Monday, March 27, 2017

Battery boxes and support frame build.

We ordered metal and have been working to get the boxes made and frame complete.  This has been a productive weekend.
If you want more explanation just ask in the comments, the pictures seem to be enough for most folks.

Mock-up of battery boxes

Donation of a cut-off saw to the project.  Blades are on order, apparently the standard size used in 1941 is not standard today.














  
Battery frame pieces cut to shape.
Taped together for a test fit.












































Tack weld together.  OH, AND another donation of an old stick welder!           


Battery boxes welded up.  10 of 11 modules shown, 11 modules do fit, we checked.  Next step here to drill 13 holes for holding the batteries in place and paint orange.
Firewall plate fit check, a bit more cutting and grinding to go on this plate.
The A/C drain hose will come out where the two holes in the middle are, and The right corner will be removed to allow for the re-installation of the shifter.
Last test fit before welding the frame in place.
If you look near the top center of the picture you can just see the corner of the license plates that arrived last week.  $18/year!
AND YES! The hood still closes with a full inch to spare.

Everything fits, we will get some pictures of the complete battery frame after the firewall plate is trimmed and front I-beam is welded in. 


Monday, March 13, 2017

Front battery boxes in the build process finally

I got some feedback on the previous blog.  It was decided that the stresses in the weld would be marginal.  We also did a few more assembly studies and could not decide if the boxes would be able to slide in to the vehicle.  THEREFORE, a slight adjustment and a few more runs on the analysis has yielded:




The changes include taller tubes, 1"->1.5" on the horizontal sections.  The 45° center section, this reduced the stress on the lower side of the section from when it was 90° degrees, and further allowed the battery box more room to slide into the rear section.  The front I-Beam connection also changed from welding to the center webbing to sitting on the beam, this significantly changed the area of loading for the better and will further aid the insertion of the DMOC into the bay under the hood.

All around a marginally more difficult design to cut and weld, but the safety factor went up to 2.7 at yield and 3.7 to ultimate on a 3-2-1 loading.  I don't see us applying a million pothole cycles while turning at speed and applying full brakes.   Then again, we use Windsor road almost every day...
Thank to Don and Brad for their stress analysis discussions leading to this solution.
FYI, the analysis was done by; taking the PTC ProE solid model, importing it into (https://cad.onshape.com/), using the split surface tool in OnShape such that uniform loads could be applied to the z-bars, importing the OnShape model into (https://www.simscale.com/), using Simscale to mesh, load, apply boundary conditions, and post process the FEA.

Material has been ordered!!!!  We might actually get something done over Spring Break!


 The boxes each hold 11 modules for 22 in the front.  We have reconfigured the Leaf cell connections in the retainer, next step, figure out the order to put the pins back in the connector for the BMS:



We have two identical pieces like the one above.  The missing connections in the corners are where we will attach between the packs.