Better Gimbals

Awesome! It would be easier if you post the stl pieces in thingiverse.

PS: Do you know where to buy the spring and piece to convert throtle gimbal into normal X Y ? my kit included it but I lost them

Hi there. I plan to improve the centering spacer, as what i posted is like a quick mod, but that requires some more time. When i find time i will post it on thingiverse.
Do you mean the lever that connects to the tensioning spring of the axis? Imho i don't know if they sell it.
But those gimbals are not that expensive. Why not get another one as a spare?

Yes, I ordered one but I was just wondering because even being cheap they are 15% of the price of the whole remote... so for a spring it is not that cheap.

I wonder if it is permitted to repost the mod on the tutorials part. As it might be useful to get more life from the devo 7e form factor.

A big thanks to Milstan for the great write up for the 3D printed parts for the gimbal swap. Worked a treat and was straight forward.

I printed mine PETG after trying ABS. ABS shrunk too much so would probably need scaling modification in the CAD program rather than in the slicer.

Thanks Milstan and also Markus Gritsch.

Thank you, i'm glad that my instructions worked, i'm still planning to revise the drawings and adjust some little things

Hi! I did the Jumper gimbals swap and installation, but the values of the axis seem fluctuating so much, they aren't really stable and had to increase a lot the deadband in BF, is it normal? Is there a way or a setting in my devo7e to make them more stable?

Thank you!

Hi Sicon, did you calibrate the sticks?, also do you have any power mods installed, do you use a 433Mhz module?
I have 2 polulu stepdown converters installed ( one for the 4 in 1 , another for the rest of the electronics) and i the only issue i got is a small fluctuation around zero of 1% but i noticed that the output if the hall effect gimbals is half of the stock gimbals. So less dynamic range gives way to more noise sensitivity.
My tx setup is flyable with a small deadband value of betaflight.

Milstan wrote: Hi Sicon, did you calibrate the sticks?, also do you have any power mods installed, do you use a 433Mhz module?
I have 2 polulu stepdown converters installed ( one for the 4 in 1 , another for the rest of the electronics) and i the only issue i got is a small fluctuation around zero of 1% but i noticed that the output if the hall effect gimbals is half of the stock gimbals. So less dynamic range gives way to more noise sensitivity.
My tx setup is flyable with a small deadband value of betaflight.

Well, Hall sensors are not necessary more accurate or reliable. First of all hall sensor is more sensitive to temperature, it can have drifting effect when temperature changes, second it is limited to effect range and D/A conversion, which normally has smaller range to achieve max span after calibration. (i.e. After calibration the min V and max V maybe 0.5 and 2.9 V, this will affect the accuracy of the D/A converter with range 0-3.3V). Third, the linearity is not good and cannot be properly calibrated for 3 points calibration.

So what is better? Obviously the one that use potentiometer can be more precise, more accurate, the only draw back is it is more subject to worn out. So using the ALPS potentiometer with customized range for gimbal can be a better choice. The only benefit of Hall sensor is it will never worn out.

I just checked Jumper's Hall Gimbal and compare with Frsky's M9 Hall Gimbal, just let you know about the accuracy differences:

Jumper Hall Gimbal (T16/T18): Effective Voltage Range 0.6-1.4V
Frsky M9 Hall Gimbal: Effective Voltage Range 0.4-2.6V

If the A/D converter is 12 bits, Jumper's gimbal can only gives around 1000 lines resolution, while Frsky can give around 2700 lines, almost 3 times of Jumper's resolution.

I do not think it is about the magnet center, it is about the mismatch of stick swing angle and voltage full swing angle. This is not only apply to Hall sensor but also apply to potentiometer type of sensor, good gimbal should have a customized potentiometer that has similar swing to the max stick swing, however the potentiometer swing should be a bit larger to ensure full stock swing can be captured.

However you have given a nice direction, what if try to fine tune the distance between sensor and magnet? Can this really help to improve the accuracy? Or try to change a better detection chip? I know that some Hall sensors is programmable for fine tuning the gain and other parameters.

vlad_vy wrote: I think with both cases you have a problem with magnet centering. At neutral stick position voltage has to be the half of power voltage, 3.3V / 2 = 1.65V, not 1.00V (Jumper Hall Gimbal) and not 1,50V (Frsky M9 Hall Gimbal).

Also, it can depends from magnet distance from Hall sensor, so at least it has to be the half of max and min possible values, if rotate magnet about 180 degree. At perfect case voltage will change from 0V to 3.3V. If magnet is too close to Hall sensor, you will have dead zones at end points. If magnet is too far from Hall sensor, you will have more narrow voltage range.

richardclli wrote:

Milstan wrote: So what is better? Obviously the one that use potentiometer can be more precise, more accurate, the only draw back is it is more subject to worn out. So using the ALPS potentiometer with customized range for gimbal can be a better choice. The only benefit of Hall sensor is it will never worn out.

Basically this statement is true, but life is not black and white. The statement that the Hall sensor does not wear out is correct, which means that the Potentiometer does exactly that.

What should be considered is, and this is a several years experience in my RC Time, that Potentiometer do not stop working right away. They start bouncing and jumping and giving wrong values at first. In the middle of a flight when a helicopter hectically reacts to every pitch input you have to keep it on height is it a acrobatic act to land it.

Yes, there is also a way to keep Potentiometer longer alive with Produkts like DeoxIT. But in the end the damage at the Potentiometer is milded but not repaired and return soon.

Pitch = Throttle => This is the most used stick on transmitters and elementary when flying Helicopters and Planes, the Potentiometer is heavily use. I must rely on my transmitter, so in my opinion the Hall Sensors are the better alternative compared to Potentiometers. Maybe sometime we have optical technology.

quick update to those who are still interested in doing this mod, the design is posted on thingiverse, at: www.thingiverse.com/thing:4590041

Happy flying

Amazing mod !!! I want to do it and print spacers with translucid pla and place led on back

There is also a way to modify the original Devo Sticks with Hall-Sensors.
deviationtx.com/forum/how-to/8770-modifi...h-hall-sensors#76591

I did the mod too. works very well but ...
the trims of rudder and aileron worked the wrong (opposite) direction.
I corrected this in the tx.ini by reversing the entries for max and min in the calibrations for gimbals 1 and 4.

Achim

Thanks for the stl files, everything worked fine!

Hello everybody,
it has been five years since I last stopped by here. It looks like there are still few active.

Since the potentiometers on my Devo 8S became imprecise, I had to look around for a solution. Replacement is hard to find and the adapter for the M9 gimbal too much work with 3D printing etc.

So I came across this conversion for the 49E hall sensors.

mcheli.blogspot.com/2020/01/diy-hall-sensor-gimbals.html
deviationtx.com/forum/how-to/8770-modifi...h-hall-sensors#76591

I came up with the following implementation for this purpose.

For me as a cutting machine operator, production is very easy.

For now I will build two sets (2x 4 pcs.)

If you are interested, I can build more for you in the future.

Very nice, I am looking forward to your modification report.

Viel Erfolg
Dirk