PlaneWave L-350 User manual

L-350
MECHANICAL INSTALLATION GUIDE

2
L-350 MECHANICAL INSTALLATION GUIDE
TABLE OF CONTENTS
TOPIC PAGE(S)
TABLE OF CONTENTS 2
SYSTEM DIAGRAMS 3-5
INTRODUCTION 6
RANGE OF MOTION 7
UNPACKING 8-13
PREPARING FOR INSTALLATION 14-17
MOUNTING DRIVE-BASE TO PIER 18
INSTALLING EQ WEDGE 19
ATTACHING DRIVE-BASE TO EQ WEDGE 20
INSTALLING FORK-ARM 21
MOUNTING THE SADDLE 22
PREPARING THE OTA 23
PREPARING SADDLE FOR OTA 24
POSITIONING THE OTA 25
SECURING THE OTA 26
INSTALLING OPTIONAL 2ND SADDLE 27
BALANCING ALTITUDE/DEC 28
BALANCING AZIMUTH/RA 29
POWER/COM CABLING FOR THE MOUNT 30
CABLE ROUTING FOR ACCESSORIES & INSTRUMENTS 31

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SYSTEM DIAGRAMS 1
SIDE-VIEW (OUTSIDE OF FORK-ARM)

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L-350 MECHANICAL INSTALLATION GUIDE
SYSTEM DIAGRAMS 2
SIDE-VIEW (INSIDE OF FORK-ARM)

5
SYSTEM DIAGRAMS 3
REAR AND OVERHEAD VIEWS

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L-350 MECHANICAL INSTALLATION GUIDE
INTRODUCTION
Direct-drive motion systems oer a number of
advantages over the more traditional systems
used in astronomy:
1) Direct-drive systems do not use gears:
Traditional, gear-based motion systems can
only move as precisely as their gears are cut.
Surface imperfections in gears inevitably result
in periodic tracking-errors.
Gears require lubrication, and consequently re-
quire routine cleaning and relubrication. This
is exacerbated in dusty environments, where
lubrication rapidly contaminates.
2) Without gears, there is no PE:
Direct-drive systems are eectively free of pe-
riodic error.
To be completely accurate, there is a small
amount of periodic error in the motion of
each of the individual bearings in the system.
However, due the number of bearings in each
assembly, there is negligible eect to motion
of the total system. Additionally, each axis is
equipped with high-resolution encoders read-
ing at 8Mhz, that are more than capable of de-
tecting miniscule deviations from the proper
tracking-rate.
3) Lower hysteresis:
Mechanical hysteresis (the dierence between
where something was, when measured, and
where it is now) is greatly reduced in a system
that does not use gears. Remember all of that
advice about how to properly balance by being
out of balance, to keep gears engaged? None
of that applies to direct-drive, and tracking is
equally good on both sides of the meridian.
Total hysteresis of the L-Series mount is further
reduced by the use of high-resolution encoders
(18.8M counts/axis, 0.069 arc-second/count).
These on-axis encoders allow the control-elec-
tronics to know precisely where the mount is
pointed, more than 100 times per second. No
auto-guider provides that volume of feedback.
4) Faster response:
Not only are the L-Series drives capable of far
greater rates of speed, their response-times
are also much faster. Consider all of the sourc-
es of backlash in a traditional system (plane-
tary-gears, elasticity in belts, and the worm/
worm-gear interface itself), and know they are
not present with direct-drive. As soon as an
L-series motor moves, your telescope moves.

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RANGE OF MOTION
L-350 mounts oer +/- 350 degrees of rota-
tion in the Azimuth/RA axis, measured from
the “No Wrap” position. The proper “No Wrap”
position is found by aligning the related marks
on the drive-base section of the mount (due
the +/- 350 degree motion, these marks only
line up at the correct position).
The Altitude/DEC axis has a xed limit at the
zenith (Alt-Az) or pole (EQ). The lower limit is
located 45 degrees below the horizon when in
Alt-Az conguration, and 45-degrees below
the celestial equator when in mounted on an
equatorial wedge.

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L-350 MECHANICAL INSTALLATION GUIDE
UNPACKING
Safely unpacking your L-350 mount will require
at least 2 people capable of comfortably lifting
60 pounds or more, if you prefer to leave the
unit fully assembled. One person can unpack
the L-350 by removing the fork-arm from the
base motor and moving them separately.
When using a crane/fork-lift or 2(+) people
for unpacking and lifting:
- All steps relating to disassembly of the mount
should be skipped. The L-series mounts are
capable of being lifted while fully-assembled
(refer to “lifting points” section of this manual,
below).
- Proceed to the “Remove the Drive-Base” seg-
ment of this section, below, and uncouple the
mount from the crate. The mount will then be
ready for lifting.
Required tools/supplies:
- Drill/driver, for removal of crate’s wood-
screws
- SAE Hex-Key Set
Opening the crate:
- Begin by nding the “front” panel of the
crate, which will be marked, by removing the
wood-screws attaching it to the bottom, top,
and side panels.
- Remove the front-panel.
- Next, remove the woodscrews that attach the
remaining 3 wall-panels to the bottom.
- Finally, slide the side/top panels (still assem-
bled) o of the bottom of the crate.

9
Removing the fork-arm:
To simplify packaging, your mount has been
shipped with the drive-base and fork attached.
While it is possible to lift the system in this as-
sembled state with a fork-lift, crane or multi-
ple people, we highly recommend that the two
assemblies are separated if only one person is
lifting..
1) Begin by detaching the cables within the
main cavity of the fork arm. These will include
all of the cables plugged into the main elec-
tronics panel (USB, encoder signal cable, and
base-motor power), shown in the top-right
photograph.
2) The power cable should also be detached
from the power input panel, shown in the mid-
dle-right photograph.
3) The cables that have been detached should
now be carefully fed into the base-motor’s
passthrough, so that the will not be caught or
pulled when the fork-arm is removed from the
base-motor.

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L350 MECHANICAL INSTALLATION GUIDE
4) Before removing any of the bolts securing
the fork-arm to the base-motor: A) be sure that
the Azimuth/RA locking knob is engaged, and
B) it is helpful to make a reference mark for
later realignment of the two assemblies. Both
are shown in the top-right image.
5) Now the bolts holding the fork-arm to the
base-motor can be removed. There are a to-
tal of 6, at evenly spaced intervals, around the
upper perimeter of the base-motor. For refer-
ence, 4 of the 6 are shown in the highlighted
part of the drawing to the middle-right.
Be careful not to bump or jostle the mount
while these bolts are removed. The fork-arm is
still being held in place by two shoulder-bolts,
but can be knocked over if one is careless.
6) Before lifting the fork-arm, it is recommend-
ed that you place something on the ground,
nearby, onto which the fork can be set without
being scratched. This could be a tarp, old blan-
ket, sheet of cardboard, or even the front-pan-
el of your crate.
7) See “lifting points” under the Installation
chapter.
8) Stand on the fork-arm side of the mount,
and slide the fork-arm laterally so that fork-
tine moves closer to the base-motor’s center
of rotation. This is shown in the image to the
bottom-right.

11
8) The fork-arm is now ready to be lifted from
the drive-base. With a good grip on the fork-
arm’s handles, begin tipping the fork-tine to-
ward you (you should still be standing on the
fork-tine side of the mount), as shown to the
right.
9) It should now be possible to lift the fork-arm
away from the base-motor. Do so carefully, to
be sure that none of the cables you addressed
previously are snagged or pinched.
10) Lift the fork-arm away from the drive-base
and set it on the surface you just prepared. You
should allow the long-side of the “L” to rest on
the ground, as it is otherwise possible for the
fork-arm to tip over.

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L-350 MECHANICAL INSTALLATION GUIDE
Removing the Drive-Base:
1) Remove the 6 bolts from the lower perime-
ter of the drive-base, which are currently secur-
ing the drive-base to the bottom of the crate.
The motor ange through which the anchor
bolts are attached is highlighted in the model
to the right.
2) Verify installation and proper tightening
of the Azimuth/RA axis locking-knob (shown
in System Diagram 2, at the beginning of the
manual, and the model to the right). Not doing
so will allow the lifting surface (black-anodized
mounting plate for the fork-arm) to rotate, and
may make it dicult to lift and maneuver the
drive-base.
3) Ensure that the cables which connect the
drive-base electronics/motor to the main elec-
tronics in the fork-arm are safely-positioned,
and not at risk of being snagged or sheared.
4) The drive-base is now ready for remov-
al from the crate’s mounting-plate. However,
there is no need to lift it until the pier or op-
tional wedge are ready to receive the drive-
base.
Dovetails / other accessories:
The dovetail saddle and other accessories may
be packed within boxes mounted to the oor
of the crate. Be sure to open any boxes and
inventory the contents.

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Unpacking the optional EQ Wedge:
The optional equatorial wedge is fully assem-
bled for shipment. Unpack and separate the
sub-assemblies and move them near your pier.
The EQ wedge weighs approximately 100
pounds. While it may be possible for it to be
moved while fully assembled, the unit will need
to be disassembled to be installed.
The wedge is comprised of three major sub-as-
semblies: the angled wedge section, the upper
mounting plate (attaches the wedge to lower
mounting plate), and the lower mounting plate
(attaches upper mounting plate to pier)
1) Remove the altitude-adjustment bolts on
the north and south side of the wedge, and re-
move the wedge section.
2) Remove the bolts that secure the un-anod-
ized rotation-hub (located around the center
of the upper mounting plate), and remove the
hub from the center-holes of the two plates.
3) Remove the six bolts that join the perimeter
of the upper and lower mounting plates, and
remove the upper mounting plate.
Installation will be addressed below, and
should be completed prior to re-assembling
the mount after its unpacking.
Important note on the gear-ratio of the L-350
wedge:
- Altitude Adjustment is 0.55 degrees/turn
- Azimuth Adjustment is 0.41 degrees/turn

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L-350 MECHANICAL INSTALLATION GUIDE
PREPARING FOR INSTALLATION
Necessary tools, equipment and people:
- SAE Hex wrenches / T-handle wrenches with
key sizes up to 3/8”. Almost all of the fasteners
you will have need to remove, install, or adjust
will require these hex-keys.
- An SAE socket-wrench set, with several inches
of extension length is required for adjustment
of the RA/Azimuth balancing mechanism.
- At least 2 people able to lift 60 pounds
comfortably. Please consider the component
weights (below) and the weight of your tele-
scope (possiblly with instrumentation attached)
before assembling your team. It is important to
note the orientation in which the telescope will
be loaded, as it is
Alternatively, a crane or fork-lift may be used
to lift and place the mount, depending upon
accessibility of the observatory and pier to
such equipment.
Component weights:
L-350 System: 110 LBS
L-350 Fork-Arm: 70 LBS
L-350 Base-Motor: 40LBS
EQ Wedge (Optional): 100 LBS

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Lifting points for people:
Your L-350 mount should not be lifted by one
person when fully-assembled. It is reason-
ably lifted by two people, if the 110LB sys-
tem-weight is accabltable.
Lifting the full-system:
With two people lifting, each person can grip
one of the handles on the fork-arm, placing
their other hand underneath the lower sectrion
of the base-motor. The image to the top-right
shows an L-500 being lifted in a similar fashion.
Lifting the system in parts:
Fork-arm:
The black handles on the fork-arm assembly
are excellent lifting points for that segment of
the mount. When being lifted by two people,
each should grab a handle, using their other
hand to support the bottom of the shorter
length of the “L”.
Do not lift by the access-panel cover handles!
Drive-base:
There are no handles available to lift the drive-
base. Instead, the black-anodized mount-
ing-plate that attaches to the fork-arm assem-
bly should be used to lift. It is a good idea to
conrm that the Azimuth lock is properly en-
gaged before lifting the motor.

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L-350 MECHANICAL INSTALLATION GUIDE
Liting Points for crane/lift:
Nylon straps should be used to make lifting
contact with the mount, when a crane, fork-lift,
or other mechanical lift is used.
For Alt-Az installation:
Use a single strap, looped through the Alti-
tude-Axis pass-through. This can only be done
when the saddle-plate is not installed.
For EQ installation:
Use two straps to hold from both the DEC-axis
pass-through and around the top of the drive
base. When wrapping the strap around the
drive-base, have it extend toward the lift on
the side of the drive-base that is opposite the
fork-arm, and wrapped at least once around
the side of the drive-base adjacent to the fork-
arm.
The relative lengths of these straps should be
adjusted so that the mount becomes suspend-
ed at an angle approximately equal to the incli-
nation of the wedge’s mounting surface, sim-
plifying the process of bolting the drive-base
onto the wedge.

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Hole pattern and pier-interface advice:
In drawing to the right, the interface pattern is
described as a 12” bolt circle, with 60-degree
separation between holes. These holes should
be tapped through with 3/8-16 threads. The
mounting surface should be oriented so that
North/South align at the midpoint between
holes in the pattern, and so that there are bolt-
holes directly aligning to East and West.
The interface between the pier and drive-base
(or equatorial wedge, using the same pattern)
should follow one of two approaches:
1) Metal piers or extensions should
have their top-plates machined so as to oer
threaded-holes that correspond to the drive-
base’s hole-pattern.
2) Concrete piers should use an inter-
mediary interface-plate. This plate will have
threaded-holes matching the drive-base’s
hole-pattern, and then a secondary pattern
meant to accept the anchor-bolts placed in the
concrete.
While it is possible to place the anchors in
the concrete so as to match the drive-base’s
hole-pattern (oering threaded rod that would
pass through the lower-ange of the drive-
base’s perimeter), the tolerances involved will
make this dicult and mistakes will be dicult
to x.
The top-plate of the metal-pier or inter-
face-plate mounted to the concrete-pier needs
to be level while rmly secured to the retain-
ing-bolts in the concrete. This should not occur
through stacking washers, as increased separa-
tion of these contact surfaces risks loss of the
rigidity your pier-anchoring should provide.

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L-350 MECHANICAL INSTALLATION GUIDE
MOUNTING DRIVE-BASE TO PIER
Mounting (Alt-Az-specic concerns):
Leveling:
L-series mounts are fully capable of operating
in Alt-Az when not well leveled. However, the
drive-base being o level will result in the fol-
lowing challenges (which increase with the ex-
tent to which it is o level):
- Pointing and tracking, prior to building a
model, will be incorrect and complicate the
process of building an initial model.
- Balancing in Azimuth becomes more critical,
to prevent this axis from wanting to rotate.
Leveling should ideally be achieved through
proper construction of the pier, not through
uneven elevation of the drive-base over a
non-level mounting surface.
Orientation of NoWrap position:
Please note that accuracy of the NoWrap posi-
tion to the cardinal directions noted below will
eect tracking, prior to building a model. The
L-350’s NoWrap marker is a notch in the base-
ange, adjacent to the Azimuth Lock (visible in
the models on page 12).
Northern-hemisphere:
The “NoWrap” mark on the Aziuth-Motor/Base
should face true-south.
Southern-hemisphere:
The “NoWrap” mark on the Aziuth-Motor/Base
should face true-north.
Before beginning, be sure that cable-routing
has been addressed. The power and communi-
cation (USB/Ethernet) cables are meant to exit
through the bottom-center of the drive-base.
If a metal pier or extension is being used, it
should have holes available for both entry and
exit of these cables.
If a concrete pier is being used, it should have
had a conduit placed at its top-center (exiting
out some position on the side of the pier) or a
channel in the top (from center to edge) allow-
ing the drive-base to sit rmly and ush on the
pier without interference from the cabling.
Installing the base motor onto the pier:
1) Lift the drive-base onto the pier (or interface
plate), making sure that the “No-Wrap” marker
is correctly oriented (see above), and that ca-
bles are properly routed into/over the pier.
2) Secure the drive-base, inserting the bolts
through the hole-pattern around its bottom
ange and lightly tightening them. To ensure
that all go in easily, wait until all are engaged
before fully tightening any of the bolts.

19
INSTALLING EQ WEDGE
Leveling:
Leveling of the wedge, while not critical to
the system’s operation, needs to be reason-
ably close to ensure polar-alignment can be
reached. This is particularly important if your
observatory is at a latitude that is near either
limit of your wedge.
Leveling should be achieved through prop-
er construction of the pier, not through un-
even elevation of the equatorial-wedge over a
non-level mounting surface.
Installing the wedge:
The L-Series equatorial wedge should be as-
sembled on the pier, to prevent its full weight
from needing to be lifted.
1) Begin by bolting the lower mounting plate
onto the mounting surface of your pier. In the
northern-hemisphere, the azimuth adjust-
ment-mechanism will be on the south side of
the pier. In the southern-hemisphere, the ad-
justment mechanism will be on the north side
of the pier.
2) Place the upper mounting plate onto the
lower mounting plate, and slide the azi-
muth-adjustment tab into the azimuth-adjust-
ment mechanism.
3) Locate the azimuth-rotation hub and apply
a small amount of grease, to prevent galling
or unnecessary resistance to motion in the
wedge’s azimuth axis.
4) Insert the hub through the top-plate, so that
it extends into the base-plate, and then bolt it
onto the top-plate.
5) Now, attach the top-plate to the base-plate
with the 6 bolts passing through the top-plates
slotted pattern.
6) Now lift the wedge assembly onto the as-
sembled base/top plates, and set the rock-
er-pins into the corresponding detents in the
upper surface of the top-plate.
7) Finally, secure the upper wedge assembly to
the top-plate using the 2 altitude-adjustment
bolts. These should be fully tightened prior to
installation of any part of the mount.
TIP:
Before installing the base-motor assembly, it is
helpful to intentionally set the wedge too high
in elevation, so that the resulting polar-align-
ment correction will be in the direction of grav-
ity.

20
L-350 MECHANICAL INSTALLATION GUIDE
DRIVE-BASE ATTACHMENT TO WEDGE
1) While ensuring that power and signal ca-
bles (stashed in the motor-passtrough earlier
in dissassembly) are safely out of the way, ip
the drive-base over, so that its lowest surface
is facing up.
2) You will now be able to see a bolt-hole near
the perimeter of the drive-base’s bottom that is
non-symmetrical with the rest of the hole-pat-
tern and is threaded (the location is shown in
the model to the right). Insert and tighten the
wedge-mounting shoulder-bolt into this hole.
It is an important part of positioning the drive-
base on the wedge.
3) Lift the drive-base onto the wedge, oriented
so that the shoulder-bolt that was just installed
settles into the notch at the top of the wedge.
(bottom image, right)
4) Now, shift the drive-base, as needed, to line
up the pass-through holes in the drive-base
with the corresponding threaded-holes in the
wedge.
5) Beginning with the pair of holes nearest the
top of the wedge, begin inserting and thread-
ing the bolts. To ensure that all go in easily,
wait until all are engaged before fully tighten-
ing them.