Battery Frame: So close…

5 04 2010

I’m getting closer….

I’ve been going around and around on the trays and subframe.  A couple of questions that I had were:

  • Will the sub frame be strong enough
  • how will the sub frame get bolted into the frame
  • will everything fit when i get it all put together
  • how will the batteries be attached to the trays
  • how will the trays be attached to the subframe.

These seem like simple questions, but espeically the “will everything fit” question has proven to be difficult without having a real cad diagram of the motorcycle frame.

I drew a frame in Sketchup:

moto frame drawn in sketchup.

but it was a copy from a picture: (more…)

Moto frame shown with picture it was copied from

Unfortunately, drawing a proper frame was a lot of work and i wasn’t sure of how to do that in sketchup. So, i  cheezed out and drew the frame as a flat structure and then extruded it out to the width of most of the frame.  This worked for a lot of the setup, but there were places where the real frame varies greatly from the sketchup. For example, since i extruded the flat surface to make one of the frame rails, and then duplicated the frame rail to make a frame, the sketchup diagram doesn’t ever come together at the head tube:

Notice how the frame diagram sort of falls apart where it's supposed to come together.

This worked out well enough for most of what i was doing, especially since i was able to keep the majority of the tray and subframe from the pictures i drew a few months ago:

All of the batteries and tray inside the moto frame

I redrew this diagram using measurements taken directly from the batteries themselves (since the dimensions of the batteries from the documentation were a little different than the dimensions of the real batteries).  I came up with a design that looked like the couple of pics shown here:

More fleshed out battery frames with subframe

Another pic of frame and subframe

Batteries in the new tray/frame

The major differences from these pics from the original ones is the subframe.  instead of using just flat bar for support, i made an actual subframe using 1″ x 1″ x 1/8″ square aluminum tube and 1″ x 1/2″ x 1/8″ rectangular tube.

However, there were a couple of places where i wasn’t sure it’d fit in the frame.

  • The batteries that fit in the green tray (pack C and D) are a very tight fit with the moto frame.
  • i wasn’t sure how the alignment of the teal tray (pack B) would fit in so close to the downward part of the cradle of the moto frame.
  • i wasn’t sure if the batteries in the orange tray (packs H and I) would fit in the fairing
  • i wasn’t sure if the batteries in the yellow trays (packs F and G) would sit inside of the motorcycle frame’s mounting points.
  • lots more that’s not worth mentioning.

So, i was trying to figure out how i could mock up the battery trays (which were already welded together) and the subframe to test if the whole thing would fit in the frame.

I thought about doing a dry run with aluminum to also use for welding practice, but that required a lot of material, and if i had to make a bunch of iterative changes, that’d be had.

i came up with the idea of using small screws to put the subframe together.  This allows for a couple of things:

  • I can cut the aluminum to the proper length and create a live mockup
  • I can change how things are laid out to a degree if needed.
  • I can use the screws to hold things together instead of (or in conjunction with) clamps when it comes time to weld it all together.

So, i started work on this, and it’s worked out great.  i’m using very small screws (#4 and #6) because they don’t really need to hold any load, and the small holes shouldn’t affect the structure of the subframe.  Oh yeah, i’m tapping each hole so i’m only using screws…no nuts.

I have been able to create most of the frame.  Everything except for the orange tray and the subframe holding it.  This has already paid off for me.  By making a couple of subtle changes, i was able to get the green tray and teal to fit and make sure that the batteries can be loaded and unloaded once the frame is in place. i just need to see if i can get the H/I battery tray mounted and fit inside the fairings.

I’ll have more pics of the screwed together frame as soon as i process them.

Anyway, more to follow.  hopefully i’ll get some more work done on it soon.  it’s hard with baby and all…there’s not much time to work on the project, so i have to get in a few minutes here and a few minutes there.

So close… 🙂

thanks for reading…wish me luck!  (I’m gonna need it. 🙂 )




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