camper trailers tech tips

DIY rear window protector





DIY rear window protector

removable polycarbonate screen for GU3 patrol


    Malcolm's GU3 Patrol's DIY rear window protector has been made from laser cut 2mm polycarbonate. The above photo shows the protector installed to the left hand rear barn door only.

    The polycarbonate has been installed using 3M Reclosable Industrial Fastening Systems This system has far superior interlocking action than velcro. The self adhesive is also of a better quality, coping with heat & vibration.

    You can also see on the left hand window the location of the Velcro loop strips which provide padding. The Velcro strips were actually left over from my first (unsatisfactory)  attempt at attaching the protectors.  I would have replaced them with more elegant self-adhesive neoprene but I found the Velcro adhesive very tedious to remove and I'm lazy!

    The performance of the rear window protector has been very satisfactory over more than 18,000km on my last 3 month trip.

    The polycarbonate sheet costs around $50 for both windows, plus the 3M dual locks at about $8 per pair. Laser cutting was done by a friend, however I would estimate that the whole job including laser cutting would cost around $100 to $150.  Much less than a replacement window and bit less than commercially available equivalents.

    Below you will find links to two dxf files which are needed if you want to have the sheets professionally cut to match a GU3 Patrol's rear glass using a numerically controlled cutter or to computer plot them as templates.  These are what you email the people doing the cutting to feed into the laser cutting machine.  The dxf files were created using AutoCAD and are the ones I used to produce the protectors for my GU3 Patrol so I know they work and I checked them before posting them to the tech tips pages. 

    The dxf files can be used without modification as input to Computer Drafting software such as AutoCAD to allow you to plot templates for accurate transfer to the polycarbonate, but note that if you use drafting software other than AutoCAD (such as Microsoft Visio) you may have scaling issues to contend with and must carefully double check all dimensions prior to cutting!

    If you are having them laser cut, I recommend double checking the dimensions with the people doing the cutting - you never know with software!  The maximum (bottom edge) width of the LH panel should be 560mm and the RH one 826 mm.  The maximum (centre edge) height of both is 477mm.  A dimensional tolerance of around +/- 1mm shouldn't cause a problem."

    The alternative of manually cutting from a template drawn on the polycarbonate backing paper is obviously cheaper but labour intensive and can be hard work to obtain a clean accurate finish. 

dxf file for lefthand Nissan Patrol GU3 rear window        dxf file for righthand Nissan Patrol GU3 rear window


 Note: Please make sure the rear window protector is positively connected to the vehicles rear window. The driver has a 'duty of care' to other road users with the operation of a vehicle in a safe manner. You must not place others at risk with the protector coming loose.



thanks to Malcolm Robins for sharing this information.


april 2008