This weekend I visited Tom in Virginia. We traveled to meet the fabricator who will be making the gear assembly. The shop was old and filled with old stamping and bending machines, and shelves full of dies used in previous jobs. We talked with the project estimator and were given a tour of the facility. Both Tom and I came away with a high degree of confidence that these people knew what they were doing. It was a worthwhile trip. We picked the brains of the people who knew more about this kind of metal fabrication then either of us do. As a result, we began work on what we hope will be the design that we will send to them. You can see it below.
AutoCad Assembled and Exploded Views
The design permits the counter to be read with the numbers from left to right, rather than the former sideways top to bottom. The drive gear is driven by a tang bent toward the spokes. It will be long enough for some bikes. A slide-on extension will be provided in case it is not long enough.
Construction will be either galvanized steel, as formerly used, or stainless steel. The metal gauge will be at least as thick as on the former metal gearboxes.
Tom and I have been working on this together, and the collaboration has been fruitful. Tom has expertise in AutoCad, which allows him to do detail drawings on the computer screen. This makes design changes easy, and also allows the fabricator to be sent an electronic AutoCad file, which most modern fabricators seem to like because their machines can be fed the data directly.
Tom also has access to a man who runs a waterjet cutting company, and he has cut out several prototype gears which Tom has been using in his development work. He used these gears to produce the working prototype shown below. A 24 hour run of the counter at 15 mph will be done to be sure there are no unexpected glitches. More as time goes by. We are very close to a final design and placing an order.
This is the Working Prototype.
We have obtained a domain name and will be setting up a web page once the counter drives have been ordered.