Better Gimbals

More
19 Jan 2020 22:24 #75755 by eried
Replied by eried on topic 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

Please Log in or Create an account to join the conversation.

More
19 Jan 2020 23:28 - 19 Jan 2020 23:30 #75757 by Milstan
Replied by Milstan on topic Better Gimbals
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?
Last edit: 19 Jan 2020 23:30 by Milstan.

Please Log in or Create an account to join the conversation.

More
20 Jan 2020 08:42 #75764 by eried
Replied by eried on topic Better Gimbals
Yes, I ordered one but I was just wondering because even being cheap they are 15% of the price of the whole remote... :P so for a spring it is not that cheap.

Please Log in or Create an account to join the conversation.

More
20 Jan 2020 21:34 #75785 by Milstan
Replied by Milstan on topic Better Gimbals
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.

Please Log in or Create an account to join the conversation.

More
06 Apr 2020 11:01 #76150 by yets
Replied by yets on topic Better Gimbals
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.

Please Log in or Create an account to join the conversation.

More
10 Apr 2020 04:36 #76175 by Milstan
Replied by Milstan on topic Better Gimbals
Thank you, i'm glad that my instructions worked, i'm still planning to revise the drawings and adjust some little things

Please Log in or Create an account to join the conversation.

More
26 Jul 2020 09:39 #76615 by Sicon
Replied by Sicon on topic Better Gimbals
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!

Please Log in or Create an account to join the conversation.

More
27 Jul 2020 00:10 #76616 by Milstan
Replied by Milstan on topic Better Gimbals
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.

Please Log in or Create an account to join the conversation.

More
27 Jul 2020 02:03 #76617 by richardclli
Replied by richardclli on topic Better Gimbals

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.

Please Log in or Create an account to join the conversation.

More
28 Jul 2020 09:11 #76625 by richardclli
Replied by richardclli on topic Better Gimbals
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.

Please Log in or Create an account to join the conversation.

More
28 Jul 2020 10:33 - 28 Jul 2020 10:43 #76626 by vlad_vy
Replied by vlad_vy on topic Better Gimbals
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.
Last edit: 28 Jul 2020 10:43 by vlad_vy.

Please Log in or Create an account to join the conversation.

More
30 Jul 2020 02:41 #76636 by richardclli
Replied by richardclli on topic Better Gimbals
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.

Please Log in or Create an account to join the conversation.

More
31 Jul 2020 09:38 #76645 by -=Hubi-Dirk=-
Replied by -=Hubi-Dirk=- on topic Better Gimbals

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.

Please Log in or Create an account to join the conversation.

More
18 Sep 2020 12:25 #76796 by Milstan
Replied by Milstan on topic Better Gimbals
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

Please Log in or Create an account to join the conversation.

More
20 Nov 2020 12:26 #77042 by Eyolon
Replied by Eyolon on topic Better Gimbals
Amazing mod !!! I want to do it and print spacers with translucid pla and place led on back :P

Please Log in or Create an account to join the conversation.

More
20 Nov 2020 19:05 #77043 by -=Hubi-Dirk=-
Replied by -=Hubi-Dirk=- on topic Better Gimbals
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

Please Log in or Create an account to join the conversation.

Time to create page: 0.068 seconds
Powered by Kunena Forum