I have a job in the construction industry where I am frequently in places where I need my laptop but there is nowhere to set it down to use it. Luckily there is already a manufactured solution for this issue in the form of a folding magnetic mount for laptops. You can find it on Amazon for about $150. If you've read any of my other 'ibles then you'll know that this just will not do. I was looking to recreate this device for as little dough as possible.
SPOLIER: I did it for $55.00.
Step 1: Material and Tools
The commercially available device is made from High Density Polyethylene (HDPE). You can buy the stuff from Amazon for about $20 a square foot. But you know what is also made of HDPE and is a little cheaper? Cutting Boards! I got a 30" x 18" cutting board 1/2" thick from Amazon for $25.00. I also needed some super strong cup magnets. I actually had 10 of them already but they cost $20 for a pack of ten. Here is a complete list:
Big 'ol Cutting Board
Four Cup Magnets
10-24 3/4" Bolts (4 of)
Step 2: Cutting and Layout
This stuff cuts like butter with a table saw and a normal drill bit. I cut out the pieces per my plans and laid out the locations of the holes. When using either the saw or the drill press just take your time. If the HDPE gets too hot it will start to melt. After cutting and layout I dry fit the pieces.
Step 3: Bonding
Finding a type of glue to bond HDPE is near impossible for cheap. You can use a torch to melt the surface of both pieces and stick them together that way which is actually pretty good for large pieces however it makes smaller pieces more brittle which I found out. So the melting method was a no-go. I decide to just mechanically fasten all the pieces with screws and bolts. To my surprise I found that the HDPE responds to screws exactly the same way wood does. This was a game changer, because woodworking I can do.
Step 4: Drilling
Like when you work with small pieces of hardwood you want to pre-drill the screw holes. For most of the holes it only took a small 1/16" bit. For the Tee Nuts it took a 5/16" bit. A tee nut is a barbed nut you can insert into wood or plastic and then run a bolt through. These tee nuts are what I used to attach the magnets. I used a forstner bit to countersink the tee nuts so they would be flush with the surface of the board. I used a 1 3/4" hole saw to create a makeshift handle and to take some weight out.
Step 5: Assembly
I hand tightened all of the screws and bolts to avoid striping out any of the plastic. I did screw up on one bolt and over tightened it which cracked one of the cup magnets. Not a big deal, it still works. The piano hinge was a little tricky because of how small it is. You can add a pad of velcro if you have any reservations about the laptop sliding off.
Step 6: Testing
The magnets are rated for a 97 lbs (44 kg) vertical pull each...EACH! I tested the device on the back of one of my tool boxes. Even though the tool box is pretty thin metal it stuck like a champ. This thing its not moving unless someone really tries to move it. The point is to have somewhere to place my laptop while I take down some information, not to provide anyone with a spot to rest their elbows. I have every confidence that it will support my laptop with no issues. I am concerned that when i'm on a roof with this thing in the desert sun it may get a little "flexible" but I will just be careful to limit the time in the sun.
The whole thing fits in my laptop bag like the commercially available one, was much cheaper, and functions as planned and only took about 4 hours to make. :)