crap, that’s a shame. Would be worth posting the feedback in the vesc-tool thread. It would appear a fair number of people are having this issue with FOC.
It is defintly a speed issue and is very repeatable and it seems to not be related to braking motor current at that particular speed when it grabs
Dont think Vesc tool has that setting
Guys I think I have found a solution to this by directly editing some motor xml file parameters. Just doing final testing now Cheers
So below is what I tried and it seems to work OK - Try below at your own risk
I an running dual DIYE 4.12HW vescs in FOC that came with 2.18FW. Updated vescs to 3.34FW using vesc tool 0.87.
The parameter “Max ERPM at full brake in current control mode” exists in BLDC tool but for some reason seems to have disappeared in the vesc tool.
So the first thing I did is to save motor xml file from vesc and then load it into BLDC tool. All parameters seemed to load OK into BLDC tool with same current and voltage settings.
Noticed that the value of “Max ERPM at full brake in current control mode” was 1500 erpm which corresponds to the speed at which the brakes were grabbing .
You may be able to adjust that setting in BLDC tool - then do a xml save and then load xml file into vesc tool and then download to vesc. I didn’t want to try this due to possibility that bldc tool could upset parameters in vesc tool and possibly fry the vesc.
So what I did was to get a xml file editor ( I used one from mediafreeware.com )
Then get the vesc motor xml file from vesc tool and load it into the xml editor.
Look for a line showing
The using xml editor - change the 1500 no to 200 ( about 1km/hr for me) with no other changes.
Then using xml editor save the xml file , then load that modified xml file into the vesc tool and then push motor config to the vesc. repeat for the other vesc if running dual drives
Note - one of my vescs came with 1500 for “Max ERPM at full brake in current control mode” and one was showing 500 . I guess these were different default settings on initial 2.18FW set-up and have not been changed by the vesc tool ( A bit strange!).
I changed both vescs to 200 erpm and it seems to work fine.
Cheers
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Can you expose that parameter in the gui in a future update?
Explains why random people have this issue. Different stock values.
Just updated my FOCBOXES to the newest Firmware… now i have this “issue” as well… pretty annoying…
Is the @SkaterBoy58 way, stil the only way ?
It’s strange that it works as in BLDC Tool that setting is in a section labeled “BLDC only”
I think so. I set mine to 500 and braking is a lot more manageable
Is it something in vesc-tool you set to 500 ? Or do i need to do this bldc/xml thing ?
Edit the xml
If I don’t edit the xml file, just use vesc-tool to setup, can I do full break? thanks
Hi SkateBoy58, personally I do prefer strong brakes over weak ones… Imagine you are going down a steep hill at relatively slow speed. You will need brakes that have some grip to prevent an unwanted acceleration down that hill. People should be able to brake to a near stand still on a hill. Without strong brakes that is not possible. It is no big trick to release the brake trigger further when slowing down to a near stand still. If you ride a car you do the same, approaching traffic lights. On the last few mph you usually start to release the brakes a bit since the kinetic energy the brakes need to work against is getting very little close before the full stop.
A lot also depends on your motor and gearing. Your setup is quite rich of torque. In consequence your brakes do also work quite well.
The post was deleted so I don’t know.
He’s not complaining about the torque of his brakes. I’m having the same issue since updating to the latest firmware. Brakes are fine, then i get to about 2-3 mph and the motors lock up. It has nothing to do with releasing the break trigger… The max ERPM setting needs to be exposed for FOC, its as simple as that.
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These two topics should really be merged
I’m experiencing this as well on my new build. 6355, focbox, FOC, 16/40 belt. Slowing down/stopping from any speed above around 4mph is smooth - all the way to stand still. Anything below 4mph and it doesn’t matter how gentle I am on the brakes it just locks up and jerks.
Manageable but annoying. I’m using ackmaniac, has anyone found a solution other than editing the xmls yet?
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