Our first crack at a logo for the Rock Bug.  Love it?  Hate it?  Leave a comment here and let us know.  Oh and please be kind :-).

Here is another rapid fire update as the week moves faster then I can type.  So far so good as assembly continues on the Rock Bug.  Our custom 4130 hollow suspension bolts just came back from heat treat, so we wasted no time assembling the front and rear axles.  Yes, we made our own suspension bolts.  Hopefully this does not come across as an “exercise in excess” as the point of the Rock Bug is to test new & innovative concepts in an effort to build the strongest & lightest vehicle possible.  We focused specifically on the suspension bolts, an area that deserved improvement on both strength and weight.  A typical grade 8, 3/4 x 2-3/4” hex bolt has a tensile strength of 150,000 psi and weights 0.46 lbs. each.  Our custom 4130, 3/4 x 2-3/4” heat treated hollow hex bolt has a tensile strength of 182,000 psi and weights 0.35 lbs. each.  So we are 1.21 times stronger and 1.31 times lighter.  When all is said and done, we give up 10% in overall strength but saved over 20% in overall weight.  This may not seem huge by itself, but it all adds up in the end.  In addition to suspension assembly, we finished up the “doghouse” on the dashboard (removable instrument panel) and have continued to make progress on the plumbing.  Plumbing will absorb most of our time this week, with our ultra light sway bar and gun drilled axle shafts still on the list, and updates will follow as the progress happens.

With only one week left to have the Rock Bug ready for final engine tuning, the pressure of time is now officially on!  As we mentioned in our last weekend update, the focus over the past week has been on overall Rock Bug assembly.   Check out the video and photos below of more Rock Bug “work in progress” as we finish up all the final details.  A few more concept Rock Bug goodies still to be covered are gun drilled axle shafts, an ultra lightweight sway bar, and performance Spider 9 third member hardware.  Since this is all happening in about one weeks time, be sure to keep checking our blog for more updates to come.

With all of the talk lately in heat treating chromoly parts for the Rock Bug, we thought it helpful to post a hardness conversion chart detailing the relationship between hardness and tensile strength.  A few things to remember before using this guide in your next engineering project.  Tensile values provided in this chart are given as the materials tensile “yield” strength.  Because the relationship between hardness and tensile strength is inexact, actual yield strength may vary depending on the material’s properties.  Special thanks to Instron, the recognized worldwide market leader in the materials testing industry, for providing this chart to us.

Although this past week went way too fast, we’re happy to say the goals that were on the table are finished.  The main theme this week was running the electrical for the Rock Bug.  With the exception of a few finishing touches to be completed when the Rock Bug is rolling, Gerald King of Finish Line Racing has tied up all the electrical and as of yesterday is on a plane back home for some well deserved R&R.  Enjoy the video and photos below of all the finished work as of today.  Next week we will be focusing on more general assembly of the Rock Bug.  With the rest of the general assembly out of the way, we will be able to create a more precise task list for wrapping up the final pieces of the Rock Bug.