Lapping machine - set up video instructions
Setting up you Kemet 15
First fill the abrasive tank with kemox 0400 conditioning slurry, after filling, insert it into the cavity of the machine and then sit the pump inside. To fit the lapping plate, remove the 3 yoke arms, the dual spray head and the plate fixing bolt. Lift the plate into place, centring it with the locating washer and then screw it down using the centre bolt. Adjust the staging using the 4 adjuster nuts so that the staging sits level with the top surface of the lapping plate. After filling a diamond slurry jar, ensuring the stirrer bar is inside, place the jar into the front position on the stirrer, turn the stirrer on making sure a vortex is visible in the fluid, push the slurry tube into the jar and fix the other end into the dual spray head.
The diamond dispensing unit is directly connected to the timer in the lapping machine, it has one side for diamond and another for lubricating fluid, for optimum performance the pressure settings on the dispenser should be about 1.2 bar, set the pressure by pressing the blue air pressure and the white manual spray buttons simultaneously, adjust the pressure settings using the air regulators at the back of the dispenser, by pressing and holding the interval button the interval time will increase, single short presses will reduce the interval time. Do the same with the duration settings until the dispenser is programmed to dispenser 2 seconds spray every 35 seconds.
Using a straight edge or flatness gauge now check the flatness of the lapping plate, in the video example the plate is flat so we position the rings centrally across the lapping plate, remember only a flat plate will produce flat components. Where a plate is convex, the rings are positioned as far towards the centre of the plate as possible like in the video above, this increases the cutting action at the centre of the plate, bringing a convex plate back to flat. Where a plate is concave, the rings are pulled out over the edge of the plate, make sure the whole plate is covered by the control rings so as not to create a lip on the plate. When the rings are in the correct position set the timer for 30 minutes, select the conventional abrasive system on the selector switch and start the machine. This blank conditioning process has 2 purposes, the first is to flatten the plate and the second is to remove all machining marks leaving a lapped and flat plate ready for component processing. When the conditioning cycle is finished, remove and clean the control rings, then clean all the Kemox abrasive from on and around the lapping plate, any Kemox left on the lapping plate can cause scratching during processing. When conditioned, your plate should look like the example in the video, now check again the plate flatness.
Lapping your first components
Now the plate is flat we are now ready to lap our first components, put the cleaned control rings back on to the lapping plate. Use the manual spray button to dispense some diamond slurry onto the plate, this is so we don’t start the machine completely dry. Set the abrasive selector switch back to the diamond dispenser setting, re-set the timer and start the machine, let it run for 5 minutes to evenly impregnate and spread the diamond. Now take a component that needs lapping, place it inside the control ring, then set a dycem faced ring on top, the dycem will stop the component moving inside the ring. Start the machine and allow it to run for the required process time. When the cycle has finished, remove the hand weight and the component, thoroughly clean the component, in this case with co-42 cleaning fluid then inspect as necessary.