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Cab Grinding
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STEP 1
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| Start on a low number grit wheel, with 80, 100, or 150 grit. Check with instructor if using opal or other soft material for your cab. |
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STEP 2
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| Wear an apron. Water splash is present and you don't want to get all wet. Position yourself comfortably and directly in front of wheel. Turn on machine. |
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STEP 3
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| After wheel is running, turn on water drip. Let the wheel stabilize, especially with corundum wheels as they absorb water and become unbalanced. |
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STEP 4
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| After wheel is running, slowly approach wheel with cab, making sure the wheel is wet and that the contact will be below the horizontal centerline of the machine. The wheel is spinning from the top down towards you. If you contact above the centerline, the momentum is spinning out away towards you and you will get a cab in the face or it will get slung across the room. If you get to low, the tendency is to push the cab down into the machine base or continue towards the rear of the machine away from you, damaging you cab. Find that happy medium location and your work is easy. |
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STEP 5
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| Move your stone slowly left to right and right to left, otherwise you could damage both the wheel and your stone. Slowly twirl the dop with your hands, while rotating it up and down. Make sort of a figure eight configuration across the stone. This motion slowly grinds your preform into the final shape. More time will be spent on the perimeter of the stone, slowly grinding the outer edge as you approach the dome. Constantly look at the stone, checking your progress as you grind towards the scribed lines. Leave the outer scribed line. You can always grind to final shape later with a flat or tapered edge treatment. |
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STEP 6
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| As your cab begins to take shape, constantly check for scratches, etc. Make sure you are moving across the wheel and not holding it in one place or position too long on the cab or wheel. This will help to prevent flat spots from developing on either. |