Lego Technic Frame Details
Trigger Warning: Lego aficionados may consider this use of Lego Technic Frames blasphemous. My apologies. Fortunately, Chinese clones work just as well.
The possibilities of Lego Technic Frame enclosures are endless. Here are a few possible arrangements.
Figure 1 shows a basic arrangement. I try to minimalize visible panel edges. The top overlaps the sides, and the sides overlap the bottom. The is a front view.
Figure 2 lengthens the side panels to provide clearance for the bottom screw heads when placed on a table. Rubber feet can also be added. This is a front view.
Figure 3 shows the front panel on the left overlaps the top, bottom and side panels.
A printed circuit board is mounted to the inside of the rear frame to provide protection for protruding switches and connectors. Alternatively, an outer panel can be added similar to the front panel shown in figure 4.
This is a side view.
Figure 4 recesses the front panel to provide protection to switches and controls.
A circuit board mounted to the inside of the frame is 8mm from the back of the panel, which is prefect spacing for 12mm tactile switches with a button through the panel and LED bargraphs and 7-segment displays showing through the panel.
This is a side view.
Figure 5 shows an alternate position for the circuit board, located between frames. This corners of the pcb must be notched to fit around the frame,
This is a side view,
Heat Stake Thread Inserts
3mm heat stake inserts fit perfectly in the Lego Technic frame holes. Inserting them takes literally seconds,
Many different styles of thread inserts are available. For this application, the type with a 5mm flange is best, but those with a smaller diameter flange work ok,
Tips are available for soldering irons to insert the inserts. The tips have a cylindrical end to hold the insert perpendicular. At a temperature of 360°C, it takes about a second to heat up the insert.
Presses are available to help insert the inserts perpendicularly, I adapted a cheap drill press stand designed for a hand told to the purpose.
