KS14c level calibration.

[LanghamP]

I think the wheel has drifted but I cannot get the five beeps indicating the level calibration is running.

What does it mean by set the EUC vertically? Does that mean I lay the EUC flat while long pressing, or do I hold it upright perfectly level? Or something else?

[Philip W]

I think it means put the EUC upright, like standing up.

[HermanTheGerman]

You must hold it upright, at best lean it against a wall in the verticalmost position you can achieve, so that it does not fall to the other side. It's very important that the wheel is nearly exactly vertical, otherwise you will not get to the beeps.

On the outer footpad place a tubular level, or better a smartphone with an appropriate and exactly calibrated App (like e.g. "Bubble" for Android), which has the advantage that you can read how many degrees you are off level.

I calibrated my KS16 so that it has a 3 degree backward tilt, and drive with that since more than 9 months. I tried settings from 1 to 6 degrees, and decided at the end that 3 degrees is best for me.

6 degrees was to much, my toes and feet began to hurt during a long cruise, and decelerating became also more difficult. A minor angle than 3 degrees was to less, there was not much difference between 2 degrees and level setting.

So for me 3 degrees was best (actually it's 3.5 ), but your mileage may vary.

PS:

I did that, because with the original level setting my wheel leant forward in sharp curves, and also on rough terrain, so I had the feeling I will slowly slip off in front, and also cannot accelerate well under these circumstances. The backward calibration solved this problem for me.

[LanghamP]

1 hour ago, HermanTheGerman said:

You must hold it upright, at best lean it against a wall in the verticalmost position you can achieve, so that it does not fall to the other side. It's very important that the wheel is nearly exactly vertical, otherwise you will not get to the beeps.

PS:

I did that, because with the original level setting my wheel leant forward in sharp curves, and also on rough terrain, so I had the feeling I will slowly slip off in front, and also cannot accelerate well under these circumstances. The backward calibration solved this problem for me.

It took me weeks before I accidentally discovered the upright to get five beeps, rather by accident.

I also have put a slight tilt back because of the falling off the front in turns problem. All my wheels seem to suffer from this after a while, and need to get recalibrated.

Dunno why, but if all three wheels do this then it must be something particular to EUC's.

 

[UKJ]

Because I find myself riding backwards almost half the time now does it not make sense to level, meaning no tilt forward or back?

ukj

 

[LanghamP]

5 hours ago, UKJ said:

Because I find myself riding backwards almost half the time now does it not make sense to level, meaning no tilt forward or back?

ukj

 

I wonder.

Is the KS14c backward and forward symmetrical? I just noticed yesterday when I was showing off my wheel that it has a back light. It looks the same as the front light.

My assumption (it was daylight so I couldn't confirm) is that the wheel detects which way you're going and makes the forward pointing light white, and the rear light red. Since I've never seen myself ride I'm not even sure the rear light is red.

It always did seem odd, come to think of it, how I would always seem to have the wheel correctly pointed forward. I'd grab the wheel, check the front to make sure the light was there, and turn it on. I just noticed yesterday there are TWO lights on the wheel.

[kasenutty]

Nope. The back one is only red and the front one is only white. It rides fine both ways, but the pedals are a little nicer going forwards. 

[Christoph Zens]

On 14.6.2017 at 6:20 PM, kasenutty said:

Nope. The back one is only red and the front one is only white. It rides fine both ways, but the pedals are a little nicer going forwards. 

Interesting. On the KS16-S, the lights change accrding to riding direction. When I ride backwards, the back light becomes white and the front becomes red. Also, the red light (whichever it is), changes brightness when braking. It lights up brighter when decelerating. So, on this model they are completely symetrical. Light intensity is also the same, no matter which end functions as the head light.

[Christoph Zens]

On 9.6.2017 at 1:37 AM, LanghamP said:

Dunno why, but if all three wheels do this then it must be something particular to EUC's.

I agree. My NB1 and my KS16 do this as well. It must be related to the way the gyro chips work. There is some kind of hardware related measurement error in some situations that would need careful error correction in software, which no one seems to bother doing. Not a real problem for me during normal riding, but there is one action where this effect is really extreme (on both wheels). Try this, just for fun:

• Hold on to a wall or something, while standing on the wheel.
• Keep the wheel still for a while, note the level pedals.
• Now turn the wheel around by 180 degrees on the spot. Do this pretty fast try both directions (on my wheel, the effect is much more extreme when turning counter clock wise).
• Notice how the pedals tilt forward and remain in an extreme 'down' position at first.
• Now slightly rock the wheel back and forth.
• Pedals slowly return to their calibrated neutral position.

I assume that spinning the gyro around its Z axis causes the Z axis to tilt, most likely due to some kind of precession movement. If not corrected in software, this will cause the pedals to tilt, as the Z axis tilts. When the spinning is stopped, it realigns itself again.

The same effect can be duplicated on smartphones:

• Install an app showing horizontal alignment of the phone (two-dimensional, using a circle which moves in X and Y direction as the phone is tilted up/down and left/right).
• Now if you start the app and put the phone on a table, the circle will be centered (if the table is level).
• Turning the phone around on the table quickly, causes the circle to leave its center position and come back slowly when the movement stops.
• In theory, there would be no reason for the circle to leave the center position, because the phone is only turned around its Z axis.

Our wheels have the same measurement error. Maybe some EUC companies already started to experiment with algorithms to compensate this effect, so some wheels will do it less than others, but in general I think it is caused by the gyro and is not something they are doing in their firmware on purpose. I am sure a physical bulls eye level would not do this. You could rotate it around on the table and the bubble would stay centered.