Today’s post is guest-written by Lee, for the tech heads out there, or the terminally bored.

I like to putter. I like to be in more or less constant motion (unless I’m staring off at the sky or the floor puzzling on something) and move things around and unpack things and rearrange them and repack them and reorganize them until I’m satisfied, which is never. The best I can ever hope for is to be less dissatisfied than I was before. I truly enjoy it though, and always have. I also like to tinker. I like to take things apart to see how they work, and see if I can find a better way to do things. Before I ever picked up a movie camera, these were my favorite things in the world:

 

When I was kid I got in a lot of trouble for taking things apart. Everyone was always “You broke this!” and “You ruined this!” and “This is why we can’t have nice things!

Pffft. It was already not good enough, I was just trying to figure out how to make it better. I think the real problem was that I was also a kid, and would lose interest or reach the limit of my knowledge/experience/skill, and just wander off to make something else better before I finished the first thing. I was also a big fan of Rube Goldberg, and would spend hours in the basement contriving unbelievably complicated “machines” using Legos and Domino Derby parts to do pointless, simple, stupid things. I once used the entire basement to make something that would just flip the light switch down. I couldn’t figure out how to flip it up. I was grounded a lot for getting bad grades (because school was boring) so I had plenty of  free time to do this.

Gate guarding is pretty simple: It’s a lot of doing nothing, and then suddenly a truck or a car will arrive or leave, and you need to log them in or out. This can be tricky, because you have to be sort of “on your toes” but unless it’s a really busy gate, an hour or more can go by between vehicles and it’s easy to forget you’re actually “working”. It’s also tricky because while you don’t have to be standing there when they pull up, you also don’t want to make them wait too long either. The solution to this problem, of course, is some kind of device that notifies you that a vehicle has arrived. At our first gate, we had super-neato-gee-whiz-high-tech motion detectors to sense vehicles coming in or out that would use state of the art radio waves to instantly send a signal into our rig which would then make a pleasant “bing-bong” sound to alert us. They didn’t work worth a damn. Half the time they didn’t bing-bong, and the other half they would bing-bong because of a bird a mile away, or a fly would fart, or the wind would blow. We got pretty tired of logging bird and wind traffic.  If a semi truck drove by the sensors would ignore it the way a teenager doesn’t see a trash can overflowing in the kitchen. So we could never really relax, because we couldn’t trust the system, and that sucked. And I tried everything. I moved them around, I masked the sensors with gaff tape (the best stuff ever invented, duct tape sucks, throw yours away and get some gaff tape like a grown up) and I tried aiming them every possible way you can imagine. Nothing ever helped, so we just lived with it, like a couple of Neanderthal gate guards. It was awful, I don’t know how we survived it. (As you can see Lee does tend towards the overly dramatic but it was a pain in the butt.  It was especially unpleasant for me at night because on a slow night the noise would startle me, but when I looked outside all I would see was a glowing pair of yellow eyes in the brush.  We had a black cat that liked to hang out on some nights and it was constantly setting off the sensor…creepy -Trace)

When we got to this gate I was thrilled to see that they had a much older, much better solution. The legendary Milton signal bell. For anyone over 50, you probably remember when gas stations had those awesome bells that would “ding-ding” when you drove up to a pump. If you’re under 50, there once was a time long ago when people called “attendants” worked at gas stations, and when you drove in, there was this awesome bell that would “ding-dong” when you drove up to a pump, and the attendant would come out and pump your gas, and even clean your windshield and in really ancient times, check your oil level. My hand to God, this is true. It looked just like this, complete with over saturated colors and period music….

The signal bell was a magnificent piece of engineering in simplicity, functionality and reliability, which is proven by the tens of thousands of them used in every gas station all over the country for decades. Wanna know how it works? Of course you do!

First of all, they look like this:

The original design is unchanged since the original patent (we can thank inventor and awesome guy Mr. George Van Zale for this wonderful piece of Americana) and Milton Industries still makes them, in America no less! Interestingly enough, they are sold mostly by a company called Milton’s Bells, which is owned by a totally unrelated guy named Milton who first saw one at a gas station when he was a kid, and was amazed that his name was on it. If you click on the Milton’s Bells link you get to hear the bell, which is a nice touch.

It is composed of a metal plate, with a bell attached, and a wire that is plugged into 120v AC. Underneath the bowl of the bell is a very sensitive diaphragm separating two conductive contacts.

The contacts are about 1/4″ apart, with the hot side of the electric circuit going to one, and the other is on the opposite side of the diaphragm. Then there’s a solenoid with a plunger/striker. Attached to the diaphragm is a length of 1/2″ rubber hose, up to 300′ long. The other end of the hose is either plugged, usually with a bolt or stopper stuck in it, or even more simple, tied in a knot. The air in the hose is thus “trapped” and at a constant pressure. There’s a 120v AC cord on the bell plate, and the assembly is either mounted vertically on a wall, or some models can be placed on a horizontal surface, like a table top, or the ground. What could be simpler? Maybe a trained monkey with a bell and a hammer, but those need to be fed and they throw poop, which is less than ideal.

When a car, truck, or a kid on a bike rolls over the hose, the weight squeezes the hose and at the bell end, a little puff of air pushes up the sensitive diaphragm. It doesn’t take much, you can even do it with your foot, and that puff of air pushes up the diaphragm and those two conductive contacts touch each other until the pressure is released. Usually it’s only for as long as it takes for the tire to roll off the hose. When those contacts meet, it completes the circuit, electricity passes through the solenoid, and the plunger/striker shoots out and smacks the bell. When the pressure is off the hose, the diaphragm opens, separating the contacts, which interrupts the circuit, and a spring inside the solenoid pulls back the plunger/striker to wait for the next cycle. Guys, seriously, this is nothing short of magic.

I found a great short video that demonstrates of all of this so I didn’t have to make one of my own!

Another great benefit of this design is that as long as you stay under 300′ of hose, you can use “T’s” and more hose to make “branches” to cover more than one location with the same bell. So at our gate, the hose crosses the ranch road at the entrance, about 75′ from our rig, and then again another 75′ down the road as you head into the ranch. This distance gives us enough time so that when we hear the bell, we can get up and go outside just as the vehicle is pulling up to our rig. It works really well, and is an excellent solution for the circumstances……..but it’s not good enough.

After doing this for a few days, I noticed a couple of flaws in the system. The bell sits on the ground just under our steps, and is plenty loud enough to hear inside the rig, unless you’re doing something noisy, like washing dishes, or watching TV. And you absolutely can’t use headphones. So problem #1 is that it can’t always be heard.

The other thing is while the “bing” itself is not unpleasant, and sort of nostalgic, when a multi axle vehicle crosses the hose, it doesn’t go “bing”, it goes “bing….bing….biiiiiing………….biiiing” while all the wheels roll over it, and it sounds more like an old telephone than a gas station in 1955. This is not a big deal when you’re inside, but if you’re outside, it can be really obnoxious. Especially if you’re sitting out in the nice weather, and the bell is only 2 feet away. It was designed to be heard in loud gas stations and over traffic and air compressors and guys named Smitty cussing because they scraped their knuckles trying to loosen a stubborn bolt. And it’s especially obnoxious after you’ve logged someone in or out and they then cross over the second hose as they continue in or out. At that point you don’t need to hear the bell, it’s just pushy and needy. So problem #2 is that even though it works really well, it works even when you don’t want it to. Here’s a little sample of how annoying this thing can be….

 

 

All my life I’ve been accused of being impossible to please. (Not true. Evidence: Pie & General Tso’s Chicken.) It’s just that once I realize something can be better, I generally categorize it as broken, and want to fix it. So, it bounced around in my head for a week, and I figured out a way to fix both problems, with very simple solutions.

Not Good Enough #1 – I added a clear 60w candelabra sized LED light to the circuit, mounted it on a little scrap of wood, and put it inside the rig. It’s small enough to go anywhere, it’s pretty bright because it’s clear and LED, and since by nature, the circuit is momentary, it flashes sort of like a lazy strobe, and allows me to use headphones to listen to a movie or a podcast or play a game without waking up Tracy, or just adds a visual cue to the sound of the bell, which helps to avoid hearing “phantom” bells. After I made it and was so pleased by how it did exactly what I wanted, I realized that I wanted to be able to move it around (See? Nothing is EVER good enough!) so instead of having it hard-wired into the circuit, I cut the wire and put a female receptacle on the bell side, and a male plug on the light side. Now I can add an extension cord and put it pretty much anywhere. At this point the only way to make it better would be to use a spring-loaded self-winding reel with enough cord to go anywhere I want, but that would be bulky and expensive. Or wireless power, which solve a LOT of problems, but doesn’t exist yet. Maybe before I die.  (Ok I have to jump in here.  I had no idea this was a problem he was trying to solve, so I went to bed and then woke up to something that looked like an 8th grade science fair exhibit.  Don’t get me wrong, the whole thing is pretty cool, but freshly awake and with no coffee in me I was understandably confused by what was happening. Then again I am married to MacGuyver so nothing truly surprises me at this point. -Trace)  Take a look at how it works:

Not good enough #2 – I added an inline rocker switch to the main power and mounted it to the outside stair rail. Now when I get alerted and I go outside to log the vehicle, I can switch off the power on my way out. I can log them in or out, and I don’t have to listen to the bells as they continue down the road, then I can switch it back on when I go back inside. (This is a pretty cool feature. For me the jury is still out on the strobe light, but I like being able to turn the bell on and off.  It’s pretty loud at night and sometimes trucks stop and sit on the air hose to talk to me and go off a ton making it hard to hear.  I also get worried in those scenarios the noise will wake Lee up, so now I can easily switch it off. It’s not something I would have even thought to ask Lee for, but now that I have it I am glad I do.  Lots of Lee’s inventions are like that. – Tracy)

It looks a little rough because it’s meant to be temporary. Added bonus, I oriented the switch so it’s rocked position is in the direction I’m heading, so as I go out the switch is pushed away from the rig, and as I come in, it’s pushed towards the rig. It’s not that big of a deal, but it’s the little things that make happy less unhappy. The only problem is (nothing is ever good enough….) I have to remember to flip the switch when going out, or coming in, or both. So I chewed on that, wondering if I could come up with something simple that would automatically do the switching as I went in and out, thus taking my ever decaying memory out of the equation. Pressure switch on the stairs? Plunger on the door? Electric eye beam? Trained monkey? Nothing seemed like it would do the trick without some sort of electronic circuit with relays or timers, and that started to get more complicated and/or expensive a solution than the problem warranted, so I decided that while what I have isn’t good enough, it’s good enough. (That’s progress – Trace)

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