BB Bonneville Bugeye

[manta22]

What aluminum alloy and type of rivets are you using?

Regards, Neil  Tucson, AZ

[Rex Schimmer]

Neil has a very good question regarding the quality of the rivets or bolts that you use also the number of that you use . You may want to do some stiffening of the belly pan in the large sections between where you have clecos. With this large of a flat area under your car you have potential to generate some large amounts of down force which is really just low pressure on the bottom of the car. What can happen is you start going fast, generate some low pressure on the bottom of the belly pan the pan deflects and closes off the air flow so the low pressure goes away and the belly pan snaps back into place and it starts all over again, and all of this happens pretty fast, so it is really important that the belly pan be well fasten and stiff. Ride height and rake are going to be important to make your car handle well.

Any thoughts of doing a diffuser on the back of the car to recover some of the energy from the flat bottom?? Probably would help the aero.

Rex

[hotschue]

Neil/Rex.....I'm using 2024 sheet .065.....rivets are 1/8" spaced at 2" intervals with four rows equally spaced running front to rear of chassis,  six cross members with equally spaced rivets from side to side.....should be plenty strong.  Was going to use general purpose rivets with proper grip however open to suggestions.  Photo doesn't show all the holes we drilled.  Thanks for watching always looking for help......Udo

[hotschue]

Rex, There is a diffuser in the design....we will test with/without....

[manta22]

Udo;

If you can find some CherryMax rivets of the proper diameter & grip length on eBay or the surplus market those would be preferable. Another alternative is the Avex rivet (see Aircraft Spruce); they are good and have a wide grip range. With that many rivets to pull you'll be ahead to buy a pneumatic rivet puller. You can find cheap ones around $40. I built an aluminum structure with a hand operated puller and it was murder.

Monel pop rivets aren't bad but they don't retain their stems like the previous two.

I'd suggest using a phosphoric acid cleaner and a passivation such as Alodine on your aluminum. A zinc chromate (or the ersatz stuff they sell these days) will provide even more corrosion protection. Good luck with your build-- see you on the salt!

Regards, Neil  Tucson, AZ

[hotschue]

Vacation is over back to work!! Yesterday painted bottom of frame with the worst smelling never rust in  a 100 years, salt proof forever sealer paint/primer.  Whew, glad thats over with!  I stink, the garage stinks!!!! Today we attached belly pan, installed front and rear suspension and BB is sitting on its own springs/tires "for the first time".  We have reached a mildstone.  This week will finish nose cone buck and misc mounting tabs on chassis......hope to finish body soooon maybe next two weeks???  Pics todays progress.

[hotschue]

Thought I'd put a couple of hours in on BB today.  Making some front frame extensions, that need to be removeable, so I can install/remove front tires.  Drill some holes for plug welds to attach brackets to extensions.  Also finalized steering joints and supports and rough in windscreen mounting flange.  Little steps but time consuming.....

[hotschue]

Today we are starting the process of building the nose cone.  The buck (plug) has been done for some time ( about a year) and we're going to get on with making the mold and then the actual nose.  It dawned on me this morning that I built the chassis and nose cone buck from schetches that were fairly close to scale over 2 years ago.  However, when the frame was done never really checked to see if it really would fit.  Thought I would check fitment with the original cardboard patterns.....Surprise, it didn't fit!!  Seems through the building process, a mode here, a mode there,  and it picked up 3/16" in width over 16' run, and I did not adjusting the plug dimension.  Soooo...... My choice modify nose or frame.....decided to remake front frame mounting points.....it's just time......add another week to the project.  We'll geter done!!!!

[Milwaukee Midget]

Seems through the building process, a mode here, a mode there,  and it picked up 3/16" in width over 16' run, and I did not adjusting the plug dimension.  Soooo...... My choice modify nose or frame.....decided to remake front frame mounting points.....it's just time......add another week to the project.  We'll geter done!!!!

Time tends to play into stacked tolerances.  It wasn't the 16 feet - it was the two years.

I've no doubt you'll geter done.  If this is the biggest headache you've had, you have NO PROBLEMS.  

[hotschue]

Chris, Think your right.......minor panel adjustments, as I worked my way forward from the rear clip, attributed to the mis-alignment.  I've decided to finish nose cone before I finish front mounts and redesign cone attachment points.

[hotschue]

Alright!.....back to the dirty work.....original nose cone was to be a single piece....change in plan, two halves, upper will be dzus to the lower, which will be bolted to the frame....figured out is was easier to build two halves vs. one whole, that really didn't influence my decision did it, you bet it did!!  I decided it would be a disaster if I couldn't get the plug out of the mold.....Found a piece of SS wire, some dowls and built a two man SS buck saw.....Worked out pretty well, did some trim work, sealed "pink stuff" with latex paint and put first coat bondo to smooth plug surface....I see a week of sanding and painting ahead, then gel coat/fiberglass and pull mold.....have all materials in hand, need to find a spray gun to shoot gel coat, tomorrows project....Next update hopefully to have pics of completed molds..... 

[Glen]

UDO, keep it up, every build has a glich somewhere along the process. BTW, it's looking real good.

[Rex Schimmer]

Udo,
Not really clear on why you cut the plug in two? It certainly looks like it has enough "draft" so that it would come out of the mold easy. If you wanted to make and upper and lower piece I would think you would make the mold with a split line and then have an upper and lower mold that would make a single part and then you would cut the part into two pieces. But as the saying goes "you are fornicating this cat, I am merely holding it's head" .
 

Great to see your progress!
Rex

[Glen]

Rex, a little off subject but I stopped by Jim Rhodans last Friday for a visit. We had a great time and caught up on a lot. Talked about the shops on Signal Hill. Good old days for sure.
 

[hotschue]

Hello Rex.....Having never made a mold, inexpience was the problem.  Biggest question was how to evenly spread the gel coat inside a one piece mold and them lay the reinforcement fiberglass without affixiating myself and getting f/g resin in my hair, arm, etc..  I have a history when I get near fiberglass/bondo of getting it all over me when I'm near it, like a fly on fly paper.  If that happen the project would go down hill very fast.  I found that two piece was much more comfortable for me to manage, I will mount each half on a backer with a four inch lip so I could bolt the mold halves.  I maintained the nose split lines very carefully so they will fit together.  Would have been nice to have someone standing over my shoulder giving some direction (courage).  Well, we will see how it turns out!!!!