T1227/28/29 Magnetic Chuck (Mfd. Since 09/17)
-3-
Surface Flatness
The surfaces of your magnetic chuck were ground
flat during production. However, it's a good idea to
double-check that the chuck is still flat after ship-
ping and handling.
To test for flatness:
1. Make sure magnetic chuck is turned OFF,
then carefully place it upside-down on a clean
work surface.
2. Use a precision straightedge to check for flat-
ness along length, width, and diagonals, as
shown in
Figure 2.
Straightedge
= Additional Straightedge Positions
Figure 2. Testing surface flatness.
3. Carefully flip magnetic chuck over, then per-
form the same check on top surface of chuck.
— If no space is detected between mag-
netic chuck surfaces and the straight-
edge, proceed to
Removing Surface
Imperfections.
— If any space is detected between the bot-
tom surface and the straightedge at any
point, the chuck has warped slightly during
shipping. Perform
Step 4 to correct
warpage.
4. Clean, then use a polishing stone on bottom
surface of chuck and table surface of your
surface grinder to remove any foreign mate-
rial and surface imperfections. Then care-
fully place magnetic chuck right-side up onto
grinder table in the position you plan to mount
it. Allow it to sit overnight. During this time,
any warping will be corrected as the chuck
becomes matched to table.
5. After allowing magnetic chuck to sit over-
night, perform
Steps 1–3 again. Repeat as
necessary until there is no longer any trace
of warping.
If, after several attempts, magnetic chuck is still
warped, you must correct warping by grinding.
If you attempt to correct for warping by grinding
away high points, you will create variations in
overall thickness of chuck across its length and
width. These variations must be corrected by
grinding portions of the other side of the chuck to
compensate.
For example, if your chuck bows upwards at
each end and you correct this by slightly grind-
ing away the surface at each end, your chuck will
be left thicker in the middle. You will have to flip
the chuck, then grind away the middle portion to
restore flatness.
Matching Chuck to Table
To ensure that the top surface of your new chuck
stays equidistant from the grinding wheel during
table travel, you must grind the surface of your
magnetic chuck to match your table.
To match your chuck to your table:
1. Very carefully clean grinder table and bottom
surface of magnetic chuck. Place magnetic
chuck on table, positioning it as desired, then
clamp it with the included holddowns.
2. Grind entire surface of magnetic chuck, mak-
ing sure chuck stays as cool as possible dur-
ing this process to avoid damaging magnets
and keep it from warping. DO NOT attempt to
remove more than 0.0001 inch per pass.
Avoid overheating chuck during grinding.
Too much heat during grinding will bow
chuck, causing middle portion to be
ground more than ends. Once chuck cools
again, it will flatten, leaving center area
thinner than the edges. Excessive heat
will damage magnets and reduce holding
power. DO NOT attempt to remove more
than 0.0001" per pass.
Summary of Contents for T1227
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