Project: Home made velomobile design with crank or mid motor

I installed a voltage/current/power/energy meter on the steering column last night. Works well, but I haven't calibrated the high current indication. Zero current calibration was easy, but I will have to get some big resistors in order to test the high current indication.

The housing is 3D printed and designed to fit on the column. I should have designet it with a glare shield.
 

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I realy like the continuity and further upgrades to this project. The solar panel is just what i have constantly in my mind for no hassle solution for top up charging.
I have asked you about rear led lights earlier, is it a led panel? I was thinking about rgb led panel to implement signals and brakes, posibly with animation but how to drive them and control certain lighting with switches?

Could you comment on glue you have used on plywood?. I want to try stich & glue techique on my velo.
 
I'll post a picture of the led arrangement later. The acrylic cover is coming loose at the edges so I will have to glue it back on soon. I used six orange leds on each side to act as direction signals, and a long red LED strip across which is pulsating at ~2 Hz. I don't have any brake lights, but maybe I should add some now that the panel is coming off. It's not required by law.

The highest power I have measured out of the boost regulator from the solar panel is 50 W, which was today in bright sunlight. I live so far north (69°N) that full capacity of the 100 W solar panel probably can't be achieved. I think the maximum is 70 W, or 62 W after losses in the voltage booster.

The plywood shell is glued with regular carpenters glue. I have used it for a while in furniture and it's immensely strong, and waterproof after hardening. I think it's a PVA compound. This is the brand and type I used: http://www.bison.net/en/products/651-wood-glues/product/248-super-wood-glue/
 
I'm tempted to buy two 15Ah Li-ion packs from BMSbattery. That will give me 42 Ah total, 120 km range in the hilly terrain up here, and basically eliminate my need for a car. I spend about 12 Wh per km.
 
Thanks. As far as i can see you have used monocrystaline cells. I wander if using amorphous cells would give you better overal output despite lower efficiency throughout the day if overcast.
 
tahustvedt said:
I don't have any brake lights, but maybe I should add some now that the panel is coming off. It's not required by law.
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When you add them, Ihighly recommend doing it as either a separate light fixture at least a small distance from the regular taillight, or making it a segment htat is not normally lit at all, easily noticed vs the brightening of an existing segment.


I've experimented with different brakek light arrangements, and find that in traffic in daylight, drviers are much more likely to notice and respond to a totally separate light or segment than anything else.


So what you could do with your presetn light without adding a whole new fixture is to "move" the taillight LEDs so they are two separate segments inboard of the turn signals, then use the center section for an independently -lit brake light.

For more effectiveness, you can also birghten the tail light segments at the same time.
 
tahustvedt said:
Thinking about making a new version.
Click to expand...

I love to read this thread and all new interesting stuff you add to your velo.
What is your average speed when you see 12Wh/km?
My long john falls into the 17-23Wh/km span at average speeds between 30-40km/h.
This means cruising between 30-50km/h depending on circumstances.
The 35-45km/h span is a reasonable compromise between speed, power requirement and wind noise.

Please talk us through your design thoughts for the new velo idea.
First hand experience is what really counts, and you have accumulated quite some with your first velo.

That said, I know that nothing I do is close to perfect the first time.
I could easily make a list of 20 smaller and larger changes, if I were to build a new electric longjohn cargobike.
I am sure you can do the same with your velo, taken you didn't have a lot of velo experience beforehand?
 
The other day I rode a 20 km lap with lots of climbing in 45 minutes and about 11 Wh/km. Roughly 26,7 km/h average, I think.

I have a lot of changes in mind. :)
 
I'm 3D-printing this now. Will take a photo of the model next to the model of the old one. :)

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The CFD run shows that this is a superb shape. A little over one fifth the drag of my first velomobile build. I will run the more blocky design tonight and will have the result tomorrow.
 

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tahustvedt said:
The CFD run shows that this is a superb shape. A little over one fifth the drag of my first velomobile build. I will run the more blocky design tonight and will have the result tomorrow.
Click to expand...
That is very interesting, what are the major factors to the so much higher drag of the first velo shape? Is it the area below the rear lights that causes too much underpressure? Is it the free standing wheels?
 
The exposed wheels create a hell of a lot of drag, and you're right about the rear. There's a low pressure area under the rear end of the old one, and the total is a strong downforce on the velomobile, which probably wastes a lot of energy. It produces a bit more downforce than drag. The new shape barely wastes any energy at all on downforce. 1,1 N on the new one as opposed to 78 N downforce on the old one at 40 km/h.
 
While talking with someone here in California , a few years ago , that had some experience with trike designs with 2 wheels in front and one wheel in back, he said that for stability / safer handling , tad pole designs need downforce on the back wheel.
so I am guessing there is a balance of having more drag in order to have a more safe design . ( the rear not sliding around )

For less drag from exposed wheels, you can make "fairings " for the front wheels, a shape in front of and behind the wheel. that leaves only the outer part of the wheel/tire exposed, that way you can view the state of the tires and change wheels much more easily.



tahustvedt said:
The exposed wheels create a hell of a lot of drag, and you're right about the rear. There's a low pressure area under the rear end of the old one, and the total is a strong downforce on the velomobile, which probably wastes a lot of energy. It produces a bit more downforce than drag. The new shape barely wastes any energy at all on downforce. 1,1 N on the new one as opposed to 78 N downforce on the old one at 40 km/h.
Click to expand...
 
What are you going to use for the windshield? Heavily convexed non glass windows make for distorted views. Learned that on an unrelated project. What type/brand of brakes are you using?
 
Turns out the boxy profile is the best. 140 W at 40 km/h is pretty good. It has the best visibility and is easier to build as well.
 

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