Commuter Booster - <1kg Friction Drive

[adrian_sm]

I new it. Woooo hooooo!

My Commuter Booster 50mm is going to rock. It looks so sweet now being compact, symmetric, has dual swing arms, all the same asjustments, will fit heaps more bikes, ... I am getting excited.

Great work John.

 

[adrian_sm]

I only just got around to reading this properly.

The previous software matches motor power input with the given speed and was tuned to a power level that would that maintain speed on a slight encline.

Ah I thought you were somehow matching motor speed slightly faster than the wheel speed, but you are actually setting the power to what would be needed for that speed. Then maintaining that power level. Very cool. As it would allow you to easily set a lower power assist, that is maintained as you pedal faster. I like it. Now I know why you were so confused by my PM question the other day.

Although this works quite well, the problem with this was that if activated on flat ground, you would endup speeding up a bit or slowing down on a steeper gradient.

That is actually what I want longer term. For it to keep assisting, even if speed changes. But I see your point on initial engagement

This new revision, matches motor power with speed in the same way but then checks if you are slowing down or in increasing speed. It then resets the power input to suit. However, this is a one shot speed re set and as such its not constantly chasing that speed like a conventional cruise control does. Every time the button is pushed the interface re matches the speed in the same way.

Keep in mind, current limiting is still the main over riding factor so the interface will can only trim power input to this limit.

That is a really nice refinement. This interface of your is going to be pretty damn cool.

Are you going to settle down on just one control method out of the various you have tried. Or is this going to be something the user can select, reprogram or whatever. I know I will be just itching to try a few different things out.

- Adrian

 

[Kepler]

Are you going to settle down on just one control method out of the various you have tried. Or is this going to be something the user can select, reprogram or whatever. I know I will be just itching to try a few different things out.

Now this is a bit of a dilemma. I know guys like yourself are going to want to experiment with all sorts of settings but without giving open access to the source code, this not going to be that easy. Basic adjustments can be done through the LCD and a 3 button pad but things like custom current limiting, PWM adjustments, etc are not exposed at the moment.

Thats not to say, they cant be added. Tell me what I think you would like access to and I will see if we add this in. One of the big things that has taken some time is making software updates easy to upload for the non programmers out there. We know that software support is very important and want to make sure we can get bug fixes and enhancements out to the end user as painlessly as possible.

Of cause a full blown GUI is on the wish list.

 

[adrian_sm]

I was wondering how long your open source philosophy would last with the amount of development effort and $$$'s you have put in.

So I totally agree that you should lock it down, and restrict access. Obviously I am an abnormal customer, hopefully more of a collaborator, and my needs/wants will be unusual.

As I haven't tried out your different control methods, I don't know how many of them provide significant enough difference that people may want the option of using them. If they are all pretty similar, just pick the best. If there are a few that work nicely, or suit different needs, then a way for the end user to select the one they like would be nice.

I won't be able to give good feedback as to what I think should be exposed to user setting until I play with it. But the key things will be to be able to adjust it to suit different motors, wheel sizes. Giving access to max power is tricky due to legalities of it (an offroad setting perhaps?), but naturally I would like to tweak it. Maybe separate setting of max current/torque setting would be good for advanced user, such that it can be dialed down in the wet if necessary to reduce risk of slip without having to adjust geometry.

What are the useful parameters that can be tweaked at the moment behind the scenes?

 

[Kepler]

I was wondering how long your open source philosophy would last with the amount of development effort and $$$'s you have put in.

So I totally agree that you should lock it down, and restrict access. Obviously I am an abnormal customer, hopefully more of a collaborator, and my needs/wants will be unusual.

When we started, our thoughts were to build some hardware and write some base code and then have others add their own features. Turned out to be much more involved then first anticipated for it to operate the way I wanted it too. Funny, the interface has been a bigger project then the actual friction drive mechanics and cost way more to develop. Nice to see some light at the end of the tunnel now.

In regards to exposed user settings we have the following:
Battery => 5S LiPo
Battery => 6S LiPo
Battery => NiMh (24V nom)
Battery => Lead Acid (24V nom

Power profile.
Low (200W nominal)
Med (850W nominal)
High (1200W nominal)

Sensitivity profile
Low (pushing the throttle button increases throttle in very small increments)
Med
High (pushing the throttle button increases throttle in large increments)

Wheel diam
16"
20"
24"
26"
700C

Max speed
15kph to 50kph in 5kph increments

Mph or Kph select

Motor Diameter
50mm
63mm

Motor KV
170 to 320kv

I am thinking we may need to add the ability to adjust low and high PWM the cater for different ESC arming and full throttle points.
Also calibration adjustment for both amps and volts

 

[Kepler]

Completed another good test ride this morning with the small motor and low power interface setting. Very positive result. Assist was adequate with the ride effort being very comfortable. Covered 35kms for a total of 200W/hrs.

Motor temp at the end of the ride 30 deg C. ESC totally cool.

 

[41south]

Max speed
15kph to 50kph in 5kph incumbents

I hope you are going to cater for recumbents as well 8) :lol:

I am thinking we may need to add the ability to adjust low and high PWM the cater for different ESC arming and full throttle points.

From my experience with model aircraft and different ECS's that would be a great idea.

This is great stuff!

Colin.

 

[Kepler]

Well that just mean Fixing it now.

 

[adrian_sm]

Completed another good test ride this morning with the small motor and low power interface setting. Very positive result. Assist was adequate with the ride effort being very comfortable. Covered 35kms for a total of 200W/hrs.

Motor temp at the end of the ride 30 deg C. ESC totally cool.

8)

I might just be able to put this to use soon then.

 

[full-throttle]

Think I spotted a CB in action on the Yarra trail this arvo

 

[adrian_sm]

Beware imitations. :lol:

 

[full-throttle]

Yeah, after all these well documented and detailed posts on a public furum it's quite likely someone has made one.

I only heard a familiar whizz, turned around and caught a glimpse of the gold 63mm Turnigy with red griptape and pivot arm just like the ones you made on the drive side disappearing into the distance.

Good news - had a first ride on my resurrected commuter (just in time for Easter ironically enough) pictures to follow!

 

[adrian_sm]

Power to them. Anyone willing to make the effort to make there own is welcome to it. That is why I posted all the details. Pity it is spread over 40+ pages. Guess only the hard-core, or cheapskates will bother. The rest will have to wait until I get my ass into gear and make a few of these.

Most likely our mate John aka Kepler, taunting the world with his interface. Which reminds me I am meant to give him a bell to try out the latest version.

Great to hear your commuter is back in business. Hope it wasn't too much drama to fix it all up.

 

[Kepler]

Hopefully we can catch up on Tuesday morning.

Ran the little motor on the medium power profile today. this is 850W nominal with a few 1000W peaks. As expected the motor got quite warm. I think it would survive but it would be pushing the friendship a bit. I am thinking I need to have a power profile in-between the low and medium settings. Say 500W nominal. Easy to add.

 

[Miles]

That looks so cute, Adrian.

 

[adrian_sm]

@ Kepler: Tuesday should be fine. Name a time.

@ Miles: Cheers. Still need to finalise the spring adjustment. But it is not needed on my frame at the moment. I can just see a production cast version of the swing arms, all nice radiused and anodised, would make this thing even cuter.

 

[adrian_sm]

Cheap Camera Mount

I bought a cheap MD80 camera a while back, and put a fisheye lens on it. But was using a rubber mount, which resulted in wobbly footage.
I recently got a few spare CA mounts, and put one to use for hopefully a more rigid mount for my cheap little camera. It should allow me to mount it on the handlebars, forks, seat post, seat stays etc.

Haven't had a change to use it yet, but I'll post videos when I do.


This is the same camera I used to take that last video of the motor engagement.

 

[adrian_sm]

I just took my road bike for a spin with the 6374 motor, simple ramp control, and push button throttle. Instead of my usual MTB with hall throttle.

It was awesome. No slip, smooth engagement. Like having a turbo kick in. Then you struggle to shift through the gears fast enough to keep up.

At the moment it gives you a bit of a fright when you hit the throttle, because you don't expect so much power. I am still amazed out how much power you can get from such a small light package.

I also took a few videos. One from the seat tube look back at the drive, which I have called crutch cam give the POV.
The other was a quick walk around.

Crutch Cam

[youtube]GoEduLz7Yxg[/youtube]

Walk Around
This shows the larger 6374 drive mounted, the 5s20Ah (~400wh) battery pack, the stock 85Amp ESC mounted in the fresh air under the battery, then follows the throttle wire up to the handle bars where I have a servo tester that sets the max throttle, the ramp controller that smooths out the engagement and disengagement of the drive, and finally the "turbo button" throttle.

[youtube]pmfz_8zCbW4[/youtube]

I orginally had the servo tester on the handle bars so I could adjust the maximum power on the fly while testing things out. But I think I might just hide it all back in the battery bag at max throttle, and just run the two wires for the turbo button up to the bars. Doesn't get much neater than that.

- Adrian

 

[Kepler]

Ramped up the power a bit on the 50-65D. 500 to 600W with some 800W peaks. The little motor wasn't impressed. I didn't break it but 80 deg C is starting to push the friendship. I will knock it down to 300 to 400W with some 600W peaks and see how that goes. This little motor really is an assist only proposition. Nothing wrong with that though

If prolonged periods of 40kph are your aim, forget this little bloke. However, providing you keep current levels under control,the motor has great potential as a true ultra light weight assist.

 

[Wheazel]

Sounds super neat. Great progress!
I like the idea of lightweight assist that keeps the bike a bike and not a motorcycle.

 

[Hillhater]

Ramped up the power a bit on the 50-65D. 500 to 600W with some 800W peaks. The little motor wasn't impressed. I didn't break it but 80 deg C is starting to push the friendship. I will knock it down to 300 to 400W with some 600W peaks and see how that goes. This little motor really is an assist only proposition. Nothing wrong with that though .

Kepler,
what voltage are you testing these at ?, and what current does the 800w correspond to ?
I am guessing it is out of its optimal current range and would need a higher voltage to be reliable at those power levels. :?

 

[adrian_sm]

Commuter Booster Update:
Took the bike for a spin today. 20kms, 220wh. Cruising at 43kph, averaged 33kph, max 53kph.

Kepler's Interface Update:
Caught up with Kepler. Gave his latest interface a run, and it is progressing nicely. He had it setup on the little 50mm motor for me, at modest power levels. And it was quite useable. Took a little bit of getting used to the button logic, after riding my turbo button throttle at 4 times the power on the ride over.

The main advantage for me is the idiot proofness of it all:
- It stops the user from hitting the throttle from a stand still
- It limits power at low rpm
- it restricts the maximum power
- It provides a type of cruise control, by matching the power output with what is typically required for the speed you are travelling.
- has a nice display with a fuel guage, speedo etc.

It has a lot of smarts behind it, and will be a sensational product, making these friction drives very useable for joe public.

But I still left thinking that I wanted to try something slightly different. Just not sure what at the moment. I think the thing that I didn't like was that you had to press the button multiple times to get full power. But having a single button is quite restrictive in what you can do.

Kepler's Bomber Update:
I also took his souped up Bomber for a spin, and it is ridiculously quick. The pedals are totally redundant with that level of power. It just accelerates like a freight train, and keeps accelerating. Apparently it does 90kph without raising a sweet, and I would believe it. You definitely want to be leaning forward when you accelerate. Looking at the CA after the ride I was using about 13kw, so maybe 10kw at the wheel. That is motorbike territory for sure.

Good fun.

Thanks again John for the hospitality.

 

[Kepler]

Ramped up the power a bit on the 50-65D. 500 to 600W with some 800W peaks. The little motor wasn't impressed. I didn't break it but 80 deg C is starting to push the friendship. I will knock it down to 300 to 400W with some 600W peaks and see how that goes. This little motor really is an assist only proposition. Nothing wrong with that though .

Kepler,
what voltage are you testing these at ?, and what current does the 800w correspond to ?
I am guessing it is out of its optimal current range and would need a higher voltage to be reliable at those power levels. :?

This was all on 6S, 24V nominal so around 30 to 35A. I doubt if more voltage will help out much. The ESC (K force100) hardly gets warm. I think bottom line the motor is good for 500W continuous and that it. Keep in mind, it only weighs 414g so theres not a lot of copper in it.

 

[Kepler]

Commuter Booster Update:
Took the bike for a spin today. 20kms, 220wh. Cruising at 43kph, averaged 33kph, max 53kph.

Kepler's Interface Update:
Caught up with Kepler. Gave his latest interface a run, and it is progressing nicely. He had it setup on the little 50mm motor for me, at modest power levels. And it was quite useable. Took a little bit of getting used to the button logic, after riding my turbo button throttle at 4 times the power on the ride over.

The main advantage for me is the idiot proofness of it all:
- It stops the user from hitting the throttle from a stand still
- It limits power at low rpm
- it restricts the maximum power
- It provides a type of cruise control, by matching the power output with what is typically required for the speed you are travelling.
- has a nice display with a fuel guage, speedo etc.

It has a lot of smarts behind it, and will be a sensational product, making these friction drives very useable for joe public.

But I still left thinking that I wanted to try something slightly different. Just not sure what at the moment. I think the thing that I didn't like was that you had to press the button multiple times to get full power. But having a single button is quite restrictive in what you can do.

Kepler's Bomber Update:
I also took his souped up Bomber for a spin, and it is ridiculously quick. The pedals are totally redundant with that level of power. It just accelerates like a freight train, and keeps accelerating. Apparently it does 90kph without raising a sweet, and I would believe it. You definitely want to be leaning forward when you accelerate. Looking at the CA after the ride I was using about 13kw, so maybe 10kw at the wheel. That is motorbike territory for sure.

Good fun.

Thanks again John for the hospitality.

Good to catch up Adrian. The Commuter boost is looking good and performs really well. Certainly plenty power and speed out of the 63-74 thats for sure.

Thanks for the feed back on the interface. I get what you are saying, its certainly is not a turbo button like your setup feels like but a 500W limit is never going feel too thrilling after the 2000W plus you have on tap

The interface is very easy to custom tune. The tune I had set today was to demonstrate the interface's ability to take control over a low powered motor to a point whereby basically it was impossible to damage the motor or ESC yet still have adequate and user friendly power on tap.

I will be interested to see what you have in mind. I really like the concept of speed matching with the first press of the button then increasing speed by pulsing the throttle button. This to me feels natural and logical.

Glad you liked the over volted Bomber, it sure is a blast to ride thats for sure

 

[adrian_sm]

I will be interested to see what you have in mind.

I am really not sure, and probably won't be until I can play with it a bit more.

I really like the concept of speed matching with the first press of the button then increasing speed by pulsing the throttle button. This to me feels natural and logical.

I did too the last time I rode it, finding it really smooth and intuitive. But for some reason I wasn't so sure this time around. Perhaps it is just a riding style thing, as I mentioned this morning. I only use my bike to commute. So 99% of the time I am either stopped, or going as fast as I can. So I don't really ever want the motor to match my current speed, as that is what I can already do with my own legs, I want the extra boost. But for that I have to keep hitting the button to up the power.

If you were trying to match speed with others, or just trying to gently cruise along and soak up the scenery, then it makes more sense. If you just want all the power it has available now, it took a bit of button mashing. But as you say, it could be because it was set-up in low power mode for the little 50mm motor, and I was still expecting more than it was set up to give.

Don't get me wrong, I found it awesome. And will be using it or something similar on my drive for sure. I think I just need to use it more to understand what works, and stop being so arrogant about thinking I can improve it.

In the mean time my turbo button, and ramp control is fine for someone familiar with the drive. But to limit power, and kill the throttle at lower speeds I need some extra smarts.

- Adrian

P.S. When can I get one again?