And now for something completely different: A little robotics project for the weekend.
The described robot can be build entirely from model making supplies and materials from the hardware store.
Also only very few tools are needed. A metal saw, a drill press, a vice and optionally a tap will suffice.
And here you can see what you can get:
From the model making store you need:
- 3 Servos with M3 thread in the axis (e.g. HX12K)
- 12 ball joints with M3 threads and 3mm holes in the sphere (e.g. Kavan Maxi Ball links 1405)
- about 4grams of Polycaprolactone (Sold under names like ShapeLock or Friendly Plastic)
Form the hardware store you need:
- 850mm of M3 threaded rod (sometimes also available for model making)
- 27 M3 screw nuts
- 3 M3 screws 5mm long
- 3 M3 screws 15mm long
- 400 mm of 10mm square hollow aluminum profile (1mm wall thickness)
- 150×150mm metal oder wooden plate for mounting
(To control the robot you need a microcontroller of your choice.)
The first step is to divide the aluminium profile in three pieces of 100mm length and three pieces of 30mm length.
Then 4 holes are drilled and tapped in each of the pieces according to the following drawings.
One timer is used to generate an interrupt every 20ms / number_of_servos. On each of those interrupts one servosignal is switched on and a second timer is started. This timer is set to overflow after 1-2ms according to the desired position of the servo. When the overflow interrupt of the second timer occurs, all servosignals are switched off. This way you do not a variable to save the current servo, because only one servos is active at a time anyway. On the next interrupt of the first timer the process repeats with the next servo. The desired positions can be saved in an array.
Read more: Delta Robot using atmega32 micrcontroller