Go Back   DIY Go Kart Forum > Building Plans And Advice > Electric Projects

Notices

Reply
 
Thread Tools Display Modes
  #1  
Old 11-12-2019, 11:28 AM
scorn001 scorn001 is online now
Member
 
Join Date: Apr 2017
Location: Dallas, TX
Posts: 33
Thanks: 16
Thanked 8 Times in 6 Posts
Default 48V 1800W Dual motor e-lock, brake, and reverse wiring

So I'm starting to wire up my dual motor setup using 2 of the Mophorn 48V 1800W setups available on Amazon. I've been running with one motor for some time, with both the brake and reverse options being used.

I'm attaching the 2nd motor and controller now, and I understand how the throttle is attached (wiring just the sense wire to the 2nd controller). I'm curious if the the e-lock, reverse, and brake wires are done the same way? With my paperwork it isn't immediately obvious which is the "sense" wire.

My thinking is that I should just be able to measure the voltage on the two wires for each connector on the existing controller, and see which is being pulled up or down (vs which is holding it's value) when engaged/disengaged, and assume that the wire that is switching it's value is the sense(ing) wire, and wire it such that those wires are tied together?

Anyone else have any insight on this?
Reply With Quote
  #2  
Old 11-12-2019, 11:56 AM
itsid's Avatar
itsid itsid is online now
Moderator
 
Join Date: Jul 2013
Location: Ruhrpott [Germany]
Posts: 10,247
Thanks: 1,396
Thanked 4,312 Times in 3,245 Posts
Default


I'm afraid

I won't go hunting down
a pic of the controller and motor on the banks of the amazonian river...
You don't even tell us if it's a BLDC or a PMDC
(I assume it's the BOMA with a different label really)

"the sense" wire?
what the...?
Either you have two (thermal sensing)
or five (hall effect sensing) [red, black , green, yellow, blue usually on one plug]

or you sense something other than motor temp or position..
in which case: please explain!

'sid
__________________
Jokes about german sausage are the wurst.
Reply With Quote
  #3  
Old 11-12-2019, 12:23 PM
scorn001 scorn001 is online now
Member
 
Join Date: Apr 2017
Location: Dallas, TX
Posts: 33
Thanks: 16
Thanked 8 Times in 6 Posts
Default

My apologies. It is a BLDC motor. My intention was not to get you (or anyone else) to go do research on my behalf. Given that it is a convenient and affordable motor and controller kit that is readily available on Amazon, maybe someone had specific experience with this setup already.

I'll try to post a better prepared post next time.

I wasn't referring to the Hall effect sensors. I was referring to specific option switches that this Mophorn controller offers (A reverse switch, a brake switch, and a lock/disable switch). Again, I'll apologize for my ignorance. Take care.

Last edited by scorn001; 11-12-2019 at 01:00 PM. Reason: Correct grammatical errors and add information
Reply With Quote
  #4  
Old 11-12-2019, 10:08 PM
itsid's Avatar
itsid itsid is online now
Moderator
 
Join Date: Jul 2013
Location: Ruhrpott [Germany]
Posts: 10,247
Thanks: 1,396
Thanked 4,312 Times in 3,245 Posts
Default

Ah..
so there was a misunderstanding on my behalf..

Well, you cannot wire just the throttle output wire to the second controller.
you MUST also connect the gnd wire .. easy to find out with a multimeter
when the throttle is connected to the controller..
one wire will be +5V against ground and the other one between 0.3 and 4.7V against ground
(depending on throttle pos) if you measure 0.3V or such the throttle untouched,
you either have the black probe on "OUT" and the red on "+5V" or the black on "GND" and the red on "OUT".. push the throttle down a bit, if the voltage reading rises the latter if it drops the first.
if you read a negative voltage just switch black and red probes first.
(the remaining wire is then obvious, no?)


ideally you want all three connected to get the reference correctly, but
the ground wire is an absolute must have for the controller to detect the voltage potential
in order to set the speed.

brake switch must be fully paralleled (so both controllers get the brake signal)
forward reverse must be paired as well..
be sure that your motor runs at the same speed in both directions (most do NOT!)
than you can wire them to the same switch I guess
again making sure to have them on the same gnd potential...
ideally you'd use some diodes in order to protect one controller from reading the other one as a signal.. I suspect pull-low to engage but can't tell.. you MUST know in order to wire that up

The engage/lock switch wires can be paired up to one switch.
I'd still add diodes in order to prevent them being wired in a crossing fashion however.
otherwise you might fry one or both controllers.

'sid

PS Still we'd love Pics!!!
with the controller and mostly wire colors for reference we can be less vague
__________________
Jokes about german sausage are the wurst.
Reply With Quote
The Following User Says Thank You to itsid For This Useful Post:
scorn001 (11-13-2019)
  #5  
Old 11-13-2019, 06:35 AM
scorn001 scorn001 is online now
Member
 
Join Date: Apr 2017
Location: Dallas, TX
Posts: 33
Thanks: 16
Thanked 8 Times in 6 Posts
Default

I got it going last night, all seems to work fine. I might connect the ground on the throttle just for good measure, but the the two systems are attached to the same power and ground source. My understanding is that if the two weren't referenced the same (same VCC and GND) then yes, ground wires for control would need to be tied together, but being that they both see the same "ground" the sensing wire will see the same 0-5V and appear to have the same relative level at both locations. This appears to be the case, both motors start at exactly the same moment in throttle application, and stop at the exact same moment. I wasn't able to make one spin without the other.

Same with the others, the 2nd controller only has the sensing wire, tied to the controller number 1 sense wire. Brake, reverse, and disable all seem to work well.

Electricscooterparts.com has wiring diagram that explains the throttle wiring, it specifically shows the ground wire NOT being shared on the connector - assuming the same voltage source, but again, I'll probably do this for good measure. Thank you.

Being on a live axle, I'm a little afraid that somehow the reverse wire on the 2nd motor could (somehow) become disconnected. If that happened, and the driver put the kart in reverse, that would put both motors driving against each other through the axle which can't be good of course. I'll probably try to implement some redundant wiring there.

I need to do a little more welding on the 2nd motor bracket, and I need to bolt some things down, but short of that I think I'm ready to take it for a test drive.

I forgot the get pics last night of the progress, I'll try to get out and snap some this evening.

Thanks again.
Reply With Quote
  #6  
Old 11-13-2019, 07:26 AM
Functional Artist's Avatar
Functional Artist Functional Artist is offline
Senior Member
 
Join Date: Jul 2016
Location: Toledo, Ohio
Posts: 1,997
Thanks: 768
Thanked 753 Times in 598 Posts
Default

Yes, please post some pics of your set-up
...even draw (us) up a wiring diagram of how you have 'er wired
(good future reference for you too)

Q:
Do both of your motors rotate in the same direction?
...or does (1) rotate clockwise & the other counter clockwise?
__________________
RESISTANCE IS FUTILE
Reply With Quote
  #7  
Old 11-13-2019, 07:38 AM
scorn001 scorn001 is online now
Member
 
Join Date: Apr 2017
Location: Dallas, TX
Posts: 33
Thanks: 16
Thanked 8 Times in 6 Posts
Default

One clockwise, the other counterclockwise. They are mounted on different sides of the live axle, opposed to eachother. So forward for one is clockwise, counterclockwise for the other.
Reply With Quote
The Following User Says Thank You to scorn001 For This Useful Post:
Functional Artist (11-13-2019)
  #8  
Old 11-13-2019, 08:17 AM
scorn001 scorn001 is online now
Member
 
Join Date: Apr 2017
Location: Dallas, TX
Posts: 33
Thanks: 16
Thanked 8 Times in 6 Posts
Default

I do have this pic from a few weeks ago. It's after the 2nd sprocket (right side) was added, I'm checking alignment of the 2nd motor and deciding how I'm going to mount it. I'll take more though.


Click image for larger version

Name:	20191016_190850.jpg
Views:	7
Size:	1.88 MB
ID:	113548
Reply With Quote
The Following User Says Thank You to scorn001 For This Useful Post:
Functional Artist (11-13-2019)
  #9  
Old 11-13-2019, 08:21 AM
Functional Artist's Avatar
Functional Artist Functional Artist is offline
Senior Member
 
Join Date: Jul 2016
Location: Toledo, Ohio
Posts: 1,997
Thanks: 768
Thanked 753 Times in 598 Posts
Default

I have found that these little motors generate different RPM's, depending on the direction of rotation
…& most (I have tested) seem to operate "more efficiently" when running clockwise.

I did RPM tests on each of the 48V 1,000W motors on the !Arriba! kart
…& got some interesting results

The top speed of the left motor (running counter-clockwise) seemed to be 3,528 RPM's
...but, the top speed of the right motor (running clockwise) seemed to be 3,801 RPM's

After running a while, I noticed that (1) motor on the !Arriba! kart seemed to get warmer/hotter than the other
...probably workin' harder

So, it may be a good idea to keep an eye on 'em

Here is a video of the RPM tests

__________________
RESISTANCE IS FUTILE
Reply With Quote
The Following User Says Thank You to Functional Artist For This Useful Post:
scorn001 (11-13-2019)
  #10  
Old 11-13-2019, 09:21 AM
scorn001 scorn001 is online now
Member
 
Join Date: Apr 2017
Location: Dallas, TX
Posts: 33
Thanks: 16
Thanked 8 Times in 6 Posts
Default

Hah, I actually found the same thing. Both of my motors are rated at 4500 RPM top speed. Left motor maxes out at about ~5200 unloaded, the right motor hits around ~5500. The right motor running clockwise of course.

I've thought about trying to put some aluminum heat-sinks on the motors and controllers. Controllers would be easy of course, wrapping heat sinks around those motors will require more thought.
Reply With Quote
  #11  
Old 11-13-2019, 10:05 AM
itsid's Avatar
itsid itsid is online now
Moderator
 
Join Date: Jul 2013
Location: Ruhrpott [Germany]
Posts: 10,247
Thanks: 1,396
Thanked 4,312 Times in 3,245 Posts
Default

Quote:
Originally Posted by scorn001 View Post
I got it going last night, all seems to work fine. I might connect the ground on the throttle just for good measure, but the the two systems are attached to the same power and ground source. My understanding is that if the two weren't referenced the same (same VCC and GND) then yes, ground wires for control would need to be tied together, but being that they both see the same "ground" the sensing wire will see the same 0-5V and appear to have the same relative level at both locations.
Unfortunately that's not true

Supply voltage is IDK say 48V
and 5V GND is NOT necessarily chassis ground

There will be two or three different voltage potentials inside the motor controller,
(usually battery supply, regulated battery supply, and 5V)
sometimes even a 3.3V rail and some internal 1.1V rails ..
anyways..

Every controller has it's own set of Powerregulators
to provide it's internals/externals with the required voltages
NONE is constant (there's always noise)
(a typical 5V regulator set by a 5% resistor can swing 0.3V easily)

So Controller 1 can have it's 5V at a miniscule potential raised above chassis ground
say it has 0.2 to 5.3 above chassis ground

And Controller 2 has a slightly worse 5V supply but is closer to chassis ground
say 0.1 to 5 V

Now the HallSensor of your throttle is powered by controller 2
and set to 75% throttle (0.3 - 4.7V swing) so it reads 3.6V
[0.75* 4.4 + 0.3 = 3.6]

Controller 2 takes that 3.6V as 73.5%
[3.6 / 4.9 = 0.7346...]
Controller 1 however reads the same signal as 3.5V (gnd potential)
[3.6 + 0.1 - 0.2 = 3.5]
and as it also has a higher Vref as well it takes that same signal as just 69%
[3.5 / 5.1 = 0.6862...]

sounds like a small difference (~7%),
and the combined powering of the axle will equalize the motor speeds for you, so you will not really notice the difference at first..
BUT motor 2 (controller 2's motor) is doing more work than motor1
thus it heats up quicker and dies sooner in the long run.

Signal ground is not chassis ground!
And the easiest to fix to at least reduce such errors,
is to combine signal ground..
let's see..
Combined signal ground would end up on 0.2V (it'd be slightly off but let's ease the math)
and essentially not much would change for controller 1 at all
0.2 and 5.3V for a total of 5.1V potential.
Controller 2 would raise it's 5V rail to 0.2 - 5V
and with it powering the throttle throttle output raises to 3.7V
(0.4-4.8V swing)
controller 2 now reads it as 75.5%
[3.7 / 4.9 = 0.7551...]
and controller 1 as 72.5%
[3.7 / 5.1 = 0.7254...]

still different, but the error is almost cut in half with now ~4%
with as little effort as combining the signal ground

'sid

PS
don't get me started on different motor speeds per applied power,
and running them in reverse vs forward
that's a fully new can of worms to open
__________________
Jokes about german sausage are the wurst.
Reply With Quote
The Following User Says Thank You to itsid For This Useful Post:
scorn001 (11-13-2019)
  #12  
Old 11-13-2019, 07:22 PM
scorn001 scorn001 is online now
Member
 
Join Date: Apr 2017
Location: Dallas, TX
Posts: 33
Thanks: 16
Thanked 8 Times in 6 Posts
Default

Understood, I tied the two together for good measure, like you say easy enough to do.

For what it's worth, I'd referenced this:

https://www.electricscooterparts.com...ntrollers.html

Anyway, I did take some pics finally. I know it's a mess right now, still a work in progress. However the 2nd motor is now working in tandem with the first motor. Appears to work great (Sid, I'm sure you'd disagree ).


Click image for larger version

Name:	20191113_183458_reduced.jpg
Views:	4
Size:	1.93 MB
ID:	113570

Click image for larger version

Name:	20191113_183504_reduced.jpg
Views:	4
Size:	2.01 MB
ID:	113571

Click image for larger version

Name:	20191113_183513_reduced.jpg
Views:	4
Size:	2.32 MB
ID:	113572

Click image for larger version

Name:	20191113_183529_reduced.jpg
Views:	8
Size:	2.22 MB
ID:	113573

Click image for larger version

Name:	20191113_183539_reduced.jpg
Views:	6
Size:	1.45 MB
ID:	113574

Click image for larger version

Name:	20191113_183546_reduced.jpg
Views:	4
Size:	1.63 MB
ID:	113575

Click image for larger version

Name:	20191113_183557_reduced.jpg
Views:	3
Size:	2.24 MB
ID:	113576
Reply With Quote
The Following 2 Users Say Thank You to scorn001 For This Useful Post:
Functional Artist (11-14-2019), Quinc (11-13-2019)
  #13  
Old 11-13-2019, 08:22 PM
pRoFiT's Avatar
pRoFiT pRoFiT is offline
Can't buy it?, build it!
 
Join Date: May 2016
Location: California
Posts: 1,044
Thanks: 161
Thanked 265 Times in 220 Posts
Default

Why not mount both motors in the same direction. flip the motor and move the drive sprocket over and bam better performance. right? its a custom build might as well make the best out of both motors.

p.s. hay everyone just popped in to add 2 cents and then leave for another 3 months.
__________________
2016 diygokart Contestant http://www.diygokarts.com/vb/showthread.php?t=33422.
Reply With Quote
  #14  
Old 11-13-2019, 09:26 PM
itsid's Avatar
itsid itsid is online now
Moderator
 
Join Date: Jul 2013
Location: Ruhrpott [Germany]
Posts: 10,247
Thanks: 1,396
Thanked 4,312 Times in 3,245 Posts
Default

Quote:
Originally Posted by scorn001 View Post
Understood, I tied the two together for good measure, like you say easy enough to do.

For what it's worth, I'd referenced this:

https://www.electricscooterparts.com...ntrollers.html

yeah I know.. unfortunately websites like those typically are run by ... how do I put it... "untrained personell"
half 455ed information partly taken from some forum posts or user info,
sometimes fully unchecked, sometimes mediocrely tested.
it works with just the signal, but it's not a good idea.

'sid
__________________
Jokes about german sausage are the wurst.
Reply With Quote
The Following User Says Thank You to itsid For This Useful Post:
scorn001 (11-14-2019)
  #15  
Old 11-14-2019, 06:51 AM
scorn001 scorn001 is online now
Member
 
Join Date: Apr 2017
Location: Dallas, TX
Posts: 33
Thanks: 16
Thanked 8 Times in 6 Posts
Default

Quote:
Originally Posted by itsid View Post

yeah I know.. unfortunately websites like those typically are run by ... how do I put it... "untrained personell"
half 455ed information partly taken from some forum posts or user info,
sometimes fully unchecked, sometimes mediocrely tested.
it works with just the signal, but it's not a good idea.

'sid
Gotcha. Thank you for your insight Sid. I'd have never known this but it all makes perfect sense.

---------- Post added at 06:51 AM ---------- Previous post was at 06:36 AM ----------

Quote:
Originally Posted by pRoFiT View Post
Why not mount both motors in the same direction. flip the motor and move the drive sprocket over and bam better performance. right? its a custom build might as well make the best out of both motors.

p.s. hay everyone just popped in to add 2 cents and then leave for another 3 months.
I guess I'm not really able to visualize what you're saying. The only way I can see having both motors turning the same direction is to either have both motors mounted on the same side, which I thought about, but it seemed like a better idea to have one motor at each wheel rather than having all the power on one side - of course that was before I knew the motors would be spinning at different RPMs in that case.

The other way would be to flip one motor around, remaining on the same side, and then either move it such that it's driving a relocated sprocket that is close to the middle of the axle which seems to me like it would mean cutting out the axle housing and adding a set of bearing and races there, which doesn't sound like a small job, - or - getting a longer axle and offsetting the wheel far enough to not interfere with the back of the motor which is now driving the same sprocket, just from a different direction. This would move that wheel out an extra 6-7 inches which sounds kinda crazy. I guess both wheels could move out that same amount for the sake of symmetry.

Of course likely, you're proposing something much more simple that isn't occurring to me (that happens to me a lot).

Last edited by scorn001; 11-15-2019 at 07:15 AM. Reason: Remove incorrect wiring diagram
Reply With Quote
  #16  
Old 11-14-2019, 08:08 PM
itsid's Avatar
itsid itsid is online now
Moderator
 
Join Date: Jul 2013
Location: Ruhrpott [Germany]
Posts: 10,247
Thanks: 1,396
Thanked 4,312 Times in 3,245 Posts
Default

Quote:
Originally Posted by scorn001 View Post
Finally, here is a diagram of how I have things wired with recommendation on shared throttle ground per Sid.

This is using the Mophorn 48V 1800W setup available on Amazon. If anyone sees any horrible errors please let me know so can correct. I don't want to be the cause of someone getting hurt.

Attachment 113580
Cool..
BUT brake and reverse might need attention
the black wire suggests it's ground, not 5V or 12V..
so again.. combine the ground plane for good measures.

since you cannot be sure at which potential that ground may be.
(if it's just 0.3V or such it might be that the right controller is NOT braking when you need it to...)
with them combined, it'll surely pull low and stop/switch when you ask it to.
Oh and btw: measuring doesn't help too much
a stray capacitor charge can raise or lower the plane at runtime..
so any static measurement might get void whilst riding.

Also blue and green swapped on both the power and the sensor?
you sure that's correct?
I think if you swapped blue and green on the motor, you'd have to swap yellow and blue on the sensors (or green and yellow? jeez what's the order again *headscratch*)

sensors nesting between the coils reading a pair of engaged wires UaVbWc back to U
splitting that into
coil and sens
UVW and abc.. (a = U-V, b= V-W, c= W-U)
BYG and byg colour coded.

reversed swapping G and B on the coil
WVU and bac.. (b= W-V, a = V-U, c= U-W)
GYB and ybg colour coded

yes.. blue and yellow on the HE sensor would be correct

uhm... disconnect the right motor's chain,
and test gyb should be off by 120° thus the motor should run
at 50% it's potential (one of the two phases being not engaged when it should)
that might explain the significant difference in rpms
But frankly
it's 3am here and my brain hurts a bit ... soooo
take that with a grain of salt

'sid
__________________
Jokes about german sausage are the wurst.
Reply With Quote
The Following User Says Thank You to itsid For This Useful Post:
scorn001 (11-14-2019)
  #17  
Old 11-15-2019, 07:27 AM
scorn001 scorn001 is online now
Member
 
Join Date: Apr 2017
Location: Dallas, TX
Posts: 33
Thanks: 16
Thanked 8 Times in 6 Posts
Default

Thanks again Sid. I'll make the modifications and update the diagram.

Looking forward to testing the motor wiring changes. That was my original drive motor which felt a little under powered so I added the 2nd. Lol. After this change I might be seeing a large power increase. We'll see.

Thank you again Sid. You're awesome.
•MERGED•

Quote:
Originally Posted by itsid View Post
uhm... disconnect the right motor's chain,
and test gyb should be off by 120° thus the motor should run
at 50% it's potential (one of the two phases being not engaged when it should)
that might explain the significant difference in rpms
I don't know how to test gyb and how far it would be off? Are you saying somehow manually energize the coils? I'm not sure I'm getting it. I can wire it as you say, but not sure how to measure it's potential other than to see of it's RPM comes up more in range with the right side (the left side is the one that was reversed - the original drive motor).
Reply With Quote
  #18  
Old 11-15-2019, 08:45 AM
itsid's Avatar
itsid itsid is online now
Moderator
 
Join Date: Jul 2013
Location: Ruhrpott [Germany]
Posts: 10,247
Thanks: 1,396
Thanked 4,312 Times in 3,245 Posts
Default

no gyb is what you have, ybg is what you want (I'm missing a comma there.. apologies)
nevermind that abbrevation madness I had to write it out to not confuse myself doing that mentally

Now for you to test is:
take the hall effect sensor plug
switch back green (motor) to green (controller)
and move yellow(motor) to blue(controller) and
the blue(motor) to yellow(controller)

test that configuration it should be the correct one...
if it's better, keep it.
if it's the same (it's easier to keep it but you could switch back if you like)
if it's worse switch back to what you had

in case you have a "learning mode" on your controller,
you might need to relearn after switching.
[in that case the motor should run in opposite direction at first just faster]
but I can't see a hint for you having such learning mode.

I'll sit down with a pen and paper and draw me a diagram
checking what shifts would void my above post's statement.
but as of now I'm fairly confident

'sid
__________________
Jokes about german sausage are the wurst.
Reply With Quote
The Following User Says Thank You to itsid For This Useful Post:
scorn001 (11-15-2019)
  #19  
Old 11-15-2019, 10:05 AM
scorn001 scorn001 is online now
Member
 
Join Date: Apr 2017
Location: Dallas, TX
Posts: 33
Thanks: 16
Thanked 8 Times in 6 Posts
Default

Quote:
Originally Posted by itsid View Post
no gyb is what you have, ybg is what you want (I'm missing a comma there.. apologies)
nevermind that abbrevation madness I had to write it out to not confuse myself doing that mentally

Now for you to test is:
take the hall effect sensor plug
switch back green (motor) to green (controller)
and move yellow(motor) to blue(controller) and
the blue(motor) to yellow(controller)

test that configuration it should be the correct one...
if it's better, keep it.
if it's the same (it's easier to keep it but you could switch back if you like)
if it's worse switch back to what you had

in case you have a "learning mode" on your controller,
you might need to relearn after switching.
[in that case the motor should run in opposite direction at first just faster]
but I can't see a hint for you having such learning mode.

I'll sit down with a pen and paper and draw me a diagram
checking what shifts would void my above post's statement.
but as of now I'm fairly confident

'sid
You were right, that is actually how I wired it originally, I just got in too big of a hurry doing the diagram and didn't actually look. I assumed I'd done it the same, and didn't. Sorry for the confusion, should be good on that front.

I'll tackle the brake and reverse wires though. I need to clean up the wire routing anyway. I don't like the wire Ts I used.
Reply With Quote
The Following User Says Thank You to scorn001 For This Useful Post:
itsid (11-15-2019)
  #20  
Old 11-15-2019, 11:34 AM
itsid's Avatar
itsid itsid is online now
Moderator
 
Join Date: Jul 2013
Location: Ruhrpott [Germany]
Posts: 10,247
Thanks: 1,396
Thanked 4,312 Times in 3,245 Posts
Default

Thank you...
So no need for me to finish that shift table then

Make sure the black wire is indeed ground on the two..
can't tell from here (and chances are one isn't floating but actually either 3.3V or 5V)

So you might want to test the wires first.
Check if there's a voltage difference between the black wire in question and the one from the throttle (that surely is ground)

'sid
__________________
Jokes about german sausage are the wurst.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 06:40 PM.