PlaneWave Instruments HEDRICK FOCUSER User manual

HEDRICK FOCUSER
TROUBLESHOOTING GUIDE

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HEDRICK FOCUSER TROUBLESHOOTING GUIDE
OVERVIEW AND TABLE OF CONTENTS
Through a variety of factors, there may be times when the focuser does not respond to move commands. These factors will relate to either software and controller settings, or
to mechanical adjustments that are needed. If the focuser stops very suddenly or does not
move at all, this may indicate a software or controller issue. If the focuser stops gradually,
makes a grinding / struggling sound, or moves only a small amount, this likely indicates
a mechanical issue.
SOFTWARE & ELECTRONICS Page 3
CABLE CONNECTIONS Page 4
HARD-STOP ADJUSTMENTS Page 5
PRELOAD BLOCK ADJUSTMENTS Page 6
LESS COMMON ISSUES Page 7

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Software issues can usually be solved just
by resetting the Home position. Using the
PWI software:
1) From the Focuser tab press the Con-
fi g button to bring up the Confi guration
screen.
2) Select Hedrick Focuser from the drop
down list and press the Focuser Confi g
button.
3) Press the Default button to return all
settings to their defaults then press Save.
4) Under the Focuser tab, hold down the IN
button until the focuser is at its innermost
position. When the focuser reaches the in-
nermost mechanical position, the position
reported by the software should be close
to 0 (within a few hundred microns).
5) If the reported position is much diff erent
from 0, press the Home button on the Fo-
cuser tab. This will send the focuser all the
way in to its inner hardstop, and then reset
the reported position to 0.
IMPORTANT:
If you are unable to move the focuser
through PWI3, check to see if the hand
controller is plugged into the EFA. If it is,
unplug it from the EFA box and try again. In
rare cases, a hand controller may develop
a problem that prevents PWI3 from con-
trolling the focuser.
If that does not help, try unplugging the
PC cable from the EFA and plug the hand
controller into the H/C port. Try moving
the focuser using the hand controller. If it
works in this confi guration, this could indi-
cate a problem with the cabling between
the computer and the EFA, a problem with
the EFA box, or a problem with the PWI3
software itself.
SOFTWARE & ELECTRONICS

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HEDRICK FOCUSER TROUBLESHOOTING GUIDE
CABLE CONNECTIONS
If the focuser still does not appear to move
with either PWI3 or the hand controller,
take a look at the cabling between the EFA
and the focuser. The type of cabling will de-
pend on when the focuser was purchased:
For Hedrick focusers shipped before Feb-
ruary 2015 (with an exposed motor), there
should be a cable that plugs into the Focus
port on the EFA on one end, and plugs into
the motor in two places on the other end.
Check all of these connections. On the mo-
tor end, the 4-pin blue plug should be se-
curely connected to the back of the motor,
and the 2-pin white plug should be secure-
ly plugged into the corresponding plug.
For Hedrick focusers shipped after Feb-
ruary 2015 (with an enclosure around the
motor), an Ethernet-style cable runs be-
tween the port labeled “EFA” on the Hed-
rick focuser and the port labeled Focus on
the EFA box. PlaneWave ships black cables
with blue strain relief boots on either end.
These are special “low-noise” cables made
by PlaneWave to improve motor perfor-
mance. If this cable has developed a prob-
lem, you can temporarily use a short (6ft
or shorter) Ethernet cable between the EFA
and the focuser. If this solves the problem,
contact PlaneWave Instruments for a re-
placement low-noise cable.

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HARD-STOP ADJUSTMENTS
If a mechanical issue is suspected, fi rst try
unscrewing the two hardstop set screws a
small amount (maybe 1/4 to 1/2 a turn).
See the picture, to the right.
In addition to the set screw indicated in the
picture, there is a second set screw on the
opposite side of the focuser.
When the focuser tube is racked out the
full 1.3 inches, these set screws make con-
tact with a ledge on the moving tube to
prevent the focuser from coming out any
farther. If these screws are a bit too tight,
they could be rubbing against the draw-
tube and causing things to bind up prema-
turely.
CAUTION:
Do not to remove or loosen these screws
too much, or the focuser may be pre-
vented from safely coming to a stop
when it is racked all the way out.
For best performance, tighten the screws
until you just start to feel them bottom out,
and then unscrew them by ½ turn. If you
have access to Loctite, try adding a drop to
each set screw before setting them in the
“1/2 turn out” position so that they do not
move in the future.

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HEDRICK FOCUSER TROUBLESHOOTING GUIDE
PRELOAD BLOCK ADJUSTMENTS
If after adjusting the hard-stops, the focus-
er still seems to be binding, you should try
loosening the preload block, pictured to
the right.
1) Start by marking the position of each
screw using a Sharpie marker so that you
can always return to screws back to their
original tension.
2) Next, try loosening each screw just a bit;
(1/8 of a turn or less).
3) Using the hand-controller or software,
command the focuser to move, in order to
check if the adjustment was correct.
4) If that doesn’t seem to help, try loosen-
ing the screws a little bit more, and re-test.
IMPORTANT:
Note that if you loosen things too much,
the sliding focuser tube will be able to
wobble freely and your imaging equip-
ment will not be held fi rmly in place!
5) If these adjustments do not seem to
help, tighten the screws back down to their
original positions.

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LESS COMMON ISSUES
Symptom: The focuser does not respond
when the Up/Down hand control buttons
are pressed.
Solution: This can be caused by either a
defective cable or a problem with the elec-
tronics on the EFA control box.
1) Check the cable by plugging the focuser
cable into the EFA port labeled “Rotate”.
2) Now use the left/right buttons on the
hand control to see if you can control the
travel on the focuser.
If the focuser is now responding properly,
then most likely the Focuser port on the
EFA box is defective ad will require repair.
However, if the focuser is still not function-
ing then the cable should be replaced, and
this test should be run again.
Symptom: Once the focuser starts moving
it will not stop until it hits a hard stop.
Solution: This generally means that the
motor has stopped communicating with
the encoder on the motor. This is usually
caused by a loose connection between the
focuser cable and the motor.
Check the connection of the blue connec-
tor on the motor encoder and make sure
that it is well seated on the pins on the en-
coder, pictured to the above-right.
For some focusers it may be necessary to
remove the cover plate in order to access
the cable connector.
For additional help:
If none of the suggestions in this trouble-
shooting guide are succesful in restoring
normal operation of your focuser, please
contact PlaneWave support for additional
suggestions or assistance, at (310) 639-
1662 or [email protected]. We are
normally reachable between 9AM and
5PM, Pacifi c Time, Monday through Friday.

PLANEWAVE.COM - 1819 KONA DR. RANCHO DOMINGUEZ, CA 90220 - 310-639-1662