Sore feet, good advice

[Bridgeboy]

2 minutes ago, LanghamP said:

Try it; grab you wheel, turn it on, place it on a flat surface, and see if it rolls forward or back.

All my wheels do not move at all on a flat surface. They stay perfectly still. As a matter of fact, even on a non-flat surface they stay still.

Can you elaborate on what you want me to try? Because I am confused.

[Bridgeboy]

1 minute ago, LanghamP said:

The pedal tilt option isn't there, true, but you CAN recalibrate the 18xl to tilt or down under the first menu in the gear menu => horizontal calibration option. The instructions say to put the wheel level but you can tip the wheel forward and it will keep that angle.

Thanks for that tip! Of course! I'll do that, thanks.

[Bridgeboy]

33 minutes ago, Bridgeboy said:

Thanks for that tip! Of course! I'll do that, thanks.

I just did this, and while it works to keep my pedals tilted forward, you are right in that the wheel wants to move forward on its own. So, while it's a work-around for pedal tilt, the wheel will not stabilize itself when I'm not on it and will try to move forward. So, not the best thing...the wheels that allow the pedal tilt option still stay stabilized and don't try to move on their own regardless of what pedal tilt you choose...

Edited April 25, 2022 by Bridgeboy

[mrelwood]

2 hours ago, Bridgeboy said:

So, while it's a work-around for pedal tilt, the wheel will not stabilize itself when I'm not on it and will try to move forward. So, not the best thing...the wheels that allow the pedal tilt option still stay stabilized and don't try to move on their own regardless of what pedal tilt you choose...

There’s no difference whether the forward or backwards tilt is achieved by calibration or pedal tilt option, the physical position of the shell is the same. The wheel will only try to keep that exact position, and if the weight balance forces it to accelerate to keep the position, it will do so.

 Just like when you’re accelerating on the wheel. You are applying more weight in front of the axle than the back, so to keep the wheel upright it has to accelerate.

 Again the same if you’re off the wheel and press the front of the wheel down. More weight on front -> wheel has to accelerate to stay upright.

[rcgldr]

On 4/23/2022 at 7:30 PM, LanghamP said:

I give my EUCs a slight tilt so they slow down instead of speeding up after a crash.

The pedal tilt setting should not cause an EUC to speed up or slow down if the rider bails or jumps off. Wrong Way has jumped off an EUC in a few videos, either going slow enough to jump back on or just sending the EUC off at a faster speed to be caught by another person. When he does this, the speed of the EUC seems to be near constant. As another example this dog going for a ride on an EUC at near constant speed:

https://www.youtube.com/shorts/MBtSQHT3CCo

17 hours ago, LanghamP said:

The pedal tilt option isn't there, true, but you CAN recalibrate the 18xl to tilt or down under the first menu in the gear menu => horizontal calibration option. The instructions say to put the wheel level but you can tip the wheel forward and it will keep that angle.

EUC's (at least most of them) use a magnetometer, which uses earth's magnetic field to determine which way is true "up". However, due to tolerances in assembly, the main board may not be perfectly aligned with the EUC, so a factory calibration should adjust for any mis-alignment, so that the end result is the EUC knows which way is "up". 

Inmotion V8F does have a calibration done with the V8F resting on it's front bumper so the rider doesn't have to guess what is vertical. The manual and some videos imply this calibration is only used to stop pedal dip in turns, and not for horizontal (left | right | forwards | backwards true up) calibration. I can set pedal tilt from - 5 to + 5 degrees, and the V8F stays in place, no tendency move other than the tilt change. 

Edited April 25, 2022 by rcgldr

[Chriull]

21 minutes ago, rcgldr said:

The pedal tilt setting should not cause an EUC to speed up or slow down if the rider bails or jumps off.

The "set" pedal tilt determines at which angle the euc stabilizes the wheel.

If a wheel is balanced at a tilt angle of zero degrees (no forward or backward torque) this implies that no acceleration happens if the wheel keeps it at this angle.

Some wheels are not balanced for zero degree pedal tilt, so if i remember right, the Z10 accelerated while just balancing the wheel.

Depending on the weight distribution a changed tilt angle can cause acceleration, as the euc has to counter any given torques for balancing. So a given torque by unsymetric wheight distribution forces a wheel to accelerate.

 

[rcgldr]

8 hours ago, Chriull said:

Depending on the weight distribution a changed tilt angle can cause acceleration, as the euc has to counter any given torques for balancing. So a given torque by unsymmetrical weight distribution forces a wheel to accelerate.

I wasn't taking that into account. My V8F is top heavy, so a riderless V8F would be affected by pedal tilt. A V8F will auto-lean a rider and auto-tilt forwards | backwards on an incline | decline, similar to a cruise control to maintain speed, and I wonder if a riderless V8F would have a similar auto-tilt reaction to stop the acceleration. With a rider, the effect is the opposite, the pedals are moved slightly backwards when tilted forwards and vice versa (pedal height 6.1 inches, axle height 8 inches), so a rider would need to lean forwards a bit to compensate for the small amount of front | back pedal offset due to pedal tilt setting. Maybe Wrong Way can do a test:

https://www.youtube.com/watch?v=qW-y5RiecMc&t=854s

https://www.youtube.com/watch?v=VYDZ6FzUEGY&t=1000s

 

Edited April 26, 2022 by rcgldr

[Robse]

12 hours ago, rcgldr said:

EUC's (at least most of them) use a magnetometer, which uses earth's magnetic field to determine which way is true "up". However, due to tolerances in assembly, the main board may not be perfectly aligned with the EUC, so a factory calibration should adjust for any mis-alignment, so that the end result is the EUC knows which way is "up". 

 

Hmnn....  that means,  i cant use my wheel on Mars ?    anyway, what about magnetic disturbances - one could imagine a situation where the wheel is affected by other magnetic fields (big power generator, transformer, wires?)  and thus perhaps thinks that it is tilted - or lies down sideways = cutoff ??

The video - 10:00

 

 

[mrelwood]

3 hours ago, Robse said:

what about magnetic disturbances - one could imagine a situation where the wheel is affected by other magnetic fields (big power generator, transformer, wires?)  and thus perhaps thinks that it is tilted - or lies down sideways = cutoff ??

EUCs use data from both a magnetometer and a few accelerometers. I don’t know which one takes precedence if the data doesn’t match though, so I wouldn’t install a large power generator or one of the city’s large transformers on the wheel. Just in case and all that.

[rcgldr]

14 hours ago, Robse said:

magnetometer

A magnetometer is a 3 axis magnetic sensor. An EUC needs to know which direction is true up (or more accurately true down) to know which direction gravity is in order to eliminate that from accelerometer readings, and its orientation relative to earth for tilt sensing (left | right | forwards | backwards). Magnetometers when combined with accelerometers and gyroscopes, can stabilize orientation calculations and determine orientation with respect to earth. The gyros alone are not sufficient enough to determine orientation with respect to earth. The magnetometer is setup and mathematically filtered along with the other sensors so that the hub motor and controller board don't interfere with it. I'm not sure of all the details. This article mentions it: "IMU sensors usually consist of two or more parts. They are: accelerometer, gyroscope, magnetometer and altimeter", ... "The block diagram of self balancing unicycle consists of a controller Arduino board with a ATMEGA328 microcontroller on it. MPU6050 module which is basically a Inertial Measurement Unit (IMU) with gyroscope, magnetometer, accelerometer and altimeter on the module itself control the position of the unicycle.", but doesn't go into detail on how it's implemented. 

http://iosrjen.org/Papers/Conf.ICIATE-2018/Volume-1/14-66-70.pdf

Magnetometers are also used in modern aircraft attitude indicators:

https://en.wikipedia.org/wiki/Attitude_and_heading_reference_system

 

Edited April 26, 2022 by rcgldr

[Robse]

On 4/26/2022 at 2:18 PM, mrelwood said:

EUCs use data from both a magnetometer and a few accelerometers. I don’t know which one takes precedence if the data doesn’t match though, so I wouldn’t install a large power generator or one of the city’s large transformers on the wheel. Just in case and all that.