§4.3,Test the Drive System, continued:
carriage moves consistently and smoothly when you turn the winches by hand, it will
also move consistently and smoothly under computer control. On the other hand, if the
winches or carriage cannot be moved by hand, then the motors on the WaterColorBot
will not be able to move them either. (And, it is much better to discover issues here in the
setup process than in the middle of a painting.)
Here are some additional things to watch for during the prefl ight:
• Make sure that the four rod-end sliders ride in their grooves.
• Make sure that the two rods are “square” to the frame. You can check this with the
carriage in the home corner: All four rod-end sliders should rest against their endstops.
• Watch for “slop” in the motion: Extra slack in the Spectra cord can cause the cord to
droop as the winches turn, with a corresponding loss of precision.
If you encounter any issues during the prefl ight, please see §6, Maintenance and Trou-
bleshooting.
Before running the WaterColorBot, always position the carriage in the aptly-named
START (Home Corner) position: As far to the left, and as far back as it will go.
When automatically painting, the carriage will normally return to this position when the
painting is complete, leaving it ready for the next painting. In some cases, you may need
to use the “Park” (AKA “Move Home”) command to send the carriage back to its home
position.
If you need to move the carriage by hand (for example, before your fi rst painting), make
sure to turn off the motors fi rst, so that you are not forcing them under power. You can
either physically unplug the WaterColorBot from power or use software to turn off only
the motors. (The software command to do so may read as “unlock motors” or “turn off
motors.”)
5.1 The Home Corner
The “spoilboard” is the lower deck of the WaterColorBot, which holds the paint palette,
water dishes, and the paper.
The standard-issue spoilboard is made of MDF (fi berboard), and is designed to hold paper
with one or more clips. It has engraved marks to help you center the paper.
The paint set indexes into the long slot.
When using the standard Crayola paint set, ori-
ent black at the top and brown at the bottom.
There are 3 round recesses, to fi t the little wa-
ter dishes. Always install all 3 dishes. The water
dishes are the lids (the shallow, larger diame-
ter halves) of the plastic petri dishes. They are
made of washable plastic.
The small plastic beaker is also made of wash-
able plastic. It has three little spouts, and is
very helpful for pouring water into the dishes.
When you pour water into the dishes, fi ll them
only about halfway, to help avoid splashing and
spilling.
The paper is normally held in place by a sin-
gle binder clip in the center. You can also hold
down the paper by other traditional means,
such as with masking tape.
An extra clip and screw (#10 from §1.1) are
provided in case you would prefer to hold down
your paper with clips in the left and right po-
sitions instead of center. (That gives more “ri-
gidity,” but it is harder to insert and remove the
paper.)
5.2 The Spoilboard
Part 5:
Basics of Using the WaterColorBot
