Friday, December 9, 2011

Home of the Braze pt. III

Okay, I lied again.
First of all, it's not like I intend to lie, it just sort of comes out that way.
So what did I lie about?
This whole frame making thing being easy.
It is easy, once you get past the hard part.
If you know what I mean.
So, you can braze two pieces of scrap together, now what?
Well it turns out there's a whole mess of whats.
First of all is the jig.
That's a whole 'nother DIY project of seemingly mega proportions.
Complex as it may seem, it actually doesn't look that difficult.
More on this later.
Anyways, you gotta find your tube set:

Nova Cycles

Boy, them tubes sure look pretty.
Looks are deceiving.
This looks easy, but isn't.
There are like a GAGILLION tube sets out there.
You got your Reynolds, Columbus, True Temper and the generic stuff.
This may take some heavy math as once you eyeball the tubes, you gotta match them up to the lugs:

All images from Nova Cycles.
Head tube, and seat tube.
Most important, the bottom bracket:

Then you got your angles.
Apparently, this isn't really important as these lugs are investment cast so they aren't perfect.
Meaning some work will be needed to get them prepped for use and the angles vary some.
Then some real rocket science.
The tubes need to be mitered.
This may be the hard part, I'm not sure for I've never mitered tubes.
At first it sounded easy, then I sort of thought about it and there are about a GAGILLION things that can and probably will go wrong.
Then again, I think I've worked through half a GAGILLION of the problems and solved some stuff, unfortunately that still leaves the other half.
I got a drill press and some bi-metal hole saws so the cutting part is not what's worrying me.
It's the holding the tubes in place while the cutting part is happening. I can see all sorts of vibrating and undulating action going on if things aren't set up right.
I mean you can't just clamp down a tube with walls less than a millimeter thick and I'm thinking drill speed is going to be sort of critical.
Not too fast, not too slow, but just right.
There's also the alignment to worry about, which mitering seems to play a large part in.
Then we're back to the brazing again.
In retrospect, it may be a bit more difficult than I realized seeing as how the tubes are so freakin thin and brazing the lugs which is different from fillet brazing.
Working with thin metals makes me nervous for it's fairly easy to burn through the stuff you're working on.
That and the potential change to the structure of the steel via excessive heat, making it brittle.
Of course there's more, like working with lugs and the prep, but I won't get into that.
Like I said yesterday, making a frame sounds easy.
Once you get past the hard part.
The thing is, I got about three quarters of the stuff I need for I've done some fabrication before.
I mean if you're starting from scratch it may take a lot to get going.
You are going to need to gather up all your stuff and then do some trial runs.
I'm pretty sure I'd go through some tubes before I got it right so you can write off at least one bottom bracket and maybe one whole set of tubes.
For me, I'd plan on doing at least two frames, the first one being sort of the test bed, the second one for keepers.
If you came away with two ridable frames, you may come out ahead.
Would I try it?
At this point, maybe.
There's very little(!) start up cost for me, most of it would be in materials.
If I was starting from ground zero, I would really have to think about what it means to me and how far I was willing to go.
I'm pretty sure the extra mile would be involved.
If you know what I mean.


Trevor said...

I think that this will only work and be worthwhile if you adopt an Italian sounding name before you start...after all I did think that it was Italian goodness that you were after......


John Romeo Alpha said...

There's some free software you can go and download called tubemiter.exe for making templates to miter your tubes. When you look at the inputs, and then at the templates it spits out, and start thinking about following the line indicated by the template, and keeping it centered since the miter on one end has to have the right relationship with the miter you made on the other end of the tube, well, it starts to sound pretty challenging. Just do it!

Steve A said...

Per Trevor's comment: you have a choice between Limono and Limoli. If you want to go in a new direction, carboni would also work.

limom said...

Trevor, from now one you can call me limomaronianoni.

JRA, I'll take a look.
Just don't be holding your breath on this either.

Steve A, you can call me SIGNORE limomaronianoni.

John Romeo Alpha said...

I think I will go by JRAiach. It's pronounced "hrrrerrch".