HELP servo is now a wiper motor

[Rezvonflux]

This all started with an attempt at correcting a centering/sticking issue.

Reassembled the whole thing and it works... just not exactly like before.

 

Servo turned wiper

Seems it'll go left and right without centering at all now.... or, go back and forth on its own like a wiper arm.

Any thoughts as to where I messed up?

[aeh5040]

No idea, but on the plus side, if you want motorized wipers....

[brickless_kiwi]

Ok... what profile are you using and code..

Other question is that s brick or some knock off ?

As it looks like a coding error?

Edited March 19 by brickless_kiwi

[TinkerBrick]

Hi,
i assume it is a third party servo? LEGO Servo have dot markings on the drive shaft and the surrounding enclosure.

The battery box/controller certainly is not a LEGO product.
Have you tried to hook up the servo to a standard TLG battery box and IR-receiver.
This way you could test to function of the servo. It should only move 90° left or right and return to center once you let go of the IR remote.

Edited March 19 by TinkerBrick

[Rezvonflux]

Ok this was a mould king knock off I believe... but also happens to my lego crawler original servo.

Since I've scrapped and cleaned around and put it together. Now it seems to go all left and stops or right and stops, but never centering.

Before picture

After some work

I've tried both the MK battery box and the Lego Battbox with IR controller. Both behave the same way.... never centering tho.

Did noticed with an axle inserted and some pressure applied, it starts to jiggle in its own

Btw, ignore any possible typos lol

[TinkerBrick]

in the clip the motor turns 180°. It should only rotate 90° to the left or right:
I suppose sth. went during reassembly. Maybe a sensor was somehow misaligned.
 

[2GodBDGlory]

2 hours ago, TinkerBrick said:

in the clip the motor turns 180°. It should only rotate 90° to the left or right:
I suppose sth. went during reassembly. Maybe a sensor was somehow misaligned.
 

No, I think his is just starting from the one extreme side and moving all the way to the other extreme. I don't think there's really any way to misalign a sensor on these?

[Rezvonflux]

You all makes valid points and assumptions, helping me run thru my own thoughts.

But not im thinking it may be the dimples kn the ring sliding along the track that isn't making contact... or possibly cause a crosswire.

But yes, I can now rotate the 90° left and right, running the full possible 180° just without any centering happening.... 

...unless like I mentioned, I insert an axle inside and apply pressure into the connector....then it tends to kinna jiggle back and forth a few.degrees

[schraubedrin]

This might be an issue of the servo not getting the signal when it's at the "right" position.
Is there any input/steering signal where it stops switching back and forth? Maybe fully left or fully right?

Have you seen this video:

 

[Rezvonflux]

Lol yup that's the video that started my venture.

Digging around for my meter to check ohmz, keep yall posted

[Rezvonflux]

On 3/20/2023 at 1:22 PM, Rezvonflux said:

Lol yup that's the video that started my venture.

Digging around for my meter to check ohmz, keep yall posted

So update, no update

Got out the voltmeter/ohm meter and all the contacts are good. Doubt it's the board as it was working semi correctly.

Leaves me to the believe its the contact ring. 

If all else fails I'll just either be content with at least the full 180° turn left to right or gut it and male a simple rubber band return inside opposed to the exterior RTC using a M-motor lol

 

[Appie]

2 hours ago, Rezvonflux said:

Leaves me to the believe its the contact ring. 

What I am about to say is perhaps a little vague, but it's been years since I read it.

 

What might be the problem on the ring is there should be some lines which seperate the different servo positions (should be about 7 or 9, you can utilize these with a PF train remote for example). Anyway, I read back then if the servo has issues, it might be because of the fluid (not sure if fluid is the correct word, but it is on there by default) is wiped across the 7-9 lines. This results in it making contact over the entire ring. To fix this, you'd need clean between those 7-9 lines to make the servo work normally again.

 

I found the post to which I am refering actually:

Wasn't fluid, but copper apparently :)

Maybe this helps

[Rezvonflux]

Success!

So tweaking the ring connector to the tracks, cleaning and the gaps between the different sections of the tracks and finally the big addition....

 

I noticed that when assembled the ring "rear"  might have been pushed and maybe making contact with the 6 contacts below.  The solution, a little clear nail polish on those nodes and on the read side of that ring