Body panels vs one piece

So I'm continuin planning of my lotus europa/elise tub project and I'm having some issues with making body decisions about going with a one piece body versus individual panels hung on the tub and subframes.

So the plan is an elise aluminum monocoque, well tub really because the body sits on top but but that's a bit tangential. Anyway so it's an elise monocoque with full cage and then steel front and rear subframes tied into the cage and bolted to the monocoque.

Now if you know anything about the Europa you know it's basically one giant piece of fiberglass and the only thing that's a separate panel is the bits that open - Hood, rear decklid/engine cover, and doors. However, most cars use separate panels - front fenders, rear quarter panels, and the rest of the panels you guys know. Which is better in terms of low weight, stiffness (though I guess the ody doesn't add much to stiffness), and ease of building and working on?

THanks

I suppose we're talking about a fiberglass body here.  A one-piece mold is going to be big and heavy.  That means it's hard to make to begin with and also hard to store.  Making one big piece is a big job to do all at once even after you have the mold.  Making the body in pieces allows for smaller molds and each piece is a smaller job to make.  I'd do it as separate panels.

In reply to enginehelp :

In the case of the Europa the 1-piece fiberglass body really does offer a considerable amount of chassis stiffness, especially when securely attached to the backbone chassis. 
 

However, in your situation it sounds like you're starting from a much better point with the aluminum monocoque & full cage. So I'd say make the body as light as possible.

If you have the ability to hand-form aluminum body panels that resemble a Europa, the result would be amazing. Otherwise I'd say either mold up individual body parts in fiberglass, or cut up an existing body if it's close enough to the correct size. 

To me, it seems like a one piece would be easier, but I'm viewing through a very narrow lens.

Questions: How do you plan to address the width and length differences between the two? It seems to me like a Europa body would need to be widened, shortened (think long, longitudinal engine bay), and maybe made taller in some way. Sounds like a super cool project.

Aree you going to have relatively stock door frunk and engine bay covers, or clamshell?

Following with interest.  I think the idea of making the male mold is something everybody here would understand intuitively, but the process of making of the female mold is something that might be a very interesting build thread.

Sounds like a great project!

When I built my Cheetah Tribute I made the body plug in 2 pieces. The tub mounts to the frame that I built. The nose fully tilts for easy access.  I molded in returns, bulkheads, firewall, and mounting points into the body.  This made the body easy to mount and align.  The 2 body parts weigh a little over 100lbs.  They can be be laid up light as the many compound curves make it stiff and my body is just decorative.  It doesn't add to the stiffness of the chassis.

Kubotai said:

I suppose we're talking about a fiberglass body here.  A one-piece mold is going to be big and heavy.  That means it's hard to make to begin with and also hard to store.  Making one big piece is a big job to do all at once even after you have the mold.  Making the body in pieces allows for smaller molds and each piece is a smaller job to make.  I'd do it as separate panels.

Yeah it's most likely going to be fiberglass although carbon fiber is looking more and more attractive. It's not that much more expensive (well sort of but you know it's not terroble) and you can work it very similarly. THanks for the advice

In reply to Pete Gossett (Forum Supporter) :

That's the interesting thing about the europa, the entire body/chassis structure that you actually sit inside of is this fierglass body. It's very scary safety wise and stiffness wise it's not great either so I figured a more modern monocoque that's also lightweight but stiffer and it's an actual crashs tructure around me would be a lot better than sitting in a fiberglass tub/coffin.

I wish I had that sort of metalworking skill, that would be the dream for me but sadly I can only sit here envying those that have that ability. 

In reply to wheelsmithy (Joe-with-an-L) (Forum Supporter) :

The dimensial difference aren't terrible - elise is 67.7" and the europa is about 64" in width, so some widening but not terrible. My plan for that if I went one piece body is to chop up a crappy europa body and add in the width in the middle through a panel, then make a mold of that as my body. The wheelbase is also similar with 90.6" for the elise and 90.98" for the europa and it would be the same method as the widening if I went one piece.

I am going to have nowhere near a stock frunk of engine bay covers or even door. It's heavily inspired by re-amemiya's europa so Porsche headlights and big flares, the frunk is going to be styled again like the re-amemiya europa but also inflluence by the f8 tributo's, or even the foose europa's frunk.

THe rear end is where it gets complicated and I still don't have it perfect but moving the sail panels inward, and giving it a very new ford gt rear end with flying butresses, and valleys between the rear fenders and the central exhaust. However, the ford get has even the passenger cabin styled to flow up into the butresses and the valley drops below the top of the wheels whereas the europa has very low wheels and the sail panels are way above the wheels. ANy advice for that? Obviously when I widen it and give it wider sills I can style it a bit more like that but it's still a hard styling choice. Also suspension would be hard because I want double wishbone. Maybe it can portrude through the top of the valley sort of like the ktm xbow's front suspension where it protrudes above the body line? Any advice?

In reply to stroker :

Thank you for following. Be warned, however, this is a long and massive project (see my later comment that responded to wheelsmithy) and you liekly won't see much for a while as I'm doing lots of planning and getting finances and other life stuff in order before I can get to building.

Mold makign has always been something that my mind just won't get around ebcause if you look at the europa body how do you do those underside inner details....IDK i'll work on it

In reply to jmc14 :

Oh my gosh thanks so much for your response.....I love your build so much.

If you hard mounted the tub to the frame could it add stiffnesss? Obviously the front clam wouldn't add stiffness but the tub, which doesn't move, might.

How did you deal with intricacies on the bottom of the body bits (if you look at the europa there's some weird frame stuff and sills and hollow bits going on

enginehelp said:

In reply to jmc14 :

How did you deal with intricacies on the bottom of the body bits (if you look at the europa there's some weird frame stuff and sills and hollow bits going on

I'm not that familiar with the Europa but I think I know what you mean.  Although the outer body surface can be made as one piece, there are going to be a bunch of other pieces that are made separately in different molds and then bonded to the inside of the outer shell after it has been made.

In reply to Kubotai :

That helps with some of it but I also mean like forming the interior and stuff

Like if you look at this diagram there is all that weird shaped stuff in the frunk and engine bay but also simply modling those cavities and the cabin ccavity

Or modling this cavity and those inner details

\

If you look towards the bottom  

In reply to enginehelp :

Spend an hour watching U tube How to make fiberglass molds. You can easily make molds from your fenders and other body parts. From that you can make parts.  
Use fiberglass Matt to build cheap splash molds.  

If you use fiberglass Matt for the pieces they will be heavier and weaker than if you use fiberglass cloth. you can also  use carbon fiber just about as easily and save 1/2 of the weight. but it will be about twice as expensive.  

In reply to frenchyd :

Alright, I will. I think making individual panels might be easier simply because it's smaller pieces and just less to worry about with less of those small details to deal with. 

I think I'll use matt to make molds and just perfect how I build it but then at then end I'll go with cloth or carbon

In reply to enginehelp :

my one bit of advice is wax & buff, Wax & buff, Wax & buff and Wax  & Buff  again. Then use a release agent like PVA 

( the nice thing about PVA is it's water soleable so it just washes off  and the original part won't be damaged. ) 
Don't use a car wax. Go to your hardware store for a good furniture paste wax. It will be high in carnuba. 

once you pull the splash mold off repeat the waxing process on the mold  and use a release agent 

In reply to enginehelp :

 I'm pretty sure the interior cavity is made separately, perhaps from several different pieces bonded together.  Then it is pushed up into the outer shell and bonded in place - sort of like the interiors in the plastic models that are being discussed in some of the other threads here.

Some molds can be complex and made of several pieces that are bolted together.  After the part is made in the mold, the mold is taken apart and removed one piece at a time.  This is necessary when the shape of the part would tend to trap the mold so that you couldn't get the part out of the mold.

Kubotai is correct, the outer body was one piece, and the inner bits were seperate.  Here's a couple pics of a Series 1 (46) or 47 type body minus the chassis:

The pics are from a guy in Europe who was selling the panels.  I don't know if these are Boss Motors panels, or someone else.

Rod

In reply to frenchyd :

Ok got it, lots and lots of prep work and then when that's done do some more prep work :D

In reply to Kubotai :

Oh ok got it, I gotta do some more research then :D

I wouldn't know where to start on such a complex mold so google here we come!!!

In reply to RoddyMac17 :

THat's almost exactly like a model car, wow. So ripping apart a crappy body to make a mold from might not be that easy if it's all bonded together :(. I gotta do some more research

Not sure that this a mold making project but rather a fiberglass fabrication project.

Molds would only really come into play if you plan to make more than one part.

If you just want to stretch the Europa body over the Elise chassis, then cut it as required, support the gaps and  fill in the gaps with fiberglass so as to make it all one piece again.  In theory you would do all this work in the first place just so that you had a plug to make a mold FROM.

The above wont leave you with the lightest part possible, but functionally it should do the job of disguising the Elise as a Europa.

In reply to NOHOME :

I suppose but it's a bit more than that because I want to do a lot of changes to the body like I said in my other comment:

"It's heavily inspired by re-amemiya's europa so Porsche headlights and big flares, the frunk is going to be styled again like the re-amemiya europa but also inflluence by the f8 tributo's, or even the foose europa's frunk.

THe rear end is where it gets complicated and I still don't have it perfect but moving the sail panels inward, and giving it a very new ford gt rear end with flying butresses, and valleys between the rear fenders and the central exhaust. However, the ford get has even the passenger cabin styled to flow up into the butresses and the valley drops below the top of the wheels whereas the europa has very low wheels and the sail panels are way above the wheels. ANy advice for that? Obviously when I widen it and give it wider sills I can style it a bit more like that but it's still a hard styling choice. Also suspension would be hard because I want double wishbone. Maybe it can portrude through the top of the valley sort of like the ktm xbow's front suspension where it protrudes above the body line? Any advice?"

ANd then I'm leaning towards carbon fiber as the body material. So my original plan was to buy a cheap body, modify it to my specification and obviously fit it over the elise chassis and my cage and frames, and then make a modl of that to make it out of carbon fiber. 

Thinking about your idea for widening the whole body, just keep in mind that a custom windscreen will cost you a bunch of money.  If you keep the greenhouse the stock dimensions, the windscreen should still work, but do get rid of the side windows.  The quarter light frame is what gives the Europa windows the odd shape/look.  Also, the rear glass is a letter slot, the road test reports from the 60's and 70's were correct in regards to the massive blind spots.  

Also, have you considered the rear body shape of the Lotus 62:

In reply to RoddyMac17 :

My that is good looking. Those sail panels always irked me so I might still move them inwards and give it buttresses because I love flying butresses but that is a much much better starting point because of how much higher the wheels go, the beautiful rear fenders and wheelwells, that curve

Regarding the greenhouse, I hadn't much thought of that. Maybe I could leave the greenhouse at its stock position and size and give it very wide sills.