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MattsAwesomeStuff wrote: ↑Sat Oct 04, 2025 6:47 pm Again, verbally describing things that you might have verbally misunderstood is challenging to diagnose.

Take pictures. Maybe you welded the wrong thing?

Like I said. I welded the planetary gears. But after careful examination after disassembling the transaxle again, I noticed that the sun gear was sitting a bit high, hence maybe the reason why things got stuck after assembling. I removed the thrust washer that sits inside the planetary gear and allows the sun gear to rest on it. I then oiled the sun gear and put it back in and hammered it a bit for it to slide and mesh with the welded planetary gears fully. Reason for removing the inside washer was because I feel its not useful anymore because the sun gear and the planetary gears all now rotate together so there won't be any friction inside the whole assembly. After this I put everything back together and my shafts are rotating again.

Below I attached pictures of welded planetary gears. Not mine but they show what I also welded.

Thank you.

Good point, might be worth installing the sun gear and maybe even assembling the planetary set into the ring gear, before welding, at least the first tack on each planetary gear to the carrier, that way teeth alignment will at least remain once the planetary set is welded up.

At this point, confusion sets in for me. MG1 will now be spinning at the same speed as MG2, so very little of that low RPM MG2 hp/kw is going to be assisted MG1 hp/kw, but all the MG1 torque will be available, so that's a plus, at around 50mph, MG1 is going to reach it's peak of 10,000rpm so all 57hp/38kw from MG1 will be added to MG2 ..... but MG2 can't spin any faster that 10,000rpm now because MG1 is locked to it, and faster will over speed MG1 .... So what was really gained? A drive system that can hold 50 mph better because of the added input from MG1 ..... but the max speed is still limited to 50mph .....

viewtopic.php?p=31602&hilit=list+of+Pri ... les#p31602

T1 Terry

Very interesting info. Will definitely read up on it, thanks.

T1Terry wrote: ↑Tue Oct 07, 2025 12:33 pm but the max speed is still limited to 50mph ....

It is a Gen2 transaxle, at 60 mph, if I remember correctly it revved lazy at 4000 rpm or so. With the OI logic and sufficient voltage you can make it go 80 mph or more.
Without the gear welded MG1 will overspeed.

T1Terry wrote: ↑Tue Oct 07, 2025 12:33 pm Good point, might be worth installing the sun gear and maybe even assembling the planetary set into the ring gear, before welding, at least the first tack on each planetary gear to the carrier, that way teeth alignment will at least remain once the planetary set is welded up.

At this point, confusion sets in for me. MG1 will now be spinning at the same speed as MG2, so very little of that low RPM MG2 hp/kw is going to be assisted MG1 hp/kw, but all the MG1 torque will be available, so that's a plus, at around 50mph, MG1 is going to reach it's peak of 10,000rpm so all 57hp/38kw from MG1 will be added to MG2 ..... but MG2 can't spin any faster that 10,000rpm ....... now because MG1 is locked to it, and faster will over speed MG1 .... So what was really gained? A drive system that can hold 50 mph better because of the added input from MG1 ..... but the max speed is still limited to 50mph .....

viewtopic.php?p=31602&hilit=list+of+Pri ... les#p31602

T1 Terry

From about the point I changed the text to red ..... my brain left the building

Somewhere I got my wires crossed between locking the shaft to the case using a one way sprag clutch, and welding the gearset causing the same thing as locking the shaft to the case ..... which isn't what happens at all

I went and measured the dia of the tyre on my Gen 2 and it's 0.6mtr x 3.14 = 1.884 mtrs per rpm.
80km/h (roughly 50mph) = 1,333.3 mtrs per min. = 707.7rpm tyre speed and therefore crown wheel speed.
707.7 x 4.1:1 ratio of MG2 to the crown wheel = 2,900 MG2 rpm @ 80km/h ..... Rough maths comes out to 275km/h before MG2 and there for MG1 in a welded/locked rotor set, would reach the max 10,000 rpm ......


So, MG1 will theoretically never add the potential 50hp/38kw .... until some where around 260km/h

Where I was going with that, before my brain left building, was:

The input shaft with a sprag clutch (one direction locked, the other direction free wheel) anchored to the case, so when MG1 can no longer drive the planetary carrier against normal engine rotation causing the sprag clutch to lock, the input shaft and therefore the planetary gear carrier would then freewheel and spin with the ring gear at anywhere up to the same speed as MG2.
When MG1 can no longer add any torque or hp/kw to MG2, there is no value in powering it to spin, all the drive would then be for MG2.

With this set up, the off the mark performance would be greatly improved, but by 80km/h (50mph) only MG2 would be driving the wheels .......

Is the 45nm/33lbf of torque up to 6,000rpm worth the 75 amps it would take to achieve it? So, where is the value in welding the gearset and powering MG1?

There is every chance my brain has never returned to the building, so probably best if some checks my ramblings ....

T1 Terry

Keep rambling, it's interesting brain fuzz material.

RetroZero wrote: ↑Fri Sep 19, 2025 5:29 am Is it possible to load throttle parameters in graph form?
I don't have the figures in front of me, but vaguely remember setting throttle. From what I remember:
There are 2 potentiometers.
Pot is for 0 to 4095 (digits)
Pot2 is the reverse 4095 to 0 (digits)

Setting Pot: note value when NOT pressed (example 500) - set your min value LARGER than this (example 550).
Now press throttle completely & note value (example 4500 - set pot max to LESS than this value (example 4200).
Pot 2 is done the same, except its the reverse of values because it reads in the opposite direction 4095 to 0.
Plot your graphs.
What you are trying to create are values where when no pedal is pressed, Pot is at 0, with a slight margin of play. The same is done for potmax.

I'm home this weekend and I'm back to throttle calibration.

I was following the above given instructions . So before pressing the throttle I got pot 963 and pot2 2013. When the throttle was fully press both pot and pot2 gave 4095.
So I did the math exactly as instructed above. Well maybe those numbers from Retro were just examples but I used them as per. The only difference was when it comes to potmin. I put in 3500 since that's the max parameter.

Then I went to throttle parameters and please see attached screeshots of how I loaded the new numbers. For pot2. I had to interchange the min and max values since retro mentioned that for pot2 its vice versa, so I wanted to make sure that i got it right in order to see which configuration works but none of those worked.

The results I got was that when pressing the throttle when it's halfway, the motor jitters, it does rotate but jittery rotation. When I continue pressing the throttle to its full capacity the motor then stops jittering and comes to a stand still. Please not that this results were same even before I changed the parameters, like when I first connected the pedal I did press it to see what will happen and this jittery rotation was the same.

I'm only half paying attention, but have you gone through the procedure Damien showed in his video for how to set up SynchOffs properly?

MattsAwesomeStuff wrote: ↑Sat Oct 18, 2025 5:57 pm I'm only half paying attention, but have you gone through the procedure Damien showed in his video for how to set up SynchOffs properly?

Yes I did Matt, I have my syncoffs set to 10120 like Damien showed on the video.

Sorry, I'm away for a few weeks, so cannot really help.
Just to be sure, you have resolver 0 to 360 graph.
You have set up syncoffs as per the video. Did you go through different values to get to 10120 or did you put in Damien's value?
I noticed that gen 2 & gen 3 are not exactly identicle. Throw in different HV setups and that changes the value as well...
I'd try a couple of different syncoffs....

voti wrote: ↑Sat Oct 18, 2025 6:35 pm Yes I did Matt, I have my syncoffs set to 10120 like Damien showed on the video.

As Retro pointed out... just making sure you aren't blindly choosing 10120. Damien showed the process everyone should follow because all units are different. It was not him demonstrating how he found the "correct" value for all Gen2 Prius's and that everyone should use that number.

I think I'll have to redo my resolver connection test and confirm that I do get 0 to 360 plot on the graph. Then from there I'll have to redo the syncofs settings.

At first I had tested my resolvers 0 to 360 plot, and me getting to 10120 I had also gone through other values testing them also, Up until I got 10120. I did put in different numbers on manualid up to a hundred to see if 10120 value was indeed correct. I followed Damiens test as is and it seemed to be working just fine for me also. But Retro mentioned something important that the HV values are not the same for gen 2 and gen 3, plus Damien had higher voltage when he did his test. But my concern is that like I said his values seems to be working just fine for me. Hence I'll have to redo the test to confirm.

But to be sure. This weekend I'll redo everything and confirm all my connections since I had some of them disconnected when i was welding the planetary gear.

I'm home this weekend.

So liek I said that I'll go back to resolver testing before continuing to throttle calibration and setup. What I noticed is that after taking the transaxle apart to weld the planetary gear set, I lost my resolver connection. When I plug in the cable back on the transaxle, either I get varying angles or no angle at all. Just now I set automatic refresh and unplugged my resolver as it was stuck to 0°. When I lugged in it again it started showing way to many angles; 48°, 75° , 180°, 336° you name it. When I restart the inverter and reconnect the resolver cable, it's back at 0°.
At some point I was able to have the angle at around 98° and when I proceeded to the resolver plot test and reotayed the transaxle by hand with the HV disconnected, the graph didn't change but it showed this waveform that fluctuated continously. On another test also, when I started the flot it just jumped from 0 to 360 without me having to rotated the shaft. This 0 to 360 pattern also was continous and like I said it just jumped to these plot without me having to spin anything. I watched Damien video to troubleshoot what was going on, all I found as that Damien did mention that just a behavior means hat I should stop because something is wrong, only problem is he didn't say what that problem is or how to solve it.

Anyone with knowledge on this please come to my rescue

Anyone, please

0 to 360 fluttering makes sense to me, as, they're the same point. 0 and 360 degrees are both the start of the circle.

As to the rest, I'm regretfully useless. I don't know what's supposed to happen, to know why you're not getting it.

I'm home this weekend and appreciate any of you guys coming through for me right now.

So you had a working resolver before taking the transmission apart. You have a non-working resolver after taking it apart and putting it back together. Correct?

You need to see a clean 0-359°C angle plot (1000 burst, 1000 points) in FOC firmware when spinning the motor by hand. Otherwise all other tuning is pointless

Compliments of the season to everyone. I am grateful to God who led me to this site because to me this is not just a forum, but its a family page were we gather to share knowledge. I'd like to thank everyone for their contributions into making this forum a success, May The Lord God who reigns bless you and your Families.

As for the project, I took a break from working on the electrical part and started working on the body. I was getting stressed by the resolver and needed to regain my strength. I have a good feeling that 2026 my EV will reverse out of the garage and go for a test run.

God bless you all

Im back at the workshop and working on the electrical part of the car. I reconnected my resolver cable and followed all the steps to test for resolver feedback. I've posted my screenshot below of the graph I got when testing.

Is this plot ok. I think I hit 360 but the 0 im worried about it

That does look more promising. What did you do? It looks like you have to stop at some moment when doing rotations as there are longish straight lines at similar points. Is this correct? Try to do 2 or 3 smooth revolutions without any stopping and plot again.

I prayed . I disconnected the resolver and reconnected everything afresh. I'll try doing the 2 or 3 rotations at once because now I was spinning by hand and I'd go maybe half a circle or 3/4, I couldn't get one clean full rotation. I will buy a vise grip for that

Just wanted to congratulate you, not for success, but for determination. You're coming up on 1 year in this thread. 250 posts. Just to try to still get a motor to spin. I am filled with sympathy, as that in part mirrors my own journeys. When you're tackling technical problems so many tiers above your knowledge level, there are so many unknowns, even if you are communicating the problem right, let alone understanding someone else's help right.

There are lots of people here I am envious of, who probably have no idea what that feels like. There are lots of people that need to ask zero questions. Either they have the base knowledge to understand things themselves and get it right, or they have the knowledge to troubleshoot on their own, but either way they can just put a little more effort in each time, and progress towards a solution. Getting stumped for 12+ months is such a defeating feeling, when, you're willing to put more effort in, you just can't, it's not a matter of effort. That's what's frustrating for me, not hitting a roadblock, but when I am ready to put time in and time isn't the constraint. I love tasks that are like assembling a LEGO kit, where there is discrete, measurable progress to each of your efforts, and, exact instructions to get from here to there.

Or maybe I have it backwards. To some degree, everyone's like this. Pick anyone who's knowledgeable. I look up to Johannes for how firmly he grasps this material, and, y'know, when he wanted an EV, he had to INVENT his own solution, from scratch. And it didn't go smoothly, and it took him a long time.

Sometimes I feel like a fish trying to climb a tree, and I think maybe I should choose simpler or different projects.

Anyway, just some sympathy and perspective. Looks like you're still making progress troubleshooting, a step at a time. Hopefully you get to the bottom of it before this time next year.

Hey, I really appreciate this comment — it genuinely means a lot.

You described the struggle perfectly. The frustration isn’t the effort, it’s when effort isn’t the limiting factor and progress still crawls. That “fish trying to climb a tree” feeling hits close to home. Some days it really does feel like I’m operating several layers above what I should be comfortable with and yet here we are.

What keeps me going is exactly what you touched on: perspective. Knowing that even people we look up to, the ones who seem to “just get it,” went through long, messy, uncertain paths themselves. That reminder helps more than you might realize. If they had to invent, fail, rethink, and grind through it, then maybe the slow pace isn’t a sign of failure, just part of the process.

I won’t lie, there are moments where I question whether I should’ve chosen something simpler. But there’s also something deeply satisfying about inching forward, even when the steps are small and hard-won. Every test, every dead end, every clarification still adds to the understanding.

Thanks for the sympathy and encouragement. It helps to know I’m not alone in this kind of journey. I’m still pushing, still learning, still troubleshooting, one step at a time. Hopefully we’ll both look back at these moments as necessary chapters rather than roadblocks.

Truly appreciate you taking the time to write this.


I bought the vice grips and tested again today. Please see the attached picture.

RetroZero wrote: ↑Fri Sep 19, 2025 5:29 am Is it possible to load throttle parameters in graph form?
I don't have the figures in front of me, but vaguely remember setting throttle. From what I remember:
There are 2 potentiometers.
Pot is for 0 to 4095 (digits)
Pot2 is the reverse 4095 to 0 (digits)

Setting Pot: note value when NOT pressed (example 500) - set your min value LARGER than this (example 550).
Now press throttle completely & note value (example 4500 - set pot max to LESS than this value (example 4200).
Pot 2 is done the same, except its the reverse of values because it reads in the opposite direction 4095 to 0.
Plot your graphs.
What you are trying to create are values where when no pedal is pressed, Pot is at 0, with a slight margin of play. The same is done for potmax.

Should I move on to this step now?

Hi
Is there still a vcu for gen 2?
Its not listed on zombie and cant find Johannes board for sale.