Bring the EggBot into the “Pen up” state, with the other
motors (egg and pen) off. The best way to do this is by
using Eggbot Control, from the “Setup” tab (as in §3.3),
but with the “Raise pen, turn off motors” action selected.
(Another method is from the “Manual” tab, where the
pop-up menu has a “Raise the pen” option.)
Insert a pen into the holder, and lock it in place with the
nylon thumbscrew. Lower the pen until it is just above
the surface. You can do so with the nylon thumbscrew
that holds the pen, with the brass Pen height thumb-
screw, or with some combination of the two (
A
,
B
).
Again, the goal is that when the pen arm lowers, and the
egg is drawing on the egg, that the arm is dead horizontal.
Viewed from the tailstock end, the tip of the pen should
point directly down towards the center line when the pen
is down. If necessary, you can move the pen arm towards
or away from the pen motor by loosening the set screw
on the pen motor shaft (
C
).
4.5 Inserting a pen, and checking alignment
A
B
The final “preflight” check is to manually
move the pen arm over the entire range of
the printable surface (
D
).
As you do so, check for several things:
1) Make sure that the pen arm has unimped-
ed movement over the full range.
2) Make sure that the servo cable moves
freely over the full range.
3) Make sure that the pen tip has a fairly
consistent height above the surface, over
the entire range of travel, like so (
E
):
If it does not, you may need to fine tune the alignment:
C
D
Move pen arm closer
to tailstock §4.3
Move pen arm closer
to headstock §4.3
Lower pen motor
vertically §4.4
Raise pen motor
vertically §4.4
E
