This falls under things I do which are so stupid I should be embarrassed to share them…
I need to run flanges on the shovelhead exhaust so the 2 into 1 pipes can be separate, in order to get them on the bike. Most exhaust flanges are rather large since they go underneath a car where no one ever scrutinizes them. Since mine will be out in the open I’m not willing to settle for off-the-shelf parts…why start now right?
So I whipped up a quick drawing, as per norm I don’t plan on getting the first one right so I made some extras.
The flanges are 1/4″ plate. I want them to match closely so I cut 2 pieces of 1/4″ plate and tacked them on the ends so I can make two at the same time. Here are the plates with the pattern transferred and the holes prick punched.
I ran a center drill on each of the punched holes to start. I’m joining the flanges with 5/16″ bolts, so I drilled clearance for those first.
Using my lowest RPM, lots of cutting fluid and slow even feeding, I managed to chew my way through the 1/2″ of material with a 1 3/4″ hole saw of unknown make. I didn’t think it was going to make it, but some how it managed to pull through. It’s pretty well useless at this point for anything other than pine I would guess. At any rate – here’s how I leave it for the evening. Tomorrow I’ll be roughing out the tabs and OD of the flanges and then filing to the final shape…not really looking forward to it. I wish I had room for a mill.
I’m too impatient to wait for the tubing notcher auction to end, so I decided to give the notching calculator a try. I plugged in my measurements and printed the results.
You’ll note that I printed a few – I figured I wouldn’t get this right the first time around. Step one was to cut out the notching pattern.
Here’s the pattern on the pipe (with marking fluid) ready to be scribed.
After I transferred the pattern, I roughed out the cut with a grinder and used a rough bastard file to clean up the edges.
Here’s a test fit on another piece of pipe.
All in all, the tubing software works like a dream and was quick and easy. I wasted about 2 hours trying to hand cope the pipes on Sunday, but using this method took about 20 minutes and the fit is beautiful. If you need to cope a pipe or two I strongly recommend the web app. For small production you’ll probably want to invest in the notcher.
After some fishing around online I’ve discovered two solutions for coping the rear pipe:
1) Purchase a tubing notching, which should solve my bit deflection issues I had yesterday. Looks like there’s one on eBay at the moment which is reasonably priced and close by.
2) Use the Online Tube Coping Calculator. Pretty damn impressive.
I’m going to start with the tubing calculator and pick up the tubing notcher if it remains reasonably priced. More later…
My plan for the exhaust is to run 2 into 1. I’d wanted to connect the rear pipe to the main pipe at the same angle as the front.
I wasn’t sure the best way to cope the rear pipe for the angle needed. I tacked the pipe to a plate and clamped it up in a vise at the angle. My plan was to run a hole saw down to cope.
The angle looked too steep, and ended up being too steep. Lots of chatter and flexing in the quill. I’d prefer to come up with an easier way than blowing out my drill press.
Anyway. Here was the setup.
My plan is to run them in tight and above the frame for decent ground clearance.
I had to carve some out of the pipe to make space for the ignition cone.
Other than putting the set screws in to hold the bottom covers on, I’m going to call it done.
I had one of these on the last version of the bike which held the speedo, but i needed an updated version to hold the kill switch.
I figured I’d better add some bottoms to the console to:
A) keep the switch dry, and
B) make it look a bit better