Meccano Boss Fitting by Dave Taylor &
Roland Jaggard
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Adapted from spanner. Original material
provided by Dave Taylor and Roland Jaggard.
Dave Taylor: I was a trainee toolmaker at MK Electric (domestic switchgear
makers). Many switch parts were bossed just like Meccano. The bosses were not
"pressed" but "spun" on a device like a drill press. The
tool used was like a shouldered screwdriver, the shouldered part being radiused
and polished. My first job was to do the polishing-hundreds of them! I presume
Meccano did theirs in the same way.
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Roland Jaggard:
The image below with numbering 7 to 12 shows some
unmounted bosses and brass blanks. An explanation of each part is
provided, left to right in the table below: The tops were countersunk at 90 degrees total included angle to leave
an edge on the top of about 0.25mm wide. This edge was then spun over at
high speed to give the finished profile. If you use a press it is
possible that the edge may split due to work hardening of the brass.
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7
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8 |
9 |
10 |
11 |
12 |
| 1/2" diameter Boss for part number 19c, 6" Pulley |
Boss for 1"
Pulleys, small gear wheels
etc |
Part number 26b
1/2" x 3/4" gear blank |
Boss for part number 187, Road Wheel |
Splined Boss for use with Plastic Gears |
Handrail Support without grub screw threads |
Below is a sketch of the small boss, it is made from brass rod.
In the late 1970's in the UK it would have come as Free Cutting Brass Rod -
S.A.E. Standard No72. There were three standard alloy property types: Soft;
Half-hard and Hard temper. I don't doubt Meccano Ltd used the soft grade,
cheapest, and easiest to work. If you have trouble peening over the boss try
extending the 0."065 rebate a bit to say 0."070. If you want a
working drawing click on the image below and you will download a 666 x 577 pixel
*.bmp image.
Finally below is a curiosity and some Meccano parts without
their boss mountings.
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1
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2 |
3 |
4 |
5 |
6 |
| Meccano Ltd "Model Room" Spiral
Helix parts. |
2" Unmounted
Sprocket Wheel. |
1.5" Unmounted Sprocket Wheel. |
Unmounted 3/4" Contrate Gear. |
Unmounted 50t Gear. |
Unmounted 1.5" Contrate Gear. |
If you want to know more about 'Meccano" parts that never
left the model room visit an
article on the subject by Roland Jaggard.
