rafe me on wednesday
After work - I’m in. I’m more likely to be on the true sHFI dremelseed tho. And that thing does not kick ass at 10s. It’s fun but not winning any drag races.
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I thought silent HFI was called ASS then got changed to VSS
ASS did get changed to VSS, but silent HFI is new to fw6.0.
Coupled v0v7 and 45deg v0v7 are new and can handle more amps. 45 deg moreso according to vedder but coupled is quite good in my testing.
What is the oldest hardware that runs it?
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The newer VESC6 MKV and MKVI have the phase filters. They make all the difference on the very bottom end of the RPM range. However, even without these filters it is quite impressive what sHFI can do. Single processor dual ESCs will always generate a bit of noise, regardless of phase shunt or low side layout. You have to split the sampling frequency and therefore you end up with 12.5khz instead of 25khz. 12.5khz is audible for most people.
The sHFI tuning will probably see some automation in future, as it should be possible to calculate the voltage parameters from the motor detection parameters and the battery parameters.
Some motors also work much better compared to others. Ld-Lq difference is one of the key factors.
A motor designed for sHFI operation should feature a high value here. Weak magnets and a big airbag reduce this value for the typical 14 pole outrunner. It also depends on other design aspects.
When everything is well optimised, then sHFI is a lot better compared to Hall sensors. But it can also be less good if the ESC isn’t optimal or the motor or the tuning. So we expect some mixed feedback because of the HW variety out there.
In general the entire sensorless startup is much better now and more quiet. No matter what HW is used, there are huge benefits when switching to FW6.
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Not from where i’m sitting.
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I have a Unity on my hubs running VSS and dual FocBox 1.7s on my off road running standard HFI, do you think it’s gonna be worth the effort to crack them open?
I’ve had a decent play around with all the silent and non-silent modes now. Some work better than others, and if I was just accelerating it may be passable, but it’s a bit of a mess on a onewheel. Can start ok, but it struggles with low speed producing cogging leading to either nosedives or tail drags. Current and duty cycle modes work ok in the VESC Tool, speed control mode will usually get it spinning in a random direction, and position control just causes shuddering with little actual movement.
Haven’t really had much luck tuning the HFI voltages, I seem to get quite a lot of noise. Data noise that is, not necessarily sound noise although there is that too. This is the foc_plot_hfi_en 1 (enabled in VESC Terminal) experiment data chart, normal ranges should be between -3 and +3 
. Any tips much appreciated.
Trampa VESC 6 mk5 with an APS 80100 50kv motor.
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Have a look at this value. The higher, the better. If this too low, then the non sHFI modes might work better for you. Motors with a tight airgap and strong magnets perform better here.
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VSS is not a good method for these controllers. They don’t feature phase shunts. VSS really wants phase shunts and phase filters. The non silent HFI modes are preferred for the designs you mentioned.
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50 KV is very low. Position control woul need much higher KV. I have an old 118KV motor that doesn’t work well, but the same motor in 160KV is performing great.
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normal ranges should be between -π and +π
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Sss56123 230kv
Ubox v2 75
Sensorless- pretty average
Hfi- shit worse then sensorless
Coupled hfi- great when both decide the same direction
45deg- more consistent in both going same direction but it rode backwards instead of forwards, but great if in same direction
Coupled shfi- shit but better then hfi
45deg shfi- again shit but better then hfi
Vss- not as good as coupled/45deg hfi but the most consistant in both motors spinning together in the same direction.
Next week i’ll do drag pulls and test the ubox on apex outrunners
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What will happen if I keep using VSS on a Unity?
Try decreasing the HFI Gain parameter. Default is 0.300 and it would send a motor in reverse around 10-20% of the time. I reduced it to 0.100 and both 45deg v0v7 and coupled v0v7 work much better on my 60d+ now.
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45deg silent is world’s better for me at hard launch over coupled, made all the difference on Tenka.
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Vedder does say 45deg will handle more amps. Oddly 45deg works very well on my stormcore 60d+ but it doesn’t work so great on the trampa mk6
does not compute
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