Thursday, June 30, 2011

Long Board - New Project

After a year of walking to class I decided I needed a long board to get to class. In my usual style I figured I should make one instead of buying one. I started by doing some research on the designs and standards for long boards and skate boards. I saw a number of different truck designs that seemed common. It seems that the rubber bushing style of truck is the most popular. In this design the truck is forced to straighten itself out by squished pieces of rubber. These pieces give the boarder more resistance as they attempt to steer the board. My personal favorite design used metal springs instead of the rubber bushings. I like to design things to last. I figured the springs would never deteriorate with time. Unfortunately I couldn't figure out how to make the trucks small and use the springs. Eventually I decided to go with the standard design for long board trucks. The one thing that really bugged me about this truck design was there wasn't a defined mechanism that caused the truck to turn. The pins in the trucks relied on a loose fit in order to actually turn. I started to look for an improvement when I stumbled upon spherical bearings on Mcmaster. These bearings gave freedom in all directions, which was the exact motion I needed. I designed the trucks around these bearings.  The spherical bearings give the trucks fully defined motion.

After deciding on the components I immediately started up SolidWorks and started poking around with different designs. Eventually I settled with this design for the trucks.
This render of the entire board has an older design for the trucks. I spent a few days changing around the design to make it easier for me to machine. The best looking board in my opinion was one made from 1/2" polycarbonate. I figure this board will really stand out when around the regular long boards.
I split the truck into many different pieces to avoid material removal. The biggest limiting factor when I'm machining is removing material. Splitting up pieces meant a large portion of the parts were extruded aluminum with holes drilled in them. Parts like that are really easy to produce with a manual machine. The design also meant that I only needed CNC work for the bearing seats and the side plates for the trucks. I attempted to locate the parts by geometry instead of the bolt holes themselves. The most critical surfaces required parallel edges, which are very easy to produce in one setup on either the manual or CNC mill. The only new thing for me on these trucks was the use of spherical bearings. I hope they perform as well as I imagined them performing.

No comments:

Post a Comment