Thursday, February 13, 2014

A Nice Clean Windshield For The Velomobile

A couple of days ago my order of material for the windshield for the velomobile showed up at the shop. I had ordered some polycarbonate plastic online so I was happy that it had arrived in one piece.  What I needed was a strong flexible plastic that would be easy to bend into a nice shape for the windshield.  I figured 1/32 inch thickness would do the trick.  This is how this idea turned out.

In my last post on this portion of the project I showed you this computer image that I had put together to show you what I had in mind.  The plastic that arrived for the windshield was a piece 2' x 4" and was rolled up and put into a box that was 6" x 6" x 36" in size.  I knew if the plastic sheet could be rolled up that small the windshield would be a snap to bend into the shallow curve that you see here.

In the lower right corner of the plastic sheet I laid my card stock template of the new windshield.  As you can see I have more than enough plastic to make several windshields.  This I plan on doing just so I have a few spares on hand should I need to replace the original windshield.  The 2 x 4 foot sheet cost just under $15 including shipping.  So I figure that I can get five windshield made from this material and it will only be $3.00 each.  Pretty cheap windshields.

After I had traced out the new windshield I cut it using a standard pair of scissors.  It took a little effort but was an easy task over all. I then placed the windshield in place on to the front hood.  It looks great here and the shape and size looked to be right on the mark for this portion of the velomobile project.  The next step was to figure out how to attach the new windshield to the hood without a lot of hassle.  I knew that I needed some kind of mount that would be easy to assemble to the hood yet could be removed if every there was a need.  

I started with this simple little triangular shaped piece that I made on my 3D printer.  It was a spark of an idea at least.    

After a half dozen modifications I came up with this clip that I thought would do the trick of mounting the windshield.  I figured that I only needed six clips to hold everything in place. Three on each side of the windshield. I made three clips mirror images of the opposite side on the velomobile so that they would look right once they were mounted.  Each clip is only 1.25 inches wide and about 2 inches long. The hole on the right holds another 10-24 bolt which will mount all of the clips directly to the hood of the velomobile. 

The windshields outer edge slides into a slot in each clip and is held in place using a 10-24 bolt.  A 10-24 nut will hold the windshield securely in place in a receiving cavity in each clip.  

After measuring the placement of the windshield I placed the mounts on the the windshield temporarily so that I could get mounting holes marked for the clips.  Here the first clip has been mounted to the hood with the second clip already marked out for drilling.   The outer perimeter of the clip was marked on to the hood so that I could keep alignment of all the clips where they needed to be for the installation. 

In these last four photos you can see how well the assembly turned out.  As I suspected the windshield has risen off of the surface of the hood because of the mounting clips.  Along the sides of the windshield this gap is only around a quarter of an inch.  At the very front of the windshield the gap has risen to one inch.  Not an alarming discovery.  

So the next step in the process will be to fill these voids once again with foam and fiber glass.  In this photos you can see the general shape that will be feathered into the hood and around the windshield assembly.  

The large strips you see here will first be hot glued to the hood to keep them in place for the next step.  I will then add smaller strips of foam between the windshield clips.  I want to have the foam just bump up against the outer edges of the windshield.  At the front of the windshield I will have to build the foam up to an inch thick and taper it off to the outer perimeter of the large strips. I'll remove the windshield and sand the foam into shape.  I will have to recheck the fit again with the windshield in place once this is done. 

You can see the gap at the front of the windshield here in this photo.  I always assumed that I would need to do more body work to get a windshield mounted on the hood.  But I have lots of time before I will be able to get at the body work again as winter is still here in the Midwest in a big way. So the nice warm workshop will make this part of the project a real pleasure to do. Once I get all of the fiber glassing done I will remount the windshield again to show you how it all turned out.  I think it will be a good look.  Also with the windshield already mounted I found it to be very sturdy.  The slight bend in the polycarbonate windshield is not so severe that it puts a strain on the mounting clips but rather gives it a nice stiffness.  A good thing to have. Nice to see another portion of the project coming together as planned.

1 comment:

  1. Thanks for always sharing your amazing automotive designs, Dave! Although this walkthrough can only be done by a person with your expertise, it’s still amazing to learn about the step-by-step process of creating these unique vehicles! Keep up the good work!

    Cleora Schroeder @ Xtreme Autoglass Pros