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Tesla SDU forward direction

Posted: Wed Mar 24, 2021 9:41 pm
by johu
Today I received the second report that the SDU spins in reverse when forward direction is selected. One user might have even damaged the gearbox because he spun up too fast in reverse.
Due to due a lack of an SDU I can't test this myself, but I'm assuming this will be the same for all SDUs and people are just used to make do. So be careful when spinning up.

Re: Tesla SDU forward direction

Posted: Wed Mar 24, 2021 10:29 pm
by Isaac96
I will test once I get my coolant lines installed. 4.97 firmware on my board.

Re: Tesla SDU forward direction

Posted: Thu Mar 25, 2021 8:11 am
by muehlpower
My LDU also runs backwards when I give a forward signal. I just swapped the cables and didn't think about it any further!

Re: Tesla SDU forward direction

Posted: Thu Mar 25, 2021 10:11 am
by Peter
As I am about to install my SDU which will be running in reverse based on the normal Tesla layout should I be concerned ?? I have removed the mechanical oil pump and added an external electric oil pump so thats not the issue.

Re: Tesla SDU forward direction

Posted: Thu Mar 25, 2021 2:39 pm
by johu
No reason for concern then. With installed in reverse you even get correct display :)

Re: Tesla SDU forward direction

Posted: Thu Mar 25, 2021 4:45 pm
by Peter
Thanks Johannes. I can dry my tears now :-)

Re: Tesla SDU forward direction

Posted: Sun Mar 28, 2021 10:45 pm
by Isaac96
Just tested my SRDU, can confirm it's backwards. Wonder how that came about...
I presume I can just switch my F/R wires and nothing will behave differently?

Re: Tesla SDU forward direction

Posted: Mon Mar 29, 2021 8:11 am
by johu
Yes, no different logic in reverse. You can also set dirmode to "SwitchReversed" if you don't want to pull wires.

Re: Tesla SDU forward direction

Posted: Wed Mar 31, 2021 7:18 pm
by EV_Builder
johu wrote: Mon Mar 29, 2021 8:11 am Yes, no different logic in reverse. You can also set dirmode to "SwitchReversed" if you don't want to pull wires.
I advice people to switch internally the motor phases (in the software configuration), not the wiring of the inputs or the software logic etc.
Forward needs to be forward en reverse needs tobe reverse...

If you swap stuff there might be a risk in the future with updates which are made to work in forward mode etc. etc..
For example a reverse throttle tuning with speed limiter for more feeling during parking etc.
Or a ramp/hold mode which activates in forward gear only...

Re: Tesla SDU forward direction

Posted: Wed Mar 31, 2021 7:26 pm
by johu
Yes, fair point.

Re: Tesla SDU forward direction

Posted: Wed Mar 31, 2021 8:05 pm
by SciroccoEV
I did at one stage suggest an option to reverse the motor direction for Forward signal.

Re: Tesla SDU forward direction

Posted: Sat Apr 24, 2021 11:38 am
by Johannes.l
I can also confirm that my SDU spins in reverse when it should go forward.
So it's enough to set it to "SwitchReversed" then? One less problem to think about at least. :)
/Johannes

Re: Tesla SDU forward direction

Posted: Fri Jun 04, 2021 9:59 am
by EV_Builder
Johannes.l wrote: Sat Apr 24, 2021 11:38 am I can also confirm that my SDU spins in reverse when it should go forward.
So it's enough to set it to "SwitchReversed" then? One less problem to think about at least. :)
/Johannes
Not too familiar with the software yet because still building the car.
The motor ran, so I left that for later.

If the forward input makes you go forward with that setting or another you should be covered.

Re: Tesla SDU forward direction

Posted: Fri Jun 04, 2021 1:50 pm
by Peter
Its good to know you can achieve max speed in forward or reverse, James Bond would approve :-)

Re: Tesla SDU forward direction

Posted: Fri Jun 04, 2021 5:50 pm
by johu
At least nobody complained so far :)

Re: Tesla SDU forward direction

Posted: Fri Nov 12, 2021 6:19 pm
by catphish
I realise this is already well established, but I just want to add a "+1" here. Like others else, my SDU runs in reverse when configured for forward direction. Would love to see a setting to reverse the hardware direction, rather than having to reverse the input direction selector if someone has time to add such a feature. I'm not sufficiently familiar with the code to do it myself yet.

Re: Tesla SDU forward direction

Posted: Tue Jan 04, 2022 12:55 am
by qmedia2651
That's weird my SDU unit runs forward like it should
Using v5 logic board done by jclpcb and populated my self.
JOHU HELP WITH THE PARAMETERS

Re: Tesla SDU forward direction

Posted: Fri Jul 29, 2022 1:46 pm
by catphish
It turns out this wasn't a problem for me because I actually *wanted* to run my SRDU in reverse. Perhaps this is true of the majority of people using these drive units :)

Re: Tesla SDU forward direction

Posted: Fri Sep 02, 2022 8:38 am
by ViktorT
I just testspinned my SDU this weekend and I have two questions. Exactly how should I apply the command switchReversed in the user interface?
Also there is a kind of cogging sound when the motor spins, is that common and no problem or something that needs a fix? There is no oil in it yet

Re: Tesla SDU forward direction

Posted: Fri Sep 02, 2022 9:48 am
by catphish
ViktorT wrote: Fri Sep 02, 2022 8:38 am I just testspinned my SDU this weekend and I have two questions. Exactly how should I apply the command switchReversed in the user interface?
switchReversed should be an option under the "dirmode" setting dropdown.
ViktorT wrote: Fri Sep 02, 2022 8:38 am Also there is a kind of cogging sound when the motor spins, is that common and no problem or something that needs a fix? There is no oil in it yet
I had the same thing while running my SDU on the bench at lower voltage with no oil, so it's probably not something to worry about. However, it's generally not a good idea to run it too much with no oil anyway, as it can reach high speeds very easily with no load.

Re: Tesla SDU forward direction

Posted: Sat Sep 03, 2022 7:20 am
by ViktorT
Thanks Catphish

Re: Tesla SDU forward direction

Posted: Fri Mar 31, 2023 5:36 pm
by caymanS
I also experienced SDU spinning backward when I selected forward (small rear drive unit).

Re: Tesla SDU forward direction

Posted: Fri Aug 25, 2023 9:07 am
by mane2
Oh! This explains why hill-hold did not work on my LDU!

Next question: How to "switch internally the motor phases (in the software configuration)" the right way?

Re: Tesla SDU forward direction

Posted: Tue Aug 29, 2023 5:00 am
by mane2
I didn't see any option in web interface where to switch motor phases.

Only parameter related to phases is

Code: Select all

syncofs	dig	0	65535	0	Phase shift of sine wave after receiving index pulse
Has anyone done this actually? Maybe it was just wishful thinking? :)

Re: Tesla SDU forward direction

Posted: Tue Aug 29, 2023 5:22 am
by johu
There is no option to swap phases in sine firmware. Only option to swap forward/reverse pins