First Lug Work

Posted: November 21, 2011 in Lugged Bicycle Frame Construction

So after many days/weeks of deciding whether or not I could do this or if I was just flushing money down the toilet I got my ducks in a row and ordered my tubes and lugs and as noted in the previous post they showed up Friday.  Then I had to go and buy the rest of the stuff on the materials list.  Stuff like a vice and grinder, some threaded rod and angle steel, etc.  I had a little epiphany in that a cabinet Lazy Susan base just happens to be the same dimensions as the vice I bought.  The Lazy Susan base is rated at 500 lbs so I thought “Why not?”  It’s pretty cool being able to easily spin the vice around while brazing up a lug.  I don’t really feel like running power out to and insulating/sheetrocking the little detached garage that will eventually become my shop in the middle of winter so for now the enclosed back porch has become my shop.

When I bought all my tubes and lugs I ordered an extra tube and a cheapo set of stamped lugs for something to practice on.  Below are the results of my first actual lug work.

I used the “Tube Notcher “ program on Nova Cycles to get my miter right.

A nice miter

Here’s a dry fit of the head tube/top tube.  When it came to the actual brazing of this joint I left the head tube out because 1.) I wanted to be able examine the penetration of the silver through the lug and 2.) I didn’t have a head tube for that lug set.  The head tube in the image below is actually the down tube for the oversized tube set that I will make the actual frame out of.

If only it looked this good after the brazing.

Here are some shots after the brazing but before the clean up.

Now here are some shots after cleaning everything up.

Left Side

Ride Side

The right side is definitely cleaner than the left.

Top

You can also see that I got a little build up of silver at the point on the lug on the top of the top tube.

But here are the important shots – the inside of the lug.

Inside

Another inside shot

You’ll notice that the silver penetrated all the way through and around the lug.

So if I understand the concept correctly this would be a strong, acceptable joint.  The only issues would be the wasting of a little silver on the outside of the lug and the time wasted in filing/sanding to clean up the lug.

All in all I’m pretty pleased with the first attempt.  I still have some practice tubing and the seat/top tube lug from the cheapo lug set so I give it another go tonight (if I’m not too zonked from sitting on the trainer after work).

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Comments
  1. Jayme Lynch says:

    what tool did you use to miter the tube? a fine? a grinder?

  2. Cyclops says:

    I used the “tube notcher” program found here…

    http://www.cycle-frames.com/bicycle-frame-tubing/Tabbed-Tube-Notcher.html

    …to get a the miter template and then used a Dremel tool (a Milwaukee actually) with a cutting wheel to rough in the miter. Then a bench grinder go get it really close and then a half round file to finish it off.

    • Jayme Lynch says:

      thank you. i am going to start building my first frame soon in my schools metal shop. i have been practicing my brazing and i am pretty comfortable with that. i just want everything to fit together the right way.

  3. Cyclops says:

    Cool, let me know how things turn out.

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