From MistiWiki
Jump to: navigation, search

Lapmaster 12 Operation and Maintenance[edit]


U of T LapMaster 12 circa 1940

Introduction to the Lapmaster 12[edit]

Photo1850.jpg Buttons.jpg Drain valve.jpg Bdhjeb.jpg

How to get rid of rust[edit]

1. Close the compound drain valve (in back map view).

Back map view.jpg

2. Add table spoon of 600 grit Silicon carbide(SiC) and 1L of tap water to inlet, cover inlet with rubber stopper.

3. Place one retaining ring on platen in “normal” position (overlap is equal on both sides).

4. Put all of three switches (lapping plate, compound agitator & compound valve) and press the start button and confirm that compound (mix of SiC and water) is reaching the platen. If not, try flipping the third switch (compound valve) on and off a few times. If still no flow, unplug machine, and disassemble compound valve and clean.

5. Run until rust disappears.

How to check for flatness[edit]

1. After the rust disappears, Turn off first switch (lapping plate), then remove retaining ring, dry a quadrant of the platen, and clean with isopropyl with using Kim wipe or clean rag for final wiping. No dust, fiber, or SiC grit should be on surface when finished.

2. To check the flatness of the platen, flatness gage ALWAYS cleanliness! Always clean when dealing with flatness gage, with new Kim wipe. Ensures flatness plate and the “feet” of the gage are clean. Place gage on flatness plate, and slide gently. Needle should stay on “Zero” as you slide the gage slightly. If “Jumpy,” clean and try again. If steady but not at zero, loosen display lock, set to zero, and re-tighten.


Place gage on platen and measure the flatness of the platen with the flatness gage (Always measure A’A or B’B, Never AB or BA) and check for flatness. Measure A'A.jpg

If >2 μm, concave or convex, then correction is needed. After checking platen for flatness, clean the “feet” of the gage and return to box. Photo1855.jpg

If flat, “Lap master” is ready for production. If concave or convex, we should make the platen flat.

How to keep a platen flat[edit]

Platen.png Normal configuration.png Concavity.png


How to clean the platen flat[edit]

At the end of the day, remove retaining rings. Open compound drain valve, flush the compound reservoir 2-3 times with a liter of water, and leave the drain open, and the rubber stopper off. Use old credit card to clean the groves.