Servo Chatter Long Strokes

mapengineer

When drawing long strokes I have a significant amount of chatter from the servos which results in a wave being drawn on the lines. The writing/drawing speed is set to 25% with a motor resolution of "normal". Is this normal?

Windell Oskay

I have never seen a case where servo chatter influenced the lines being drawn-- the servo horn should not be in contact with the vertical slide when the pen is down. If the horn is touching the vertical slide while the pen is down, then you should select a lower position for the pen-down position.

That said, 25% speed at the low resolution setting is relatively fast, and you should expect to see some wiggling of the lines, regardless of the pen height. We normally only use this kind of speed or faster with broad felt-tip pens. There is always a tradeoff between speed and precision-- you may prefer to go slower for higher quality.  Another thing to consider, if only long strokes are causing problems, is to use the "constant speed" option, which turns off the acceleration. That will slow down the speed on long paths, and move faster on short paths, in comparison with the default behavior.

mapengineer

Windell, I've looked to ensure the horn is clear when in the drawing position and redrew the file with constant speed and it seemed to help. I should clarify chatter, when the pen is raised and the carriage is traveling along the X or Y axis between objects this chatter is almost like the belt skipping the gear or biding. I'm attaching a link to video as I may not be accurately describing the issue. https://vimeo.com/172899429

Windell Oskay

Yup, that sounds awful! My guess is that something in the XY motion control system was genuinely broken in shipping. It looks like you've followed up with us directly by e-mail, so we'll follow up with you there.