The parts found in my garage to build the target are:
- 1 old wiper motor from a Mini Austin
- 5 microswitches
- PC power supply
- 1 power switch
- 2 ikea boards from an unused shelf for the box
- 50mm washers (5)
- 5 hinges
- flat bar steel (12mm x 1mm )
- steel rod
- zinc sheet for shielding
Step 1: Soldering the Targets and Lift
I have cut 5 steel bars 100mm long from a 12mm x 1mm x 1000 mm bar.
Then I soldered a washer and a hinge on each bar using a mig welder.
The lift is made with 2 hinges and 5mm steel rod 400 mm long.
Step 2: Cleaning and Modification of the Wiper Motor
The motor has 3 contacts:
- constant power, that allows to go back to origin position
- contact to start a cycle.
The modification consists in modifying the arm and replace it by a formed steel rod.
This new arm will push the lift when the engine will be on.
Step 3: Cutting Wood for Case
The case is designed with a front opening allowing to only see the washer part of the targets.
Step 4: Placing Targets, Lift and Motor
The main point is to get the system to move with no constraint.
Step 5: Electrics Installation
No electronics, only contacts.
The contact C1 on a constant positive is the automatic back to origin
The contact C2 of the motor is the usual "on" for a wiper motor. Once you even just pushed on the button, the motor is going for one complete cycle, due to the C1 contact.
Here, I replaced the usual contact by five microswitches in serial. When all the targets are down, they push on the microswitches levers and the 5 contacts are connected. So the motor goes for its full cycle.
Step 6: Painting and Inside Assembly
Step 7: Front Shield
For this, I used a leftover zinc sheet that I just had to cut and fold for my needs.