College Level E-Bike Class

[methods]

Outline:

Class fulfills EE core credits or elective for ME, Software, Mechanics, etc
30 person class

Preparation:
Funding must be secured to order 40pcs Hubmotor, Controller, Battery, Throttle, CA
Budget for non-general miscellaneous items - torque arms, zip ties, duct tape, band-aids, random hardware bits

First day of class
Students are introduced to ebikes and the ebike community. Course outline. etc.

First homework assignment
You have 48 hours to procure a bike. Any bike. Your moms bike, a pink kids bike from the discount store, a mountain bike, a downhill bike, a trike, a 10speed, a Walmart bike... your call.
(Dont come back without a helmet and a pair of gloves)

By the end of the first week
Proposals submitted for configuration: Hub motor mounting front or rear, battery mounting, controller mounting, torque arm solution.
Projections on top speed, range, available thrust, and likely failure modes
Peer reviews, group work, single work, expansion proposals (like totally out of the box trailer configurations... or 2 bikes one battery... or off the wall ideas)

Second Week - getting things working on the bench
General bringup and confirmation that base kits work.... throttle stimulates controller, battery powers controller, hub motor spins, etc.
Theory slides on Battery technologies and configurations, BMS's, BLDC controllers and methods of drive, BLDC motors, etc
Equal balance of lecture and Lab - where lecture directly drives work in the lab

Lab Exercises
Reverse engineer controller, modify PCB's to meet requirements, change current limits, expand voltage range, troubleshoot common problems
Characterize batteries, simulate failures, practice safety, let some smoke out.

Overall goals
Take a cheap sub-par 200W ebike kit and turn it into a 2KW runner. Leave the class with a tool that you built and understand completely.

Final Project
30 mile class ebike ride PASS or FAIL
Team work, trailers, tow rigs, you name it... however you cross the finish line... it must be crossed. Push your bike, carry your bike, pedal your bike, or ideally... just cruise on your power system.
Big hills... big enough to overheat your motor for sure. Big enough to stall out your controller. Big enough to fail your brakes on the way back down.
Bumpy terrain - enough to break your spokes
Tough intersections... better be reliable enough to cross 4 lanes of expressway...

Option to take the class for a letter grade
Focus on extra credit in the form of exceeding expectations or creating an exceptional solution to a set of simple problems.
Adaptive curriculum that is focused on the total nOOb but can accommodate an expert who wants to have some fun for credit

Now that would be fun... and cool...
Educational and directly applicable
Something a future parent could take home to the garage for a parents/kids project... or a grad student could use on a daily basis... like building your own tools and then using them.


-methods

 

[The fingers]

Program prerequisites?

 

[teklektik]

Posted a day too early...

 

[methods]

Program prerequisites?

EE101 - ohms law, current law, super position, RLC, soldering, dmm, oscope, safety
ME101 or equivalent experience - competent with hand tools & power tools
SW101 - understanding of peripherals and firmware basics, PID, UART, spi, i2c, JTAG

Proven ability or driven desire to complete a project end to end on a budget inside of a schedule.

?

-methods

 

[methods]

Posted a day too early...

-methods

 

[The fingers]

Posted a day too early...

-methods

It's tomorrow already in the Philippines. :lol:

 

[spinningmagnets]

"Starter" DMM ($15 Sparkfun?)

5V power supply made from plastic cell-holder using four AA Enelooops rechargeable NiMH's

100W soldering iron...

Several identical throttles will be provided, each with a specific fault, students will learn to troubleshoot.

A small hubmotor will be provided with one bad hall. Students will learn to troubleshoot without disassembling the hub. Students will learn and display an adequate proficiency in disassembling the hubmotor with the supplied 3-arm puller.

Students will learn to test a 3-phase motor for phase shorts.

 

[Dauntless]

Posted a day too early...

-methods

It's tomorrow already in the Philippines. :lol:

Something you're keeping from the rest of us?

I'll tell you that someone who needed a teaching job would probably get such a class started fairly easily through the local ROP. High school kids would get credit, the adults just get a certificate. You get up a list of collateral skills they develop, (Soldering, electrical knowledge, etc.) go find the county Dept. of Education, they'll hel you work up a curriculum and get the money to start it, yada yada yada. My advice is to tell them to put it at an ROC, rather than on a campus. Win win situation for you.

 

[nutnspecial]

It could be a community level non-establisment private thing too. I like that better. It would be really cool to see many people doing a financially attainable version of this all over the place, and not just with dc electric and ebikes!
. . . .

Something you're keeping from the rest of us?

 

[methods]

Only because you opened the gates for me... Im going to take the opportunity

"Starter" DMM ($15 Sparkfun?)

I am certainly guilty of buying at least 20 meters like this in my life. If there is a person reading this who does not own a DMM... your homework is to buy one today - even if it is with your lunch money. If on the other hand an EE or a Tek or an installer is reading this and you use a DMM that cost less than than a used fluke the only thing I can say is "dont do it".

I know some people are brand whores... and others are elitists... but believe' me' this'.... I have yet to use a non-fluke DMM that did not waste my time, give me bad results, or piss me off. Its super easy to put a chip on a board with a 14bit ADC and some signal conditioning. No doubt Accuracy and Precision can be achieved when measuring pure signals.

Where the Fluke is different than all other meters is how it responds to the real world when leakage currents and bias voltages are all over your read. Somehow the Fluke just does a better job at tolerating noise while it settles. It settles quicker and more reliably. Its not that it can get a reading that a cheaper DMM cant... its that the Fluke is more likely to *indicate* that you are taking a bad reading while cheaper DMM's will *false indicate* with what appears to be a steady reading.

Each engineer should learn the lesson themselves... and hopefully one day the quality of the knock-offs will catch up (may have by now)>

If I built a DMM... when you set it to read Resistance... the first thing it would do would make a decision: "Is this going to be a good reading or a bad reading" - then display accordingly.

The Fluke always indicates in a reliable way when I am trying to take a bad measurement. Especially the older flukes... like the 87V. They are simple, cheap, they start up instantly, they are basically indestructible, and I am still kicking myself in the ass for selling both of mine to Matthew.

(But I got them both for only $50 each on Ebay with blown Current fuses)

5V power supply made from plastic cell-holder using four AA Enelooops rechargeable NiMH's

Omfg...
The epic time-bomb chase your ass troubleshooting power supply. I can hear it already: "Well... it was working yesterday! I dont know what happened :-/ ". Lol...

100W soldering iron...

Hell yea!
My favorite is an 80W Weller with the dial, Big, Medium, Small tips
Old school sponge for cleaning, flux in the tub, in the dropper, in the pen
Real 60/40 Rosin Core in hair thin, regular, and fatty

Several identical throttles will be provided, each with a specific fault, students will learn to troubleshoot.

No
We cant have young people learning skills like troubleshooting. ISIS may use information like this to get a Jeep running out in the desert or something. We pretty much need to consider that every man, woman, and child in the country is a terrorist and keep them fat, dumb, and happy.

A small hubmotor will be provided with one bad hall. Students will learn to troubleshoot without disassembling the hub. Students will learn and display an adequate proficiency in disassembling the hubmotor with the supplied 3-arm puller.

Students will learn to test a 3-phase motor for phase shorts.

Ah what? We never got to use a 3-arm puller... what about the monkey-bang method?
1) Remove fasteners around cover plate
2) Tape up the end of the axle on the side that has the wires coming out
3) Hold the hub in your hands... "wires axle" facing down.... and slam it into the ground over and over until the top cover plate separates from the stator

I am embarrassed to say that I must have done this procedure... 50 times?
(Yes... when Matthew and I were working together we actually procured a puller... those CroMotors were finger-eaters)


Anyway... thanks for contributing guys.
If we ever taught a class like this it would be targeted at second semester undergrads and up. Think of it more as an opportunity to pull the academic balloon back to earth than as a general service announcement. ES serves as the self-help center. I want to offer more of a break / reality check / real world opportunity. Along with the class I would speak of my experience working with the man after 9/11, bootstrapping a startup, working other startups, working big names.... what it means to hit the ground running... and how far you need to throw your feet out these days to cover the ever expanding gaps in knowledge (as technology diversity outpaces the human mind).

-methods

 

[methods]

I dont know what this is... but its f'ing rad.

( 123.jpg ) above

Is that... er... Irish Spring being painted with nail polish


-methods

 

[nutnspecial]

Lol, laughter is so healthy and it's also interesting to consider underlying psycology behind it and also 'pranks'. Utube is amazing with some of the best and worst examples. I think painting the soap with varnish/ nailpolish could be fairly innocent and fun hehehe. I did try soap in the end of the toothpaste tube one time, but no one noticed I guess. Forgot about that lol.

For april fools, and ot for students/ teachers, this is a great prank and the teacher proved to be a good guy. "best classroom april fools" https://www.youtube.com/watch?v=R9rymEWJX38

 

[amberwolf]

If on the other hand an EE or a Tek or an installer is reading this and you use a DMM that cost less than than a used fluke the only thing I can say is "dont do it".

How about if I'm using a DMM that *is* a used Fluke but it cost me less than a used Fluke?

 

[spinningmagnets]

30 students per class? I will never say that a $15 sparkfun is as good as a Fluke (even the cheapest model), I am a fan of deals where you find a used fluke with a blown fuse and buy it for $50, but there's no way to do that 30 times when you get approval to start the class and start taking applications for students.

Even if graduates are dealing with expensive Bosch mid-drives from Haibike, over 90% of electrical problems can be diagnosed with a $15 Sparkfun. There's nothing wrong with never compromising and demanding that new students get a Fluke as part of the course, but I just Googled new Fluke 87, and the price was $230-ish. You either have to add that to the cost of the course (which will reduce the number of students willing to sign up) or trust the students, which means half the class will show up with a $5 Harbor Freight DMM.

Serious ebike mechanics need two DMMs, and the $15 Sparkfun is not bad, for the cheap "starter" one.

 

[John in CR]

Do you even own a functioning ebike anymore?

 

[nutnspecial]

I'm still seeking words to describe the positive vibes Method's is giving off -not just with this thread.
He seems like a really cool person and member of the community.

I can think of a few people I've wanted to ask that John, but Methods wasn't one of them. . .

Regardless if so, I notice there's to be 30 students and 40pieces cro/kit :wink: . . . Perhaps there will be at least one 'model' build and a perk for the teach. Can't deny they wouldn't deserve 'ownership' as a form of payment in gratitude for the time and effort of positive community outreach!

 

[methods]

Do you even own a functioning ebike anymore?

Hi John

Well...

I rode on the back of a 2015 Zero SR last night... And for the last year I helped found a robotics company that heavily leverages ebike R&D, and before that I helped ensure production of BMS's at Tesla Motors, and before that I helped double production at Zero Motorcycles, and before that I imported and distributed containers of ebike stuff while building 20 ebikes of my own that explored the limits.

So ... John - big slap on the back for being the same guy you were when I left. Keep up the attitude and I am sure you will thrive.

-methods

 

[John in CR]

So the answer is no. If you need a controller to help get you on the road, I'll send you the DOA one you sent me that I'm sure just has something small wrong with it. I haven't touched it since you tried to walk me through a diagnosis.

 

[methods]

Great - I will PM you my address and let you know what I find. -methods

 

[markz]

My DMM is very physically similar to this, but my labels on the dial look different.
http://www.canadiantire.ca/en/pdp/autoranging-digital-multimeter-0520052p.html

The label dials on mine look more like this
http://www.canadiantire.ca/en/pdp/mastercraft-digital-multimeter-0520060p.html

I know for a fact I did not pay retail, CrappyTire puts on "sales", you have to know if they are scamming you or not, they tend to jack up the retail price on the sticker then take money or % off. I think too their repair counter gets commission, I know a private repair shop at a Petro does it.

I would say I spent $10 or $15 on my DMM. I have blown a few fuses.

 

[John in CR]

Great - I will PM you my address and let you know what I find. -methods

Cool, but no need to let me know anything. Get it going for yourself to get an ebike running. I hate to see someone so into ebikes drift so far from the flock, so It's good to see you back. If you still happen have any of those surfboard cap components laying around, I'll buy some of those.

 

[nutnspecial]

I agree with the sentiment, bikes are cool as hell. But rather than 'from', it appears drifting 'beyond' may be more accurately descriptive, because bikes def aren't everything.(and)Technology isn't even everything . . yet while nothing is everything (scratches mind)

imported and distributed ebike stuff
building 20 ebikes that explored the limits
helped production at Zero Motorcycles
helped production of BMS's at Tesla Motors
helped found a robotics company

. . . . .

I'm basic electrically (and physically, etc), mainly auto dc and house ac basics, so cheap multimeters have worked for me. I'm not even sure what to expect for the extra money when buying a fluke mm. I assume mostly increased accuracy/reliability, and then typical improvements in ergonomics/function and aesthetics.
For me so far the cheapies have been accurate enough though, allow for cheap reduncancy in multiple toolbags, and cheap replacement when I do something dumb, as an amateur. That prob shows my greenness when it comes to very fine dc/pcb/resistance measurements the cheap mm's fall very short with, but that I've had no need for and little knowledge of yet?