Hi guys
I am finally running my Gokart with :
75/200 ESC by Splinted
13S7P battery 35Ah 21700 210A
150A DALY BMS
2 x 800W 48V wheels
so , let me explain my issue
Motor detection is around 30-33A current from Wizzard , hoverer accelerate is not "strong" ..it will accelerate till 50km/h of course "baby drive"
No matter how hard I push accelerate paddle it speed up from 0km/h till 10km/h...then also accelerate but motors give a knocking ,,and when it reach 20km/h it accelerate also without any issue till 50km/h...no knocking, no issue, very smooth and silent (accelerate is press till max)
while "knocking" I need to press very little accelerate paddle to let him reach 20km/h and after 20km/h and can push it max and will drive ok
I did motor adjust to current 70A , ...speed up is big different , but more "knocking" between this same speed range
with for example 70A motor current , accelerate from 0 till 10km/h is very fast (i like it) ... then from 10km/h ...till 20km/h I push accelerate to max and I can hear very hard motor knocking, after 20km/h , even if accelerate is still push to max , it will speed up to 50km/h smooth and silent
"bench test" passed, no issue with detection, minor different between both motors
I did motor open, and there is no issue with bearings etc
there is no mechanical issue , it seems like motor is loosing synchro with ESC ? but why always with this same speed range ?
who can give some advice , where to look in a settings , maybe some ERPM adjust , ?
Motor is set up BLDC , direct output
Thx for all advices
Hi,
Do you have Hall sensors for your motor? If so, the problem could be due the lack of fine tuning the transition for sensorless mode. I recommend to use FOC as this helps with efficiency and also slighty quiter.
I would try the following steps:
1, try to run in sensorless mode
2, try to increase the switching speed to 30kHz, or even higher up to 60kHz. I think "sample in v0 ans v7" option should be only used if switching speed is 30kHz or lower.
Some loose electrical connection (like battery to vesc) could also create strange things.
Hi.
yes, I have sensor in both wheels
due to bad weather I cant to test drive right now
on the bench with simulate test - from 0 to 20km/h is no issue , both motors show similar diagrams , but there is only minnor load
so not a reall test
thank you for advice , i will do changes
Martin
Hi ,
Settings was check , default value was 30Mhz
when I move it to 60Mhz , issue was even higher - still start from speed near to 10-12km/h but keep till 30km/h ...couldn't even drive faster because did not speed up smooth
when I move that down till 10Mhz , similar like 60Mhz , also issue to speed up, so the best is 30Mhz
When I change to senseless motor - that not even move , as is can not recognize direction i think
some pictures from FOC settings
https://imagizer.imageshack.com/v2/640x480q90/924/e7AO16.png
https://imagizer.imageshack.com/v2/640x480q90/922/8B1Ul5.png
https://imagizer.imageshack.com/v2/640x480q90/924/eASmKe.png
https://imagizer.imageshack.com/v2/640x480q90/923/4KHySQ.png
https://imagizer.imageshack.com/v2/640x480q90/924/CEJaH8.png
https://imagizer.imageshack.com/v2/640x480q90/922/CzoauY.png
https://imagizer.imageshack.com/v2/640x480q90/924/sN25rO.png
Martin
Seems I Fixed that :)
result is amazing, just minor knocking when low speed anc accelerate
I set up :
Sample in V0 and V7 from FALSE to TRUE
High Current Sampling Mode from FALSE to TRUE
in both motors
and is seems fix 99% issue
now I only see small issue with speed up from 0.
if I press accelerate to max - it will very slow accelerate with knocking (not sure if that is a knocking or not, or some "noise")
but If I relist accelerate paddle , and press to max again (remember wheels turning and Gokart drive about 5km/h) it will speed up very fast without issue
from what i see , is require not much accelerate on the begining just to let him slowly speed up , and then you can be a drag racer
Martin
Hi.
if anyone is follow my issue ..... hope there is a someone :)
2 possible options, or I am not smart and cant find proper settings , or vesc is too smart for me ;)
anyway - with my friend , we did a analize erpm , and we reduce Ampers till motor reach a limit erpm with cause a issue
durring test , I found that 70A is a max that can be push to motor till 1900erpm , after that ERPM , I can push 95A - this is my Max current
add erpm control limi in to my software
so now I have a drag race , as 70A in low speed is also good ;)
Martin
I know this knocking behavior only from bad resistance value. Are your connections from Motorphasewire to Vesc 100% fine?
You can try playing a bit with the resistance value or even better measuring the motor with an LCR Meter.
Oliver
Link to forum post: VESC help offered for private persons and companies
Website: www.electricfox.de
Hi.
thx for message , yes connection is ok , 5mm gold
if use small power like 30-50A ...is no issue at all till max speed , but ride is little poor
if I use 90A power - ride is much better , but with issue at the begining
you suggest to measure phase resistance in motor and manually type that into vesc settings ?
It was small changes if I was use FOC_CC_DECOUPLING - after play with that settimngs , my "knocking" just change range of erpm, but always exist
Martin
I meant lowering or rising the value in Vesc-Tool a bit (10-20%) and trying out.
Link to forum post: VESC help offered for private persons and companies
Website: www.electricfox.de
ok, thx for your feedback, will do test soon.
Martin
ok, thx for your feedback, will do test soon.
Martin
I have the very same problem on my new 100v/250a version.My motor knocks if my motor amps are raised above 170a.All phase connections are fine (stripped and check)First i thought i did not have enough motor amps and was spiking on hard acceleration causing it to hold back then knock.Ive since uploaded the unlimited fw version raised is 25mps at a time retested and no matter what i do its same result.Coming from an old Sabvoton controller that allows me to ride at 500 motor amps with no problems at all this makes no sense.I have done all that has been suggested in this thread and nothing helps.Setup is 22s 30ah battery,qs205 hub motor low kv 7.29 new 100v250a vesc from TrampaBoards