Alrighty folks thank you for the 55+ people that submitted their votes into the post/polls I made here: What do you want out of a Gear Drive?!?
What the people want
Overwhelmingly, 86% of votes stated the reason people didn’t touch gear drives were due to cost. Followed by 15% due to lack of gear ratio options.
Along with this, premium materials and compatibility were also concerns. This conflicts with cost, but who knows maybe we can do everything.
Gear Ratio’s
55% of votes said a gear ratio between 2.5:1 and 3.0:1 is ideal, which hints at the majority of riders using 83-110mm ish wheels, 28% wanted 3.5-4.0:1 and the rest wanted something below 2.5:1.
Cost
51% of votes said they would pay between $175 to $250 USD for a dual gear drive setup. Seems pretty reasonable. 40% of votes wanted it even less at $100-175 for a set. That’s tough but who knows. 9 and 7% wanted even more expensive options which hints at a high end several thousand dollar builds.
Who wants them
Well, i’m glad to say that 72% of voters said they would be willing to put their money towards something that met some of their expectations highlighted above.
Now, with that being said, lets get this party started.
Trucks and Wheels
I have noticed that the large majority of riders use caliber style or hexagonal (heXL, etc) hangers so that is what development will start with. In hopes of retaining a cheap development process and specifically prototyping costs down we will start with these truck styles and stick with them until the opportunity to branch out presents itself.
Adapters will be made for different wheels, but primarily Abec style during development. This will branch out to pneumatic wheels
Gear Ratio
2.5:1 to 3.0:1 to start. Second version following soon after will be 3.5:1 and higher reductions.
Style
2-gear and 3-gear.
Getting gear drives to a 2.5-3.0:1 reduction is very challenging with 2-gears without wide hangers due to center distances between gears bringing a 63mm motor sphincter clenchingly close to the trucks. It can and will be done for those with wide hangers, but hangers under 200mm of width cannot support most motors. A 3-gear drive with a single transfer idler in the center brings the motor further away from the trucks and allows smaller hangers to be used. This will be the one for those with small hangers. It will be louder and slightly less efficient than a 2 gear.
Cost again
Alright here is the important part. How much does this cost?
I don’t know. My gut reaction is that 75% of the costs will be machining and impossible to determine right now. Many things I can make myself, including bored gears with pressed bearings and all 3D printed parts (if any) but I do not have direct access to a CNC and I don’t want to have machining done in China. I want this to be made in the good old US of A. It isn’t a quality concern, it’s a time concern. I am not willing to wait a month for a part to arrive to then realize that my center distances are off by 10 thousandth. To drive down costs, many things will be in imperial. I would prefer metric but in the US there are suppliers that can get me 50 different types of imperial bearings overnight, but only 5 types of comparable metric bearings. It’s what is is.
The goal is ~200usd a set shipped. Don’t quote me. please.
Development Process?
I am going to go about this piece-wise. We will start with the truck mounting situation, move onto the gearbox plates and gears, then prototype and test, repeat. I will attempt prototyping with 3d printed plates, lapping to get a nice flat surface and praying it works well enough to test functionality OFF the board. Once I am happy with the way it looks, I will move to aluminum plate and test on a board.
If at any point shit hits the fan, costs get to high, someone makes a set for $25 made out of titanium and solid gold, or it impedes my final year in college I will stop development. I am as motivated as those who are interested and if I can make something high quality for a low cost I will.
Thank you to anyone who supports the development, starting with @Skunk for offering his trucks for science.
also i’m calling it the Vulcan gear drive