VECTr – Variably Expanding Chain Transmission

Chain ring bolts interfere with movement of gear segments

It has been a while since I updated the progress being made on VECTr (in part because that progress has been slowed by my day job consuming the free time I would have devoted to inventing). Well, a couple of developments have taken place since January. First, while the 110 BCD five gear segment design showed promise, the placement of the bolts in that design interfered with the movement of the gear segments.

So in January, I modified the design of the base plate to allow the free movement of the gear segments, and began testing the design in February.

Throughout February and March, I tested various designs for the locking pin, trying to find one that would keep the pin perpendicular to the plane of the base plate while sliding into and out of the locking notches in the base plate. In addition, I was trying to figure out the best spring type to bias the pin into the locked position, a type that would fit into the very small space between the gear segment and the base plate.  The locking pin/spring combination is really the key to VECTr being able to achieve expanding gears at a light weight and hopefully low production cost.

One other improvement was to affix the control plate guide more securely to the frame. In the end, I replaced the temporary wooden bracket with a steel one I fashioned which is much more durable, and will probably be incorporated into the final product design.

New 5-Bolt base plate with gear segments and control plate guide affixed with steel bracket.

Now, as I had indicated in the prior blog post, I still need to find the proper angles for the control plates that will unlock and move the gear segments both from inner to outer positions, and vice versa.  We are getting close!