Well here in Phoenix it gets really really hot... so I am trying some stuff to see if I can get the temps down on my BLs during my flights. They are getting pretty dang close to the upper limits. Anyways here is what I have come up with. I haven't had a chance to fly yet but I am hoping to tomorrow... We shall see if it works or not. It's all easily reversible if it doesn't and the fan was only $13. The fan size is 120mm x 120mm x 12mm. Josh
Ok so I was able to test a little yesterday. Ambient temps outside was 99*F. With out the fan in a hover for 2min my hottest BL went to 99*C with an average BL temp of 92*C. With the fan on and in a hover for 2 minutes my hottest BL temp was 84*C with an average of 79*C. I will be doing more testing soon to confirm my findings. This was on a CS8 with 5Dmkii. Josh
Josh That sounds encouraging. Wonder though that with the fan on one side and cooling the top side of the FEC's what is going on with the sides that are on the bottom?
Run power straight off the PDB. On 4s it was ok to use still. Now I would need a BEC to power it. Josh
Maybe it would make sense to move your BLs out to the booms right under the motors. There's a pretty good downdraft coming from those props...has anybody tried that?
Steve I've seen that done with standard ESC but not the MK Bl's. The wiring might be problematic. Power to each. Then the multiple DC connections. I'm assuming you would have a D&C pair from each running to a collection point then connecting to the FC. I'm getting a headache just thinking about the failure points
If it's not too much trouble, can you post technical details of the fan, Josh? 12v? 5v? Current draw? Also, where did you mount it, please? Just along one side of the PDB and blowing across it? With a CS8, 3-axis, 5D Mark III, using 4S and an ambient temp of around 85F/30C, I was seeing hover temps of 99C, that dropped rapidly to 87C when the copter was laterally translating (posh speak for flying sideways, innit, eh? ) Andy.
I was in 104 today Andy... our shots were literally 1minute and 15 seconds from takeoff till land. Highest temp was 97C
I see that Southwest Airlines was having to cancel some flights yesterday -- air temps of 119F but the aircraft max out at 118F -- I suspect it's the density altitude/runway length issue rather than the actual ambient temp. Major heatwave in the SW USA. Andy.
Josh are you pushing the air down into the PDB or pulling it up? I have been contemplating doing this also, since we are getting 105 degree temps in New Mexico.