I thought i would try and put a custom motor mix on my FR7 v5.1. to see if it flyes nicer.
Does this look right to you (props out)? Is there something i need to know before i try it?
https://www.iforce2d.net/mixercalc/

I tried to find the motor mix figures by the designer of the FR7 in the 5.1 version and couldn't.

He does say there is a slight difference in measurements between v1 and v2.  He also says in a later post that the differences in geometery between v2 and v3 is zero.  So maybe that is the case for the difference between v2 and v5, I don't know.

Below is his motor mix for the v2

Yours is so close to his, I say give yours a try.  If you have flight anomalies then try his settings.

# mixer
mixer CUSTOM
mmix 0  1.000 -0.809  0.659 -1.000
mmix 1  1.000 -1.000 -0.659  1.000
mmix 2  1.000  0.809  0.659  1.000
mmix 3  1.000  1.000 -0.659 -1.000

(26-Jun-2021, 07:18 PM)Krohsis Wrote: I tried to find the motor mix figures by the designer of the FR7 in the 5.1 version and couldn't.

He does say there is a slight difference in measurements between v1 and v2.  He also says in a later post that the differences in geometery between v2 and v3 is zero.  So maybe that is the case for the difference between v2 and v5, I don't know.

Below is his motor mix for the v2

Yours is so close to his, I say give yours a try.  If you have flight anomalies then try his settings.

# mixer
mixer CUSTOM
mmix 0  1.000 -0.809  0.659 -1.000
mmix 1  1.000 -1.000 -0.659  1.000
mmix 2  1.000  0.809  0.659  1.000
mmix 3  1.000  1.000 -0.659 -1.000

Thanks, yeah looks close. I messured from the middle of the motor shafts with a tape mesure. I see some of my numbers are inverted. I guess this is the props out while your numbers are props in?

(26-Jun-2021, 07:21 PM)Myman Wrote: Thanks, yeah looks close. I messured from the middle of the motor shafts with a tape mesure. I see some of my numbers are inverted. I guess this is the props out while your numbers are props in?

Yeah a tape measure is less accurate than with a caliper.  That could be why there are differences.  I know Jeremy used a caliper, so his are likely closer to correct.

Yes, Jeremy's measurements are props in, but not entirely sure that is why there is a discrepancy.  I have never ran props out, so I can't say for sure that is why things are inverted, but it is a plausible explanation.

(26-Jun-2021, 07:26 PM)Krohsis Wrote: Yeah a tape measure is less accurate than with a caliper.  That could be why there are differences.  I know Jeremy used a caliper, so his are likely closer to correct.

Yes, Jeremy's measurements are props in, but not entirely sure that is why there is a discrepancy.  I have never ran props out, so I can't say for sure that is why things are inverted, but it is a plausible explanation.

I see, yeah a caliper is best.
When i change direction on the motors in the mixing calculator page the last number changes inversion so it seems to be what tells the FC if the props are in or out.

The motor directions affect yaw which is why their signs (+ve or -ve) will change depending on motor directions.

Based on the motor mix command:

Quote:mmix [motor number] [throttle] [roll] [pitch] [yaw]

Here is an example for one of my quads:

Normal props (props in):

Quote:mixer custom
mmix reset
mmix 0 1 -1 0.765 -1
mmix 1 1 -1 -0.765 1
mmix 2 1 1 0.765 1
mmix 3 1 1 -0.765 -1

Reverse props (props out):

Quote:mixer custom
mmix reset
mmix 0 1 -1 0.765 1
mmix 1 1 -1 -0.765 -1
mmix 2 1 1 0.765 -1
mmix 3 1 1 -0.765 1

We can see from the above examples that changing the motor direction of rotation affects the yaw values which are are inverted.

(27-Jun-2021, 04:35 AM)kafie1980 Wrote: The motor directions affect yaw which is why their signs (+ve or -ve) will change depending on motor directions.

Based on the motor mix command:


Here is an example for one of my quads:

Normal props (props in):


Reverse props (props out):


We can see from the above examples that changing the motor direction of rotation affects the yaw values which are are inverted.

Thank you, thats good info as i was still a bit unsure about that part.

Btw, when choosing custom motor mix there is still the slider for reverse props availible in the interface. Does it still reverse the direction? That could be bad if setting the mmix with props out and then the slider inverts it?

Be aware before trying motor mixings that your yaw is actually working as it is supposed to. I took the props off and put some tape on the shafts to feel what motors spin up easier. Started the motors and yawed on the control. It was as i thought.
It seems if i used the custom motor mix i dont need to use inverted numbers as i can invert the yaw direction by using the slider in the interface. Have not flown yet but thought id mention it is best to test without props before actually flying or it could flip/crash at takeoff.

*edit*

Testhover went fine. To bad its going to rain for a couple of days.
Anyway thanks for all the input. Now i will do the same procedure on all my "none X shape" quads.

(27-Jun-2021, 09:47 AM)Myman Wrote: Be aware before trying motor mixings that your yaw is actually working as it is supposed to. I took the props off and put some tape on the shafts to feel what motors spin up easier. Started the motors and yawed on the control. It was as i thought.
It seems if i used the custom motor mix i dont need to use inverted numbers as i can invert the yaw direction by using the slider in the interface. Have not flown yet but thought id mention it is best to test without props before actually flying or it could flip/crash at takeoff.

*edit*

Testhover went fine. To bad its going to rain for a couple of days.
Anyway thanks for all the input. Now i will do the same procedure on all my "none X shape" quads.

I usually fly my quads props in or normal direction as per BF. And I never had issues with the motor mix.

But then I saw your question and instead of guessing whether the yaw_motors_reversed setting would conflict with mmix inverted values for yaw, I decided to do a real test.

So I quickly reversed props and set mmix to inverted yaw values and set reverse direction in BF. The quad freaked out when I tried to take off and tried to yaw.

This means that the yaw_motors_reversed command set to ON inverts the already inverted yaw coming from the mmix command. If the yaw_motors_reversed command is set to OFF then it does nothing to the mmix.

This is dangerous

The mmix command came in from cleanflight and not many people fly custom mmix's or reverse props which is probably why people have not complained much about it.

(27-Jun-2021, 11:56 AM)kafie1980 Wrote: I usually fly my quads props in or normal direction as per BF. And I never had issues with the motor mix.

But then I saw your question and instead of guessing whether the yaw_motors_reversed setting would conflict with mmix inverted values for yaw, I decided to do a real test.

So I quickly reversed props and set mmix to inverted yaw values and set reverse direction in BF. The quad freaked out when I tried to take off and tried to yaw.

This means that the yaw_motors_reversed command set to ON inverts the already inverted yaw coming from the mmix command. If the yaw_motors_reversed command is set to OFF then it does nothing to the mmix.

This is dangerous

The mmix command came in from cleanflight and not many people fly custom mmix's or reverse props which is probably why people have not complained much about it.

Thanks for testing! Hope nothing broke. Now atleast other ppl that wants to try will know what to be aware of 
I run props out mostly becouse i come from smaller quads where props out help to push away grass/debree/small twigs intead of sucking em into the quad.

(27-Jun-2021, 12:23 PM)Myman Wrote: Hope nothing broke.

I tested this indoors in my apartment living room on my 5” quad Just a test hover flight.

But I did switch to angle mode since I was doing it LOS and I didn’t want props splitting my TV in half