This is a portion of CNC motion control board assembly documentation.

CNC Controller Motion Board Initial Placement (Rev. D)

Before actually drilling any holes, it is useful to do a rough placement of the larger pieces to get an idea of where everything goes:

The aluminum box is Jameco 11893 and is 7.0"L × 6.2"W × × 4.6"D in size. It comes in two "U" shaped pieces that slide together and are attached by 4 sheet metal screws. Aluminum boxes are easy to make holes in for various components.
Unlike most boxes of this style, the folded over lips for this box are designed to go inisde the metal piece. The picture shows how the lip fits inside.
When the box is closed it looks like, well, a box. How profound. (Yeah, the thumbs are mine; I'm not that good of a photographer.)
The transformer is Jameco 221410 and it measueres 4.63"L × 3.75"W × 4.63"H inches. It weighs in at 11.2 pounds. It takes 117VAC in and produces 24VAC at 12A out. Since AC is measured in RMS (Root Mean Squared), the actual peak voltage is actually 1.414 times larger at 33.9V, or call it 34 volts.
The transformer barely fits into the box. In order to maximize space inside the box, I wound up putting the transformer on its side. In this orientation, the transformer "feet" interfere with the lips of the other box piece. Thus, when it comes time to install the transformer, it is mounted on top of some washers to provide some space for the box lips to slide in. This is lip interferance problem is annoying, but all the other transformer orientations I tried caused other even more serious component interference problems. (Yeah, that's one of my fingers.)
The fan is Jameco 174107 and it is the next item that needs to put into the box. It is placed next to the transformer towards the "bottom" of the box. With this transformer orientation, the fan does not have box lip interference problems.
The rest of the 117VAC components are placed on "top" of the fan. These components are the line cord plug (Jameco 147109), the fuse holder (Jameco 120993), and the on/off switch (Jameco 76232). Again, there is just barely enough room to avoid lip interference problems with the other box piece.
The printed circuit board (PCB) is placed on the other side of the box. The L298's and their heat sinks poke out and come close to touching the transformer, but do not actually touch. The mounting holes for the PCB are close to the box lips, but do not actually interfere.

While there are going to be a number of tight fits, everything should fit into the box.

	The aluminum box is Jameco 11893 and is 7.0"L × 6.2"W × × 4.6"D in size. It comes in two "U" shaped pieces that slide together and are attached by 4 sheet metal screws. Aluminum boxes are easy to make holes in for various components.
	Unlike most boxes of this style, the folded over lips for this box are designed to go inisde the metal piece. The picture shows how the lip fits inside.
	When the box is closed it looks like, well, a box. How profound. (Yeah, the thumbs are mine; I'm not that good of a photographer.)
	The transformer is Jameco 221410 and it measueres 4.63"L × 3.75"W × 4.63"H inches. It weighs in at 11.2 pounds. It takes 117VAC in and produces 24VAC at 12A out. Since AC is measured in RMS (Root Mean Squared), the actual peak voltage is actually 1.414 times larger at 33.9V, or call it 34 volts.
	The transformer barely fits into the box. In order to maximize space inside the box, I wound up putting the transformer on its side. In this orientation, the transformer "feet" interfere with the lips of the other box piece. Thus, when it comes time to install the transformer, it is mounted on top of some washers to provide some space for the box lips to slide in. This is lip interferance problem is annoying, but all the other transformer orientations I tried caused other even more serious component interference problems. (Yeah, that's one of my fingers.)
	The fan is Jameco 174107 and it is the next item that needs to put into the box. It is placed next to the transformer towards the "bottom" of the box. With this transformer orientation, the fan does not have box lip interference problems.
	The rest of the 117VAC components are placed on "top" of the fan. These components are the line cord plug (Jameco 147109), the fuse holder (Jameco 120993), and the on/off switch (Jameco 76232). Again, there is just barely enough room to avoid lip interference problems with the other box piece.
	The printed circuit board (PCB) is placed on the other side of the box. The L298's and their heat sinks poke out and come close to touching the transformer, but do not actually touch. The mounting holes for the PCB are close to the box lips, but do not actually interfere.