Friday, January 9, 2009

Chop....chop....chop....

I finished up some small fab jobs this morning, and left the afternoon for the frame. First, I bent the backbone. I came up the backbone tube 11" from the seatpost, and made the first bend at 10 degrees. I wanted a nice, long, straight section on the backbone for the gastank.

I know the frame looks like it's stretched up and out, but it's not. I used a neck/old backbone section that Dennis Goodson had given me a few years ago. The neck is welded lower on the backbone section Dennis gave me than the position of the neck on the VL forging . The neck height is only a 1/4" higher than the VL was, and the distance from the seatpost to the neck is exactly the same distance as the old VL backbone. I put the donor neck/backbone in the chop saw, and cut it to length, with a 45 degree angle on it's end.

After I trimmed the new 1 1/4" OD backbone to length, I slipped the donor neck section over it, and got the angle I needed for the new 1 1/4" OD downtube. I bent this to 15 degrees, and it was perfect. I layed the downtube up against the neck, and got the angle for the fishmouth joint on the neck. After cutting the fishmouth, it was just a matter of making sure all the new sections aligned and fit tight. Done!

Also, if you look right below the tranny plate, you'll see the sleeve for the downtube fishmouthed and cut on a 45 degree angle. That will slip over the downtube to give it the original look of the old VL downtube. The backbone and the downtube will both get shorter sections with 45 degree cuts added to those end cuts, to resemble the original double VL frame sleeves.
Some high-tech alignment shit going on here! Hey, plumb bobs, levels, tram gauges, and angle finders don't lie. They're a quick and accurate way to determine if you're on the right track as you're fitting everything up. What do you think we used before lasers and computer generated images????

And......we hit our neck angle at 35.5 degrees. Very cool. Notice the nice fishmouth for the downtube - that couple Hundred for the fishmouth jig was money well spent years ago, along with the hydraulic E-Z Bender for the tubing. You'll also notice I've ground out some of the weld on the neck - I didn't like it, and I'm going to go over it with the TIG. Now, I'll have to spin the table around, unbolt my tubing bender from the table, bolt the neck tower fixture on the table, and the hold-down fixtures for the frame so we can clamp everything in place, and start welding.

1 comment:

Neil said...

Looking cool. Your step by steps are very helpful.