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

CNC Controller Motion Board Installation (Rev. D)

The motion board is installed into the box via the following steps:

The bare controller board looks like this.
For revision D, the upper left mounting hole is too close to N7.
Luckily, there is plenty of space to the lower left to relocate the hole down to.
The DIN5 connectors N1 through N4 have there mounting holes messed up. I need to redrill all five holes.
Here a DIN5 connector is installed in N3 using the new holes.
This is an upside-down view of the board with the mounting hole relocated and all 4 DIN5 connectors redrilled.
This is the upright view of the board with the mounting hole relocated and all 4 DIN5 connectors redrilled.
The board is very carefully placed on the the box (opposite side from the fan and power switch) and taped down. (This picture is a retake, since I accidentally deleted the original picture.) The DIN5 and DIN8 connectors need to be just under the aluminium top. Similarly, the USB, parallel port and serial port connectors need to be positioned just behind the side of the box. This is a little harder, since all three of these connector hang over the edge of the board.
The drill press is used to drill out each of the mounting holes.
Now, the motion controller board is mounted on 3/8" #4-40 spacers with #4-40 round head screws with a #4 washer. The board is attached to the box using #4-40 round head screws. A number of the conenctors are placed on the board to verify the fit. In addition, the L298 with heat sink is test placed to ensure that it does not run into the the transformer. So, far everything looks like it is going to fit just fine.
Now, comes the step of drilling holes in the top of the box for the stepper motor connectors (DIN5) and auxilary connectors (mini-DIN8.) The DIN5 and mini-DIN8 connectors are press fit into the printed circuit board. A piece ` of paper is cut out such that it will cover all of the connectors ends.
Using adhesive tape, the paper is attached to the side of the box and folded over so that the connectors are covered over.
Using a pencil, the edges of the connectors are determined.
The paper template is taped to the box lid.
The box lid is removed and the flapping edge is taped down.
Now the printed circuit board is removed.
Now I took way too many pictures of the holes being drilled out. Here is the box before the first hole is drilled.
Here is the box after the first DIN5 hole is drilled.
Here is the box after the all four DIN5 holes are drilled.
Now I change the drill bit and prepared to drill out the mini-DIN8 holes.
Now the mini-DIN8 holes are drilled.
The DIN5 connector holes are too small, so they need to be enlarged using a rotary file.
After enlargment they look as follows.
Using the DIN5 cables, the basic fit of the holes is verified.
Now comes the fun of installing the DB9 connector and a DB25 connector.
Using the same technique as before, a piece of paper is cut out, taped to the box side, and folded to cover the DB9 and DB25 connectors.
Using a pencil, the connector outlines are marked.
Using a drill big enough for the nibbler head, a hole is drilled into the center of the DB25 connector outline.
Using the same drill, the center of the DB9 connector is drilled out.
Using the nibbler tool, the connector outline is nibbled out. Using some small files, the final outline is filed out.
The DB9 connector is nibbled and filed out as well. Please note that I used a random male DB9 connector to do the final nibbling and filing. The final connector that is installed on the board is a female DB9 connector. Also, there is a missing photo where I drilled out the holes for the DB9 and DB25 attachment spacers.
After all of that, the connectors are soldered in. While I was at it, I soldered in the IC sockets and screw terminals as well.
Now that the serial and parallel ports are ready, it is time to make the hole for the USB connector. The technique is the same as always. A piece of paper is taped to the box and folded to cover the USB connector.
Using a pencil, the outline of the USB connector is determined.
The printed circuit board is removed and the box lid is installed. The paper is taped to the box lid.
Using a drill that is a little smaller than the USB connector, the hole is drilled. The drill bit wandered a little, so my hole was off center and got a little too close to the parallel port connector.
Using some small metal files, the round hole is squared off to match the USB connector.

That is a good stopping point for mounting the board.

	The bare controller board looks like this.
	For revision D, the upper left mounting hole is too close to N7.
	Luckily, there is plenty of space to the lower left to relocate the hole down to.
	The DIN5 connectors N1 through N4 have there mounting holes messed up. I need to redrill all five holes.
	Here a DIN5 connector is installed in N3 using the new holes.
	This is an upside-down view of the board with the mounting hole relocated and all 4 DIN5 connectors redrilled.
	This is the upright view of the board with the mounting hole relocated and all 4 DIN5 connectors redrilled.
	The board is very carefully placed on the the box (opposite side from the fan and power switch) and taped down. (This picture is a retake, since I accidentally deleted the original picture.) The DIN5 and DIN8 connectors need to be just under the aluminium top. Similarly, the USB, parallel port and serial port connectors need to be positioned just behind the side of the box. This is a little harder, since all three of these connector hang over the edge of the board.
	The drill press is used to drill out each of the mounting holes.
	Now, the motion controller board is mounted on 3/8" #4-40 spacers with #4-40 round head screws with a #4 washer. The board is attached to the box using #4-40 round head screws. A number of the conenctors are placed on the board to verify the fit. In addition, the L298 with heat sink is test placed to ensure that it does not run into the the transformer. So, far everything looks like it is going to fit just fine.
	Now, comes the step of drilling holes in the top of the box for the stepper motor connectors (DIN5) and auxilary connectors (mini-DIN8.) The DIN5 and mini-DIN8 connectors are press fit into the printed circuit board. A piece ` of paper is cut out such that it will cover all of the connectors ends.
	Using adhesive tape, the paper is attached to the side of the box and folded over so that the connectors are covered over.
	Using a pencil, the edges of the connectors are determined.
	The paper template is taped to the box lid.
	The box lid is removed and the flapping edge is taped down.
	Now the printed circuit board is removed.
	Now I took way too many pictures of the holes being drilled out. Here is the box before the first hole is drilled.
	Here is the box after the first DIN5 hole is drilled.
	Here is the box after the all four DIN5 holes are drilled.
	Now I change the drill bit and prepared to drill out the mini-DIN8 holes.
	Now the mini-DIN8 holes are drilled.
	The DIN5 connector holes are too small, so they need to be enlarged using a rotary file.
	After enlargment they look as follows.
	Using the DIN5 cables, the basic fit of the holes is verified.
	Now comes the fun of installing the DB9 connector and a DB25 connector.
	Using the same technique as before, a piece of paper is cut out, taped to the box side, and folded to cover the DB9 and DB25 connectors.
	Using a pencil, the connector outlines are marked.
	Using a drill big enough for the nibbler head, a hole is drilled into the center of the DB25 connector outline.
	Using the same drill, the center of the DB9 connector is drilled out.
	Using the nibbler tool, the connector outline is nibbled out. Using some small files, the final outline is filed out.
	The DB9 connector is nibbled and filed out as well. Please note that I used a random male DB9 connector to do the final nibbling and filing. The final connector that is installed on the board is a female DB9 connector. Also, there is a missing photo where I drilled out the holes for the DB9 and DB25 attachment spacers.
	After all of that, the connectors are soldered in. While I was at it, I soldered in the IC sockets and screw terminals as well.
	Now that the serial and parallel ports are ready, it is time to make the hole for the USB connector. The technique is the same as always. A piece of paper is taped to the box and folded to cover the USB connector.
	Using a pencil, the outline of the USB connector is determined.
	The printed circuit board is removed and the box lid is installed. The paper is taped to the box lid.
	Using a drill that is a little smaller than the USB connector, the hole is drilled. The drill bit wandered a little, so my hole was off center and got a little too close to the parallel port connector.
	Using some small metal files, the round hole is squared off to match the USB connector.