



New Lightweight Lexan Hardtop Design

New Lightweight Lexan Hardtop Design



Date Created: 06/01/2012 Author: JF_Admin Share:



This project started last winter when I was asked by a friend why I never took the hardtop off of my jeep. I told him that it took three people to get it off and guaranteed that it would rain the next day. Now I have a hardtop, a soft top, and a Bimini top; plus hardtop and soft top doors. I realized that none of this is what I wanted. I wanted a lightweight top that would keep the rain off yet allow me to see through it as if I didn't have a top on at all.



So this is what we came up with: A lightweight, semi-transparent top that matches the factory front cap line to within a couple of thousandths. It weighs in at around 65 pounds, uses three stainless steel clamps to seal the front edge to the top of the factory windshield frame, a rear support brace attached to the factory roll bar, and two additional safety straps midway that secures the top to the roll cage.







The top is vacuum formed 6 mm polycarbonate that is virtually bullet proof, as will be shown in a couple of future YouTube videos we are making. This is the same material that the F-18 canopies are made from, just thinner. Our primary concern was safety. We wanted something lightweight yet able to protect the driver from falling debris. If a rock came loose and smashed into the windshield, you or your passenger could get hurt or worse. If a rock hits the top, it'll bounce right off.



The lid has gutters that start at the front and converge in the rear. Both soft and hardtop doors just clear the gutters so almost all of the rain is channeled to the back drain. In addition to protection from the rain, the tint softens the sun's rays and makes the driver and/or passengers feel much cooler. You wont be baked by the sun.







The pictures are of the prototype, made from acrylic for ease of molding and design of our clamping system. We used acrylic because it has similar shrinkage factors to the Lexan polycarbonate that will be used in the production mold (which is eight weeks out from the pattern maker in Ohio). The production mold is made from aluminum and has to be heated nearly 250 degrees to ease the molding of the poly, which has a very narrow temperature window that allows the material to conform to the mold.



We are at the stage where we are working on the final designs for the third generation front clamps, and aside from that, everything has been done. We are also working on the patterns for side panels of the same material that slip under the top and snap into the Jeep body at the bottom. Unsnap them and they're stored behind the back seat.



The lid fits all Jeeps from 1997 to 2006, and the Lexan has a high UV inhibitor that gives it a ten year guarantee against color change. We should have our website up and running in about two weeks.



Blair McIntire

B & L Design LLC

Keywords: hard top, soft top, polycarbonate, lexan, lightweight, jeep, top, transparent Discuss This Article



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