Sunday, November 8, 2009

Tres Chic

The rear support for the Upper Battery Tray is done.  It joins the rear of the tray to a rectangular cross piece that ties the frame rails together.  The piece required about 105 degrees of bend, which my tooling is not able to do, so I had to fudge the last 20 degrees. You can see where it doesn't sit flat along the cross piece, but through the miracle of modern coping techniques, I will live with it ( 1 deep breath and repeat "not everything can be perfect" 10 times).

The rear support piece requried four bolts thought the rectangular section, where I had previously mounted the controller.  So I will need to figure out how else I mount the controller and ther rest of the electronics.  Another goofy thing is that the whole tray seems to be skewed to the left side of the frame (look where the support joins the tray), but I can't see what is causing that, except that front frame rails are not exacly parallel.  The good news is that there is plenty of material on the rear tab of the tray, and you need to allow for such variations in a kit.

My lithium pack models fit fine on the tray.  The cardboard models simulate 12 Thundersky 60 AH batteries in the upper tray and 8 in the lower tray, giving an approximate 60volt setup.  I designed the trays to have enough room for Lithium Modules made of 5 units.  The model batteries were originally made to simulate modules of 4 batteries, but ended up too long by almost 1/2".  There should be enough room to squeeze in 24 cells, for an effective 72v system, but it's going to be tight in the back of the tray.  I can worry about that more when I can afford the lithium batteries.

Monday, November 2, 2009

Tres Magnifique (almost)

I got the upper battery tray cut and bent, but ran into a few hiccups in the bending process

After bending the front and rear tabs, the part will no longer fit into my bending brake, so I ended up finishing the bends in a vise.  The bends forming the side tabs are not uniform and the flat area where the batteries are supposed to sit is distorted.  The good news is that this piece is functional.  I will need to make a few changes to my tooling in order to accomodate future versions. 

I've also come to the conclusion that 3/16" stock is just too thick.  On version 2.0 all pieces will be made from 1/8" material.  This will help reduce the raw material costs and will be a lot easier to work with.  It also will save a little weight.