Some questions regarding a servo motor's data sheet.

[Acetronics2]

probably they just sleep when you posted your thread?

Hi, Steve

We do not sleep ...

Just remember some previous posts ...

That's all

Alain

[selbstdual]

malc-c, you are talking about angular travel. In my experience the amount of ms stands for an absolute value...

I actually was able to let the servo rotate 180°. There are mechanical elements to prevent the shaft from rotating too far. Can't they be the actual limits?


Acetronics, I remember you fairly well. You and mister_e didn't know anything but tried to pass your misanthropy due to a need to compensate for your feelings of insufficiency.

You are no role models to me and that is why I couldn't care less whether you answer or not.

[JD123]

I actually was able to let the servo rotate 180°. There are mechanical elements to prevent the shaft from rotating too far. Can't they be the actual limits?

As long as you don't run off the limits of the feedback pot. A JR digital servo I have runs off the pot before the physical limits. This is becuse JR does not use a D key on the pot shaft. Since it's digital, they assembled the servo without making sure the pot was centered and then they 'teach' the servo where center is. With the pot off center, in one direction the full movement allows the pot to run off the end. The servo then tries to run 360 degrees. The metal gears were stronger than the mechanical stop and it was broken off. On this servo this happens at .89ms.

[selbstdual]

Currently I am using gear wheels to make the 180° servo rotate a shaft 360°.

This happens(The shaft is being stressed):

1. Servo gets the order to drive to a position X and does it.
2. Shaft rotates to a new position Y close to X.
3. Shaft successfully rotates back to X.
4. Shaft rotates to a new position Z being distant to X.
5. Shaft is to rotate back to X but stops at a different location - in between X and Z.

This occurs every time the shaft travels over an angle greater than 120°(60° without gear wheels).
According to my calculations the servo's torque is high enough.

Any Ideas of how to explain that?

[malc-c]

Assuming you want to control the rotation, such as a gun on a tank turrett then you could use pulleys and a standard servo. I've seen this method used on model warships to move sets of guns through a larger angular swing than a standard servo. Simply place a large diameter wheel on the servo, and a small one on the item that you need to rotate. With some maths to work out ratios, you might be able to get the result you want without having to overdrive the servo.

[selbstdual]

Currently I am using gear wheels to make the 180° servo rotate a shaft 360°.

[selbstdual]

For a better understanding, I uploaded a video: Here: http://rapidshare.com/files/112603057/c.avi.html which is 2 minutes long. You will need the xvid codec aswell as a mp3-codec. You should see that the part moving is almost parallel to the cam when being in position X. In software I tell the program to make the servo turn back to the old position as mentioned. But it doesn't as you can see.

And I would like you to tell me why.

EDIT: OR here if you prefer some service like youtube: http://www.revver.com/video/863645/problem-with-servo/

[selbstdual]

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