Thud
1 MW
Hello from the shop of Thud.
I have made some desisions regarding the design of my 2 speed transmision & its application to my light EV comuter. I thought I would show some progress & hear any comments.
The "To Gear or not to gear" thread showed me that there are more than a few guys looking for a way to optimise their set up & extend the operational envelope
That said, I guess it is no secret that the majority of the builds I see around here (all of mine so far & in the future) are kinda illegal. so I can only recomend that you submit to your local ordinaces
Here are some design goals:
#1 maintance free
#2 quiet operation
#3 ease of integration
#3 is the puzzler-The bigest issue with any of the RC reduction units & this unit also is getting it to fit somewhere. This is really not an issue for myself, But I have had several inquiries asking for units for bicycles & still am looking for a better solution. There is no simple "bolt on" given the miriad of bike frames out there. I apreciate the input about size, but in reality this is the lower limit I am comfortable building & offering.
As of now the design has evolved into a closed case to allow an oil bath for all components. #1 acomplished! This should also reduce the whine inhearant in the rc reductions.#2 addressed! We the option of mounting the motor anywhere about the case with a simple bolt on mount. Orentation can be vertical or horizontal.
after optimizing sizes & reduction senarios I am right back where I started with the 1st prototype. roughly 2-1 reduction in low gear & 1-1 in high. 87% reduction to be precise. The rest of the gearing is acomplished in the primary & final reduction.
Several have asked to add reduction in the unit but the size grows exponentialy just getting to 3-1 in low range. Gears would solve the size issue but raise more design challenges regarding shock loads & set up manufacturing costs.
I plan to use this current version on my comuter Bike this summer. I will also be testing it with a shimano 3 speed hub & 6kwatts. A true EV comuter. The pedals (should I include them) will be for emergancy only. I am very close to starting the production of the units. Like Mud, I am not looking to get into full time production, Just off setting the devlopment costs & looking to make the e-bike experiance that much better for ever one.
Here is a foam pattern I will cast in aluminum. the finished tranny will weigh apox. 3 lbs not including the motor.
the bulges are bearing pockets. it will have a pr of .5 x 1.125 x .312" ball bearings & a pr of
I am certain the design will get another round of refinements before I am satisfied. the built up foam pattern is still a bit time consuming. Thats all for tonight. I need to switch gears & get My motor build back on track.
Todd
I have made some desisions regarding the design of my 2 speed transmision & its application to my light EV comuter. I thought I would show some progress & hear any comments.
The "To Gear or not to gear" thread showed me that there are more than a few guys looking for a way to optimise their set up & extend the operational envelope
That said, I guess it is no secret that the majority of the builds I see around here (all of mine so far & in the future) are kinda illegal. so I can only recomend that you submit to your local ordinaces
Here are some design goals:
#1 maintance free
#2 quiet operation
#3 ease of integration
#3 is the puzzler-The bigest issue with any of the RC reduction units & this unit also is getting it to fit somewhere. This is really not an issue for myself, But I have had several inquiries asking for units for bicycles & still am looking for a better solution. There is no simple "bolt on" given the miriad of bike frames out there. I apreciate the input about size, but in reality this is the lower limit I am comfortable building & offering.
As of now the design has evolved into a closed case to allow an oil bath for all components. #1 acomplished! This should also reduce the whine inhearant in the rc reductions.#2 addressed! We the option of mounting the motor anywhere about the case with a simple bolt on mount. Orentation can be vertical or horizontal.
after optimizing sizes & reduction senarios I am right back where I started with the 1st prototype. roughly 2-1 reduction in low gear & 1-1 in high. 87% reduction to be precise. The rest of the gearing is acomplished in the primary & final reduction.
Several have asked to add reduction in the unit but the size grows exponentialy just getting to 3-1 in low range. Gears would solve the size issue but raise more design challenges regarding shock loads & set up manufacturing costs.
I plan to use this current version on my comuter Bike this summer. I will also be testing it with a shimano 3 speed hub & 6kwatts. A true EV comuter. The pedals (should I include them) will be for emergancy only. I am very close to starting the production of the units. Like Mud, I am not looking to get into full time production, Just off setting the devlopment costs & looking to make the e-bike experiance that much better for ever one.
Here is a foam pattern I will cast in aluminum. the finished tranny will weigh apox. 3 lbs not including the motor.
the bulges are bearing pockets. it will have a pr of .5 x 1.125 x .312" ball bearings & a pr of
I am certain the design will get another round of refinements before I am satisfied. the built up foam pattern is still a bit time consuming. Thats all for tonight. I need to switch gears & get My motor build back on track.
Todd