So I have / had two big projects under way that ill finally let people see, they consist of:
1) Di2 Homemade version,
2) Carbon Frame
So i decided Di2 wouldnt be that hard to build so i had a crack at it, i wanted to make it so radically different. So i decided why do you need two jockey wheels? Big question, in short i don't believe i needed two in parallel. So i made concepts and working prototypes of a system that would work on one jockey wheel. What i did was start with a standard MTB single Speed tensioner and tried to figure out if i could adapt it to shift gears on a cassette. What i did was put a 9 speed wheel onto my single speed MTB and the tensioner and pushed and pulled the tensioner's arm which was reasonably long. Essentially i did shift gears. The tensioner's arm was rather short so i could only get it up to a 19 tooth cog, but with later experiments i could achieve a 23 tooth. The problem then came that i couldnt achieve a high enough chain tension in cogs below 13 teeth. turns out this is the reason why why have 2 jockey wheels. Then using resources at my school i made a PCB circuit and programmed a vague shifting system. Basically "push button, different gear" I then made the circuit work with a stepper motor, which allowed me to program it to move how ever many steps it toiok to get to the next gear. This allowed me to get a better tune from the gear.
However at this point i lost interest, as i couldnt find a suitable way to make a spinning motor move something in and out. I had ideas on how to do it but to no avail. So i have a completed electrical circuit and a shifting rear derailleur just no complete functioning unit. So i made a final push, i made a threaded pin that moved the arm in and out across the cassette, i had at this point made a shifting rear derailleur, using one jockey wheel. And to this day thats where the projects sits. I dont have any pictures of the actual unit as they are buried under my bench in the garage, but here is a CAD drawing of the rear "derailleur".
The arm attached to the jockey wheel moves in and out across the cassette, moving the chain.
My Second project was to build my own frame. I have spent hours and hours on this project to date, right now im waiting to save some money so i can purchase the carbon tubing to create my first prototype. At the moment i have done research into idealistic geometries, integration of components, and a significant amount of drawings on all of it. Unfortunately im not a big computer person so all my notes are in booklets that i write in, i have about 150 pages of info already! Ive included some pictures from my booklets, and a picture of my 1:1 scale drawing of the frame, also hand drawn. I had another 1:1 but mum got some meat out of the freezer, put it on the drawing and then promptly left it there so it has stains all over it... whoops. I have the jig built ready to hold the tubes in the correct location, i have built the Bottom bracket and Head Tube bearing inserts ready for their respective bearings. all i need is the $$ to buy the carbon tubes so i can glue them together!
Sorry if none of my notes make sense, im one of those people that understand everything in my head and nothing on paper, so all the neccessary stuff is stuck in my brain, it makes sense to me?
also the last picture is of a CAD drawing i did while at a 5 day uni course i completed in 3.5 hours, so i spent the other 4 days making designs of a monocoque frame i'd like to build one day , it shares the same geometry as the current frame design that will just be tubes joined together.
So thats basically all the things ive built recently, enjoy them, hopefully i can rope together some money for this frame build one day, its the ultimate thing that i want to do!