EGG Electric Unicycle: DIY and OpenSource design that is easy to customize for your specific needs

[electric_vehicle_lover]

Maybe this is what you are looking for: http://www.thingiverse.com/thing:1370948

[Polpus]

nope. I saw this but it's a custom shell , it has nothing to do with an original one !

[electric_vehicle_lover]

I am now modeling and testing the battery and control board box:

 

 

[electric_vehicle_lover]

I really like this design :-)

Later I would also like to explore the possibility of use the board and the battery only on the top side and so leaving all the sides space for the legs.

[electric_vehicle_lover]

[electric_vehicle_lover]

I am really happy with this design!!

See for yourself:

 

[electric_vehicle_lover]

And it works!!! :-)

First try: 

And the first riding: 

 

Soon I will document and share the all project.

 

[baltimorecity]

 @electric_vehicle_lover what size is the wheel that your custom shell is on?? Does the 3d print from the link to thingiverse  designed to fit 16 inch wheel?? That is incredible. I can appreciate the solid design because on my wheel the part of the shell that scrws into pedal/frame is loose and allows too much play which results in the "death wobbles".. But the video showed that your shell customization is very functional!!!

[electric_vehicle_lover]

My motor is 14 inch. But this design can adapted very easily to other sizes - it is just a matter to have longer thread rods and longer electric wires.

[electric_vehicle_lover]

I am documenting and I did a rename: https://github.com/EGG-electric-unicycle/documentation/wiki/EGG-Electric-Unicycle

EGG Electric Unicycle is a DIY and OpenSource design that is easy to customize for your specific needs:

• Do you want use a bigger wheel other than the 14'' wheel?
• Do you want use a powerful motor that also runs faster like 30km/h?
• Do you want to use more batteries to extend the range of your EUC?
• Do you want to add more lights to improve your EUC visibility and be safer?

[electric_vehicle_lover]

On current design, and after some optimizations, the space for legs is still low and so is a bit unconfortable to ride the EUC.

I did a test to put the MicroWorks 30B4 electronic board on top horizontal and tried to calibrate, but the calibration don't work when the board is placed horizontally - I had that expectation because I tried other board GEN1 that worked.

Ok, so placing the board as it need to be, I can save 10mm which should make diference. Next I tried to place the battery on top horizontal, this times 2 battery packs because it is what I will want to use (at least 2 battery packs but this design seems god to expand for more battery packs).
The EUC worked well, I did a few quick test rides. I am thinking to make next design like this.

 

@esajDo you still use your EUC with that custom design?? what is your opinion after all this time? what are the advantages and diadvantages??

[esaj]

1 hour ago, electric_vehicle_lover said:

 

@esajDo you still use your EUC with that custom design?? what is your opinion after all this time? what are the advantages and diadvantages??

I still have the frame, although I've removed the batteries (for storage over winter). Last I rode it sometime in late October or early November, I think... The problem was that the wheel tilts forward easily on forest paths when hitting a stone or such, and when it does it on the slightest, then the motor does a REALLY strong (remember, I was using 4 x packs with 80+A/closer to 5kW peak capability at that time) acceleration to regain balance. Never faceplanted or fell on it, but the strong acceleration was a bit problematic, because it's hard to stay on the pedals when it suddenly does that (if you didn't notice the bump/stone on time)  

I did look for a suitable casing to get the mainboard closer to the axle (my theory is that the accelerometer in the gyro-chip gets "too high" values because the mainboard is tuned for it to be about 2-3 times closer to the axle, so further away the angular acceleration gets much larger), but never found anything that would fit the mainboard and still be low profile enough to fit between the frame and the tire. Probably getting the center of gravity lower would help also, but that would require a design where the packs can be placed alongside the tire/motor.

Other than that, it wasn't that bad to ride. The riding posture is very different in comparison to Firewheel or the generic, as it's so much taller (it's about the size of a KS18 or a couple of centimeters smaller in width/height, probably about the same size with padding), so riding without your legs touching the frame is nearly impossible. Never tried to sit on it, although the frame probably could have withstood that. The stability on paved road seemed good (at least for lower speeds, I kept the speed below 20km/h or so).

I'll see if I still continue with it, but right now I'm already pretty swamped with all sorts of other projects   Also my custom-batteries had their BMSs replaced due to issues in the ones used originally and I (after lots of procrastination ) sent them for replacement some weeks back, after which there were further delays, but are finally en-route back (expected to arrive tomorrow or the day after that at the latest).

[electric_vehicle_lover]

OThanks for all the feedback!! That's a lot of value.

So seems that the further the motor axle (and heavier), the worst. Like a taller rider VS a short rider.

I would like to understand what you mean "so riding without your legs touching the frame is nearly impossible".

On current design of EGG, there is a bit little space for legs/foots. I wonder if is better to have nothing in the laterals of the EUC... would that be good or not??

[OliverH]

On 17. Mai 2016 at 10:30 AM, electric_vehicle_lover said:

Maybe I will go with a mix of metal and 3d printed parts. Metal for a structure frame and printed parts for the board enclosure, battery enclosure and handle.

On the pictures that's 8mm thread rods. They bend slightly and If not enough I can go with 10mm thread rods. I can use the thread to fix with nuts that 3D printed plastic parts.
This threaded rods and easy to find on local shops and are also cheap :-)

This is not a new idea - OpenSource 3D printers like RepRap Mendel used a lot of this rods :-)

 

Is that the 3D printer used for the parts? It looks weak and not solid. I thought more about using a Prusa metall like here:

http://www.amazon.com/s/ref=as_li_ss_tl?fst=as:off&rh=n:6066127011,k:prusa+3d&keywords=prusa+3d&ie=UTF8&qid=1447427518&rnid=2941120011&linkCode=sl2&tag=3dhu-20&linkId=60205b86dfecd4cef84cf365d11c0d22

[esaj]

1 hour ago, electric_vehicle_lover said:

I would like to understand what you mean "so riding without your legs touching the frame is nearly impossible".

The height and width of the frame make it pretty much impossible to stand on the pedals without my legs (not feet) touching the sides (like I rode with the Firewheel, only squeezing it between my legs when going over curbs or larger bumps or such):

 

41 minutes ago, OliverH said:

Is that the 3D printer used for the parts? It looks weak and not solid. I thought more about using a Prusa metall like here:

http://www.amazon.com/s/ref=as_li_ss_tl?fst=as:off&rh=n:6066127011,k:prusa+3d&keywords=prusa+3d&ie=UTF8&qid=1447427518&rnid=2941120011&linkCode=sl2&tag=3dhu-20&linkId=60205b86dfecd4cef84cf365d11c0d22

3d-printer might be nice, but personally I've been dreaming of a small CNC or PCB milling machine, but even the "semi-decent ones" easily go up to around 1000€ and over, which already buys quite a lot of veroboards or (Chinese) fabricated PCBs. The reason I'd prefer to mill my own PCBs is of course the speed and easy access (no weeks of turnaround from a Chinese PCB manufacturer and then noticing I made a mistake in the layout/tracing)   But for now, I'll stick with dot matrix/veroboards, although I must admit that pretty much the least interesting/fun part in circuit design is doing the layout on the "terms" of the premade board layout (and/or using lots of jumpers/copper wire, especially with dot matrix boards)... My cousin does have some hobbyist-level 3d-printer, but I think it cannot produce very large parts (maybe something like 20x20x<few> centimeters or thereabouts?).

Edited May 24, 2016 by esaj

[electric_vehicle_lover]

So after all the information I have I will keep placing the board at one side, near the center of the axis as much of possible. The 2 battery packs will go to top of the wheel but near as possible to the wheel and horizontal so this why the distance to the motor axis is the lowest possible. I want to have most lateral room as possible for the legs and area for the foots in the pedals.

In may case, the thread rods are placed at center of the pedals arms and that makes the waste is some important millimeters... maybe I can find a solution to take the thread rods out of the center of the pedal arms... right now the structure is very strong I wouldn't prefer to loose it. Creativity I need :-)

[baltimorecity]

Hey Fellas,

So @Polpus i ordered epoxy resin (added pic). Didnt apply because found makerspace group that has a 3d printer. Im going to download @electric_vehicle_lover's design off thingverse. By the way @electric_vehicle_lover back in February you told a member that u were havin challenges with motor and its application. Can you explain what the issue was and what was solution???

 

[electric_vehicle_lover]

@baltimorecity

First, the design on Thingiverse is not mine. My design I am releasing on Github and I currently optimizing but is fully functional right now as you can see on the pictures and videos.

My design uses 10mm metal thread rods that gives a very strong structure, the printed parts are then smaller and so faster to print and more cheap.

If you decide to use my design, I can help you. The files are designed using FreeCAD and this way you can learn and design for free.

Please find the instructions here (that I need to improve): https://github.com/EGG-electric-unicycle/documentation/wiki/EGG-Electric-Unicycle

You can see directly on your browser the 3D files, like this: https://github.com/EGG-electric-unicycle/shell/blob/release/v1.1/files_to_3D_print/electric_board_box-part1.stl

Edited May 25, 2016 by electric_vehicle_lover

[Polpus]

so @baltimorecity you are going deep in the challenge ! Great thing but it will involve opening the case and move motor, wheel and electronics ... it will take time !

[electric_vehicle_lover]

13 minutes ago, Polpus said:

so @baltimorecity you are going deep in the challenge ! Great thing but it will involve opening the case and move motor, wheel and electronics ... it will take time !

I did that and the tools needed are cheap and available in local stores. The only thing I think may be bit difficult is to unscrew the original nuts but since @baltimorecity refers an makerspace , then everything will be possible :-)

[electric_vehicle_lover]

So I am improving the design, mainly to have the most clearance possible for the pedals and so making the ride most comfortable as possible.
The MicroWorks 30B4 electronic board still need to be placed on the side of the wheel (because it just works like that) and the 2 battery packs I will be using will be placed on top of the wheel, in horizontal.

I am buying right now from MicroWorks another pack of parts, to build the 2nd EGG EUC :-)

MicroWorks is selling a "converter DC 60V to 12V, connecting light or speaker"* that I plan to use to add lights - it's the next step, add lights to ride safe at night.
https://wholesaler.alibaba.com/product-detail/converter-DC-60V-to-12V-output_60461417441.html

Edited May 27, 2016 by electric_vehicle_lover

[electric_vehicle_lover]

Current state and I am very happy how things are going. I am pushing my 3D printer to his limits :-)

[esaj]

7 hours ago, electric_vehicle_lover said:

MicroWorks is selling a "converter DC 60V to 12V, connecting light or speaker"* that I plan to use to add lights - it's the next step, add lights to ride safe at night.
https://wholesaler.alibaba.com/product-detail/converter-DC-60V-to-12V-output_60461417441.html

About that converter, do check that it can handle (above) 67.2V, not just 60V, as the fully charged batteries will give out around 67.2 or even 68V (for some cell-chemistries & chargers). Leaving more "headroom" above wouldn't hurt either. I have one converter that's (supposedly) good for 36...72V input to 12V output. Better safe than sorry   Although it's a cheap Chinese converter, so not that sure on it's safety

Edited May 27, 2016 by esaj

[electric_vehicle_lover]

They don't provide that information but they say is for electric unicycles. I just bought 2 units because I am building 2 EGGs EUCs where I want to have lights.

One thing that I miss is to known how much current this board can handle... I want to use high amperage LED.

Also I want to use the RGB LED bar... I also bought from eBay to play with :-)

[electric_vehicle_lover]

@esaj I have an idea: let's say the board outputs the speed and current value constantly, then other microcontroller can read that information and control the RGB led strip to make the brake light and flash the LEDs related with current speed :-)