Hello everybody,
The situation is as follows:
I have a repaired unity, the side that is repaired gives a consistently bad reading in the form of a too high resistance. It spins fine when doing detection but after it just starts sputtering and being inconsistent.
First post
Boys i need your help.
One side of my unity is detecting weird resistances in the motors. I used the newest VESC firmware (5.2) didnt use unity tool since i have a uart remote (vx1)
I switched the motors and these were the results.
Motor 1 detection
Motor 2 detection
It seems like it reads 50 mili-Ohms too high
(This is detection before and after motor switch)
It detects normally but when i try spinning the motor to check directions it starts cogging a lot. Broken unity? Broken firmware?
Incompatible firmware maybe?
Follow up post
As you can see it spins detection flawless, results below.
[16151492483784331096535259337369]
Then when moving forward or reverse this happens and it also does this when riding
I increased the max and min amps to 5 as you can see in the first video and it still has this problem.
I did reflow all the connections so there is no way thats the issue. Its a pre blood unity btw@Deodand @MartinSp @seaborder @linsus
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I am about to test it with two racerstar 5045 motors to see how it detects these.
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if the other side works, driver and logic should be fine.
check all that points, the bridge looks a bit squisy, when the unity works again give it some epoxy there.
check the fets
Is there a bridge or just solder on the shunt? Also check for solderballs
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The other side is good i think. I will check, thanks!
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linsus
March 8, 2021, 1:43pm
5
Is that a patch? So whats actually broken here? The antispark? Cause I’m guessing the red wire bypasses it entirely?
Check all voltages, VBAT->5V->3.3V that they’re fine.
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I have no idea what broke actually but i guess not the antispark, that one still works.
Ill clean the pcb too
Cleaned the pcb for you @linsus
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These are the results with the 5045 200kv racerstars, as you can see, again 50 mili-ohms too much resistance.
Again, same problem. (Excuse me for the jank setup)@MartinSp could it be you wired it to the wrong resistor?
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i had one like this. it was the first one i got from the raptor clearance shop.
i was told there is an known production issue that sometimes causes this.
i don;t think you are going to be able to run 2 motors on this…
i still have mine laying around and plan on running a single motors off one side… not entirely sure i can do that.
2 Likes
here is the link on my previous discussion
I tried to put my new unity from the raptor shop to work.
I had bench tested it on different motors and seemed fine.
So I decided to put it in my DB Coreflex build.
It has a 10s4p 30q pack.
Maytech 6354 170kv motors.
14/38 on 100mm Boas.
It had a Flipksky 4.20 dual in there and ran fine. But I thought it would be an upgrade to add the Unity instead.
I keep getting some weird values with motor detection. One vesc recommends 35 amps and the other 50…
I had turned both to 60 amps and tried …
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here is the issue @Deodand had mentioned.
If you switch motors and it remains this way than something is wrong with the controller. One seems to be detecting double the winding resistance, my best guess would be a bad leg in the three half bridges. Check solder on bullets. Otherwise it could be the FETs in which case it would probably need an expert to repair.
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I think the three half bridges got repaired, those must be these right?
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Thanks for the info @rafaelinmissouri very interesting informatiom you have provided!
Btw i am no guru whatsoever so i have no idea what values to check etc.
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Sorry but that is beyond me.
and regarding the values. what i used as a reference was the recommended motor amps. and expected them to be within 5 amps or so.
so mine were way different regardless of which motors i tried.
This jumper wire just connects V+ to V+… it really shouldn’t do anything and can likely be removed. No idea why that would be there, there is a big V+ power plane of copper connecting these.
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How weird, do you think the 3 repaired half bridged need to be redone?
Thanks for your help to mister!
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linsus
March 8, 2021, 5:48pm
17
Half bride is one leg of the Mosfets that controls a phase. Not sure what you’re refering to. I asked you the check the mosfets just to see if they’re whole, resistance should be in the ballpark similiar to the other side of the unity f.e
2 Likes
Ok will check, sorry, like i said im pretty bad with this stuff.
3 Likes
linsus
March 8, 2021, 5:53pm
19
No problem, if we’re speaking greek just point out what is unclear to you
3 Likes
Would you mind pointing me to the fets and what points to measure? All the components are unmarked as in there are no serial numbers etc on them.
i had to get it off my heatsink which was a pain in the ass.
