Build a Flat Lap

[1dave]

I've come close to purchasing a flat lap many times over the past 50 years, even bought a 220 grit charged 8" aluminum lap back in the 60's. A glance around my workshop assured I had enough scrap to at least build the box.
I made it out of Formica coated mdf with biscuit connected oak corners and edges.


Now for a pan for the lap to set in.
I was fortunate to find a 9" aluminum cake pan for the lap to sit inside of.
I used a 1 1/4" hole saw to cut the hole in the bottom, a 2" rigid coupling on the inside and a trailer hitch ball on the outside to make a rim with a 1 1/2" raised opening.


A 1 1/2" to 1 1/4" PVC reducer fit perfectly in my pan.
I sanded the bottom of the reducer to a taper so it starts easily into the table top hole.


I have a two speed motor (Home Depot swamp cooler motor) and will have a switch to turn the motor and light on and off, a switch for high or low speed, and a switched outlet and one that is always hot when the cord is plugged in. The wire rack is to hold grit charged old CD's for grinding and polishing.


My holesaw cut a hole a tad too large, but gluing in 4 strips of emery cloth (grit side to the wood) made a perfect tight fit!
With the motor wired, wire Ty-wrapped in place and glide feet gorilla-glued in place.


My holesaw cut a hole a tad too large, but gluing in 4 strips of emery cloth (grit side to the wood) made a perfect tight fit!
With the motor wired, wire Ty-wrapped in place and glide feet gorilla-glued in place, the end is near.


Slipping the pan into place. I needed to lift my lap 9/16" so the lap would clear the PVC fitting. I didn't have enough 1/2" flat washers, so I drilled the threads out of a 1/2" nut. That + the one washer I had worked perfectly.


Some screws to hold the top secure, the end is near.





7/20/2017 ADMINISTRATIVE EDIT: Repaired broken PhotoBucket images - original code below

[img alt="01" src="http://i1298.photobucket.com/albums/ag56/DaveCrosby/FlatLap/2013-10-14OctFlatLapt01_zps09ee23f3.jpg" style="max-width:100%;"]
[img alt="02" src="http://i1298.photobucket.com/albums/ag56/DaveCrosby/FlatLap/2013-10-14OctFlatLapt02_zps81b76859.jpg" style="max-width:100%;"]
[img alt="03" src="http://i1298.photobucket.com/albums/ag56/DaveCrosby/FlatLap/2013-10-26-OctFlatLap002Reducer_zps271aadde.jpg" style="max-width:100%;"]
[img alt="04" src="http://i1298.photobucket.com/albums/ag56/DaveCrosby/FlatLap/2013-10-19-OctFlatLap01_zps753f8c52.jpg" style="max-width:100%;"]
[img alt="05" src="http://i1298.photobucket.com/albums/ag56/DaveCrosby/FlatLap/2013-10-26-OctFlatLap001m_zps42acb7e7.jpg" style="max-width:100%;"]
[img alt="06" src="http://i1298.photobucket.com/albums/ag56/DaveCrosby/FlatLap/2013-10-26-OctFlatLap002ReducerB_zpsfcf76dc2.jpg" style="max-width:100%;"]
[img alt="07" src="http://i1298.photobucket.com/albums/ag56/DaveCrosby/FlatLap/2013-10-26-OctFlatLap005m_zps3f8a4118.jpg" style="max-width:100%;"]


[1dave]

As a retired Master Electrician, the wiring was a snap. As previously mentioned, I want to have the top half of the outlet switched, the bottom half hot all the time the unit is plugged in, so the first step is to break off the tab that connects the two brass screws together.


Next I need to know which 3-way switch screw becomes hot when the bottom switch is in the same position as the top switch when it is off. This will be the low speed position. A continuity tester gives me this information.


The green ground wires from the power cord, motor, and a jumper to the outlet tie together under a 10-32 screw tightened into the tapped hole in the back of the junction box. Make the connections.


For those of you that prefer a wiring diagram:





7/20/2017 ADMINISTRATIVE EDIT: Repaired broken PhotoBucket images - original code below

[img src="http://i1298.photobucket.com/albums/ag56/DaveCrosby/FlatLap/2013-10-28-OctFlatLapW01_zps2801578d.jpg" alt="W1"]
[img src="http://i1298.photobucket.com/albums/ag56/DaveCrosby/FlatLap/2013-10-28-OctFlatLapW02_zps402c5b21.jpg" alt="W2"]
[img src="http://i1298.photobucket.com/albums/ag56/DaveCrosby/FlatLap/2013-10-28-OctFlatLapW03_zps75f65f90.jpg" alt="W3"]
[img src="http://i1298.photobucket.com/albums/ag56/DaveCrosby/FlatLap/2013-10-28-OctFlatLapW04_zpsbd1e3e48.jpg" alt="W4"]


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EDIT 8/3/2017 after being schooled by tommy on grouping ALL the tutorial near the front.

Too many projects!

I finally got around to installing the pan drain.
First I needed to pound out a flat lower place to drill the hole:


Next, find a 3/8" hole somewhere and drag it to the right place:


Then waterproof the threads and tighten in the drain:


Several coats of poly-urethane and on to the next project.

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EDIT 8/3/2017

I drilled a hole and forced in a 16 penny nail to keep the cord out of the way when not in use, and a magnet to keep the 3/4" wrench handy.


And a view of the finished unit.


I'm thinking about installing a latch that will slide up against the shaft extender to stop the bolt from rotating for tightening or removing the nut and disk.

Nov 15, 2013 10:38:28 GMT -7 1dave said:

I faked the water support platform In the last photo, but real life requires it, so I had to build it.

The main support board just needed a slice taken out for the platform to slip into, and a bolt to tighten and hold it in place. I drilled a 1/4" hole on a 45^o angle, enlarged the lower end to hold a T-nut with two of the brads clipped off. That was gorilla glued into place.

I glued some trim around the edges of a thin sheet of plywood to keep the water supply (a cashew container) from rattling off, then painted it white.



Wedged the two pieces together.



And there it is for real.

[1dave]

Too many projects!

I finally got around to installing the pan drain.
First I needed to pound out a flat lower place to drill the hole:


Next, find a 3/8" hole somewhere and drag it to the right place:


Then waterproof the threads and tighten in the drain:


Several coats of poly-urethane and on to the next project.

[1dave]

I faked the water support platform In the last photo, but real life requires it, so I had to build it.

The main support board just needed a slice taken out for the platform to slip into, and a bolt to tighten and hold it in place. I drilled a 1/4" hole on a 45^o angle, enlarged the lower end to hold a T-nut with two of the brads clipped off. That was gorilla glued into place.

I glued some trim around the edges of a thin sheet of plywood to keep the water supply (a cashew container) from rattling off, then painted it white.



Wedged the two pieces together.



And there it is for real.

[1dave]

Dec 2, 2013 4:46:23 GMT -7 @jamesp said:

My homebuilts look like something from Mad Max movie.