Soft top ideas?

B

Burton-e

Daily Driver
I have been thinking about a little engineering project for the X this winter, and I think a "quick soft top" would be really cool. I wonder if anyone has made any progress on this.

This topic comes up every few years, but as far as I can find other than Tony working up a "too-light for driving" prototype discussed in a brief thread in 2010, and an early snap-on accessory not much seems to be out there. Drilling snaps into the nice clean X lines is not appealing to me.

My seats got soaked in the parking lot at work last month when it rained when it was not supposed to, and my son who for the most part is really happy he picked his X over a Miata has that quick Miata top as his main regret. Sometimes he wants to throw a top on his car if he's going to be away from the car for a while, but would rather not dig around in the frunk, easy with a miata, easy with my old 124 spider.

Anyway, I have been thinking about three main approaches to the problem

First - a rollup quick cover for keeping out the rain while parked and reducing temptation to passersby to search the car when you leave the car a while, but it is not really intended for driving with any speed.
Maybe using a lighter version of the support bars and latches in our standard tops on each end and thick cloth flaps for the windows. Definitely not car pressure car wash proof, but better than nothing.
(My neighbor growing up would have called this "leaks like a Triumph" level engineering.....he drove an MG)

Second - attempting to beef up Tony's design using a donor top and side supports and heavier top material, that could roll or fold and slip behind the seats.

Third - a folding hardtop/reduced hardtop or frame made out of some really light material- with a canvas cover over the frame. But not complicated enough to be worse than getting the current top out of the frunk.

Anyone create anything like this? Better ideas? Pictures?

Burt
 
Sounds like a lot of work but a fun project.
I just put the targa back on and off several times a day sometimes.
We also have a miata and though it is quick and easy the rear window zipper is a nightmare. The blind spots with top up are horrid too.
Nothing is perfect I guess.
Hard to imagine any makeshift sft top being less work than the targa but I say go for it.
 
Burt... I still recommend the design I once submitted...

using the latches and mounts from a donor top. It fits neatly in the rear trunk and folds or rolls flat around itself. Hardly takes up any room back there and leaves the front trunk wide open and easy to use for groceries and the like.

The improvements needed would be stronger side rails, or side rails that scissored in the middle... and a better top canvas that did not shrink.

My problem at speed was the top EXPANDED and then collapsed all stretched out. HA! Then it shrank more when it got wet... I think the idea was good, the material I chose wasn't.

Note also that this is kind of a "Bimini Top" which is a temporary shade top or something to stop rain, but not necessarily SEAL the windows or cockpit.

I sent my proto over to Ricardo to play with or to use the parts n one of his clear tops. You might page him to see what he has done with it.
 
Set The Design Parameters...

I am intrigued...

I think that the basic design parameters have to be decided first:

Is it a quick cover for safe parking only, or must it withstand highway speeds when in place?

Will it cover the sail to windshield like the hardtop, or back deck to dash ala tonneau?

I like Tony's idea of a top that stows in the rear trunk, uses the hardtop mount points and folds neatly, but is a parking only device.

This could be interesting....
 
I put some thought into this years ago

I never got past the planning stage. JoeF nailed the main issue: that everyone has a different reason as a starting point.

My goal was to create a fairly stable fold-able roof that went in the rear trunk rather than the front. I wanted to vent the radiator thru the hood, so the roof had to go somewhere else if I wanted it to come with me. I never got past the planning phase after spending some time trying to figure out how to keep the fabric from flapping all over at speed.

Here is a quick sketch of the idea for using all the outer edges of a stock targa:


So my next project was to create a quick parking lot cover from light weight waterproof fabric. I did buy a roll of fabric for that project and worked on the pattern. Then I sold my only running X and the need for a parking lot cover goes away when you can't drive to a parking lot. :) I may get back to that someday.
 
Pontiac Solstice Coupe had one available - as the targa panel couldn't fit in the car. I believe there was one available for the Lotus Elise as well.

As mentioned, donor latches and hooks - a nicely welded steel frame mockup (and then go to aluminum) would be nice. It's do-able, and it would probably look good!

Wouldn't be inexpensive, but whatever... you can't take $$$ it with you ;)
 
Wasn't this an option...

From that company back in the 70's that made the luggage racks and such? I can't recall their name now.

Pete
 
I don't mean to hijack the post,

I would love to have a taunue (sp) cover for mine.
All us in the middle belt of the globe, where summers are dry and it rains only in winter, such a cover is ideal.
I drive my X top off (stowed in the garage) all the time, leaving the interior exposed. Parking in the sun is difficult on the seats (and my bottoms as I seat in it...).
I used to have such a cover on my MGB and Sprite.
Now I do miss it.
 
AMCO

This is the top that required drilling holes to attach snaps to the targe bar. No thanks. :)



I have that luggage rack on my 78 and that arm rest looks nice.
 
TONY!!!!

Black-Tooth said:
using the latches and mounts from a donor top. It fits neatly in the rear trunk and folds or rolls flat around itself. Hardly takes up any room back there and leaves the front trunk wide open and easy to use for groceries and the like.

The improvements needed would be stronger side rails, or side rails that scissored in the middle... and a better top canvas that did not shrink.

My problem at speed was the top EXPANDED and then collapsed all stretched out. HA! Then it shrank more when it got wet... I think the idea was good, the material I chose wasn't.

Note also that this is kind of a "Bimini Top" which is a temporary shade top or something to stop rain, but not necessarily SEAL the windows or cockpit.

I sent my proto over to Ricardo to play with or to use the parts n one of his clear tops. You might page him to see what he has done with it.
Click to expand...

Tony,

I NEVER RECEIVED IT THE PROTO, I MADE MY OWN PROTOTYPE ON SCALE IN CARDBOARD AND IS SITTING IN MY DESK,

If you send me the prototype, I can compare and mix the ideas to get one SOFT CANVAS TOP.


Regards
 
308 ish possibilities?

Ricardo I'd be interested in your cardboard mockup? Any Photos?

I think something that would ideally quick stow behind the seats if I did not want to open either trunk would ideally be in my design parameters.

I know thats how it works on the 308 gts but how such a scheme would work with the geometry of our top and the space behind the seats is an issue and makes the tonneau more attractive.

I need to get out the tape measure tonight when the day job let's me go....

Burt
 
Joe, Ricardo... Like Jim said...

I used his basic design and then attempted to devise some hinges and a collapsible side rail.

One basic design requirement was that it MUST remain taunt while driving at speed. Kinda like tensioning an umbrella. Secondly, it should stow easily and simply in the rear trunk, and third... it should shed rain reasonably, but not necessarily seal.

The major failure in my attempt was using a cheap canvas. I would spread the front clamp section away from the rear mount and lock in the side rails pulling the glued down canvas taunt. After a 5 minute drive the canvas had stretched and everything came loose.

Back to the drawing board and I lost interest.

I believe stronger mounting and hinge points for the side rails need to be fabricated as well as a better method of folding or tensioning the material.

And I KNOW Ricardo can do that...
 
inflatable bladder

Tony,

My latest "design" ideas have revolved around creating and inflatable bladder roof. For example, this fireplace blocker is only a few inches shy of the perfect size to span the targa opening:

[ame="http://www.amazon.com/Fireplace-Chimney-Draftstopper-Plug-Balloon/dp/B0001HA8MC/ref=sr_1_50?ie=UTF8&qid=1378498947&sr=8-50&keywords=inflatable+bladder"]Amazon.com - Fireplace Chimney Draftstopper Plug Balloon (Large Pillow - Fits Any Masonry Fireplace with dampers up to 38x16")[/ame]

If you have the right equipment you can custom make your own bladders out or rubberized materials. Even thin plastic can be glued to form a bladder, but I think that is a gamble for the application. Of course while this would give a more rigid roof when inflated, it has to be deflated to roll it back up.

I have lots of ideas, most of them are not that good or cost prohibitive. :)
 
I was thinking...

Something like the current 500 ragtop: A frame that attaches to the car like the hard roof, but instead of the frame folding, why not have the top retract on rails and bunch up at the back?

Hummmmm.....
 
Have you seen how a stock Scorpion roof works?

Joe F said:
Something like the current 500 ragtop: A frame that attaches to the car like the hard roof, but instead of the frame folding, why not have the top retract on rails and bunch up at the back?

Hummmmm.....
Click to expand...

Almost exactly what you describe. Except instead of bunching up, there's a little panel back there that flips up, you stuff it under, and the panel flips back down and covers it.

Pete
 
Not a bad idea... but the side rails would need...

to somehow fold so it can fit in the rear trunk.

I was also thinking of using some stranded wire or cable...

Maybe have some way of re-tensioning the wires to allow for stretch or shrinkage. This just may be the easiest and simplest way to go!
 
Rough measurement and design constraints

So the minimal width of a top as I measure it is about 42" which happily is almost exactly the usable width behind the seats and less than the
comfortable storage rear trunk width of easily 46". Good for any roll up design.

Usable depth behind the seats is about 18" without rising above the rear platform level. Rear trunk flat space is about 12.5", but can accomodate at least 14" angled.

Our full top is just about 30.75" deep so folding in 1/2 would work behind the seats except there is not a lot of clearance for anything bulky behind the seats. To fit in the trunk it has to be more folded or rolled.

If the depth of the top is less than standard there may be more options. There is about 28" to the back of the rear latch plates and 2" less to the latch pits themselves, but then some of the latch plates must show or be covered by something foldable.

Basically the trunk is probably harder to design for than the behind the seats option except for bulk.

Measurements are on an 86, not sure about earlier incarnation's variations on this.

Burt
 
Magnetic Tonneau?

Ok I am posting a lot on this thread today but I have one more thought tonight.

Tonight I had some cardboard out for measuring and held it in place under my handy magnetic bowl for keeping track of nuts and bolts.

Then it occured to me that instead of snaps holding the top I could use magnets like the bowl. A couple years ago I made a really handy tool drilling a hole in a hammer handle and fixing one of those rare earth magnets with epoxy. That has held up great to a lot of abuse. Why not put rib in the back of a roll up tonneau, have bumpouts to go into the slots in the plates for positioning and fix it with magnets either mounted in holes drilled in a thin support beam or in the fabric of the top. This might really simplify the project of a quick parking lot cover.

Has anyone seen such a magnetic cover work on anything else.

What do you think?

Burt
 
this is a first and nobel idea, Burt

It might develope into a usefull cover.
Lets put more heads into it.:eyepop:
 
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