I'm using M3 x 8mm screws. With the 1/8" thick motor mount plate, I have almost 1/8" clearance between the screw's tip and the windings on my outrunners. Not sure how much room there is to the windings on the bigger 400 size inrunner I'm testing. It came with M3 x 5mm screws though. I think that it'd be a good idea when we get a new motor to test, to take a skinny piece of wood (like a toothpick or something and use it like a depth micrometer to see how far in you can go without hitting the windings. If we can save the data with the part number/motor type, it could be posted (like a sticky on here and a page on the MWC HowTo page, and any other club's page that wants it). Maybe include a brief statement on suitability for a particular application ("good for 14-pound cruiser drive motor", etc). If you guys need to borrow any of my short M3 screws, I'll have them with me Thursday night before the battle. I order a hundred at a time from McMaster. I had to run up and down the line at the last Brouha to find the right M2.5 screw and I don't want to do that again, so I maintain a healthy stock in the parts box. Finally a good use for all those left-over pill bottles!
Well today we had Don's Duke already to go using the brushless 30 amp controllers, on the 550 series brushless motors. Ran great on the bench, but as soon as we put it into the water nothing but problems. The brushless ESC's after various times, 10 sec, 2 mins, etc, would come unlocked from the receiver. The only way to get them working again was to power down the receiver, and power it backup again. We tried, direct power from the main's, then powering the receiver off one of the ESC's, then a receiver battery pack, even at different power levels down to 60%, and nothing mattered, the ESC's continued to unlock. What was strange, was the pump ESC would also unlock, even though it was not in use. We also tried a different brand of radio and receiver with the same results. Mike M is working with a 100 amp ESC, so I'm suspecting it must be a power loading issue on the 30 amp units, with the big motors. Later after the battle next weekend we will try again with the 100 amp controllers. Mike was right about the improved turning, when it was running the Duke was turning inside its hull lenght, we were really impressed with that part of the trials.
You may also have to change the settings on the ESC's you are using. some of the outrunners like slightly different than others, and I have found that playing around with start power and motor timing (if those options are available to you) can fix some of the current inrush issues. as can punch control, if that option is available to you. Also, check your voltage cutoff settings, if they are set too high, the initial current draw can pull the voltage down and cause them to go into cutoff mode, which usually goes dead till you return the stick to 0 throttle then you can move again. If the pump ESC stops working, it really sounds like a voltage drop issue to me when you start the motors.
Yes I talked to Mike like 3 times while we were testing. I have the voltage cutoff set to Zero, and timing also set to Zero. The motors do say 35 amps ESC required, and we only have a 30 amp on it. But I did not think that it would draw that much, but it looks like it does for a few microseconds. Also we have the punch control set to max, 29%. We can set that down to Zero, it is setable. I will try that option next.
depends on your punch control, in my ESC, 0% turns it off. 100% turns it to max (max being highest degree of limiting). You may try setting the timing different, and also check for binding in the drivetrain, as that can be particularly problematic at startup. does the ESC drive the motor properly if not in the water or not installed in the boat?
On the bench it drive train is free spinning, nothing is binding up, and when run on the bench everything seems to run fine. I have 3 ESC's installed, 1 on the pump, 2 on a Y going to the 2 drive motors. We did notice before we added the pump ESC, just turning on the old brushed pump setup, it would also cause the drive ESC's to unsync. Why we switched over to a brushless pump setup.
Sounds like you are losing power on the BEC side, how much draw can your BEC handle? Have you tried an independant power supply for the servos?
Only a few tries used the BEC. After that we used main power, and even tried a independant battery on the receiver, nothing worked. It looks like a current trip, just not sure why the pump ESC also tripped every time, even when it was not in use. Only thing I can think of is the ESC's themselves are overly sensitive. We were running them on extensions, receiver is in the front of the boat, ESC mid rear. May need to try servo extenders, plus they add isolation.
check your connectors for your wires. you might want to try running shielded wire as well, see if that helps.
We tried that Mike, it has 6, 8 or 10%. We did have all breaking set to max. What do you have your breaking set to on the 100 amp units?
We took it down to 50% with the same results, between 50 and 60% looked like it was on speed, any lower and it would not meet 26 second speed.
