Trevor Jarvis On Lug Cutting

Trevor Jarvis demonstrated how a lug cutter might work out his designs and transfer them to lug stock. First, he works a out complete design set on paper. (Below.)

planning the lug set

Second, he sketches each design to scale separately on paper. Then he folds the paper in half and cuts out one half of the design, much as you probably cut out valentine hearts as a youngster. Unfolding the paper gives you an exactly symetrical pattern. (Below.)

Valentine cutting    Valentine cutting

Valentine cutting

Next, the paper pattern is glued to lug stock and spray paint is applied. After the paper pattern is removed, a stencil is left over to be cut and filed away. (Below.)

transferring the pattern to lug stock

The lug blanks themselves may start out as castings or as pressed steel. If pressed steel, then these are stamped from flat stock and pressed round a mandril to produce the lug blank with two sockets. (Below, a piece of flat stock, half-way to being a lug blank.)

former flat stock
former flat stock

(Below, paper pattern, pressed steel lug blank; the arrow shows the welded seam.)

pressed steel lug blank

The same procedure is applied to flat stock for making embelishments, such as fork crown extensions and seat tube ornaments. Some lug cutters call these 'bi-laminations' or 'bi-lams.' Some frame builders fillet braze their frames and then add these bi-lams to the joints, a technique developed by Claud Butler.

The flat cut-outs or bi-lams are then hammered into tube-fitting curves using a vice and appropriately sized pieces of round stock. (Below, Trevor hammering flat stock into a round shape using a cross-pean hammer and a mandril.)

rounding flat stock    rounding flat stock

Below, one of Trevor's finished seat tube ornaments, showing the round saw blade necessary for such work.

lug cutting tool

Below, some samples of Trevor's work. What can't be shown, of course, are the hours of cutting, filing, drilling, and sawing which go into a hand-made lug set.

Trevor's work, top head lug
Trevor's work, bottom head lug
Trevor's work, fork crown, ornament

Below is a foto of Trevor's workshop with a Gate on the jig.

Trevor Jarvis' own Flying Gate

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