Vallie Components - bicycle part and accessory design

With just a few thousand turns of the lathe and a few pulses of the TIG torch, I've managed to create what may be the worlds first Sram I-motion 9 compatible Gates CDC cog!

Its a ridiculously tight fit, but it works! This is going on a Civia Bryant, which is thankfully already belt compatible. 

Sometimes things get dark and complicated.

But then they don't look so bad in the next day's light.

I didn't go to NAHBS this year, and so this past Sunday morning, hungover from a friends birthday bowling party the night previous, I set out to design a fixture that would allow me to accomplish all the major rear end mitering operations involved in bike building. Slowly through the course of the afternoon, I chipped away at a 3D model. All this while checking out photos of rad show bikes.

The fixture had to:

• allow chainstay mitering at both ends
• allow seatstay mitering at both ends
• accomodate tube sizes to fit most bikes
• accomodate tube lengths from BMX to tall guy touring bikes
• accept all new fat/DH axle/BB standards.
• be intuitive enough to set up, that I don't forget how to set it up

I ended up with this later in the day (click for bigger and less jpg compression):

It seemed passable, as a first draft. No need to get any approval stamps when you're also the guy who's going to cut the metal.

Monday I got started on the small pieces. Its tough to decide whether to build up something like this from the biggest, or smallest parts first. In the end, I decided to do the V blocks first, as they seemed the most complicated, and there were eight of them.

They do make a nice V shape with the 25degree cut.

Next up was a quick mock up of the basic shape. I enlisted the help of my coworker for a sizing guideline. If the stays are cat-length, then we're pretty much good to go.

According to my model, I had to drill something like 22 holes, but of course, once I got the part squared in the mill, and started tapping, I couldn't stop. I ended up doing a nice matrix of 3 x 19 M6 threaded holes. Accurate to within 0.001" over the entire cat length. The entire baseplate took less than 1.5 hours. Tappa Tappa Tappa

I opted to not put a sliding key way on this one. The sliding plates have their slots precision milled for very little play to the 6mm bolts. I figured that each time I set it up for an operation, I would be double checking the symmetry by mounting it in the mill and referencing off of the stays anyways. By Wednesday I was itching to get it all assembled and tested, so I hit up Pacific Fasteners with a specific list of hardware. No suprise, they had every single bolt I needed. Thanks again guys!

I got back and got to work making the rotary table mount, modifying the sliding plates to clear said rotary table, and assembling. I ended up having to modify the narrow end V blocks in a couple of operations as well. By the end of the day I was FINALLY ready to do a test cut, and I grabbed some scrap stays from a bent up Surly Pacer. I straightened them as much as possible, and threw them in the fixture. After setting everything up in the fixture, and having a look at it, I called it a day there. what would the point of rushing through the fist cut be if I was too tired to enjoy it?

This morning I had some CAD work to get through, so I managed to avoid the fixture creeping behind me on the milling table for like 3 hours. Finally I broke down and paid it some more attention.

Knolling out the tools needed for setup is a vital operation. It sort of a mental prep to get in the headspace. Ask any under water welder just how important it is to have everything ready before hand.

Here's how I left the stays in the jig overnight. I decided to emulate the mitre on the rear end of my new Brodie Romulus. This meant I actually had to pre-cut the stays to get them close enough before the actual hole saw mitre (not shown). After everything was clamped down again It was time to play with my newest toy. I call it "Mr Tilt Box". I'm willing to bet this little box contains the same chip that I installed on the rear axle of my track bike.

At this point I would like to break to mention how addicted I am to 44 bikes Flickr Stream. He makes all sorts of rad bikes in New England, and his shop pics are a huge inspiration to me. Follow/Add him if you have not already!

Anyways, four days later, and I'm at the moment of truth. I finished my coffee, got the coolant spray bottle handy, did a handful of setup checks, and fired up the machine. Slow and steady pressure on the drill handle is key, as you can feel the teeth digging into your work. I think I did the cut at around 450RPM, and only started spraying coolant halfway through.

Made it through! Now a shot from the underside. This is a rare view that usually only a seat tube sees:

I'm sure that after a handful of frames I'll find a bunch of flaws in this fixture, but for now, it will have to do. Next up I'm going to make a dummy axle holder so it can be used to weld rear dropouts, and to hold the stays even for BB shell mitering.

We're getting very close to the first frames out of Vallie Components! Be warned!

Currently building up a new cargo test mule. Being an organized parts hoarder finally pays off, in the form of a simple chain keeper system.