The Beginings

It is said that once the first step is taken the battle is half won. It has taken me two months of procrastination to take my first step into the domain of the custom frame builder, after 3 hours spent on the project confidence is high.

Preperation is key. Half of my first session as a frame builder has been spent welding up a basic brazing table. At first glance an ugly, rusting fusion of mild steel but look a little closer and it will all make sence. I cut the box-section to make a table the perfect size for my frame so that each frame tube will have two adjustable supports resting on the table when i come to final assembly ready for brazing. The size also allows the lugs to overhang the table so that no heat is directed onto it causing expansion of the table which would affect the positioning of the frame compnents. The centre is left open to allow me to stand in the middle so that i have easy access to all sides of the lugs when brazing. Finally i have welded a second cross member at the front which will allow me to position the
frame vertically when constructing a jig for the rear triangle, helpfull as this means that i can set the axle width & alignment along with the bottom bracket drop with ease.

Now to beggin the frame. After studdying my current cycles i decided to opt for a 57cm top tube and a 73 degree teat tube & head tube angle. Once i had established these angles a bit of trigonometry was implemented to calculate the other lengths. With all legths and angles establised i was able to begin cutting and the logical place to start was the seat tube. The first task is to insert the seat tube into the bottom bracket and mark the miter that needs to be cut so that the tube does not protrude into the BB shell.
Once marked the tube is removed and i used a bench grinder to form the miter.

Once this is done the seat tube can be cut to the correct length and the top mitered to follow the profile of the seat tube / top tube lug.

Seat tube finished my attention was next directed on to the top tube. The top tube abuts the seat tube inside of the seat tube / top tube lug so the mitre has to be more precise than the the first two which do not abut another tube, i used a simple bit of software to produce a template to follow grinding down the profile using a rotary tool which is more precise than a bench grinder.
Perfectly formed miter:


So at the end of evening one i have cut and mitered the tubing for half the front triangle.