Tuesday, February 18, 2014

Refining The Velomobile Windshield Design

The last few days have brought more snow to the workshop along with some nice improvements with the velomobile windshield installation.  As I do not much care to even look at the additional snow doing anything in the workshop is always the better choice.  So with that in mind here is how this portion of the velomobile project has progressed.


In my last post this is as far as I had gotten with the windshield installation.  The black clips that you see here gave the right shape that I wanted for the windshield but just not the right look.  So I shifted gears and started planning a new course of action to get what I was really looking for.


What I did as shown in this photo was to first remove the two front clips as I found that they distorted the shape of the windshield just a bit when installed.  I then removed the windshield and covered the lower edge with painters tape, re-installed it back into place using the four remaining clips as guides to hold the shape that I wanted.  I then covered the clips on the outside again with more painters tape.


Here I laid out two pieces of fiber glass cloth that would make up the new mounting for the windshield.  This will make more sense once I proceed so that you will get a better idea of where I was going at this point. 


Here the windshield has been completely wrapped with several layers of 8 ounce fiberglass cloth. Already the assembly looks a lot better than before.  The blue tape allows the windshield to be removed after the fiberglass has cured over night.


The next morning I was able to remove the windshield with a little effort by sliding a Popsicle stick between the windshield and the painters tape.  Once I got that far I was able to break the seal between the fiberglass and the tape.  Then the windshield slide out easily.  Only took me two or three minutes.  I then unbolted the four remaining windshield clips as they were no longer needed. The next step was to remove all the remaining blue painters tape to clean up the assembly.  This was accomplished using a small grinding cone attachment that I had in my Dremel tool kit.  Made the task fast and easy to accomplish.



In this photo you can see that the first go around with painters tape worked out very nicely and I have a nice strong clean lip now to mount the windshield to.  The only problem that needed to be worked out was how to fill the voids now left by the four missing windshield clips.  I backed up the inside of the voids with styrofoam and more painters tape where I did not want epoxy resin to stick.  The lower portions of the opening needed to be filled completely to match up with the inside lines of the earlier mounted styrofoam. 


There is a closer look at what needed to be filled in on both sides of the new windshield mount.  


I laid down four more layers of eight ounce fiber glass cloth to fill the void and get a nice smooth flowing outer shape for the new mount.  


You can see in this photo where the rear windshield clips were and have now been filled in with new fiberglass.  The white that you see at the previous voids is a fiberglass resin and micro-balloon mixture that makes a great filler for just this purpose. This filler was put on to the exposed foam where the voids were and then the new fiber glass was laid over top to keep everything nice and even.  The inside of the lip also received additional coatings of micro-balloon mixture and another layer of fiber glass cloth to cover up any exposed surfaces to seal up this portion of the assembly completely.




After yet another night of letting the new fiber glass cure I needed to trim the upper edge of the new mount using my Dremel tool once again with a carbon fiber wheel.  I taped off around the upper portion of the mount again with my handy painters tape to create a guide line and started cutting.



Taking my time with the cutting wheel and then a small sanding wheel and then more hand sanding I ended up with the shape I was looking for. Now I was able to call the operation a success.



After installing the windshield once again without the black clips was just a matter of sliding the windshield under the newly created fiber glass lip.  This lip by the way now has seven layers of  fiber glass in it.  This has made is very strong and stiff.  Just what I was looking for.  


I took a look at the original mounting holes that were drilled into the windshield for the little black clips and compared the locations to the new fiber glass lip.  As I figured the holes were not in a good location.  So I traced out a new windshield without holes in it so it could be drilled at the same time the fiber glass lip was being drilled. 


 I was able to slide the new windshield into place quite easily as it was a perfect copy of the first one I had put together.  I then marked out where the new holes needed to be drilled and crossed my fingers just for luck and went for it.    It is hard to see but the idea worked perfectly.  So I (pardon the expression) managed to kill two birds with one stone once again. 


 Now that I have the holes drilled where I need them it will be an easy task to mount the windshield using 10-24 hardware.


I tracked down this type button hex head machine screw today so it will give the windshield a nice clean look. 



 Assembling the machine screws into the windshield and  fiber glass lip started with the one right at the very front.  This one needed to be first as the back of the windshield needed to be raised so that I could get my hand between the windshield and the dash to hold the nut and then tightening the screw.


I worked my way down the rest of the windshield from side to side  to get everything tightened up as you see it here.  Not hard to do  but just took a little while. The look now is just what I wanted when I started. 







 I still have to do the finishing work to blend the new fiber glass windshield lip into the body and the mounting already is a vast improvement over the black clips that I started with.  The clips were useful just the same as they helped keep the windshield located correctly onto the hood while I got the new mounting sorted out.  I can't wait to see the entire body of the velomobile smoothed out and painted..... ready for my first test ride.  Wishful thinking today as I look out my window at five foot of snow piled up next to my driveway......(sigh).  Stay warm and keep tinkering.





2 comments:

  1. I hope you don't mind an observation after the fact. I have a flip-up visor on my WAW velomobile. The leading (lower) edge of the visor overlaps a portion of the cockpit cover that has an upward sweep. This enables the relative wind to scour the inside of the visor of moisture from various sources.

    I've found that in well-lit conditions when it is cold enough to keep the visor mostly or completely closed that the yellow paint on the upward swept portion is reflected into the main observation area of the visor. I will eventually paint that area matte black to remove this reflection. It is bright enough to mask the road ahead in some conditions.

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    Replies
    1. Hello Fred,
      Thanks for the info about the windshield and reflections. That's something that never crossed my mind. I will have to keep an eye out for that when it comes time to paint the velomobile. I would do the same as you and black out that portion of the dash out so that it would not reflect the light and not cause any problems.

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