Tag Line

"Built Dam Strong!"

23 May 2012

Cardboard conundrum, or Poor Man's CAD

Today I spent some time getting down and dirty with cardboard. If you're on the internet, I am pretty sure you've heard about CAD, or Computer Aided Design. It's really rad and all, but, for many people who build stuff, it is still out of reach other price wise for software, or, in my case stupidity. (I've never learned to use any of it.) There is another alternative, however, that works better for many people, especially if you like to get hands on and try to make things work, or, if you have something that you only need to make one of and that one thing has to fit on something that wasn't made with particularly tight tolerances, like Mike's bike, for instance.

I will say today was semi-embarrassing. Well, it is only embarrassing if I tell you about it, which I am going to so that makes it embarrassing. What shouldn't have taken more than a couple of hours took me all day. Being out of practice sucks, and not being with the tools I am normally accustomed to have to aid me in my pursuits. Enough excuses, on to pictures!

I started with the battery tray, since that needed to be set at a depth that would allow for a maximum of 60mm or so for the battery and electronics:



This also led to the first of many revisions to my measurements. The gap you can see on the sides of the straight up and down piece were too great and with the next version, I tightened that up considerably. 

Lots of scribble, lines, and mistakes that all get confusing:


But, after cutting the right pieces out, I end up with this:


Very minor profile! The gap there is from the thickness of the cardboard hitting the brackets. I might have to make a slight trim on the actual metal, but it is nothing more than about 4 seconds with a cutoff disc won't cure. 

Here's the interior of the battery tray:


Plenty of space for whatever Mike wants to stuff in there. 

Here is a view from the other side: 


I didn't get a lot of in-progress pics for the next part because I was busy and email cell phone pics to Mike to clear up some concerns I had with how things should fit around the tank. 



One of the reasons why it took so long to do was that I discovered that with the tank in place, it was impossible to get the seat pan as close to the tank as Mike wanted while having the top of the seat be completely flat, as if you look from the side, there is a lip that comes off the back of the tank. So, I raised the front support for the seat (I didn't grab pics of that, oops) by a 1/4" and that gentle slop raised the front of the seat pan enough to clear the tank. Also, in the side view pic above, I had to slowly trim back the front of the side sections in order to clear the lip. Lots of back and forth and fit and test and cut and draw and cut. LOL!

Before I get too far ahead of myself, I should explain a bit more about what is going on. Mike wants the seat low and lean, to keep the lines of the bike flowing with minimal visual interference. The custom hoop that I installed a few days ago is part of that design. Looking, well, staring at the bike when I first got it, I saw a natural break in the supports for a seat pan. What I envisioned was making the front section (as you see above) then making the rear section (as you'll see following this mess of text), joining them together at their vertical supports in the middle. This would make the seat stiffer and the metal easier to handle. (Separate pieces are easier to move around, cut, form, drill and weld on than larger, bulky and floppy pieces.) With that being said, it's time to move on to more pictures.

This is a support I made for the template:

The longer piece that is inline with the frame is not going to be in the final seat. I just make it to prevent the cross-brace from falling over. heh 

There was a huuuuuuge gap in pictures again, but here are the final ones:




My brain is so rusty. It took hours to figure out the rear section. What happened was I wasn't using the correct radius for the ID of the bent tube for the hoop. I was using the centerline radius (4") instead of the ID radius (3.75"). UGH! I wasted a lot of cardboard and time. BUT . . . I got it figured out!



I don't have a ring roller (yet) so rolling that ring for the rear of the seat is going to be tricky. I have something I want to try with my newly acquired bead roller (thanks again, Mike!) to mimic a bead roller. Since I am only dealing with 18g steel, I think it will work. Time, and this blog, will tell.

Side view of everything mostly in place, though not everything is seated as it will be:


And the final pic for the evening:


As much as this was a pain in the butt, I really enjoyed the work, even the frustrations of it. My brain was actually working (though creaky and in need of lots of WD40). It is so hard to describe the joy I get from doing this kind of thing, and that is why I want to keep doing it, constantly improving in everything I do. I love these kinds of jobs, as I get to learn-relearn, improvise, adapt, overcome and ultimately bring something into this world that was previously only a dream or a sketch or a thought or simply a desire. Mike said "I would go so far as to say I'm alarmed at how perfect that seat is to what I envisioned." That's the kind of work I try to do.

Now let's see if I can translate that mess of tape, cardboard and pen lines into a functional version in metal that will be enjoyed by Mike and probably his wife. I can't wait! =)