I shopped around for various parking assistance devices for tight garages, or any garage really. There are various types but most require that you park a specific vehicle in a specific way to work. For instance, the old tennis ball on a string really only works for the vehicle you set it up for, parked the direction you set it up for. I wanted a system that would allow me to park any of my vehicles either direction while minimizing the distance to the garage door. This way you maximize the space at the front of the garage.
Years ago in another garage I built a simple system using standard garage door sensors, some LEDs, and an old cell phone charger. It works but this time I wanted something a bit better. I searched again on the internet for a kit or system I could just buy and install but to my surprise there really is not one like the system I made.
50' 18ga 5 conductor sprinkler system wire (obtained from local hardware store)
Various screws and clips
I mounted the alarm sensors 18" high and the distance away from the door opening that I wanted. This was about right for most bumpers or license brackets to interrupt the beams. I wired one power supply to the sensor that does not have the alarm relay (less terminals). The other power supply supplies the main sensor and the LEDs. The sensor has a normally open (NO) and normally closed (NC) contact which is used to switch between the green and red LED strips.
Main sensor
Terminal block above main sensor. Wire pair on right is power supply. Wires going up go to the LED strips. Wires heading down connect to the main sensor.
Front LED strips (wall with garage doors)
Back LED strips
My system spans both doors as in this case there are on the same wall. Other garages stagger the doors so you may need 2 systems. I had the aim the sensors a bit into the garage to get the performance I wanted. I had also planned to add some reed switches and a relay to disable the LEDs when the doors were both closed but after I got it working I decided it was not necessary. The extra wires were for that. There are many variations to this approach. I like not having anything to trip over on the floor, or things hanging in the garage. I like that I can pull the vehicles in either direction, and move vehicles to different stalls and it still works.
These doors do have sensors already to prevent closing the doors on things. However, those don't indicate if you are parked in the right spot or not. You can only guess and try to close the door. I also found the sensors are mounted much too low to prevent closing the door in your car.
I have a set of Polk Monitor series speakers from the late 1980's. These are fantastic speakers in my opinion, even now. However, in one of the speakers (each has 2 drivers) both drivers started crackling very bad. Upon inspection I found the coils dragging on the magnets. The drivers in the other speaker were fine. You can hear the dragging when you press in on the passive bass radiator which pushes the drivers out.
I looked into these drivers with are part number MW 6503 and have been discontinued. There are copies available for $35 to $70 range each.
I experimented with pressing on the cone in various places to find a place where it would not drag. It seemed to be an alignment issue. Maybe they creped a bit over time? I decided I would try to align them back. Nothing to lose here right? Either I fix them or I needed to replace them anyway. I took a piece of plywood and a vise and began carefully pinching an edge of the magnet where the dragging was gone. This basically bends the driver frame a bit to realign the coil with the magnet. To my amazement it actually worked. Here is the after video.
This is tricky to get right. The metal has significant spring back and you want to bend in small increments. You have to carefully get it to yield just a bit at a time and retest.
