"Just what equipment does it take to build a frame?" This is a question that gets asked across the forums and of builders literally weekly by those that are enamored with the idea of crafting bicycles for a living. It is interesting that within this small niche, just how diverse the approaches can be to reaching the same end...a self propelled construct on wheels that brings a smile to your face. Often the competitors that end up in the ring to battle it out are the hand filing/minimalist tooling vs. machine driven ideology. Recently, this discussion surfaced again on velocipede salon. Here are a few of my thoughts as shared with the original poster....
Here's my perspective. It is not necessary to have heavy machinery to build a simple bicycle frame. If your goal is a single frame at a time, custom designed for it's intended user and defined purpose, your money and time would be better spent as noted by the respondants above. Richard and Dave are two fine examples of folks who operate as professionals that fabricate their style of bicycle with minimal tools and loads of muscle experience. This maximizes their time and ultimately, their money. Low capital investment in machines and tooling allow them to pay themselves a living wage, actually surviving long term in this business.
Machinery becomes necessary when your desire moves beyond simply shaping a bicycle frame, one at a time. Machines allow two distinct advantages; the ability to miter multiple tubes with fantastic speed, accuracy, and repeatability for production runs, and allowing for the creation of fixtures, tooling, and the ability to fabricate your own unique products (bb's, dropouts, derailleur mounts, etc..) that solve either design or function issues, extending your ability as a builder to create custom products that go beyond just geometry. The trade off is that to do so means a substantial investment in not only money, but of time. Careful planning of time allocation and customer billing is required to insure that this business model not only pays for it's self, but pays you.
So, it comes down to what do you want? Will this continue to be a hobby or a career path?
If choosing this as a career, do you have the machining foundation and knowledge of fundamentals to put your purchases to use immediately, offsetting the cost with profitable fabrication?
Frame fabrication can be as simple or complex as you choose it to be. Ultimately the process is defined by your vision and it's requirements.