Tweet
That's correct Martin, this was unloaded. The vibration now is the same as when it was new and didn't feel like it was going to shake the boat apart. When I temporarily had the Octura compression collette installed, the vibrations were so bad that I was afraid it was going to eventually crack the plastic mounts.
-
-
If its not vibrating in the water under load dont worry about it, not advisable to run any motors with no load on them apart from just checking that the motor is running & in the right direction ecspecially outrunners as you do get more vibration over inrunners ecspcially some cheap outrunners have a lot of end float on them which isnt a problem once under load in the water. My outrunners that were running at over 42000rpm unloaded were unbeleivable on vibration, once in the water no problem at all.Comment
-
Thanks Martin, I only ran it for literally 5 seconds each check.Comment
-
Well, the motor is just cookin' Just a matter of time before a winding shorts. It's impressive though. I did put the original 30mm prop back on.
I'm thinking of putting the spare CF2812 rated at 1600KV and sticking the 32mm prop on and run it like that, or even mate it to a 3 blade prop. I've tried just about all the timing settings and have her at 3.5 now to try and keep her cool.
I did try swapping the 14 magnet shell of the CF2812 to the Joysway coil, but it didn't like it.......must be the way they were wound.
This is a testament to the Boca ceramic bearings though. Still going strong.Comment
-
Did WOT run yesterday, about 5-6 laps. Motor was still hot, but not as hot.....still could not keep my finger on for 5 seconds.
I'm wondering if the motor is pulling more amps now that it's being fed by a 120A ESC vs the stock 20A and that's actually causing the overheating. The boat is faster...........using the same battery and prop, so if there were drag in the new drivetrain, I would think it would be slower.
Stock CF2812 1600KV can pull max of 18 amps. This Joysway variant is rated at 3300KV. I can confirm that it's actually faster as I stuck the 1600KV motor in for a test run and it was dog slow. You figure twice the KV.......this motor is capable of pulling 36 amps, which is more than it's size was designed for as far as dissipating heat?
Joysway normally fits their boats with 30 Amp ESC's. I wonder if putting in a 20 Amp is their way of not overheating the motor.
Is there a way that I can use resistors to limit the maximum amps my ESC can feed to the motor to 20-25 amps? Say a modification of a Spark Arrestor. Would this hurt the ESC? I noticed the newest version of the Turnigy 120A ESC has acceleration settings. I wish I had that option now to test with.Comment
-
No offense but you really need to learn a little bit of electrical theory.
Check the answers you got on RCG about the esc, it was explained to you correctly there by Boaterguy no less!
"Quote:
Nope, the ESC does not push current, neither do the packs.Originally Posted by MassiveOverkill 
You guys think the Seaking 120A ESC is feeding the motor too much current?
The motor will draw the amount of current it needs to spin the load, the bigger prop, the more current it will draw. If that current is higher than the motor can take, it will heat up until blowing. The current is drawn from the batteries through the ESC. If there is more current passing through the ESC than it can handle, it will also heat up until meltdown. There is nothing pushing current, therefore you can have components rated for as high as you want, I ran a 140A ESC on an airboat drawing 20-25 amps once."If my boats upside down then who owns the one I thought I was driving the last two laps?
Comment
-
If you are refering to the specs that HK have on the T120a esc re brake - non, soft or hard. This info is wrong on the Marine 120a esc, their is no brake setting. Should read.
running mode
lipo cells
low voltage
timing.Comment
-
-
Yep crossed wires, i was reffering to the T120a & not the Aquastar.Comment
-
PROBLEM SOLVED!!! Thanks to all whe helped. Thanks to Rabosi (not on this forum) for pointing out my 'thrust' bearing was in the wrong place. Motor mount is nice and cool as well as the engine. Thing really flies!!!. I'll take another video after TS Debbie gets her butt out of town.Comment
-
Well problem partially solved: Throughout all my troubleshooting I've been using the stock 1800 mah 20C battery that came with the boat. Last night after getting the thrust bearing put on the front bearing everything ran nice and cool. I take her out this evening and figured "my problem's fixed, let's use the Grayson (2200 30C) batteries." First run went well and checked for heat afterwards and the damned thing is running hot again...........not so hot that smoke\steam was coming off of it but barely passing the finger test. I do a 2nd run with my 2nd Grayson pack and same result. Finally on my third run, I use the stock 1800 pack and what do you know...........running cool.
Stock battery 1800x20=36amps max draw.
Grayson battery 2200x30=66 amps max draw.
Grayson pack is also 179 grams to the stock battery's 138 grams. The boat only weights 514 grams without battery. Boat actually seems to run faster on the stock battery speedwise.
Videos of the two runs on Grayson batteries:
Comment
Comment