Difference between revisions of "Eggbot Troubleshooting"

:If, when you start a plot, the pen arm swings to one extreme end or the other of your egg and stays there, then you may need to adjust the current to your stepper motors.  See [[Eggbot Troubleshooting|stairsteps]] for help on adjusting the stepper motor current.

:It is also possible that you are plotting a drawing whose vertical drawing coordinates are outside of the expected coordinate range for y-coordinate values.  Check to make sure that your Inkscape drawing page does not have an excessive height via the "Document Properties" item of the File menu.  A drawing height in excess of 1000 pixels is suspect.  Even heights of 1000 pixels or less still may require care in framing.  See [[[framing and pen centering]] for assistance with framing.  Also, make sure that you are using v2.1 or later of the Eggbot Control extension.  It supports arbitrary y-coordinate range offsets.  With v2.0 and earlier, the y-coordinate values could not stray far outside of the range [0, 1000] (i.e., couldn't be offset too far from y=500).

If your text appears "mirrored" (e.g., inverted from left to right) then first check the assembly directions to ensure that you have wired the egg motor correctly.  Check that the ordering of the colored wires matches the picture.  if they do not, then correct their ordering and try replotting.  If you are sure that they are wired correctly then everything is still okay: some stepper motors are just backwards.  From the Eggbot Control extension, check (or uncheck) the "Reverse motion of Motor 2 (egg)" checkbox on the "Options" tab.  Then click the "Apply" button.  Then plot your test again.  If things are still reversed, then make sure that your change to the setting took effect.  If there is still an issue, then perhaps you need to instead or also change the "Reverse motion of Motor 1 (pen)" setting. Note that after doing an upgrade of the Eggbot extensions, it is possible for this setting to get lost.  In that case, simply set it again and save it with the Apply button.

Is your text plotting upside down?  First, let us be clear: the (vertical) top of your Inkscape drawing should correspond to the pole of your egg closest to the egg motor.  That is the end of your egg closest to the Eggbot's headstock.  With this orientation in mind, if your text is plotting upside down then change the "Reverse direction of Motor 1 (egg)" setting.  This setting is under the "Options" tab of the Eggbot Control extension.  After changing the setting, click the Apply button to save your setting.  Note that after doing an upgrade of the Eggbot extensions, it is possible for this setting to get lost.  In that case, simply set it again and save it with the Apply button.</div>

Are your circles or other figures looking squashed?  This can be expected once you realize that the Eggbot doesn't attempt to do any special transformations on your drawings when it plots them.  As such there's two immediate sources of distortion when plotting your drawings.  First, the horizontal component of line segments become physically shorter as they approach either pole of your drawing object.  This is a consequence of the diminishing circumference of circles of latitude with increasing latitude (i.e., decreasing distance from either pole).  A second effect comes into play when plotting on non-spherical objects such as eggs.  Eggs are longer in one dimension than the other.  Typically longer from pole to pole than they are wide.  This means that a single step of the pen arm produces a longer stroke than a single step of the egg motor. As such, a vertical line in your Inkscape drawing can produce a longer stroke than a horizontal line of the same length, even at the egg's equator.

:To counter this effect, you can try horizontally stretching your drawing by upwards of 150%.  To do this

:When the ends of figures do not line up, this strongly suggests an alignment or slippage problem with how your egg has been secured into the Eggbot chassis.  To check the alignment, rotate your egg with the motors disengaged and see if there is any perceptible wobble.  Sometimes it helps to life the Eggbot up and sigh down the long axis of the egg as you turn it.  As regards slippage, the egg needs to be held in tightly by the tailstock spring.  That spring should be compressed around two-thirds or more (but not fully compressed).  See [[Improving precision|improving precision]] for many more tips on improving your plots.

:If you are having difficulty with framing or centering, see [[framing and pen centering]].

:On Macs, if your "Paste" or "Paste in Place" operations are resulting in bitmaps being imported into your Inkscape drawing, then you need to change your X11 preferences.  X11 is the windowing system which Inkscape runs to manage its windows.  If you click on any running Inkscape window, you will see in the Apple menu bar along the top of your screen the menu item "X11" just to the right of the Apple-icon menu item. Click on the X11 menu and select the "Preferences..." item.  In the resulting popup "X11 Preferences" window, select the "Pasteboard" tab.  In the resulting option set, unset the item "Update Pasteboard when CLIPBOARD changes".