Tensioning Headstock Height Chain; Adjusting Cutterhead Parallelism - Grizzly G0890 Owner's Manual

Tensioning Headstock
Height Chain
The headstock height chain transfers movement
from the elevation handwheel to the columns that
control headstock height. The chain drive can be
adjusted to remove slack if the chain stretches
over time or is loosened during headstock leveling
procedures.
Items Needed
Hex Wrench 5mm .............................................. 1
Wrench or Socket 12mm ................................... 1
To adjust headstock height chain tension:
1.
DISCONNECT MACHINE FROM POWER!
2.
Remove motor access panel to access head-
stock height chain (see Figure 51).
3.
Loosen the two chain tension lock bolts, then
push idler sprocket against chain with mod-
erate pressure to eliminate slack in chain.
While maintaining pressure on idler sprocket,
re-tighten lock bolts (see Figure 51).
Idler
Sprocket
Lock Bolts
Figure 51. Headstock height chain adjustment.
4. Clean and lubricate chain and sprockets (refer
to Headstock Height Chain & Sprockets on
Page 34 for detailed instructions), then re-
install motor access panel.
NOTICE
DO NOT let chain fall off sprockets. It can
be very difficult to return chain to its proper
location on sprockets without changing
table adjustments.
G0890/G0891 (Mfd. Since 06/19)
Adjusting Cutterhead
Maximum Allowable Tolerances:
Cutterhead/Table Side-to-Side .................. 0.002"
Head Casting/Table Front/Back ................ 0.020"
Cutterhead parallelism is critical to the operation
of the machine. As such, it is essential that the
Cutterhead is parallel with the table (within 0.002")
Qty from side-to-side, as illustrated in Figure 52.
Parallel
NOT Parallel
Figure 52. Side-to-side parallelism of table and
How the table sits in relation to the head casting
from front-to-back is also important (see Figure
53). Because the feed rollers and chip breaker will
be adjusted off the table position, the tolerances
on the front-to-back positioning are not as critical
as the cutterhead/table side-to-side positioning.
Therefore, the maximum allowable tolerance for
the front-to-back parallelism is not more than
0.020".
Parallel
NOT Parallel
Figure 53. Front-to-back parallelism of table and
Parallelism
SIDE-TO-SIDE
(Front View)
Cutterhead
Parallel
Table
Cutterhead
NOT Parallel
Table
cutterhead.
FRONT-TO-BACK
(Side View)
Head
Parallel
Table
Head
NOT Parallel
Table
cutterhead.
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