Search for Replacement 9x Potentiometers!

[bob195558]

The 9X Radio's, Gimbal Sticks, only have a total travel of 55 degrees.

I do not have access to a 9XR Radio, dose the 9XR Radio have the same gimbal sticks Travel of 55 degrees?

And if it dose, Then dose, the 9XR Radio's Potentiometers with there 80 degrees of working Rotation, have poorer performance
then our 9X Radios Potentiometers with there 60 degrees of working Rotation?

[Flaps 30]

The 9X Radio's, Gimbal Sticks, only have a total travel of 55 degrees.

That would explain where the 0.55 Volts (out of the 10 Volts available) went. That would equate to 0.275 Volts with a 5 Volt supply that the 9X has.

As for the other points.. I hope someone tests it out to see what the voltages are on the 9XR gimbal.

[mpjf01]

I do not have access to a 9XR Radio, dose the 9XR Radio have the same gimbal sticks Travel of 55 degrees?

Yes, roughly (within 2 degrees).

[bob195558]

View of installed 9XR Throttle Potentiometer in our 9X Radio.
100_9490.JPG

Hi Every One,
I have just received a pair of the Hobby King's Left and Right 9XR Gimbals Sets (Replacement Parts)
and this is some of the info that I have discovered so far:

Over View:
1) These 9XR Replacement Gimbals Sets by themselves will not fit into our 9x Radio's with out some modifications.
You may not want to try to use the 9XR Gimbals Sets because they only have 42 Degrees of Stick Travel and our 9X Radio Gimbals Sets use 55 degrees of Stick Travel.
Also in the Hobby King 9XR Gimbals Sets, Three of the Potentiometers are not the same (B502 80 degrees) as our 9X Potentiometers (B502 60 degrees).
But, Good News, one of the Potentiometer in the 9XR Gimbals Set (Left Side, Throttle and Rudder Stick Controls) Mode 2, uses a B502 60 degrees Potentiometer .

2) So after making modifications to the 9XR B502 60 degrees Throttle Potentiometer and our 9X Radio Gimbals (Throttle, Rudder Gimbals),
I was able to replace the original 9X Throttle Potentiometer with the new 9XR B502, 60 degrees Throttle Potentiometer.

Info of 9XR Gimbals Replacement Parts
The 9XR Gimbals are smaller then the 9X Gimbals, where as to the locations of the 3 attaching screw holes do not line up.
But the large hole in both the 9XR and 9X Radio case are the same size.
And so the 9XR Gimbals will fit the large hole in the 9X Radio case.
If it were possible to fit the 9XR Gimbals into the 9X Radio case, there are still other characteristics and obstructions to over come.

Take Note, that the 9X Radio Gimbal sets have 55 degrees of Stick Travel and
take note that the 9XR Gimbal Sets have only 42 Degrees of Stick Travel.
9XR has 12 degrees less Stick Travel, that may cause less control when flying your model.

Also Take Note, the 9XR Gimbal Set (Left, Throttle & Rudder Stick Controls) Mode 2, ......... has TWO different Potentiometers installed in them.

The GOOD News is that one of the Potentiometers in the 9XR Gimbal Set (Left) Mode 2, uses a B502 60 degrees
potentiometer for its Throttle Stick Control, which has the same data requirements needed for our 9X Radio Potentiometers.

The BAD news is that this 9XR Throttle Potentiometer is not constructed in the same way as our 9X Potentiometers
and so it will not fit into our 9X Radio Gimbals with-out some modifications being done to it.
Also our 9X Radio Gimbals will need some modifications done to it, so that the 9XR Throttle Potentiometer will line up correctly.

The 9XR Throttle Potentiometer has a small circuit board soldered to it's three Potentiometer connectors and this small circuit board needs to be unsolder
and flipped over 180 degrees so that it dose not obstruct one of the attaching Case Screw Holes. (See picture: 100_9281)

The next Problem is the Locating Tab on the 9XR Throttle Potentiometer.
This Locating Tab is 90 degrees° out of place, (See picture: 100_9394) so you need to make another Locating Hole in your 9X Gimbals.
I took the 9XR Throttle Potentiometer and inserted it to where the 9XR Potentiometer Locating Tab just touched the surface of your 9X Gimbal.
I then rotated it using the Locating Tab to making a light scribe line to mark the Center location for the new Tab Locating Hole.
Next I eyed, where 90 degrees came and used a small hand pin vise with a small drill to make a small pilot hole.
I then selected the proper drill size to make the Tab Locating Hole, using a larger hand Pin Vise. (See picture: 100_9415)

The next Problem is reconnecting the wires from your 9X Radio to the new the 9XR Throttle Potentiometer.
The wire colors are different between the two Throttle Potentiometers and when we flipped over the small circuit board we also change the two end wire colors.
So be careful when wiring your 9X Radio to the new 9XR Throttle Potentiometer.
This is the color match up that I used: (See picture: 100_9479)
9X Radio Black wire to the Black wire of the 9XR potentiometer
9X Radio Red wire to the White wire of the 9XR potentiometer
9X Radio White wire to the Red wire of the 9XR potentiometer

I also install a connecting-plug with my modifications so to make it easier, if I needed to trouble-shoot any future problems with the replaced 9XR Throttle Potentiometer.

So replacing the 9X Radio's Throttle Potentiometer using the 9XR Gimbals Set (Left) Mode 2 B502 60 degrees Potentiometer,
is one of several options, that we can use to replace a damaged 9X Radio Potentiometers.
I hope this is helpful to those of us who are having problems with 9X Radio Potentiometer failures.

................................................................................................

[feket663]

[quote="Flaps 30"][/quote]

Dear Flaps 30!

Can you tell me some info about long term usage of hall effect device in gimbals?

[Flaps 30]

Hello feket. I have only fitted one hall effect device to one of my transmitters and it is in use on the throttle. No long term stability problems have been found.

It wasn't easy to set the final position of the magnet, but it was easy to move around, so finding the sweet spot required fine movements of the magnet. There is a small gap (two sheets of paper) between the magnet and the hall effect device.

The output of the hall effect device is fairly linear, it depends upon how accurate you are with centralising the magnet with the centre of the spindle, along with ensuring that the zero field of the magnet is at the centre point of the pot/joystick. The closer you get with those two things, the better the linearity will be, not that it is all that bad even on a rough alignment.

The output of the hall effect device was as follows:

Stick down/zero= 0.02 Volts
Stick Centre = 2.40 Volts
Stick High = 4.83 Volts

All measured with a supply voltage of 5.04 Volts

The output range of the hall effect device is greater than that of the original potentiometer which is no bad thing.

If you are thinking of doing this modification, it is a good idea to change the 5 Volt regulator (78L05) for a 7805 as the hall effect device draws anything up to 11mA each.

[feket663]

Thank you very much!

[HC1969]

9XR gimbal inside:

More info:
http://rc-miskolc.emiter.hu/rc-miskolc/ ... Itemid=185

[bob195558]

Hi HC1969,

I went to your web page and I am, not knowing how to read other languages.
But I like your pictures, they are good and Clear.

The Gimbal on the other side of your 9xr radio, the Throttle Potentiometer uses a B502 60 degrees Potentiometer for the Throttle Stick Control
and this Potentiometer has the same data requirements that is needed for our 9X Radio Potentiometers.

Why when they designed the 9xr radio, they uses 3 different potentiometers and for the Throttle Stick Control Potentiometer they used the B502 60 degrees Potentiometers?

Thanks,
BOB

[bob195558]

Hi Flaps 30,

With your 9X Radio with the one Hall Effect Device fitted to your Throttle Stick Control,
is there any functioning characteristics that are different from the first original B502 60-degree Throttle Potentiometer ?
Dose the Hall Effect Device perform just the same as the 9X B502 60-degrees Throttle Potentiometer ?

[Flaps 30]

Bob - The characteristics are the same with the hall effect when compared to the potentiometer.

If you look at the voltage outputs they are close as they can be to each other, which is good news. It was a bit of luck to find a magnet and a hall effect device that matched up so well to the original potentiometer.

[bob195558]

So the Hall Effect Device has the same resolution values as would be with the stock 9x Potentiometers?

[Flaps 30]

As good as if not better than the original pots. This is what I posted on the previous page regarding the original pot

Supply voltage=10.0 Volts
Centre=4.74 Volts
End=0 Volts
Other end=9.45

That gives the pot voltage range of 4.72 Volts as against the hall effect range of 4.81 Volts using the normal 5 Volt supply.

[joeham]

Inspired by the work of Flaps 30 on the use of Hall devices I'm trying a different approach.
the original 9X gimbal uses a keyed shaft on the pots this requires the careful alignment of the
magnet as the pot shaft is fixed and cannot be rotated for setting the center voltage of 2.5v.
My approach is to replace the entire gimgal with one removed from a old Futaba transmitter.
These gimbals are about the same diameter as the hole in the 9X case. I made a simple bracket out of 1/8 inch plywood to mount them in the original 9X mounting holes. These gimbals use pots with round slotted shafts that allows easer adjustment.
I couldn't find the specific magnet here in the USA an the listed one wouldn't ship after looking
on E-Bay I found a diametrically magnetized disc magnet item 1900930128617 about the same size
but neodymium. After receiving the magnets I the was faced on how to mount it to the pot shaft.
At first I tried just sticking it to the steel plate that held the brushes but found I couldn't get 2.5v swing
but holding the magnet near the Hall sensor showed plenty of range. As test I removed
the steel plate in the pot and carefully glued the magnet to the pot brass shaft now I could
get the required voltage change as the gimbal is operated my conclusion is that the steel plate is acting as a shunt across the face of the magnet.
The next problem a better mounting for the magnet The only thing I could think of to provide more
mounting surface was to ream out a brass nut and carefully solder it to the part of the shaft that held the
removed brush plate now at least I have more area to glue in the magnet. what I tried was using rubbery glue called GOOP in the US. After drying I used some Epoxy around the sides followed
by a small piece of shrink tubing. The jury is still out on this and someone else may be better solution please let me know.
Now the throttle pot worked fine with a junk box Hall device but after ordering some Allegro
xxxx I found that the voltage swing on the rudder was only 1v each direction. After looking at the data sheets the A1202 has the lowest sensitivity so it's back to DigiKey for a more sensitive part
A1324 which I now believe is the same as the junk box one on the throttle. This part may not be
needed with a stronger magnet. I'm still waiting for the new sensors will keep this group posted of the
results.
Joe

[Flaps 30]

Nice work Joe.

I tried the Ebay item number with the USA Ebay site and came up empty.

Getting the right match between the magnet Gauss and Hall effect device sensitivity is key. It was partly by luck that the Allegro 1302 combined with the Diametrically Magnetised Samarium Cobalt magnet with a Gauss level of 4200 came right in my case.

Regarding the shunt effect. With the 9X pot assemblies. The brass shaft sits above the steel plate (as can be seen by the gap in the picture) hence the magnet doesn't come in contact with the plate. It also allows a nice gap that you can fill with your favourite goop to fix the magnet.

[G550Ted]

Yikes! In days gone by people who spoke like that were burned at the stake for being witches.

Ted

[Bill]

Yikes! In days gone by people who spoke like that were burned at the stake for being witches

??????????!!!!!!!!!!!!!

That aside the problem of resolution of the 80 degree pot can be overcome by using silver conductive ink on the ends of the track thus making the voltage change greater for a smaller amount of stick movement.

simples.jpeg (7.56 KiB) Viewed 21629 times

[jhsa]

ABBC3_OFFTOPIC

"What this world needs is more impeached imprisoned and unemployed politicians."
“A good politician is quite as unthinkable as an honest banker”
Hey politicians keeping our word is one of the things that make us better than you!

Sorry guys about the off topic but I do like this
I always wanted to be an honest polititian, they kicked me out..

João

[joeham]

Corection for magnets on E-Bay search 190930128617

Joe

[volumax]

Somebody asked and nobody answered so I will ask again, are the pots on the flysky ct6b the same as the 9x? Can they be used as replacement?

[volumax]

Nevermind opened up a friends ct6b and they are different

[joeham]

Both Futaba gimbals have been modified with the new Hall sensors and installed in the 9x.

The new Hall devices are almost to sensitive for the magnets that I have and there is just
enough space for adjustment getting full range 0+5v which requires some fiddling.

I'm in the process of test flying currently and will post the results.

Joe

[Flaps 30]

Hope it goes well Joe.

I looked at the picture again and noticed that the hall device is on the end of the magnet and some way in. That might have been the cause of the lack of sensitivity, as the greatest force will be on the side of the magnet.

Yes the final adjustments are a bit of a fiddle, but it is worth it in the end. Have you changed the five volt regulator to allow for the extra current demands from the Hall effect devices?

[bob195558]

Hi Volumax and Kaos,

Any one know if the Flysky CT6A or CT6B pot can be used on T9X? they are both made by Flysky. any chance they are the same. if they are, there are cheap CT6A/B out there people wants to throw away. Actually, I still have a CT6A sitting there. would be great it can be used for spare parts for T9X.

Somebody asked and nobody answered so I will ask again, are the pots on the flysky ct6b the same as the 9x? Can they be used as replacement?

No you can not use a AT6A and/or CT6B Pot in the 9x Radio.

That's why its so difficult to fine a replacement, But you can use the Throttle Pot from the 9XR replacement Gimbal (Mode 2) from HobbyKing.

(Click Here: > http://openrcforums.com/forum/viewtopic ... 394#p54150 )

If you have time to check out all the postings in these 6 pages,
you may find an option that will work best for you.
There maybe more options to fix and/or replace failed pot in the future.

[ShowMaster]

FYI if it helps?
Those with bad 9x pots please post the symptoms. There are a few tests that can determine if they can be repaired easily.
If you push on the pot board or wires carefully, does the pot work again with the pressure on it?
Does the pot work normally 1/2 of the travel?
It's been covered many times over the last 2 years but in case you missed it. HK/FlySky stopped using the silver conductive paint that usually is/was used to bond the ends of the resistive element to the eyelet that connects the pot wires to it. If the pot PC board is moved much the leverage on the pot leads at the element eyelets can become intermittent or not at all. In the past the silver conductive paint guarded against that. This started to happen more about 2 years ago I think.
If moving the pot PC board or solid leads heals the pot even for an instant there's a good chance it can be repaired.
Take the pot apart and re-crimp the eyelets with a needle nose pliers carefully. The eyelets are soft brass and you don't want to crush them or the pot element.
I've done this many times for club members and they've been good to go for sometime now.
There were pictures of the element posted if you search for it. If there's interest I'll look them up. It's the first thing to try before a total swap out or major pot redesign if you just want to keep flying.
A final fix would be a drop of silver conductive paint but it's expensive and I haven't needed it yet.
Btw
This usually happens if the radio was worked on and or modified. It's really easy to to move the pot PC boards not realizing the pressure they put on the solid pot element leads. Please be careful of these boards and moving them in my experience.
I hope this helps.

[volumax]

My aileron pot was moving my "center" to about half way of total right movement, so I basically didnt have left aileron and I took off, my plane went like crazy to the right and I had enough left aileron just to keep it from hitting upside down. But after moving the sticks a few times it went to center. Had a few flights and same thing happened but I noticed on the ground. When I got home I opened up the pot and wiped it clean with paper towel and use one those sanding sticks girls use on their nails to lightly sand the pot like I saw somebody do it on youtube. Didnt have conductive paint though like the guy recommended but its on its way. Anyways after closing up and calibrating it was centered, but when I moved my elevator up, it wouldnt go straight up, it had a little turn to the left at the top, so I kept calibrating until it was good, but then full forward-right movement wouldnt show complete, so I opened up again and touched the little strings of metal inside the pot (was this wrong?) and after closing again now I have no right movement. Anyways do taranis gimbals work on t9x because they just put them up on alofthobbies?

[ShowMaster]

The usual failure is the black resistive element ends and the pressure connection, silver in this picture, not mine. My fix is to simply re-crimp the small eyelets at the ends with my needle nose pliers as I mentioned. Yours won't have the silver paint I'm assuming.
About the sanding down of the black carbon element. The carbon coating is what's giving you the resistive change when the pot wiper moved over it. In my opinion it should never be sanded as removing the surface will elevate the total resistance and it's a very thin coating. Any force on the ends risk breaking the connection.
There are pot cleaning sprays that used sparingly will clean intermittent wipers and lube the surface.
As for the utube video, I haven't seen it but sanding down the element would only be done if it was badly pitted like this picture is at the element top but I'd never do it to fix the pot failures I've seen. It's almost always the end connection on the pots I've seen.
So how good are you with an ohm meter to see if we can save your pot? This is assuming the work on it hasn't done more damage?

[volumax]

I can try to follow your directions, just tell me what to do and I will try to follow.

[ShowMaster]

I don't have a 9x case open to give exact instructions for measuring but here's the idea.
If the end connections are bad you'll not read a solid 5K or close to it across the 2 outside pot wires. All the pots in your radio are in parallel with the + and - voltage buss. Reading a pot will not give you a 5k reading but much less1-2k as I remember.
If your pot is still working you could measure with power on from the center pot wire to ground and it should be around 2.5v at pot center. If you move the stick from center to both ends the voltage should swing from ground 0 to +5v if it jumps high or low instead that should mean That the connection is bad. Pushing on the pot wires will also cause these values to jump or chance with no stick movement.
Or since you've already done so much to the pot element and I'm not sure what condition it's in now, you can try re-crimping the end eyelets and see if you luck out.
Just open the pot to get to the element and with a needle nose pliers careful pinch both element eyelets without breaking the element.
If you do have some conductive paint ordered wait and so this all at the same time. You'll damage the pot or it's case if you keep opening it too many times.
I wish I could explain it better or make or easier but I can't.
Please post the utube link showing the pot being sanded. I want to see if it's valid.

[volumax]

This is the video, on thursday I get delivery of some conductive paint so I will try to fix the pot then, but I also get delivery of taranis gimbals from aloft hobbies, hope they really fit.

http://www.youtube.com/watch?v=NqVyfSeN4po