Introduction: Two Bicycle Bells From a Rotary Telephone
I'd been cleaning up the estate of a late friend, and came across some old rotary phones. While I have thrown out a mountain of trash, I could not see these babies go to waste. They were made from quality components and built to last a lifetime. When the black wall phone popped open and I saw the brass bells* in the ringer, I immediately recognized their similarity to a bicycle bell and started thinking about how to make the conversion. How appropriate this would be for a device built for a company known colloquially as "Ma Bell"! I let the wheels in my head turn on the bike bell idea, and one day I had a few minutes to tackle the project. It ended up taking no time at all, and produced two bells. I should mention that rotary telephone models vary a lot. If you do not have a phone of the same type and vintage as mine (ITT Model 554), you may have to make considerable modifications to my methods. Be flexible and adaptable and you'll get it done.
Rotary telephone: I used a wall phone, the kind that hangs on the wall vertically, like we had in the hallway when I was young. I can't tell you how many girls hung up on me while I was on that phone in high school.
Bicycle reflector: the type that attaches to the handlebars. It's the bracket you need, not the reflector itself. It will require two of them to make two bicycle bells.
Bicycle spoke: for making the clapper on the second bell. Any similar wire, such as a coat hanger, should work.
Screwdrivers: One Phillips and two flat blades (one average sized and one tiny).
Needle-nose pliers: for cutting and bending wire.
Air cut-off tool (or hack saw): for modifying a clapper.
File: for removing burrs after cutting metal.
Electric drill and bit: for drilling holes in a reflector bracket, if necessary.
Fine steel wool (optional): for shining up the bells.
*technically, the ringer in such a phone is composed of gongs and strikers, but I'm going to call them bells and clappers, respectively, for the purposes of this Instructable.
Step 1: Remove Bells From Phone
The entire front cover of wall phone pops open via spring clips on the top and bottom to reveal the guts inside. Your method may differ depending on what telephone you use. The two brass bells are each held in place by a single 5/16" bolt at the center of the back, which is easily removed with an appropriate wrench. Save the bolts for later. I shined up the bells with some fine steel wool, and if I can find my brass polish I'll make them really bright. Now, these bells are kind of heavy by bicycling standards, so if you're a weight weenie, these might not be the things for you. But then, if you're a weight weenie, you probably don't put a bell on your bike at all!
Step 2: Remove and Modify Clappers
One of my goals for this project was to use only phone and bicycle parts; the other goal was zero cost. Re-using the phone's clappers was fairly obvious. By removing two machine screws, as shown in the photo, I freed the entire ringer apparatus. This phone has two clappers (the weighted arms that strike the bells), perhaps because it was capable of producing two tones. One is large and one is small, so I'm calling them the major and minor clappers, respectively. Removing two small screws at the base of the minor clapper freed it. I used the minor clapper for the first bell. I removed the major clapper as well, but that wasn't really necessary because I used only the weight from it. If the arm of the minor clapper that had been screwed into the ringer apparatus were removed, then the remainder could be used to attach it to the bell and bracket, so I cut it off with an air tool (cutting wheel), though a hack saw would have worked. I filed off the burrs afterward.
Step 3: Attach Clapper and Bell to Reflector Bracket
I took one of my many reflectors salvaged from various project bikes (I once bought 10 rusty bikes for a dollar at an auction), and unscrewed the reflector. Like a miracle, the screw from the reflector bracket happened to be the same exact size and threading as the bolt from the bell (I cannot guarantee this will happen for you). I used the screw because the bolt wasn't long enough. I screwed the reflector bracket and minor clapper onto the bell (via the original bolt hole) as shown.
Step 4: Final Adjustment and Test of First Bell
All that remained was to bend the wire of the minor clapper as shown until the weight was within about 1 mm of the bell. It sounds louder if the weight is closer to the rim of the bell. When the weight is pulled out and released, it returns to strike the bell, creating the ding sound. Many store-bought bicycle bells operate in this fashion. The wire should not be touching anything along its length to its point of attachment, or its action would be dampened. I mounted the bell on one of my bikes and gave it a try. Enjoy the video.
Continue on to see how I made the second bell.
Step 5: Make the Second Bell
After I had finished the first bell, I kept looking at the leftover bell and trying to figure out what to do with it. I wanted to make a second bicycle bell, but I couldn't use the major clapper because it was not springy at all. I needed a different wire and a weight, and I would have to fabricate them. The weight on the major clapper was removable! I backed out the tiny screw with a tiny screwdriver and removed the weight from the major clapper. I had an old bicycle spoke that seemed to have the right size and springiness. I cut a 4-inch length of spoke and screwed the weight onto one end. The other end I bent into a loop with needle-nose pliers. I grabbed another reflector out of my box and removed the reflector proper from the bracket. This bracket had no holes, so I drilled one for the bolt that had come with the bell and another for the little stud that protrudes from the back of the bell. By sliding the stud into the hole, the bell would be a lot more stable on the bracket. For this one, I put the spoke between the bolt head and the bracket to provide more space between the clapper and the bell. After all was screwed down tight, I used the needle-nose pliers to bend the spoke in two places so that it came within 1 mm of the bell. Again, the spoke does not touch anything but the bolt (even though it kind of looks like it does in the photo). The spoke was not quite springy enough for the pull and release method, but I found that slapping the weight with my middle finder produced a pleasing tone (see video). Now I can blast Queen's "Bicycle Race" and ring my bell, then play "Fat-bottomed Girls" and yell, "Get on your bikes and ride!"
Step 6: Make a Bell From a More Recent Phone
The older phones are perhaps too valuable to scrap and harder to find, so I added this step to quickly describe making a bell from a relatively new phone. It has to be a phone with a mechanical ringer, not an electronic one. More details are in the photos, but I'll summarize the process briefly here. I opened up the phone by removing screws and removed the bell. Removed the bracket from the bell. Removed the magnet and coil from the bracket and put the bracket back on the bell. Screwed the bell bracket to a bicycle reflector bracket. Screwed a spring to the bell bracket and screwed a large screw of just the right size into the spring to make a clapper.