Home > Dalek Project > Eyestalk Mechanism Construction
Modified:22:20, 22 October 2013
DALEK PAGES
EYESTALK MECHANISM AND CONSTRUCTION

The eyestalk mechanism was quite a challenge. It needed to fit inside the head so there was not much room and some of that had already been taken for the comutator rings. Much of it was thinking on the spot so when looking through these photos I can see where I would make improvements - remember there are no instructions.

Building and Fitting the Eye Stalk:
The eyestalk components consisting of laser cut transparent blue acylic rings, 10mm chrome plated pipe and a smaller inner aluminium tube. The eye was made form a vacuum formed parts in 1.5mm polystyrene. The outer tube is cut to allw the rings to slide over the inner tube and hold them in place. The outer tube was spaced from the inner with very thin cut MDF spacer washers. The inner tube gives passage to the wires to the LEDs.
Tapping a thread on the end of the inner tube to enable the whole assembly to be bolted together. note the tube was was only just thick enought to take a thread. A view of the PCB with LEDs for the eye. These are multicolour types, the same as used in the base, and the joystick cases. Testing the LED with the front off. A dedicated circuit drives the LEDs and responds to signals to change the colour. The eye is generally always pulsing bright and dim.
The two parts of the Eye Housing were held together by a laser cut ring from 9mm MDF. It has a rough enough surface to hold the two halves together as a friction fit. The lens is made from some 3mm opaque white acrylic to diffuse the light and hide the LEDs with a half concave lens in front and screwed to some MDF stuck in the front of section of the eye. Testing the LEDs in the eyes. The opaque acrylic diffuses well with the lens finishing off the effect.
Mounting the EyeStalk:
Left: The eye slot in the head enlarged and shaped with a file and a lot of care. The size is large enough to allow the clear acrylic gear to fit.

Right: One of two brackets to hold the pivot point of the eyestalk. In fact there are 2 4mm bolts protruding into holes in the eyestalk. These have plastic bushes to reduce wear.

The gear wheel is for effect and supports the eyestalk. It was made from 3 layers of 8mm clear acrylic glued together and yes it had red LEDs attached to make it glow. One of the eyestalk supports in place and attached to the upper wooden ring in the head section. The outer tube fits through a hole in the centre of the gear. The completed support with both parts in place. Note also the locking nut is added to the stalk to hold the entire eyestalk assembly together.
Eyestalk Movement Gearbox:
The gearbox was made from more 8mm clear acrylic. Just 2 plates with holes in the right places and a 3mm piece to hold the motor in place - again from a printer. The motor has a worm gear attached and drives a 52 tooth gear. The worm drive later had to have an end plate to stop it popping of the motor shaft. The axle will later have another gear attached.
Left: The main lever section of the mechanism to move the eyestalk. It is made from 6mm MDF and mounted on a 9mm MDF support with 3 arm as before.

Right: The motor atached to the lever mounting. An extra gear from a meccano set has been attached only to allow the offset fixing of a 4mm bolt that will ride a slot in the lever section.

The eyestalk mechanism inserted to the neck fitting just to check for brushes lining up and movement of the main lever. This moved up and down continuously independent of which direction the motor turns.
Eyestalk Movement Mechanism:
A linkage made from 2 strips of meccano was used to provide some flexibility between the eyestalk and the drive lever. It was expected that the eyestalk would be heavy to move and proved too much for the gearbox. So 2 springs were attached to counteract the weight of the eyestalk and take the strain off the motor and gearbox. It worked a treat!
Left: Testing tosee if the motor and gearbox will fit inside the head section. Note the extra rather last minute method of mounting the gearbox.

Right: The mechanism all complete and attached to the eyestalk.

Left: The completed Eyestalk fitted to head.

Right: Just a good picture of the eye showing the definition in the vacuum forming. So easy with a centre lathe.

Written and Constructed by Phil Townshend 2009
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