heatsink.

Also, the fan cannot be very effective, the grill on it doesn't allow for good airflow and the upside of the ESC casing also doesn't allow for good airflow.

You could try the following to fix the cooling:
1. Remove the plastic casing and clamp the two case halves together using some threaded rods in combination with braces.

2. Use a big (60x60 or 80x80) high-flow fan and mount it half an inch or so higher (not directly on top of the ESC case).

[othello]

Thank you lizard for sharing your findings. This corelates well with the fact that while the XL2 logs do show temperatures up to 100°C the aluminium cases remain relatively cool (around 45°C max).