Thursday, November 28, 2013

TerraTrike Velomobile Retractable Headlight

The dust has settled once again here at the Tinker's workshop this week with the completion of the retractable headlight assembly for the TerraTrike velomobile project.  I've put together a good video of the assembly and how it all goes together which you will find below in this post.  For now here are a few photos of the newly created assembly.

I started the assembly with the purchase of the light that you see here from a company named Cygolite.  It is a 420 lumen LED light that has a rechargeable battery that will be good for 25 hours of use.  This along with five different functions makes this little 4 inch by 1.5 diameter light really stand out.  

After over 40 hours of design time I came up with this assembly.  The light is mounted in the inside of the cylindrical body of the assembly to hide the light when it is not being used.  This assembly will be mounted to the inside of the hood on the velomobile and only the opening for the light will be visible from the outside once it is mounted in place. 

Inside of the enclosure you can see the LED headlight tucked into the back of the assembly.  

The rear of the assembly has a removable cover so the LED light can be taken out so that it can be recharged when need be.  This cover is held in place using a Velcro strip that is fed through the enclosure and the cap to hold it all into place. 

To move the light into position for use all you need to do is remove another Velcro strip from the rear tabs in the assembly, slid the center tab forward and  reattach the Velcro strip once again to lock the light into position. 

The light is activated from a switch on the underside of the assembly through a hole in the white outer enclosure.  Once you have turned the light on the inner light assembly is moved forward to bring the light out into the open for an unobstructed beam of light.  
  The retractable headlight assembly only weighs 11 ounces and is  10.5 inches long, 2.5 inches wide, and 4.5 inches tall. The large white outer tube assembly was 3D printed in two sections and then bonded together using a fiberglass resin and micro-balloon mixture. Total print time for all of the 3D parts came to 14 1/4 hours.  I think the wait was worth it.  Check out the video below to see the entire assembly in pieces and an animation below of how the assembly is put together along with further information about why it was designed an built.  

Click the YouTube link for a larger view of the video.


  1. I've been watching your progress since I discovered it. Your skills are just as impressive as the results. Many velomobiles are built on a monocoque structure, while some are faired-in trikes such as yours. Have you considered to build a monocoque with suspension for a future project? I drive a WAW which has front but no rear suspension.

    Your video is the first time I've heard velomobile pronounced in that manner. Most of the videos have people pronouncing it vell-o-mobile as opposed to veel-o-mobile. I suppose European languages would be different.

    Great project!