Making SLOW progress...
Gosh - these last two days have been PAINFULLY slow... But that's ok - I have to keep reminding myself that I'm in no hurry and to slow down, enjoy the process and do a quality job. It's when I rush that it seems to take longer because I'm not happy with my workmanship and end up re-doing it - or it doesn't work as advertised and I end up having to re-design.
I really wanted to fabricate my above seat steering bar out of aluminum. I have a bunch of good aircraft grade aluminum tubing and I have welded aluminum only once, so I thought this would be a good opportunity to try again. Man - compared to steel, this stuff is very tricky. Aluminum heats up like crazy and once you break through the oxide layer with a melting temp TWICE as high as the aluminum itself, the weld pool gets bigger and bigger unless you really watch your power. I went ok - I was fairly happy with the steering bar, but not so much with the hinge.
My idea was to hinge the steering column so that I could rotate it up and over the front tire to allow getting in and out of the fairing. The aluminum for the hinge and column is 1/8" thick and welding a flat bar onto the side of a round tube is always tough - this was especially difficult. When I completed the steering bar, I discovered that the hinge didn't exactly work as planned - If I kept the bolt loose as planned then there was way too much flex in the hinge area, so the bolt needs to be really tight. SO now, in order to loosen it to rotate the steering column up and out of the way, I'll have to use a wrench or something.... Going to need to re-think that. For now, I'll finish it as is, use it for a while and think about some other way of moving it for entry and exit.
I'm using a handle bar stem for now so I can make sure I know the exact best location for the bar itself before welding the bar onto the steering column. The steering bar works awesome! I went for a short spin and it's a million % easier to steer than the underseat system (well, at least 20 percent better). My arms are up higher and it feels pretty comfortable. The steering leverage is also much greater and the biomechanic action of turning the bar above is more natural than below. My hands are also at a comfortable and natural angle - much like the hand grip angle on the M5 lowracer steering tiller.
If anyone out there in internet land has some aluminum welding hints for me - let me have it.
Also - Ben did some new roll over calculations on the new lower geometry. Details are in this addendum paper. My roll over limit with a safety factor at 45 kph is a turn radius of 76.8 feet or .68 g's. I've been looking for some highway design guidelines on the internet to see if there are some rules regarding highway speeds and minimum turn radius to get an idea of what the tightest highway corner would be. If anyone has any insights on that, please let me know.
TCR2 (track) 2Do LIST:
1. Make a platform for the wind trainer (mini-rollers)2. Add front caliper brake
3. Mount first fairing and all the work required with that4. Make CF front wheel fairing
5. Make CF rear wheel discs
6. Make a new steering bar that rises up a bit higher - also takes up less room on the sides so fairing can be tighter
7. Adjustable seat height
8. Make fiberglass canopy top with acrylic bubble and tailbox
9. Paint this puppy!
10. Rear strut supports
11. lower and chop
TCR1 (cross country) 2Do LIST:
1 Add front derailleur
2 Run road, roll-over and watts tests for new suspension system3 Worm gear steer prototype (Waiting for final design and parts list from Ben)
|TOTAL distance on TCR1|
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