A friend gave me a little Fro mini greenhouse from IKEA a while back. I was uninspired with what to do with it until I put it together with the new side table I wanted to make, and then I thought: wouldn't it be cool to have this greenhouse inset into a table? The answer was clearly "yes."

This instructable will be focused on insetting this particular object, but you could do pretty much any shape in the same way.

What you'll need for this:

1 big board for the table top, good wood:22.5 x 17 x 1 3/8
4 legs: 1 3/4 square, however high you want it, in this case 29 inches
4 hangar bolts
4 threaded inserts
1 nut
1 Fro mini greenhouse

1 thin flat, straight piece of scrap wood
some scrap MDF and/or plywood
some clamps

Tools you need:
Router, 5/8ths bit
Drill and related accoutrements (variety of bit sizes)
Drill press
Sander and sandpaper
Circular saw and/or mitre saw
Woodworking tools for chiseling the corners

Step 1: Make Your Measurements

First it's important to make sure all your pieces of wood, etc. are square. You can check this by measuring the diagonals. If your table top isn't square, you'll want to square it yourself. If it's too large, you'll want to cut it down to size, as

Next, mark out the places you are going to rout. Here I'm making a space for the greenhouse and two inset coaster type areas The greenhouse, miraculously, was square, so we could just trace its footprint where we wanted it (1 inch from the sides and the back). The coasters we also traced from a can of rubber glue or something. The coasters are approximately the size of the largest possible cup or bottle anyone would want to use.

Step 2: Mill Out the Rectangular Area

The rectangular piece being rather large, it is also rather tricky to cover the full area without the router dipping down and leaving divots in the wood. First we rout three sides of the rectangle. Then we work our way to the back of the rectangle inch by inch. You can use a straight edge as a guide for the router.

All this is illustrated in the pictures below.

After routing the rectangle, chisel out the corners with some woodworking tools. I actually used some chisels meant for linoleum printing. They work just fine.

Step 3: Making the Coasters

There are lots of ways that you could make the coasters. One way would be to use a pre-cut circle, I was thinking some kind of plumbing fitting or roof flashing. Then you can use a router bit with a guide above the cutting blade. If you can't find a pre-made circle of the appropriate size, you can make a circle in MDF or plywood using a circle cutter. Since we just had a regular routing bit, rather than one with a guide on top, we took a different route. What we did was make a large circle into which the entire router base fit. This is also probably the easiest route.

To make a large circle you have to first figure out the right size for the circle. You want the radius of the full circle to be the radius of the coaster plus the distance from the edge of your router base to the outer cutting edge of your routing bit, as illustrated in the diagram below.

Once you've figured out the right radius for the guide circle, attach the thin, flat piece of wood to the router and nail it down at the appropriate radius. Cut the circle out of your material of choice, in this case plywood. Practice routing the coaster on some scrap wood before you move on to the real thing.

Step 4: Attaching the Legs

First you have to put in the threaded inserts. Although the threaded inserts usually come with suggestions of what size hole to drill for it, you should practice with different drill bit sizes 'til you find the perfect one. We made the holes with a drill press so that we didn't go too deep and poke through the other side. It doesn't necessarily help the inserts go in straight, though. It doesn't matter in the end, because the pieces straighten themselves out.

Next you want to drive the hangar bolts into the legs. First mark the center of the legs, then drill a hole. You want to drill a hole the appropriate size for the bolt, but you don't want to stress the wood too much, so you should widen the hole in stages. We used three stages. To drill the bolt into the leg, you stick a nut on one side and then use a socket attachment for your drill.

When you screw the leg into the table top, they will straighten out, even if the inserts and/or the bolts aren't straight.

Step 5: Finish It Up!

Now it's pretty much all done! All that's left is to sand everything down, and throw on some oil and wax.

Voila!

Since it's rather tall, I am thinking of installing a grow light panel underneath and put some plants down there. We shall see. For the moment, there it is.