HP 5528A User Manual page 161

Model 5528A
Straightness Measurements (Along A Hori zontal Axis)
10-6
Procedure
NOTE
Use o f the Gunsight A lignment method is described In the
following procedure. Once you become familiar enough with
alignment principles, you may wa nt to start with "Au tore-
flection" (d escribed in Section 15).
1. Move the machine's tab le (if it moves) as d ose as possibl e to the laser Head.
Move the mach ine's spindle (if it moves )
iIS
I~r ~
possible
away from the laser Head .
Note that the " moveable" part of the machine may depend on the ax is you are measuring.
That is, th e
"X
"-axis moveabl e pari may not necessaril y also be the " Y"_axis or "Z"-axis
moveable part.
Thi s wi ll keep the ma chine fro m hitting the laser Head during a measurement and w ill help
establish the "near-end-of-travel".
2. Visua lly ali gn the laser Head as well as you ca n parallel
10
the direction o f travel and position
it at an appropriate heigh t. Some things to cons ider
are-
• Posi tion for an axis appropriate for what you want to acco mplish (review Section 4's
mat erial on this).
• If
you think you wil l be making
a
Distan ceor Angular measurement later, establish a
measurement axis at
II
height above the table Ihal will allow easy interchanging o f
Ih e Optics . To do this, mou nt the Straightness Reflector as shown in Figure 10-4,
and keep the Reflector as low as poss ible o n its lJase, without covering up the hole
in the Reflector Mount's Post. Then position the laser Head so its beam strikes the
cent er of the slot.
• Use " Autoreflection" to help you do this once you become proficient at laser
System measuremen ts. If you usc " Au lorefleclion " you won', have to do any
further alignment. you'll only need to check for beam strength (and remove slope,
if you don 't usc the HP Dimensional Metrology Analysis Syslem).
3. Decide where you will position the Op ti cs so that:
• The Interferometer is between the Reflector and the laser Head. (Alsosee" OTHER
MOUNTING REQU IREMENTS", below.)
• The Interfe rome te r
is
whe re the tool mounts.
• The Reflector
is
where the workpiece mounts.
• The Optics are at the " near end o f travel". (This meanslhat any subsequent motion
of Ihe machin e wi ll sepa rate th e optics further rather th an bring them closer
togcther.) (See Figure 10-2. )
For Short range measureme nt s thiS should be about 100 mm (4 in ches ).
For long ran ge measurements Ih is shou ld be abo ul 900 mm (3 fee t).