Moebius Skipjack

[Bob Gato]

Man I am sorry-when you said you " burnt up two ESCs" my head jumped to twin motors-the diodes wouldn't come into play on a single-it really sounds like it might be a "big Prop" mismatch with the motor or very long leads from the battery to the ESC.(Ron van Sommeren from over in RCG has done a lot of writing on the water hammer type effect of long supply leads and the slow death of model ESCs)
https://www.rcgroups.com/forums/show...ns-workarounds
Please feel free to PM me if you want as not to hijack Ken's thread.

[Das Boot]

Thanks, Bob. What I don't get is I was using a 15 amp ESC then a 40. Both would work, get hot, stop and work again. I imagine it's the thermal SCRAM, but I don't know why. I never ran it full bore. Read your post. I've used diodes countless times to incur voltage drops in ham radio gear, especially the old Heathkit stuff. That's all we used until the surface mount stuff came out.

[Bob Gato]

Casey-this might help- I use it on my Mark V and I can access 10 amps combined from both ESCs at the same time. I came up with this a few years back-it also keeps my radio running if one side fuse blows. https://www.rcgroups.com/forums/show...-Diodes-anyone

[Das Boot]

https://m.youtube.com/watch?v=qrXxNlTTYKI

this video outlines what a BEC is and why a lot of people like them versus using the built-in BEC in many speed controllers.

Bob

Well hell, that may be why I've burned up 2 ESC's in that fishing boat. That's probably the only one of your video's I haven't watched.

[Bob Gato]

LOL Sorry man!!

Great video-tells all! If you are still on the hunt for a UBEC, I wonder if you could use a buck converter-I use them for accessories-they'll take up to 40 volts and hold it at your setting at least 1.3 volts below the input voltage regardless of changes in input voltage-they are quite cheap...and small. I've bought them for as low as 10 units for $7...dial in the voltage and it just stays and it doesn't waste power as heat. These are 3amps at $4 each-but if you shop around you can do better . https://www.amazon.com/LM2596-Conver...a-754523673785

[Ken_NJ]

Good thought Bob. Tried your suggestion, it was actually worse.

Made a video to show everyone the problem. The stuttering may not be a big deal, I don't like it. I may just not use a BEC and stick to the ESC BEC. As you can see at the end of the video, the current draw is 230ma which the ESC BEC can handle.

https://youtu.be/94mP_PZ43fQ

Why is my video not embedding here?

[Bob Gato]

Ken just for s's and g's... Try disconnecting the black wire to your ESC from the radio also.. and just leave the signal wire connected you could be getting something trying to find a ground/back feed through the m-tronics ESC... The ESC and radio already have power and ground without that black wire... So they should not need it anyway-just a thought-BG

[Ken_NJ]

Casey, Bob covers everything as to why using one in the video. The ESC I am using has an output of 1.2 amps. In my testing, with as many things working, running that I could, I measured 0.5 - 0.7 amps drawn from the BEC. So adding a BEC with an output of 3 amps ensures I wouldn't be overtaxing the ESC BEC.

But, in my setup, the ESC-motor is getting noise from the two BEC's that I tried so far. According to Mtroniks I need to use a opto-isolater that they sell. Can't find it in the US and it's costly to ship it across the pond. This week I'll be trying to add additional caps to the motor to see if the problem clears up. If that doesn't work then may go back to the ESC BEC and not use a dedicated BEC. Or will have to go for another ESC.

[SubHuman]

https://m.youtube.com/watch?v=qrXxNlTTYKI

this video outlines what a BEC is and why a lot of people like them versus using the built-in BEC in many speed controllers.

Bob

[Das Boot]

New diagram/layout....
[/QUOTE]

Ken, I'm missing something. I see you have a BEC from the battery going into the receiver for power. Don't all modern ESC's have a built in BEC? I just plug my ESC into channel 3 on my targets receiver. Is this just extra protection or a power issue? Forgive my ignorance.
Casey

[Ken_NJ]

Plenty of waterproof ESC's with 3amp output. Brushed and brushless.

https://www.amazon.com/ESC-Boat/s?k=ESC+for+Boat

[Bob Gato]

Oh pleeze! I have heard this from Mtroniks many times-Every body drinks the Kool-aid I don't know why anyone talks so highly of Mtroniks! All the other (cheap) ESCs can tolerate a noisey BEC!

It would be cheaper to buy a new ESC!!

[Ken_NJ]

Email from Paul at Mtroniks...

It sounds like the BEC you are trying to use is a switching BEC? These are very noisy electrically and could be causing a lot of interference with the control signals to the motors. Evidence for this is that the system works ok when running on batteries.

We would recommend you use the following, one on each speed controller. These opto-isolators cut all noise and leave a crisp signal for the speed controllers.

https://www.mtroniks.net/prod/RC-Accessories/ZGM.htm

In a quick search did not find that ZGM anywhere in the US. Cost with shipping from overseas is about $55. Not worth it. I'll keep looking for one here. In the meantime will look at what I have on hand for an ESC to try out and look for something other than the Mtroniks brand. Any other ideas?

[Ken_NJ]

I'll have to check the the spare parts box. I probably do.

[Bob Gato]

In the mean time.. do you have a spare brushed ESC-like a $15 hobby king 45amp crawler unit..to try and see if its an Mtroniks problem or something else?