Next up is the long and drawn out process of CAD: Cardboard Aided Design! (I got the name from this article: C.A.D.
I started off making a half-template of the battery tray from cardboard:
I started with the half for several reasons:
1. I wanted to see if Mike thought that the profile was OK with what he envisioned
2. Making the template "blind" from the drawings (that I linked to above) verifies that my measurements are correct.
3. Correcting any mistakes now by doing so checking saves much time in the future when you are working from known dimensions that fit well.
4. Start thinking of mounting solutions that are easy to access yet still secure enough to hold the weight against vibration and still out of sight so they don't impact the look of the bike.
Mike approved of what he saw so I started moving forward with the "final" template for the battery tray.
My scribbled mess of lines:
Final cardboard template:
The gap on that side is from the thickness of the cardboard hitting the tabs that are still on the frame. I really don't recommend using corrugated cardboard for templates for thin sheet, but it is what I had on hand. If you do have to use it, just be conscious of where your dimensions are taken from (either the inside or outside of the bends you make in the cardboard).
A view from the other side:
I managed to shorten the depth of the tray a bit, too, which helps in the overall look of the bike, I think, which is, again, what Mike wanted, and that's what he gets. =)
Plenty of space for whatever Mike wants to add in!
I didn't get a lot of in process pics of the next template because I was busy! heh This one wasn't too complicated, but took a few tries to get it to suit Mike's taste:
It might not look complicated from the side:
But it really is. Mike wanted a flat top, originally, but due to the tank shape, the front of the seat pan had to be raised up a little over a 1/4 inch at the front, which meant that the front support shape had to be changed, and the sides had to changed to accommodate the new height. This is all while the front section tapers to the centerline of the bike, making the angles even funkier. Also, the front section of the sides had to be trimmed back to fit around the edge of the tank and still allow room for seat material while remaining as tight to everything as possible. It was a headache, but I think I got all that stuff accomplished well, and Mike certainly was happy with minimizing the upward tilt and the low profile of the seat pan in general.
I thought the front part of the seat pan was going to be a headache, and I was right, but the front had NOTHING on the rear, mostly because of one mistake that I spent hours trying to "fix." heh
I started off with a simple mockup and support for the bracing:
I am not going to have the longitudinal brace in the final design, but since cardboard is floppy, I added it mostly to keep the rear transverse brace in place.
This next piece I added on was the killer:
It took hours to figure out WTF I was doing wrong, since nothing was matching up at all! I was a dolt and was using measurements from the centerline radius of the tube instead of the inner radius! ARG! That 1/4" difference was messing with all my math and drawings. After I "saw" my mistake, everything clicked into place.
Upper view of the proper radius fitted into place.
Once I got that figured out, I quickly moved on to the "ring" to trim the back of the seat:
I think that will be the hardest part to fit nicely without a ring roller, but I have a few tricks up my sleeve I am going to try. Worst case . . . it will be hidden by the seat cover and padding. LOL !
General side view of how it should look:
Making the templates gave me the exact measurements I need to make all the separate pieces for everything. The next step is going to be layout and triple checking measurements then cutting the pieces out of the big sheet and then using my band saw to make the final cuts. I'll actually use a hole saw to drill out the round sections that fit around the tubes. I am going to be adding "feet" to the supports to spread the force a bit and hopefully minimize paint wear, so I am going to use a 1 1/8" hole saw to accommodate the extra material. Lots of work left to do, but, the hardest parts (for me) are now done. =)
Much more located here:Poor Man's CAD!