LEGO TECHNIC (TM) parts can be bought separately and in that way you can get just what you need to create
assemblies to hold your robotics motherboard and other electronics interface boards.
Notice I have cheated by using the small plastic LEGO (TM) inserts as well as using M4 button head cap screws to
hold the LEGO strips together:
If you are making a temporary prototype you can simply use the LEGO TECHNIC (TM) inserts but for a more solid
assembly that won't fall apart use small 4mm metric (or equivalent) nuts and bolts. Use washers so you do not damage
the LEGO parts when you hand tighten the nuts and bolts.
If you live in South Africa in the Johannesburg or Pretoria area you can take a look at our partners
pages for ENGENIUS that supplies LEGO TECHNIC (TM) parts individually for around R1 per gram. Get a big bag of these handy bits from them for R200
and you should be able to do just about anything.
If you live in Alaska you may need to get what you need on the internet.
Now lay out your electronics on the workbench with the LEGO TECHNIC (hereafter LT) strips and figure out how to make a frame:
Join the frame together using the M4 nuts and bolts:
Put your circuit board back in to see it fits.
Notice here I have made a slide-in frame
so the robotics motherboard can be easily removed and put back. It's loose fitting and slides
out sideways. The washers prevent the PCB falling out when the assembly is upside down. Use plastic
washers if a short circuit is a possibility.
You can also make a slightly smaller frame and then mount the board to the frame using screws or nuts
If your electronics is an odd size (quite likely) or there's no spare space or mount holes see our note at the end
about gripping the board at the edges between to LT strips with an M5 bolt.
Now you can add more LT strips to mount your electronics to your machine or robot.
You can keep adding bits like this until you get the desired effect:
Below we need to mount a small unit to the assembly but the hole spacing
on the hobby servo does not quite match the holes in the LT strip.
We overcome this problem by using smaller nuts and bolts in this instance 3mm
metric cap head screws (M3) and nuts and washers.
If you are in the USA you will need to experiment with the non-metric nuts and bolts they
have over there. God bless America and the members of my family that live in Atlanta, Georgia.
In this particular case carefully tighten each screw a little bit to take out
the slack so that the assembly does not end up all crooked and out of alignment.
Here we can see a perfect result. Fortunately in this instance the distances between the two
flanges was okay in terms of screwing these two LT strips holding the hobby servo to the main frame.
Whatever you are making there is a professional looking solution. If you are a MECCANO (TM) enthusiast
you can use their wonderful metal strips. Watch out for short circuits because the paint is not adequate insulation.
For a purist MECCANO (TM) model you can cover the strips with heat shrink tubing where it comes in contact with
the electronics. You can also use those nylon plastic spacers and nylon nuts and bolts from your nearest electronics
parts supplier. The new MECCANO (TM) range also offers plastic strips.
To fit odd size circuit boards with no mount holes like Veroboard prototypes a great solution is to use LEGO TECHNIC strips
clamped together on the edges. The way to do this is with 5mm metric nuts and bolts.
If you take a 5mm bolt you will find
that it jams up and won't fit through the hole in the LT strip. Take a 5mm metric drill and slightly ream out the hole in the LT strip
until it just fits snugly. Now take the two strips and put the bolt through and tighten with the edge of the circuit
board between the two strips so the assembly clamps onto the edge of the circuit board.
WARNING: be careful the edge of the circuit board does not make a short circuit especially with multi-layer PCB assemblies.
In this way you can mount even the most irritating circuits where the manufacturer has not been
considerate enough to give you some means to secure the board to your brilliant invention.
When I find some spare time I will put a picture of how to do this but I'm sure you're smart enough to figure it out yourself.
Finally, tidy everything up by making wiring harness assemblies. For my prototypes I wrap single strand wire around groups of wires
that can be easily pulled away to make changes. For permanent assemblies I simply place thin zip-lock cable ties at even intervals
to hold the wires together like a pony tail in my daughter's hair.
Using these methods will give your project a truly professional appearance without having to manufacture special mounting
systems that would normally only be economically feasible with mass production techniques making this ideal for small runs and once-off situations.
This page was inspired by Chris Vermeulen whose amazing invention using our electronics proves you don't always need a giant corporation
backing you to do incredible things.
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