Student project: bike drive [Team1]

[[Team1] Gabriel]

@bandaro: you didn't read my text properly, I said the grey parts (including the battery, motor and conroller) wouldn't move (spin) with the wheel.

Also take a look at the http://neodymics.com site; there is a document there with a battery / motor wheel too.

lol, that looks a little bit like "Tim Taylor"-style ^_^


@miles:
Yeah, quite similar: the M.I.T as executing institution, the same idea behind it, the same structure... I think that is like the prototype series of the copenhagen wheel.

Supremely poor motor and ESC choices for an EV appliction.

This was just an example how it could be. I drew the motor in this version, so that you all could imagine the structure a little better.
But if one wants a stronger and quicker responding tourque, a version like this may be be better (I believe) - what do you say?.

But I think too that a hubmotor will be more efficient.

In my post before I said that a hub motor is out of the question, but I ment that >>just installing a hub motor set - and leave it like that<< would be too blunt.

But using a premade hub motor to create something new/different than before, is entirely all right.

 

[amberwolf]

Gabriel"]

Also take a look at the http://neodymics.com site; there is a document there with a battery / motor wheel too.

lol, that looks a little bit like "Tim Taylor"-style ^_^

I'm guessing you're referring to the main page design. There is a link to another design more like your integrated wheel; ah, I found it here:
http://www.neodymics.com/Images/BMU1.pdf

 

[Miles]

Gabriel"]
@miles:
Yeah, quite similar: the M.I.T as executing institution, the same idea behind it, the same structure... I think that is like the prototype series of the copenhagen wheel.

They really were two independent/parallel projects - a bit silly really... The Green Wheel has the ability to charge from an external supply, the Copenhagen Wheel is limited to regenerative charging.

 

[[Team1] Gabriel]

Oh... thanks for the info you two.

@amberwolf
Wow, yes, that looks more like it

 

[jag]

Gabriel"]

Also take a look at the http://neodymics.com site; there is a document there with a battery / motor wheel too.

lol, that looks a little bit like "Tim Taylor"-style ^_^

I'm guessing you're referring to the main page design. There is a link to another design more like your integrated wheel; ah, I found it here:
http://www.neodymics.com/Images/BMU1.pdf

I read in the beginning of the thread that you have just one month, right? It would be challenging to design, build and test an integrated hub drive with batteries and controller. It might be easier if you do a prototype by modifying an existing product. One ES member found one of these big hub motors in a neighbours garage in Croatia. Looks like there is room for a small controller and batteries for a proof of concept of a low power, "just bolt-on" eBike conversion. Can also upgrade to an RC style BLDC motor for better power to weight and efficiency.

These big hub motor wheels were made in Holland during the 80's. Maybe you can pick one up if you look around or post wanted ads.

Link to original thread:
http://endless-sphere.com/forums/viewtopic.php?f=3&t=20575&hilit=+hub+motor

 

[[Team1] Gabriel]

Nice one, jag!
That idea is not bad after all!

But we don't have to build it; and we are not going to build it. (Don't know how many times more I have to say this :lol: )

- but I will build it later (as a private person) - I will begin shortly after the completion of this theoretical project.

 

[[Team1] Gabriel]

Just to sum it up:
Here all "just-bolt-on" kits I've collected so far.

(1) a drive similar to Kepler's
(2) something similar, just attached to the seat stay
(3) something smaller, like Hidden Power

Something like go-ped
(I know, the lever ratio and the resulting force is too much, but this is just a draft)

Some BB drive variation

A "all in one wheel" with a RC setup + some gear ratio (batteries, motor & controller don't moove/spin with the wheel)

A "all in one wheel" with a hub-motor

Something like amberwolf's drive idea:

A drive where motor + gearbox are in one block and this block acts as a derailleur by mooving laterally on some ball bearing, actuated by the gear shift cable
(I drew the drive sprocket too high and too far to the right)

Again, motor+gearbox, but now the whole block follows the the chain passively in lateral direction. Derailleur is a standard one.

An old hub motor, something like this, turned into a "all in one wheel"

 

[[Team1] Gabriel]

So guys, today we held our meeting, discussing the advantages and disadvantages of the most ideas and we came to a conclusion.

We decided to design a mix between go-ped and Kepler's drive.

------------------------------------------------------------------------------------------------------------------------------------

- Pedellec version, assisting to 25km/h (16mph) (=Austrian law for pedellecs)

- all included-system, max. 250W setup (=also law)
- seat stay or seat tube mounted drive, preferably compact and inconspicuous
- hard to detach - against theft (maybe special screws)

- extra small and easy detachable batttery pack shall suit into any normal bag
- basically for one ride, range approx 10-20km (6-12miles)
- charger included into battery pack -> plugin battery pack anywhere
- maybe multiple charge speed option, maybe 2 buttons: [2h] and [45min] (or 15min -> that would mean LiFePo only - but who needs his pack charged in 15min??)


?- batttery pack mounting still not clear, either in the big triangle most likely seat tube, or on top of the drive
?- pack voltage?
?- still not sure if wired or wireless sensoring and power output adjusting
?- power output adjusting, or just pedal sensor = one power level
?- not sure which type of motor to use
?- grip-problem with the friction roller, but there is plenty stuff about that in this forum

------------------------------------------------------------------------------------------------------------------------------------

The main idea we all agreed on is to make a version of a bike drive, wich is beginner friendly and very handy.
Also our professor gave a valuable input with that "I would want it small, because then you can take it with you/into your bag everywhere you want" and contributed developing the idea.

So we chose a design which fits most of the city-zens needs:
Driving from A to B, may it be a businessman, pupil, student or an adult visiting his/hers parents - they all would'nt need to get back right away.
So they snatch their battery pack, plug it in where they are (office, school, old home) and take it with them when they leave - and have fresh power for the returning.

Just like you take your key for your bike lock with you every time - you take the small battery pack with you when you want to use it.

EDIT: I kew Kepler's drive just from one picture you guys showed me in this thread - but just now I watched the TV show where it was presented - funny, our goal is just about the same
At least I can be sure now that in reality this project would have resulted in a good outcome, if we actually were going to build it. (maybe we are later, who knows)

 

[jag]

Gabriel"]
- extra small and easy detachable batttery pack shall suit into any normal bag
- basically for one ride, range approx 10-20km (6-12miles)
- charger included into battery pack -> plugin battery pack anywhere
- maybe multiple charge speed option, maybe 2 buttons: [2h] and [45min] (or 15min -> that would mean LiFePo only - but who needs his pack charged in 15min??)
:

So they snatch their battery pack, plug it in where they are (office, school, old home) and take it with them when they leave - and have fresh power for the returning.

I particularly like the idea of a small, portable "1 way ride" pack. My batteries have always been 5+kg. At 1-2kg battery bringing it in on every stop becomes more feasible. I think you still will want a battery of about 200Wh. Long lived LiFePO4 is mostly about 100Wh/kg (Hard to get A123 pouch cells are 140). Some LiPo approaches 200Wh/kg. Then of course weight is added for BMS, charger and case.

Quick charge at 15-30 min is not to be looked down upon. Perfect for when stopping for a snack or lunch. Bring pack in, plug in the nearest outlet. Then when finished coffee ready to go again. A123 Cells and some LiPo can take 15min charge.

 

[[Team1] Gabriel]

We have also decided different tasks for everybody untill next week:

2 people make marketing, law, cost accounting...
1 battery technology
1 motors (myshelf)
1 construction schemes, drafts
1 sensors and power output adjusting

Then next week we will collect, compare and fuse what everybody has got so far. Every topic will influence the other I think.

@ jag: Thanks for the input, that I can tell the guy who researches whats possible with batteries.

Looks like I endned up beeing the only guy of my group posting here.
It is not very likely that the others will post their researches, insights and drafts here during the project, but maybe that would be better anyway.
(would be too much uneccesary information, this thread would get too long and confusing, maybe in another thread)

But I will keep sumarizing and posting our interim results and keep you up to date

lg,
Gabriel

 

[Bubba]

Gabriel"]We have also decided different tasks for everybody untill next week:

2 people make marketing, law, cost accounting...
1 battery technology
1 motors (myshelf)
1 construction schemes, drafts
1 sensors and power output adjusting

Then next week we will collect, compare and fuse what everybody has got so far. Every topic will influence the other I think.

@ jag: Thanks for the input, that I can tell the guy who researches whats possible with batteries.

Looks like I endned up beeing the only guy of my group posting here.
It is not very likely that the others will post their researches, insights and drafts here during the project, but maybe that would be better anyway.
(would be too much uneccesary information, this thread would get too long and confusing, maybe in another thread)

But I will keep sumarizing and posting our interim results and keep you up to date

lg,
Gabriel

Any updates?