I’ve been building a door for my hangar. The door has been installed in the opening. Now I have to finish installing the mechanical and electrical components that make it work.
The motor is a reversible 2HP 220VAC single phase motor. It has a brake installed between it and the right angle gearbox. The gearbox has two shafts. I used both shafts and two ANSI 60 chains. When I did the load calculations on the chain it came out to be right at the maximum for an ANSI 60 sized chain so I went ahead and used two. If those chains break the door comes crashing down so I didn’t want to risk it.
I couldn’t find any limit switches that I liked that didn’t cost $700. I wanted to have two sets because if one set fails and the door continues to open, really bad things will happen. The controls are set up so that one set of limit switches go into the PLC (Programmable Logic Controller) as inputs and are the primary way to stop the door at each end of it’s travel. The other set of switches are set just further up and down than the first set and they are wired directly into the motor control circuit. This way, if the PLC fails or one of these limit switches fail then the motor will still stop.
The limit switches work by turning a couple of Acme thread lead screws that have a two nuts on them. I welded a washer on the nuts that I cut grooves into. These grooves ride on the small aluminum angle pieces and this keeps them from turning. I can make very fine adjustments to this by pulling the aluminum angles out and turning the nuts. One of the nuts is the down limit the other is the up limit. The turning of the screw causes the nuts to move back and forth and actuate the small lever switches on each side.
The limit switch lead screws rotate from sprockets that are attached to the main shaft.
The main control panel controls the hangar lights and the door motor. It uses a small Automation Direct PLC. There are open/close buttons on the front of this panel and it also has the capability of interfacing with a keypad and a remote control. I can open and close the door from the cockpit of my plane as I taxi up. It’s pretty cool. The PLC has a couple of communication ports on it for programming and for communication to other devices. I used one to talk to a touchscreen that is near the walk in door of the hangar so that I can open and close the door from the entry door. It’s a bit spoiled I know, but since this is the kind of thing that I do for a living I thought I should make the controls a little bit over the top.
I can also turn on the lights in the hangar from this touchscreen. There are four banks of lights in the hangar. I don’t always want all four banks on since I may only be working in one corner of the hangar so I can individually control them. I had extra outputs on the PLC so I figured why not control the lights too. This will give me the ability to control the lights from home at some point too. Having the door computer controlled gives me lots of options on how to manage it.
Once I got everything installed I slowly opened the door a bit at a time and made sure that everything was working / holding. It took a bit of fiddling to get the limit switches set and the tension on the straps set right. Overall it works pretty well.
This turned out to be a much bigger project than I ever imagined. It seems simple enough just looking at one but like most projects, the devil is in the details. It’s nice to finally have my plane in a home of it’s own without a big hole in one wall.