mranlet
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| posted on 30/7/03 at 04:09 PM |
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Gull-wing doors and windshield material
Hey all,
I'm making a hardtop for my car with a targa-style roof. I'm also going to have minuature doors with lowering windows that will hinge
away in one way or another. However, I'm not sure what the best way to achieve this is. The appendix in the book shows several Locosts with a
double-overhead-bar style roll cage ()which my build will include) and at least one caption mentions that the owner is planning to fit gullwing doors.
Does anyone have gullwings installed or know of anywhere where I might find pictures of gullwing assemblies?
I'd like to have both a semi-removable roof and doors that make getting in and out as easy as possible, and designing them so as not to be
mutually exclusive has proven somewhat difficult... I'm thinking that it might be coolest to have suicide style doors and a seperate panel on
each side at the top that would rotate up when the door opens and be pulled closed when the door closes. I've been condering the idea of using
a cable system from bicycle brakes to squeze the top panel closed and have a spring return to open it (the panel will most likely be a piece of
acrylic or fiberglass, so weight isn't a big issue). I could have the rotating panels sit in a locking slot for easy removal when I want to
have the car be in targa mode.
I've also thought about having jack-knife / Lamborgnini style doors or angled jack-knofe doors with a lightweight frame along the roof that
would retain the targa panel.
In a somewhat unrelated subject - I know that many racers, including those at Le Mans 24 hour, use Lexan or acrylic sheet for the windshield. I know
that Foose hot rods also use acrylic sheet that is molded to shape by a specialist. Question is: would I be able to introduce a curve into a piece of
acrylic by creating a form and heating it with a heat gun and still have it be resistant to scratching and chipping? I am quite the acrylic sculptor,
but I've never had any of my bits be exposed to 80mph highway or 150mph track driving.
Thanks for any light that you folks may be able to shed on this!
-MR
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mranlet
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| posted on 31/7/03 at 03:54 PM |
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Maybe there's too much to read there...
I'm trying to fit gullwing, jack-knife, or hybrid doors, what would be the best way to do this?
Does anyone know of any pictures that illustrate this?
Can Lexan or Acrylic sheet be used for the windscreen?
Thanks
-MR
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andyps
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| posted on 31/7/03 at 07:07 PM |
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definitely not locost, but have a look at the doors on an ultima - they are gull wing, probably fibreglass and perspex/polycarbonate.
They work and stay on at 200mph!
Andy
An expert is someone who knows more and more about less and less
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mickeeblooeyes
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 posted on 22/8/03 at 01:13 PM |
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I have pondered about the same thing. I am one of those people who is considering a locost because it is low cost. I t also has to be a practical
everyday car. And that includes the changeable British weather. Soft tops seem to be a soft option and I would feel more 'secure' with a
hard top. Gull winged doors first caught my eye when I first saw 'Back to the future'. They seemed to maximise space with convenience.
So I also intend to build a hard top with removeable doors! Any information I find, I will gladly share.
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carcentric
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| posted on 22/8/03 at 01:57 PM |
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An answer and an idea
First, Lexan holds up pretty well to windshield use for racing. Over here, at least, it's illegal to use anything other than laminated safety
glass for a windshield on public roads, however. There are special cleaners and polishing compounds you can use to keep it clear for a while, but
eventually sand-pitting will ruin it and wipers leave scratches almost immediately. The good thing is that if you have the mold, it's not a big
deal to make another every other year. 
Second, a much simpler approach to the opening top: hinge the whole hard top at the rear and use soft top latches to hold the front on. Add
something like a Triumph Spitfire bonnet support (folding rod with "locking knee" feature) to hold it in the up position for
ingress/egress. Locost yet unique! 
[Edited on 22/8/03 by carcentric]
M D "Doc" Nugent
http://www.carcentric.com
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Noodle
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| posted on 22/8/03 at 02:21 PM |
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quote:
Originally posted by mickeeblooeyes
Gull winged doors first caught my eye when I first saw 'Back to the future'. They seemed to maximise space with convenience.
Try opening the doors in your local-multi storey car park! Scissor doors would be more convienient.
Neil.
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mickeeblooeyes
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| posted on 22/8/03 at 03:37 PM |
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Mr Noodle,
What is the average height of a Lowcost?
Then please consider the following equation:
v = C - (Hx2)
C = Average Ceiling height
H = Average height of Lowcost
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JoelP
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| posted on 22/8/03 at 08:55 PM |
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What does the 'v' equal? Would that be the gap left? Doors like a bugatti eb110 would be neat, are they what would be called jackknife or
scissor doors? They look much better than gullwing doors.
[Edited on 22/8/03 by JoelP]
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Noodle
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| posted on 22/8/03 at 09:18 PM |
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quote:
Originally posted by mickeeblooeyes
Mr Noodle,
What is the average height of a Lowcost?
Then please consider the following equation:
v = C - (Hx2)
C = Average Ceiling height
H = Average height of Lowcost
Yes, yes. It was the arc the travel through when opening I was pointing out. Could take a swipe at some mummies Discovery adjacently parked.
Some super clever hinges could sort it, but it'd be a lot of work.
ATB
Neil
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mickeeblooeyes
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| posted on 27/8/03 at 08:48 AM |
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MR Noodle.
Consider the idea of a targa top with the T-bar being the pivot point. The doors would have no swing-out because at close they would be at 270 degree
point and opening would swing through to 360 degree point. Light weight doors with gas rams for lift, removeable pivot pins and you have the targa/
gull wing solution.
And yes V does equal the space left. Perhaps I should have explained myself better!
Oops.
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Noodle
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| posted on 27/8/03 at 09:13 AM |
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Mr BlooEyes,
Were you perchace considering something like this?
(With acknowledgment to David Ashurt's photo archive)
Cheers,
Neil.
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mranlet
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| posted on 28/8/03 at 10:06 PM |
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Hmmn... thought that this post had died...
Given the narrow cabin width of the Locost, the extra space needed on either side of the car to clear any cars parked next to you is minimal - the
distance from the pivot point to the adjacent car would be much in excess of the arc length required for a gullwing. DeLoreans, Mercedes, etc. would
be more prone to door-scratching since they are much wider cars with much larger doors (refering to the distance between pivot point and lower door
edge).
I'm not so much worried about hacing enough clearance as I am about constructing doors that would be lightweight enough to be lifted with
minimal ram-assist and strong enough to stay shut and be rigid at speed. I have thought about scissor or jacknife doors, but gullwing would
ultimately make the most sense.
The flip-up roof idea is something which I have thought about, and is intriguing, but I would be warry that the seal between the lid and window
frame/window would be a tricky thing to master, and would undermine the point of a hard top if done unsuccessfully.
I am envisioning my doors to be similar in structure to those of the Callaway C7, with 3/4 of the window panels lowering much like the old Subaru
SVX's, and a removable tinted Lexan panel overhead to create a pseudo-targa top (given that sealing them off from water is not a problem)
I'll keep you all updated as I progress and come up with drawings
-MR
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macspeedy
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| posted on 29/8/03 at 06:45 PM |
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Windshield?
 
Rescued attachment S1-bild-overall.jpg
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thekafer
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| posted on 5/9/03 at 04:08 AM |
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gull wing doors/fun with paper
What i did was to get a good head-on drawing of a seven.I enlarged it on a copier and then cut out a profile of what I thought might work as a
door.Mine had the hinge about 4 inches from center.Then I tacked it at point so I could check out the swing.It barely swings away from the car at
all!Try it,you'll see what I mean.My idea was to make a composite top&doors using e-glass w/a nomex or clegicell foam core.I was going to
leave the core out where ever a window was to go, cut the hole leaving a flange I could either bond or fasten the lexan to from the inside.The doors
would be extremely light and ridgid.A relatively modest pair of gas struts(15 to 20lbs w/6" throw) with "an over center
geometry"would not only lift and hold them open but also help hold them closed. The challenge for me is going to be anticipating seal
thicknesses and faying surfaces so that when the doors are closed you dont still have that "wind in your hair" driving thrill. It would be
neat if the doors pip pinned in so that they were easily removed. Just a thought! Fletch
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mranlet
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| posted on 5/9/03 at 03:11 PM |
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Yeah, that's what I'm talking about. Space on the side of the car for door swing is not a problem on a car this small and short.
I was thinking a similar thing about having the doors be removable, but I would prefer having a tighter hinge and more secure structure with a
piano-hinge style connection and make the overhead panel removable and the window retractable.
In my photo album is a crude and older drawing of that the door (on the Kamikaze) will look like, with the black line partway into the window being
the H-shaped weatherstripping that joind the lower retractable window portion with the upper fixed portion Subrau SVX style.
-MR
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