JJRobots COMMUNITY
Height degradation - Printable Version

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Height degradation - smellyboy - 08-25-2018 08:31 AM

Hi
I was wondering if anyone else has an issue with the height of the arm/pen degrading each time a lift/drop is done, to the point where the pen is dragging over the object when the pen is 'up'.
I have tried increasing the pen up/down value but I still get this degradation.
Obviously on plots that dont have a lot of lifts its all good and works great, however for more complicated plots it fails to maintain the same height.


RE: Height degradation - JJrobots JP - 08-27-2018 11:53 AM

You mean, the servo horn ends at different position every time it moves?


RE: Height degradation - smellyboy - 08-27-2018 06:52 PM

Hi
Yes over a series of lifts and drops of the pen, the lifts get lower gaining less height each time until the lift no longer is enough to clear the pen from the object and thus ruining the plot as it traces lines as it moves to the next plot point.

(08-27-2018 11:53 AM)JJrobots JP Wrote:  You mean, the servo horn ends at different position every time it moves?



RE: Height degradation - JJrobots JP - 08-29-2018 10:48 AM

That is strange. The only explanation for this is that the internal potentiometer of the servo (in charge of translate the pulse signal into a position) is failing. Some info about how a servo works here: https://www.jjrobots.com/remotely-controlled-laser-pointer/ (How does a SERVO MOTOR work?)
The easy way to solve this is to get another servo (SG90, for example, they are inexpensive).


RE: Height degradation - smellyboy - 08-29-2018 08:48 PM

(08-29-2018 10:48 AM)JJrobots JP Wrote:  That is strange. The only explanation for this is that the internal potentiometer of the servo (in charge of translate the pulse signal into a position) is failing. Some info about how a servo works here: https://www.jjrobots.com/remotely-controlled-laser-pointer/ (How does a SERVO MOTOR work?)
The easy way to solve this is to get another servo (SG90, for example, they are inexpensive).

Thanks for the reply.
Maybe I received a bad one as its all pretty new and has not been used much.
I have ordered in a few spares to have a play with and see if they make a difference.
Ill report back my findings when I have some.
Cheers


RE: Height degradation - JJrobots JP - 08-30-2018 01:55 PM

(08-29-2018 08:48 PM)smellyboy Wrote:  
(08-29-2018 10:48 AM)JJrobots JP Wrote:  That is strange. The only explanation for this is that the internal potentiometer of the servo (in charge of translate the pulse signal into a position) is failing. Some info about how a servo works here: https://www.jjrobots.com/remotely-controlled-laser-pointer/ (How does a SERVO MOTOR work?)
The easy way to solve this is to get another servo (SG90, for example, they are inexpensive).

Thanks for the reply.
Maybe I received a bad one as its all pretty new and has not been used much.
I have ordered in a few spares to have a play with and see if they make a difference.
Ill report back my findings when I have some.
Cheers
Yes, keep us updated please
;-)


RE: Height degradation - smellyboy - 09-21-2018 10:27 AM

Just to follow up on this for anyone else reading...
I replaced the servo and it appears to have fixed the problem.

Thanks for your help