Enclosure Modification & Unit Assembly

Hopefully the many pictures above are fairly self explanatory as there are many different ways to cut holes into a plastic box.

I laid out the holes based on measurements taken from the Keypad, LCD, PCB assembly and various connectors. Once I was happy with the layout I used a "Dremel Drill" with a cutting attachment (careful, this can get away from you if you are not very careful) to rough out the various holes and then filed them to a final fit. The cutout for the PCB assembly should have a very small amount of space around the edges. The pictures of the PCB assembly to box fix is a little tighter then it should be, but it was good enough.

I used a good quality, heavy "double sided sticky tape" to attach the box to the heat-sink. Be careful and make sure that the fit of the box to the heat-sink is exactly how and where you want as you will only get ONE chance to place it. Once the box is taped to the heat-sink it is extremely difficult to remove! At least it was for me with the "Gorilla" tape that I used.

NOTE: One wiring "oddity" that I need to mention is that the DB-9 Step and Direction  connector needs to have a common ground with any other system connected to the TinyCNC-II at the Step and Direction DB-9 connector. That ground is the center most top pin in the DB-9 connector. The above picture on the left shows this as a black wire in the center of the top row of pins on the DP-9 connector. On this version of the unit I connected this wire to the incoming power supply ground shown as the connector at the bottom center of the picture.

NOTE: Another way to wire the common ground to an external system connected to the Step and Direction connector,  is to connect the wire to the ground of the CPU. I have no feed through specifically designated for this so I soldered it to the ground wires that I have designated for the "T-Start" and "E-Stop" signals on the PCB pictured above on a prior version system. Both this and the previously described termination points to the power supply ground for the Step and Direction connector seem to work equally well but my gut feeling tells me that this termination point might be somewhat better being located closer to the control signals.

Download and print out the character grid that I created pictured above on the right. Cut out a set of the keypad characters and, using tweezers, coat the back of each character with some "Glue-Stick" glue. Place the character in the center of the proper key indicated in the picture above on the left. When all labels have been applied and the glue has dried, take a piece of clear packing tape and lay over the entire keypad. Finally, using a very sharp Xacto knife, carefully cut the clear packing tape away from each key. Cut just to the inside edge of the flat on the keys to seal and protect the labels.