Hardware
Steelmate Slave Door Lock Actuator [ Jaycar 14.95 ]
Vinco DBL 60/70mm Deadbolt Latch Bolt [ Hildebrandt Locksmiths 12.00 ]
Piano wire [ Extreme Hobbies 2.80 ]
25mm square section aluminium [ Bunnings Hardware ]
Tag: mechanics
Window update.
If the window were a pivot style window, and balanced in an open state, a pump and a pair of ballast tanks might be enough to open and close the window. A pair of slender chambers (Melinda suggests containing oil) could be inserted in to each of the vertical pillars of the window. Even better the pair could be the top rail and the bottom rail with tubes running between in the verticals. Figure 1 shows a piston tank which uses a rotor motor rather than a pump.
Fig. 1
Alternatively some sort of mechanical counterweight might be good. Perhaps a threaded lead counterweight on a threaded rod.
v1 hardware.
Interior of the door with the actuating hardware (stepper motor geared down). Wood, aluminium, door and deadbolt.
Howstuffworks “How Power Door Locks Work”
Howstuffworks “How Power Door Locks Work”
The stepper motor / gears option is very noisy. I am considering ditching the variable lock and going for something like this car door lock. The part (from Jaycar) is 10AUD and very nearly thin enough to fit within the door cavity.
The mechanism should have heaps of torque – that would mean I could replace the spring on the deadbolt returning the authentic noise. I think its a simple motor with gearing – when i supply 12V it shoots out and stops – the motor still tries to run but the sound isn’t bad.
Test computer controlled lock.
The gear and other parts arrived from Small Parts on Friday. I cut the gear by hand and assembled a temporary fixing. Here the Arduino runs a test cycle on the system.
[flv:/wp-content/uploads/2008/11/test-mechanics.flv /wp-content/uploads/2008/11/test-mechanics.png 320 240]
Lynch pin.
These two aluminium pieces lock the rotating gear to the main driver of the deadbolt. The L-shaped piece both spreads the split cylinder and acts as the turning arm.
Motor mounting.
Gear to bolt connection.
Â
The small metal plate needs to be milled. The centre two tabs adjacent to the axle hole bend toward the bolt, becoming the turning arms. The outer two bend toward the gear into outer holes to locate the plate on the gear.
An arrangement of gears.
The new deadbolt with its top spring removed slides with less force than expected. Two gears (white) from a scavenged VCR match nicely with the Tamiya on the stepper. The black gear (Jaycar) will mate with the turning axle in the bolt. The axle rotates only 90° between fully extended and fully retracted.
