Around the world on a solar ebike

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solarEbike   100 W

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Re: Around the world on a solar ebike

Post by solarEbike » Jun 06 2020 11:43pm

I wasn't expecting this much trouble with wind because the previous single wheel trailer (almost) never had this problem. This version is 26% lighter, has 7% more surface area, tilts to 85° from horizontal instead of 45°and is a little higher off the ground for more suspension travel. Each of these changes makes it more sensitive to wind and they just add up.

Also, the previous linear actuator locked the panel tilt in place whereas the clutch on the drive shaft here is slipping due to wind gradient (wind shear?). When I modeled the fluid dynamics in my head, this didn't happen but it appears that the wind speed at the top of the panel can be significantly higher than at the bottom. This is why we test things.

This was so bad on my first ride that I had trouble getting back home but it was largely because the tilt motor controller was stuck on "follow the sun" mode. I enabled "keep panel level" mode on later rides and the handling was just about manageable even with strong wind but I found I hated having to pick between full range of travel and no travel.
fechter wrote:
Jun 06 2020 9:46pm
If you had some kind of wind force sensor, you could have it automatically flatten out during a gust. Not sure if it could react fast enough though.
I had the same thought but looking at available wind sensors I didn't see anything that looked small enough and robust enough. I picked up an accelerometer for the Arduino but I'm not confident I'll be able to differentiate between acceptable and unacceptable movement in software. Reaction time might be tricky, as you say. With manual control, I can anticipate but it's kind of taxing to have to think about all the time.
Cowardlyduck wrote:
Jun 06 2020 9:59pm
I think a simple solution would be to have the panel able to shift sideways so that the pivot point is further forward into the wind direction. That way the wind will help stabilise the panel rather than catch it like above. Kind of like the trailing edge of a arrow.
Interesting. I hadn't considered that. Unfortunately, the tilt motor / gearbox / clutch assembly is sized to fit inside the boom tube and to handle a perfectly balanced panel so I don't think I could do that without major re-work. If it's windy enough for the trailer to get pushed around this much, I'm resigned to taking the solar performance hit and leveling out the panel.

The solution I'll be ready to road test tomorrow is relatively low tech: use a handlebar-mounted potentiometer to trim the panel on the fly by setting the maximum tilt angle. One end is full travel and the other end is no travel (horizontal only). This way I can let the sun tracking algorithm follow the sun as much as current conditions will allow based on how the bike is handling. If it works with a manual input, I could try to automate it later.

I might also try adding weight to the trailer using stuff I would otherwise be carrying on the bike anyway, like extra water bottles.
SWB recumbent, Grin DD hub, Phaserunner, 6x LiGo battery, 238 watt sun-tracking solar trailer and 76 watt solar roof with 3 Genasun MPPT boost controllers, CA3 w/ solar FW & GPS Analogger, Rohloff hub. Solar ebike build, Website, Instagram

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Re: Around the world on a solar ebike

Post by thundercamel » Jun 07 2020 9:36am

I was going to say, add weight right above the trailer wheel?
My Ebike builds - Existing bikes, affordable motor kits, self built 14s6p batteries - Now with more recumbent!

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Re: Around the world on a solar ebike

Post by solarEbike » Jun 18 2020 12:41pm

Final assembly of the trailer panels is proceeding apace. Tab wires and Kapton tape on the back of the panel for bypass diodes.
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Epoxy potting compound candy-coating to keep them dry. This stuff takes 4 days to fully cure at room temperature or two hours at oven temperatures so I do this under a heat lamp and keep drizzling on the epoxy until I get good coverage.
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Testing each smart bypass diode after potting.
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The idea is to fit them into a 0.25" (6.4 mm) cavity in the honeycomb sandwich panel. However, waterproofing the solder joints here is proving to be more difficult than I imagined. In hindsight, I should have used the traditional approach of putting the diodes in a junction box but I wanted sleek and sexy. I'm coating the solder joints with several coats of clear nail polish and then building up a couple of layers of Permatex black silicone. This might be backwards but I'm thinking that soft encapsulation on the outside will allow for troubleshooting and fixing problems like failed diodes in the future whereas hard potting will not. If the seal isn't perfect I'll get leakage currents when the panel gets wet. The decision to use conductive carbon fiber here also doesn't seem ideal. I've been told one of the solar race cars caught on fire for this exact reason.
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In the meantime, I've been doing increasingly longer training rides with just the 78 watt roof solar panel and 518 Wh battery to prepare my body for the 200 mile attempt in a few days. June 20 is looking to be a little cloudy so maybe Sunday?
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4th and final rest break at Richmond Bridge (San Quentin side).
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111 miles (179 km) yesterday doesn't seem like much compared with 200 miles but using only 1 kWh compared to the 3 kWh I expect to have for the longer run made it physically demanding. About 9.5 hours of pedaling and I still had energy to spare so I think the 13-13.5 hours of pedaling for the long run is feasible.

I got my Analogger sorted (bad SD card) so I was able to capture all the sweet, sweet data in 1Hz resolution:
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The blue arrows show where I took my rest breaks at roughly 2 hour intervals. I keep the panel nearly horizontal while riding. The increase in solar output while stopped is from orienting the bike and solar panel at 90° to the sun's rays. More irradiance means more power. The higher blip at the start of each break is before the panel heats up due to the higher insolation and reduced airflow because the bike isn't moving. The second break was my lunch stop, a little past solar noon. I was already getting the sun optimal angle while riding (the solar elevation angle is over 70° at that time of day around this time of year) so stopping actually results in a decrease in solar output due to the cell temperature increase from reduced airflow.

The yellow line traces the position of the sun in the sky. I started 3 hours after sunrise (the trip was a last minute decision) and ended half an hour before sunset. In spite of this, the total solar Wh was 10% higher than the model predicted. Either my model inputs are too conservative or the perfect cloudless day had more insolation than the typical meteorological year used for the PV production modeling or my solar Hall sensor needs to be re-calibrated. It could be all three but I'll take more solar Wh over less any day.
SWB recumbent, Grin DD hub, Phaserunner, 6x LiGo battery, 238 watt sun-tracking solar trailer and 76 watt solar roof with 3 Genasun MPPT boost controllers, CA3 w/ solar FW & GPS Analogger, Rohloff hub. Solar ebike build, Website, Instagram

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Re: Around the world on a solar ebike

Post by rowbiker » Jun 18 2020 4:45pm

solarEbike wrote:
Jun 06 2020 11:43pm
fechter wrote:
Jun 06 2020 9:46pm
If you had some kind of wind force sensor, you could have it automatically flatten out during a gust. Not sure if it could react fast enough though.
I had the same thought but looking at available wind sensors I didn't see anything that looked small enough and robust enough. I picked up an accelerometer for the Arduino but I'm not confident I'll be able to differentiate between acceptable and unacceptable movement in software. Reaction time might be tricky, as you say. With manual control, I can anticipate but it's kind of taxing to have to think about all the time.
Another approach, while definitely not "simple", I think might solve the problem. Look at your trailer when it's parked, and pretend that you're the wind -- pushing at the solar panel until it starts to tip the trailer. Determine where the 'fulcrum' is, i.e., which part of the solar panel(s) support structure transfers the solar panel's torque (like a sail on a boat) to the trailer. Putting a strain gage there would let you sense the wind pressure in real time, and the instrumentation amplifier you'd use to read the strain gage sensor(s) would turn the panels out of the wind (let the 'wind out of your sails'). I think the strain gage will not be as subject to the wrong inputs of an accelerometer, but, as you say, "that's why we test things". Assuming you could get a reliable sensor input, you could do some very fine tuning, allowing a fair amount of 'sail effect', but not enough to tip the trailer.

Justin has managed to use strain gages to maintain fine enough throttle control/response on an e-assist unicycle, so I'm pretty sure response times can be very fast. Your tilt motors, as was mentioned, might not be fast enough (yet).

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Re: Around the world on a solar ebike

Post by solarEbike » Jun 19 2020 2:48pm

Thanks for all the suggestions. I've done several test rides with the handlebar mounted potentiometer to limit the maximum tilt angle and it appears to be quite effective in terms of giving me fine manual control of the wind profile on the fly. I don't mind having to fiddle with it for now since it's new and I'm still learning how the trailer handles under different conditions but eventually the full manual control will get tedious. One thing I've learned is that the acceptable level of risk of being blown sideways by a wind gust varies depending on circumstances: high speed traffic passing next to me on a narrow shoulder vs. wide, empty road, for example. I'll probably want to keep some amount of semi-manual control to adjust on the fly even if I find an automated sensor-based solution.
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thundercamel wrote:
Jun 07 2020 9:36am
I was going to say, add weight right above the trailer wheel?
Between the need for suspension clearance and trying to manage sprung vs. unsprung weight, this is about as far back as I can put any additional weight. Didn't seem to make a huge difference. I deliberately designed the trailer to not carry cargo as a way to make it lighter and to enable more tilt travel. I never imagined I would be looking for ways to make it heavier. :shock:
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rowbiker wrote:
Jun 18 2020 4:45pm
solarEbike wrote:
Jun 06 2020 11:43pm
fechter wrote:
Jun 06 2020 9:46pm
If you had some kind of wind force sensor, you could have it automatically flatten out during a gust. Not sure if it could react fast enough though.
I had the same thought but looking at available wind sensors I didn't see anything that looked small enough and robust enough. I picked up an accelerometer for the Arduino but I'm not confident I'll be able to differentiate between acceptable and unacceptable movement in software. Reaction time might be tricky, as you say. With manual control, I can anticipate but it's kind of taxing to have to think about all the time.
Another approach, while definitely not "simple", I think might solve the problem. Look at your trailer when it's parked, and pretend that you're the wind -- pushing at the solar panel until it starts to tip the trailer. Determine where the 'fulcrum' is, i.e., which part of the solar panel(s) support structure transfers the solar panel's torque (like a sail on a boat) to the trailer. Putting a strain gage there would let you sense the wind pressure in real time, and the instrumentation amplifier you'd use to read the strain gage sensor(s) would turn the panels out of the wind (let the 'wind out of your sails'). I think the strain gage will not be as subject to the wrong inputs of an accelerometer, but, as you say, "that's why we test things". Assuming you could get a reliable sensor input, you could do some very fine tuning, allowing a fair amount of 'sail effect', but not enough to tip the trailer.

Justin has managed to use strain gages to maintain fine enough throttle control/response on an e-assist unicycle, so I'm pretty sure response times can be very fast. Your tilt motors, as was mentioned, might not be fast enough (yet).
Interesting idea. I knew about Justin's use of strain gauges on an electric skateboard (at the 33:17 mark) but not the unicycle. I can see how a properly located strain gauge might be able to directly measure wind pressure from the sides and produce a reliable signal for the control algorithm. Maybe one of the four brackets connecting the solar panel to the main trailer boom tube could be redesigned to incorporate a load cell or even measuring the flex of the panel itself.

It takes the tilt motor about 3.5 seconds to move the panel 85° from nearly vertical to horizontal so I would likely be detecting an average wind pressure and reducing the profile proportionally as opposed to trying to instantly react to individual wind gusts.
Last edited by solarEbike on Jun 24 2020 5:14pm, edited 1 time in total.
SWB recumbent, Grin DD hub, Phaserunner, 6x LiGo battery, 238 watt sun-tracking solar trailer and 76 watt solar roof with 3 Genasun MPPT boost controllers, CA3 w/ solar FW & GPS Analogger, Rohloff hub. Solar ebike build, Website, Instagram

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Re: Around the world on a solar ebike

Post by yahh2725 » Jun 21 2020 12:09am

solarEbike, wow it looks awesome. Thanks for sharing. It's great when sun can help us in travelling, especially in such way. Astrology and numerology - are such things, which also help a lot for every of us. You can take a look at this page ( link: https://www.sunsigns.org/angel-number-707-meaning/ ), just to realize how much one number can tell you about certain things in your life.
Last edited by yahh2725 on Jun 28 2020 10:44am, edited 2 times in total.

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Re: Around the world on a solar ebike

Post by solarEbike » Jun 24 2020 1:45pm

yahh2725 wrote:
Jun 21 2020 12:09am
solarEbike, wow it looks awesome. Thanks for sharing.
Hello and welcome to the forum. Thanks for creating an account just to leave a kind comment here.
solarEbike wrote:
Jun 18 2020 12:41pm
the total solar Wh was 10% higher than the model predicted. Either my model inputs are too conservative or the perfect cloudless day had more insolation than the typical meteorological year used for the PV production modeling or my solar Hall sensor needs to be re-calibrated.
So it turns out that the solar current Hall sensor was reading about 12% too high. That's consistent with the too-high daily solar Wh I was seeing and the errors in my DIY-battery-state-of-charge-percentage-Cycle-Analyst-upgrade on trips with lots of solar generation. The SOC indicator was very accurate when running on battery alone but it was over-counting the solar Wh going into the battery so I would hit LVC sooner than expected which is a real drag at the end of an 8, 10 or 12 hour day. The odd thing is that I calibrated this Hall sensor a year ago and I wasn't expecting it to drift like this. Maybe it's getting magnetic interference from the tangle of wires next to the battery?

I took the newly completed trailer for its first test ride yesterday. After 30 miles (48 km) when my battery would typically be nearly empty, it was still at 95%. Regenerative braking performed poorly because the battery voltage was too high to permit adequate braking force. This trailer and roof canopy generate 70% more solar watts than my old trailer. It'll take a little while to get used this being the new normal. It feels weird. Good weird.
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Wind is still a problem but I need to fix a hardware problem problem before I try sensors and automation: the torque limiting clutch on the tilt motor driveshaft is not strong enough to hold the panel against wind gusts. I'm going to try replacing it with one of these spiral-cut aluminum flexible driveshaft couplings and see how that works out. Hopefully, the coupling will snap in case of crash and protect the gearbox from damage. On second thought, I think I'm going to order an extra one and test it to destruction with a torque wrench...
8mm-Shaft-Coupling.jpg
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SWB recumbent, Grin DD hub, Phaserunner, 6x LiGo battery, 238 watt sun-tracking solar trailer and 76 watt solar roof with 3 Genasun MPPT boost controllers, CA3 w/ solar FW & GPS Analogger, Rohloff hub. Solar ebike build, Website, Instagram

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Re: Around the world on a solar ebike

Post by solarEbike » Jun 24 2020 5:27pm

Here's a short time lapse of the sun tracking while the bike is stationary. I'm looking forward to doing these in more scenic locations in the future.



Eliminating the clutch will reduce the backlash which means I could do smaller, more precise angle adjustments but having the sun's rays 2-3° off-axis makes almost no difference in output so I'm prioritizing lower motor duty cycle over having smooth-looking time lapse videos.
SWB recumbent, Grin DD hub, Phaserunner, 6x LiGo battery, 238 watt sun-tracking solar trailer and 76 watt solar roof with 3 Genasun MPPT boost controllers, CA3 w/ solar FW & GPS Analogger, Rohloff hub. Solar ebike build, Website, Instagram

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Re: Around the world on a solar ebike

Post by JackFlorey » Jun 24 2020 8:32pm

Indeed, even if you went to 20 degree adjustments you'd see almost no change in harvested power.

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Re: Around the world on a solar ebike

Post by solarEbike » Jun 24 2020 11:07pm

JackFlorey wrote:
Jun 24 2020 8:32pm
Indeed, even if you went to 20 degree adjustments you'd see almost no change in harvested power.
Sure, for some definition of acceptable loss. At 20° error, the loss is around 6% which kind of defeats the point of having automated sun tracking. Admittedly, the tracking is more of an interesting exercise than something I can justify in terms of effort, cost and weight.
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SWB recumbent, Grin DD hub, Phaserunner, 6x LiGo battery, 238 watt sun-tracking solar trailer and 76 watt solar roof with 3 Genasun MPPT boost controllers, CA3 w/ solar FW & GPS Analogger, Rohloff hub. Solar ebike build, Website, Instagram

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Re: Around the world on a solar ebike

Post by JackFlorey » Jun 25 2020 11:05am

solarEbike wrote:
Jun 24 2020 11:07pm
Sure, for some definition of acceptable loss. At 20° error, the loss is around 6% which kind of defeats the point of having automated sun tracking.
Well, with 20 degree steps, the worst error is 10 degrees (plus some uncertainty around actual sun angle/mechanical angle) so you are losing more like 2%.

If there is some mechanical benefit in having fixed stops it might be an option.

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The 200 mile test ride

Post by solarEbike » Jul 02 2020 7:27pm

A deadline has a wonderful way of focusing the mind. I got my custom encapsulated solar panels in August of 2018 and kept putting off the irreversible final step of bonding them to my new nearly-finished trailer until two weeks ago. Some of it was about wanting higher confidence that I hadn't overlooked some design flaw or missed an opportunity to make the trailer better in some way which might be impossible once the panels were bonded. Some of it was project burn-out and absence of an externally-imposed deadline.

Maybe if I had sponsors who expected me to make and keep commitments to a timeline? Nah. I probably would have been out on the road when the pandemic hit. How about if I set my own deadline and tell everyone I'm going to ride 200 miles (322 km) on the summer solstice? Surely that will shame me into getting the last stage done. Well, it worked.



Compared with the 1 inch (25 mm) thick red foam trailer at the start of this thread, this one has:
  • 25% more solar power with only 7% more surface area thanks to
    • tighter cell spacing
    • reduced border
    • 72 cells instead of 60 and
    • slightly higher efficiency cells
  • 5% lighter (25.8 lbs / 11.7 kg)
  • increased tilt range
  • slightly better aerodynamics
  • this handy folding feature for transport...
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I started one hour before sunrise and ended two hours after sunset.
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I've uploaded the Analogger data if anyone is curious.
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2266 solar Wh from a 315 watt array is 7.2 Wh/W. The SunTrip 2018 average was 3.5 Wh/W with the best team averaging 3.9 Wh/W over a period of many weeks with rainy days and rest days and mechanical issues to bring down that figure. My value is for the sunniest day of the year. I'll be satisfied if my long-term average ends up close to 4 Wh/W.

I had to increase my power consumption in the middle of the day because the steady 270-280 solar watts was bringing my battery voltage high enough that regenerative braking stopped working and I couldn't even take food/toilet breaks without losing potential solar Wh. Normally, I wouldn't call this a problem but when you're trying to cover this kind of distance you want every Wh. In hindsight, I should have started earlier and/or depleted my battery faster in the early morning and/or had a larger battery. I brought a backup battery which I didn't want to use but ended up needing for the last 13 miles.

I'm optimizing the bike for 80-100 miles per day (130-160 km) over the long haul so I'm not inclined to make any changes based on what works best for 200 mile marathon days.

This was 44% longer than my previous longest day so I'm content to bask in the satisfaction that man and machine can do this distance before attempting anything similar again. Next milestones would be to do 200 miles without an extra battery and/or with a fully loaded bike and/or using only solar energy generated on the day of the ride (without banking energy from a previous day). With no hills, no wind and smooth roads I can see 400 km (250 miles) being an achievable goal once I have my "touring legs."
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SWB recumbent, Grin DD hub, Phaserunner, 6x LiGo battery, 238 watt sun-tracking solar trailer and 76 watt solar roof with 3 Genasun MPPT boost controllers, CA3 w/ solar FW & GPS Analogger, Rohloff hub. Solar ebike build, Website, Instagram

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Re: Around the world on a solar ebike

Post by rowbiker » Jul 03 2020 9:09am

It will take a while to digest all of the data in your magnificent post, but I think you've definitely earned a place in the history books for this achievement. Your persistence in putting all of the bits and pieces together to bring this to fruition is truly inspirational. To do this in the middle of a pandemic elevates this effort to a holy grail level. Congratulations!

I, for one, don't mind playing the role of being a small fragment of your conscience. If you end up missing one of 'our' deadlines by a bit, I'm sure 'we' can find some forgiveness there somewhere. After all, it's better to have biked and failed, than to have never biked at all.

You're also providing me with the inspiration to complete my transition to a StreetMachine with an all-axle Grin front hub, with all the other goodies -- except for the solar panels, which I'm leaving up on my roof (for now).

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Re: Around the world on a solar ebike

Post by solarEbike » Jul 03 2020 2:52pm

rowbiker wrote:
Jul 03 2020 9:09am
It will take a while to digest all of the data in your magnificent post, but I think you've definitely earned a place in the history books for this achievement.
I appreciate the sentiment but I've managed to remain humble by remembering that the solar bike record is held by 2018 SunTrip participant Eric Morel who rode 265 miles (427 km) between 7 am and 9 pm one day in Kazakhstan under ideal conditions with a tailwind. The 24 hour endurance record is 585 miles (942km) set by Christoph Strasser on an indoor track. No motor, no solar. I’m just a filthy casual by comparison. Averaging over 24 mph for 24 hours?! I could possibly maintain that speed on a road bike for an hour if I trained hard but keeping it up for that long boggles my mind.
rowbiker wrote:
Jul 03 2020 9:09am
If you end up missing one of 'our' deadlines by a bit, I'm sure 'we' can find some forgiveness there somewhere.
Nooooo. You must crack the whip. I must be punished for my transgression! :D
rowbiker wrote:
Jul 03 2020 9:09am
You're also providing me with the inspiration to complete my transition to a StreetMachine with an all-axle Grin front hub, with all the other goodies -- except for the solar panels, which I'm leaving up on my roof (for now).
That's great. Go for it. I ran four different motors on my old StreetMachine over the years with thousands of miles on each and the front direct drive hub is my favorite. I started with a 24 volt mid-drive running on lead batteries until the motor/controller died due to water ingress. I upgraded to a BMC geared rear hub which was great except for one clutch failure and a Hall sensor malfunction. I replaced that with a Bafang BBS02 only because I got fed up with the rear derailleur maintenance issues and got the Rohloff hub (don't ride around the world without one).
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Finally, I replaced the still-functioning BBS02 with the Grin All-axle direct drive front hub because I wanted the simplicity for middle-of-nowhere reliability. It's by far the quietest of the bunch and proportional regenerative braking is extending my range by 8-20% on local rides and making my brake pads last forever.

Just be careful on wet roads. I've had two falls caused by the front wheel losing traction during heavy regen braking. I have TripWire switches on standard Avid brake levers which activate minimal regen right before the pads touch the rotors and I increase regen (up to about 1000 watts) using my Domino throttle. That's pushing it a bit for 10s6p LG MG1 cells. The trouble is that you don't get much feedback like with the disc brakes and the bike is so low to the ground that there's no warning. One millisecond everything is just fine and the next you're sliding to a stop with the bike on its side with nothing in between. Both incidents were on the same treacherously slippery-when-wet stretch of road. Injuries were minor.

I sold my StreetMachine to a fellow ES member who subscribes to this thread. I kept the Grin hub motor to put on my new HPV Grasshopper fx and he ended up getting his own Grin hub. Maybe he'll chime in with his experience here? I've now put an additional 9,500 miles (15,000 km) on the hub on the new bike and have had zero problems. I've disassembled the front fork a couple of times for routine maintenance and to reduce its travel to fix a clearance issue and found no excess wear or play.

One thing I missed when using the Grin Motor Simulator before my purchase was that my top speed would drop to around 22 mph (35 kph) at WOT as the battery approaches LVC. It's fine for long distance touring when towing a trailer but I would have preferred to have a little more top speed for local rides where I sometimes find myself playing in traffic. This is with a 36V battery. I briefly tried connecting my 6 LiGos in 20s3p configuration to get 72V. The speed increase was insane but I can't charge with my GenaSun controllers while riding so I'm sticking with 36V.
SWB recumbent, Grin DD hub, Phaserunner, 6x LiGo battery, 238 watt sun-tracking solar trailer and 76 watt solar roof with 3 Genasun MPPT boost controllers, CA3 w/ solar FW & GPS Analogger, Rohloff hub. Solar ebike build, Website, Instagram

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Re: Around the world on a solar ebike

Post by rowbiker » Jul 04 2020 7:23am

Thanks for the great advice -- the arrows you've taken in your back are definitely making life easier for those of us who are following in your footsteps. The warnings about losing traction in the front wheel are especially welcome, since I'm starting to get too old to crash the way I used to. I've adopted BMX tires that are as grippy and wide as possible for my 20" front wheel recumbents. I, like you and Justin, am a firm believer in regen braking, and frequently end up in the double digit percent regen category, even up here in the relative flatlands of MN. I've documented some of my recent trips with the all-axle front hub at https://erowbike.com/eG20. I've long ago forgotten how to fix brakes. :)

Unfortunately, due to my own fault of forgetting to properly tighten the torque arm retaining bolt, I've spun out the Grin all-axle motor, and have lost my speed sensing ability. I've already got a new L10 wiring harness from Grin and plan on opening the motor and fixing this issue when I move the motor from the Bacchetta G20 to the StreetMachine. I don't suppose you have any tips there -- with all your miles on that motor, not ever having to open it up ...? Also, I have some StatorAde on hand, but so far the motor has never gotten really warm, so should I use it?

I'm continuously re-reading your thread and being inspired to steal your ideas for my StreetMachine conversion. Next up for me are 1) creating a 'universal' battery rack system for the bike's undercarriage; and, 2) using your idea for housing the CA3 and a headlight on the derailleur post on the front of the bike. Since I have the model with a single chainring, that post on the boom is completely uncluttered at this point.

I do have a small CNC ("Handibot") and an old 3D printer, but I'm not anywhere in the class that you're in when it comes to fabrication. We remain inspired by your efforts, THANK YOU!

Stay safe and healthy.

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Re: Around the world on a solar ebike

Post by solarEbike » Jul 04 2020 2:27pm

rowbiker wrote:
Jul 04 2020 7:23am
Thanks for the great advice -- the arrows you've taken in your back are definitely making life easier for those of us who are following in your footsteps.
Hang on a sec... If I'm in the front, you're following in my footsteps and the arrows are in my back, who is doing the shooting?
rowbiker wrote:
Jul 04 2020 7:23am
Unfortunately, due to my own fault of forgetting to properly tighten the torque arm retaining bolt, I've spun out the Grin all-axle motor, and have lost my speed sensing ability. I've already got a new L10 wiring harness from Grin and plan on opening the motor and fixing this issue when I move the motor from the Bacchetta G20 to the StreetMachine. I don't suppose you have any tips there -- with all your miles on that motor, not ever having to open it up ...? Also, I have some StatorAde on hand, but so far the motor has never gotten really warm, so should I use it?
Ouch. That sucks. You're correct that I've never needed to open mine up but I have the following notes from Justin from when I asked about tools needed to do emergency field maintenance:
Opening up and servicing the motor to replace the bearings is a bit of a pain, since you have to unlace half the wheel, and remove and reapply the sealant on the side cover plate, but it is doable without too many fancy tools.

[I imagine a bearing puller may be required?]

Nope. The bearing on the disk side plate is removed by evenly turning three M4 bolts as we put three M4 holes located just over the outer bearing race. For the non-disk side, you just need a piece of material of suitable diameter to tap it out. The bearings have a slip fit on the axle and an interference fit in the side cover, so they stay attached to the side plates on disassembly.
V2 has O-rings instead of sealant so that part is simpler for you. Not sure if the bearing changes and wire exit location being on the other side means the procedure is different now.

As for the Statorade, I had Grin Tech put it in my hub when they built it. I don't need it for any local hills but I figured I would eventually encounter long enough climbs that I would want to have it and there didn't seem to be any significant downside. I've never had the motor get above 70°C with Statorade. Unfortunately, my motor is V1 which was found to have some issues with Statorade leaking through the bearings. Since you have V2, this shouldn't be a problem. My suggestion would be to leave it out until you actually start encountering overheating situations. Once you get your wiring sorted and the temp sensor working again, that should be adequate protection if you configure to CA3 to roll back power at higher temps. I'll probably have Grin take a look at mine when I eventually make an extended pit stop in Vancouver.
rowbiker wrote:
Jul 04 2020 7:23am
I'm continuously re-reading your thread and being inspired to steal your ideas for my StreetMachine conversion. Next up for me are 1) creating a 'universal' battery rack system for the bike's undercarriage; and, 2) using your idea for housing the CA3 and a headlight on the derailleur post on the front of the bike. Since I have the model with a single chainring, that post on the boom is completely uncluttered at this point.
That's gratifying to hear. You can check out my housing in 3D here. I can PM you the STL file or even let you order a print directly from Shapeways. My part was not designed for fused filament printing so I don't know how that would work if you wanted to try it on your printer. Also, the front is designed to fit a Feniex Apollo white strobe light which appears to be a discontinued product, it has holes for switches on the bottom and I drilled and tapped the top of my derailleur post for mounting. The front derailleur post might not be the same length/angle on Grasshopper as on the StreetMachine which could cause foot/crank clearance issues? The clear plastic tube around the post is there to hide the wires. I painted it black on the inside. Maybe just use this as a starting point for your own design?
SWB recumbent, Grin DD hub, Phaserunner, 6x LiGo battery, 238 watt sun-tracking solar trailer and 76 watt solar roof with 3 Genasun MPPT boost controllers, CA3 w/ solar FW & GPS Analogger, Rohloff hub. Solar ebike build, Website, Instagram

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Re: Around the world on a solar ebike

Post by rowbiker » Jul 04 2020 4:55pm

Thanks for the tips re the all-axle motor. I was convinced I'd have to remove all of the spokes, so removing only half would save significant time. Also, the advice as to the Statorade is encouraging. I'll wait until I end up chasing you through the Alps.

I looked at your link to your CA3 housing on A360.co and downloaded both an *.stl and a *.dxf version of your drawing via Fusion's 'export' feature. I've been looking at your design in a 3D viewer, showing all the details and dimensions, giving me a head start in putting something together on this end. I might even print out a cheap filament version just for modeling purposes. I agree that using your design as a "starting point" is likely the wisest approach, since my foot/pedal clearances might just be sufficiently different. Having an actual printed piece would allow me to get more accurate dimensions, and would be an easy way to produce a prototype.

On your StreetMachine photos I noticed some really nice round clamps holding some assembly to the main tube, just behind the boom adjustment clamps. Are these clamps commercially available or did you machine them yourself? I'm going to be attaching some kind of battery support device to the tube and your clamps look like they're perfect for the job.

Happy 4th!

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Re: Around the world on a solar ebike

Post by solarEbike » Jul 04 2020 7:01pm

rowbiker wrote:
Jul 04 2020 4:55pm
I agree that using your design as a "starting point" is likely the wisest approach, since my foot/pedal clearances might just be sufficiently different. Having an actual printed piece would allow me to get more accurate dimensions, and would be an easy way to produce a prototype.
Sounds good to me. Having a physical model as a starting point would have definitely saved me some time.
rowbiker wrote:
Jul 04 2020 4:55pm
On your StreetMachine photos I noticed some really nice round clamps holding some assembly to the main tube, just behind the boom adjustment clamps. Are these clamps commercially available or did you machine them yourself? I'm going to be attaching some kind of battery support device to the tube and your clamps look like they're perfect for the job.
The black anodized one up front is an idler clamp from TerraCycle. They make some lovely products. Looks like they're got a whole recumbent battery mounting product category now. I'm guessing this is the 60mm size as I'm using one on my Grasshopper. I don't care for HPV's standard chain routing so I've done this mod on both bikes.

The silver ones I made myself. Up close, they're a little crunchy as they're some of my earliest efforts. I believe I cut them out of 1/2" 6061 Aluminum stock using a hole saw on a drill press and a band saw? The round main tube profile flattens out as it gets to the rear pivot point so that gets a little tricky. They seem to fit the Grasshopper so I may try to use them for an under-seat water hauling solution I'm still working out.
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Re: Around the world on a solar ebike

Post by rowbiker » Jul 04 2020 8:10pm

Thanks -- this has been *very* useful information and will save me from multiple trips down the wrong rabbit holes. I can't begin to express the real gratitude I feel for the amount of your time and hard work that you're willing to share with total strangers like me. If your travels ever take you through the Twin Cities (MN), I'd love the opportunity to try to make it up to you!

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Re: Around the world on a solar ebike

Post by solarEbike » Jul 05 2020 2:07pm

rowbiker wrote:
Jul 04 2020 8:10pm
Thanks -- this has been *very* useful information and will save me from multiple trips down the wrong rabbit holes. I can't begin to express the real gratitude I feel for the amount of your time and hard work that you're willing to share with total strangers like me. If your travels ever take you through the Twin Cities (MN), I'd love the opportunity to try to make it up to you!
You're welcome. I think of all this as giving back to this community which has been instrumental in getting me as far as I've gotten with this project. Apologies for the esoteric recumbent tangent to anyone who follows this thread for the solar stuff.

I'm starting to entertain the idea of doing some kind of US tour later this summer/fall depending on how the virus situation continues to evolve. Once I'm in full solar hobo mode, a hot shower will be the one thing I'll miss the most about my current lifestyle.
JackFlorey wrote:
Jun 25 2020 11:05am
solarEbike wrote:
Jun 24 2020 11:07pm
Sure, for some definition of acceptable loss. At 20° error, the loss is around 6% which kind of defeats the point of having automated sun tracking.
Well, with 20 degree steps, the worst error is 10 degrees (plus some uncertainty around actual sun angle/mechanical angle) so you are losing more like 2%.

If there is some mechanical benefit in having fixed stops it might be an option.
Got it. That makes more sense. In fact, I'm exploring a solution that would introduce fixed stops in 5-10° increments. My temporary work-around for wind gusts overpowering the tilt driveshaft clutch is a hose clamp between the fixed and moving parts of the main trailer tube. I'm thinking I might be able to replace that with a 3D-printed toothed coupler (Hirth joint) which immobilizes the tilt except when a solenoid pulls the coupler apart. That way, the tilt control Arduino can engage and disengage this lock only when it needs to move the panel. Selecting the right solenoid, springs, tooth size, etc. for this is a whole new domain of problem solving for me.
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SWB recumbent, Grin DD hub, Phaserunner, 6x LiGo battery, 238 watt sun-tracking solar trailer and 76 watt solar roof with 3 Genasun MPPT boost controllers, CA3 w/ solar FW & GPS Analogger, Rohloff hub. Solar ebike build, Website, Instagram

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Re: Around the world on a solar ebike

Post by JackFlorey » Jul 05 2020 7:16pm

solarEbike wrote:
Jul 05 2020 2:07pm
Got it. That makes more sense. In fact, I'm exploring a solution that would introduce fixed stops in 5-10° increments. My temporary work-around for wind gusts overpowering the tilt driveshaft clutch is a hose clamp between the fixed and moving parts of the main trailer tube. I'm thinking I might be able to replace that with a 3D-printed toothed coupler (Hirth joint) which immobilizes the tilt except when a solenoid pulls the coupler apart. That way, the tilt control Arduino can engage and disengage this lock only when it needs to move the panel. Selecting the right solenoid, springs, tooth size, etc. for this is a whole new domain of problem solving for me.
It might also be worth exploring a half-cylinder array with each coplanar row on its own charge controller. You won't get more power than an equivalent flat plate tilted at a good angle, but you might get more power than an equivalent wind profile flat plate (since a half cylinder with wind over the top won't generate as much lift as a flat plate.)

Even ten years ago residential systems were being installed with trackers - but nowadays solar is so cheap that it's generally more cost effective to add solar than add a tracker. Some large installations are even going with some north facing panels because the ~50% of the power you get with a poorly aimed panel is still worth the cost of the panel.

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