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Here is all the equipment ready for work. Emery cloth,
replacement bearings, Delrin shims, digital caliper and of course lithium
grease. |
This is a picture of the replacement worm roller end
shaft bearings. These are superior quality to the ones that the factory fit to
the mount. Note: These
are supplied un-lubricated so require the seals to be gently pried away with a
very thin screwdriver and the bearing to be lubricated with the lithium grease
before replacing the seals. |
During rebuilding of the DEC and RA axis before
reassembly commences place the original factory teflon washer onto the face
plate and then place the worm gear onto the main shaft as in this picture.
Note: This is the same procedure for both the DEC and RA axis.
Measure the distance from the top of the worms gears face to the face of the
mount..... |
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......Here is the measurement in close up. From the top
of the gear teeth of the worm bearing to the face of the mount. Obviously when
you do this the digital caliper must be square to all faces. Make a note of
this measurement which we shall call 'A' |
Now measure the depth of the worm gears machined teeth
and make a note - this is 'B' |
Measurements 'A' and 'B' are used to
calculate the centre of the worm gears teeth from the mount face. This is
achieved using the simple calculation above. The result of this calculation is
measurement 'F'.
You can however simply enter
your measurements into the calculator on this page and it will carry out the
shim size calculation for you. |
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Replace the worm roller end shaft bearing into the worm
carrier having first made sure it is suitably lubricated with lithium
grease. |
Measure the distance between the edge of the worm
carrier and the inside of the worm shaft end bearing. This will be a
measurement 'C' make a note of this. |
Finally measure the width of the worm roller end shaft,
this will be measurement 'D'. Make a note of this. |
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Measurements 'C' and 'D' are used to
calculate the centre of the worm rollers teeth from the base of the worm
carrier. This is achieved using the simple calculation above. The result of
this calculation is measurement 'E'.
You can however simply enter
your measurements into the calculator on this page and it will carry out the
shim size calculation for you. |
Now Simply Subtract F from E
and you have the shim size required.
Note: Sample
data from 2 other EQ6 Mounts is given in the tables below to give you some idea
of what sorts of numbers you should be seeing.
All of these calculations are done for you by just entering your
A, B, C and D measurements into the following
table |
Enter your A, B, C, D
measurements into this table to calculate the correct shim to place between the
worm gear and the bearing face.
Note: When you
click SUBMIT the page will reload and you will need to scroll down to the table
to see the result. |
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Sample EQ6
Shim Values |
A |
0.780 |
B |
0.470 |
C |
0.391 |
D |
0.310 |
E |
0.546 |
F |
0.545 |
Shim Size |
0.001 |
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RESULT = No shim required |
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Sample EQ6 Shim
Values |
A |
0.776 |
B |
0.461 |
C |
0.390 |
D |
0.311 |
E |
0.546 |
F |
0.540 |
Shim Size |
0.000 |
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RESULT = No shim required |
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Sample EQ6
Shim Values |
A |
0.775 |
B |
0.476 |
C |
0.390 |
D |
0.313 |
E |
0.547 |
F |
0.537 |
Shim Size |
0.010 |
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RESULT = .010 Shim Required |
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To provide you with sample data these are the
measurements from an EQ6 DEC gear. Tolerances are fine so no shim is
required. |
Here is another sample from my own EQ6 RA gear. As you
can see tolerances are fine and no shim is required. |
Finally here is the data from an EQ6 RA gear which has
been poorly set up from the factory. A .010 shim is required. |
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Replace the gear ready for assembly with the correct
sized shim washer from your calculations. Note: If the
original teflon washer from the factory is badly worn you can replace it with a
similar sized washer OR simply carry out your measurements with
NO washer in place and then use the appropriate sized Delrin shim
washer from the measurements and calculations |
POINTS ARISING....
You MAY find after rebuilding that the DEC is either loose and
can be pushed up and down OR that there is a gap between the DEC scale/collar
and the mount. This is a possible sign that you either have too much shim or
not enough. Read the notes below for more detail.You should also refer to the EQ6 Case Study guide for
shim washer considerations at the bottom of the page
HERE |
Finally you need to carry out worm tuning as per the EQ6
Strip Down and Rebuild Guide
HERE |