Firefly chain stays require two separate jigs to make them fit between the dropouts and the bottom bracket. One for each end of the stay. Here we are going to take a look at the slotter. The slotter makes a slot on the dropout end of the stays to line up the dropout in it’s desired location. This is more than just a jig, it is a purpose-built machine made right here at the Firefly Workshop.

The stay fits into the slotter which makes a consistent and accurate cut with no need to set it up differently for the multiple shapes and tapers that we are using. This machine falls in line with our newly formed tool making motto: first cut = only cut. If the jig is right, the cut is right. We like to take the time up front to really think these things through, saving time later and making it easier for us to repeat processes within a predictable time frame.

Another bonus of creating efficient jigs and methods is that we can be more accurate at tracking our throughput times and then be able to predict lead times accurately, delivering the finished bikes on the date we say we will.

A couple of things we have been striving for are making the tooling as small as we can to do the job and as simple as possible so that we can be as efficient as possible with the least amount of set up and changeover times.

The slot serves to set the chain stay length in reference to the dropout and then register the bottom bracket miter on the chain stay mitering jig. Being that each bike has the potential for different length chain stays having a machined and consistent slot makes everything line up accurately, again confirming the math from our formulas.

Now it’s time to put it in the mitering fixture…