I believe that is the approach used by @Strongarm with his Zero Tow boogies. I think there are a bunch of it and various details if you go looking through his posts
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Thanks mate ill check it out.
Update with the APD 200 amp ESC’s. So, I think my issue is power cable length. These ESC’s only have 3 x 180uF capacitors, so cable length is key and my cables are way too long. I added 3 x 330uF to each one and it helped, but not as much as needed. So, I am waiting on some more cells to build another 12s12p battery and will use 6awg wire and have a QS-8 for each speed controller with 8awg and will keep wiring as short as possible. I will keep using this battery with the x-cross 120a as it works well. I was thinking to add bigger capacitors, but I think it will be better to get the cable size and length fixed. I’ll probably use 10awg for the motor wires as well. Heat does not seem to be any issue as I set the temperature protection to completely stop the ESC if over temped.
The problem with long wires and too little capacitance is not necessarily the resistance of the wire but the inductance… this won’t improve much with bigger wire, only with length or can be compensated by more capacitance at the ESC…
Just as an example, 50cm of 6awg vs 8awg:
Inductance 544nH vs 566nH
And for reference, 500nH at 100kHz (don’t know the switching frequency) is 300mOhm…
Even at 20kHz that’s 60mOhm, as much as 50m of AWG6 cable at DC
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Thank you so much for this knowledge!
So, no need to go bigger than 8 awg, shorter wires and maybe build a capacitor pack. What do you think a good uF rating to shoot for on caps?
Also, made a beefier motor pod if you need it. Posted on printable. I had a guy that had one of his break and the thinner version does have a bit of a weak point in the middle. I haven’t had any issues with the ones ive been running.
The needed capacitance is hard to say, I would say in total 3000 to 5000uF should be good
However, also for caps there is more than just capacitance: Similar to battery cells they have internal resistance and maximum allowed ripple currents they can handle
So like with a battery pack, it is wise to put smaller caps in parallel rather than one big one alone
That is also why some properly designed ESCs look like this and cheap ESCs tend to blow up their capacitors after a while… they get hot due to the internal losses, dry out or break down, boiled and eventually explode
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So after each ride you rinsed the motor and each 3-5 times disassembly with spraying corrosion x, and that was all waterproof you made at that moment + ceramic bearing?
Friend of mine have liquid Corrosion X from gallon bottle and wondering how much corrosion x I need to spray or submerge motor there.
Since I took the circlip off the front of the motors I pull the rotor each time and rinse with fresh water and wipe down with alcohol. I let it dry and then just spray a little corrosion x on everything and wipe it down and then squirt some in the bearings. I quit using ceramic and use stainless bearings now. It doesn’t take much corrosion x to coat everything. I’ve been using the same 16 ounce bottle for over a year and have plenty remaining.
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Thanks for clarification, I have 6384 for skateboard but didn’t make it resin coated and was very surprised that you have used same motor with out resin and only later decided to isolate it.
Right now you are using “usual” stainless bearings (mass market from any shop) or you could recommend some specific models?
nice connector, there are lot 2-3$ antennas on Ali w/o 20$ shipping like on Maytech ot Flipsky site, but connector required
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I realized I haven’t updated since I got my APD’s to work, so they work awesome now. I am not 100% sure on exactly what the main issue was, so I threw everything at it as I was determined to get the expensive things to work.
I first decided that my battery leads were way too long as the ground ran the entire length of the battery and I was losing voltage from resistance. So, I built another battery keeping the power and ground on the same side. I was also using one QS-8 connector that connected to both speed controllers, so I put 2 separate QS-8 connectors to connect each speed controller independently. I also used 3 layers of .2mm nickel to make sure I wasn’t losing current across the series. I think I went a little overkill. The first time on the water with this battery started out good, but one speed controller starting cutting really bad. Turns out one of the stupid BEC’s was acting up. Once I got a new BEC installed this thing runs like a beast. I am using half the throttle I usually do with the Flycolor’s. I dont know if the extra $200 per speed controller is worth it, but these things are nice. I still love my X-Cross 120’s and will continue to run them, but this is my main boogie now. I have built 4 so far and this one runs best by far.
I have been playing with the external antenna and haven’t noticed a huge gain from the little internal one ive always used, but is an improvement. I am gonna keep tinkering with it, but really am just waiting for the new BREmote by @ludwig_bre.
Sorry no pics at the moment. I am not nearly as good at documenting these things when im in the middle of building.
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Yes, just the usual stainless bearings from aliexpress.
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The motor being louder than it was in the beginning - it is because of the bearings? (I replaced with hybrid bearings)
Did you buy corrosionX in spray with actual gas?
I have corrosionX in spray like bottle, but it doesn’t spray , rather drip like.
Yours also have very strong smell?
I personally found the ceramic bearings got louder after a few uses and I have never used hybrids. I don’t have the same issue with the stainless ones.
Yes, the corrosion x I have is in an aerosol can, but I have also used a regular non-aerosol also. I just spray/pour a little on and then rub it in with my hand, with a glove on and then you can just squirt it down in the bearings. Yes, corrosion x definitely has a smell, I have a truck so it’s not an issue.
The biggest thing I have found with the cheap out runners is if you just take 5-10 minutes when you get home to clean them up and lube them they are awesome. If you neglect them at all, especially in salt water, they deteriorate quickly.
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What has happened to the motors which did not held up?
which one, the 6900 ?
I use the red one. I have never tried the hd, but have heard great things, but it is thick.
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I have used both the regular and HD. I find the regular penetrates better and stays on just as long as the HD. The HD is very thick.
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The oily CX (its green in colour)…is really good…ive got a spray bottle of it…lost forever…half the time i just soak the parts and pour it back into the bottle. Shouls.last ages.
K
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