EKartGo Project

Electric cars, trucks, ATVs, NEVs - things bigger than a motorcycle.
Upperfoot   100 W

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Re: EKartGo Project

Post by Upperfoot » Jan 08 2021 7:23pm

I would try out those cell holders you can put together like logo, I personally use the ones from https://e-bikestuff.com/en/11-cell-holders

thepronghorn   1 kW

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Re: EKartGo Project

Post by thepronghorn » Jan 09 2021 3:35am

Where did you get the printed parts from? That looks pretty bad. I have a printer myself, but I've thought about using online services for some bigger parts that I want, but that quality does not inspire confidence.

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hallkbrdz   100 W

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Re: EKartGo Project

Post by hallkbrdz » Jan 09 2021 7:57am

thepronghorn wrote:
Jan 09 2021 3:35am
Where did you get the printed parts from?
I went though Craftcloud, and the actual printer was DTEV LLC in Vero Beach, FL. I can't believe they shipped something so poor in quality.

The reason I am making my own holders is to allow the cells to go end to end and eliminate welding. Placing them end to end saves weight in copper bus bar material since only the final positive and negative ends need to handle the full current. The rest just need to carry 1/10 that amount with my 42SP10 battery.

I have already revised this design with some improvements and I am seriously looking at buying a Prusa I3 MK3S+ with the multi-material option to fill voids after this experience. Once I get this process down I may go into the high-current battery business.

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hallkbrdz   100 W

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Re: EKartGo Project

Post by hallkbrdz » Feb 15 2021 4:24pm

Update:

Back on 2 Feb I ordered new rev 6 battery parts in ABS. I would prefer nylon, but until I build a printer to make them myself that is just too costly due to the small number of places that can create them in that material. From the looks of i-Solids in Texas, I think this round will be better than the last one.

Here's some photos of the new parts they sent me after printing (I hope to get them tomorrow or Wednesday, weather depending).
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On the same day I received an email from DHX Machines with the CAD file for the new Peregrine alpha-test motors. So hopefully they will be out for testing sooner than later. Yes!

I then worked on the motor support. I think this will prove to be a good and flexible design. There were lots of things to consider for this torque monster (estimated to be about 120Nm, 89ft. lb) to keep from bending the frame. For reference, an IAME X30 Super Shifter Spec. USA 175cc only delivers 27 Nm, 19.9ft. lb!
Motor Frame.jpeg
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Now I'm working on the controller mount. I think something like this will work with ducting added to the bottom to draw cool air across the heat sink. If not, I'll get a water cooling plate for it and upgrade to a double pass radiator.
Controller mount.jpeg
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hallkbrdz   100 W

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Re: EKartGo Project

Post by hallkbrdz » Feb 20 2021 11:14pm

Build progress...

3D printed parts in hand, look great. Only issue is the dimensions are slight smaller due to ABS shrinkage. So I'm having to bore and smooth the cell connections out, and slightly enlarge the copper plate paths. Certainly not show stoppers by any means. Next battery will have revised designed to allow more space for this issue. FDM 3D printing is somewhat of an art vs CNC.

Kelly bluetooth and various connectors ordered. The bluetooth will allow connection to a laptop or Android tablet for programming.

Motor coolant pump ordered. It is a Toyota Prius inverter pump and will run off the tool battery.

Orion2 BMS and battery charger will be ordered Monday.

I plan to have a Battery Day by the end of the month. There will be a scheduled live event assembling it, as it should not take that long using this new weldless method. Stay tuned!

Here is the current working idea for the controller coolant duct and possible placement for the water pump.
Rear controller duct.jpeg
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hallkbrdz   100 W

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Re: EKartGo Project

Post by hallkbrdz » Mar 04 2021 1:43pm

Here is the current "simplified" wiring diagram for the system. Doesn't even show all the cell tap wires! Wire management is key.
20210304 Electrical SimpleBatt - Orion.png
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Last edited by hallkbrdz on Mar 04 2021 9:44pm, edited 1 time in total.

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hallkbrdz   100 W

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Re: EKartGo Project

Post by hallkbrdz » Mar 04 2021 6:28pm

Top tip: To smooth out 18650 holes on the 3D printed part, I found a 47/64" drill bit works pretty good.
Last edited by hallkbrdz on Mar 07 2021 4:03am, edited 1 time in total.

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hallkbrdz   100 W

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Re: EKartGo Project

Post by hallkbrdz » Mar 06 2021 11:49am

Rendering showing that battery configuration in it's packaging. Four variable speed BMS controlled 120mm fans for cooling.
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hallkbrdz   100 W

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Re: EKartGo Project

Post by hallkbrdz » Mar 09 2021 7:45am

Here is the end plate collector showing how a copper strip ties together two levels (for the Z fold). Experimenting to find just the right height and size of the bumps to make the easiest contact with the positive side of the cells.
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Here's a look into the battery compartment with the lid off. Each printed part has a quarter inch of heavy foam rubber for shock and vibration cushion. Six layers of 7 for 42x10. Not shown are the Velcro straps used to hold everything together until it is secured in the compartment. The over-rated contactor and first 200A battery fuse are internal (there is a second fuse on the controller). The contactor can only be turned on by the BMS when it is satisfied with the condition of the cells, and no other safety switch is off. The green mil-spec connector is for all the BMS taps, contactor wiring, and temperature probes.
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fechter   100 GW

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Re: EKartGo Project

Post by fechter » Mar 09 2021 9:17am

How are you going to attach the copper bus to the cells?
"One test is worth a thousand opinions"

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spinningmagnets   100 GW

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Re: EKartGo Project

Post by spinningmagnets » Mar 09 2021 10:04am

I apologize if you already know this, but...the sides of an 18650 cell are electrically hot with the negative end. This also means the cell shoulder on the positive end is hot, and it is only a few millimeters of distance away from the positive nipple.

I am also curious about the connection method. Right now it looks like compression to hold the bus onto the cell?

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hallkbrdz   100 W

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Re: EKartGo Project

Post by hallkbrdz » Mar 09 2021 11:36am

fechter wrote:
Mar 09 2021 9:17am
How are you going to attach the copper bus to the cells?
It uses compression to hold the stack together.
spinningmagnets wrote:
Mar 09 2021 10:04am
I apologize if you already know this, but...the sides of an 18650 cell are electrically hot with the negative end. This also means the cell shoulder on the positive end is hot, and it is only a few millimeters of distance away from the positive nipple.
Yes of course. I don't think this should be a problem as I added an additional PTFE layer to the positive ends of the cells and only the raised portion comes in contact with the hat such as...
IMG_20210308_215128 (Medium).jpg
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Hillhater   100 GW

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Re: EKartGo Project

Post by Hillhater » Mar 10 2021 4:44am

Do you have any info or proposed performance specs , power /efficiency plots etc, for the “Perigrine” motor ?
The website is a little bare on details ?
This forum owes its existence to Justin of ebikes.ca

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hallkbrdz   100 W

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Re: EKartGo Project

Post by hallkbrdz » Mar 10 2021 3:38pm

Hillhater wrote:
Mar 10 2021 4:44am
Do you have any info or proposed performance specs , power /efficiency plots etc, for the “Perigrine” motor ?
The website is a little bare on details ?
Not yet. I've only been told it should be a little lighter, and with slightly more performance than a Hawk motor. Size-wise they will be virtually the same. The big change will be the cost, going from a difficult to manufacture hand assembly ($$$$) motor to an automated assembly motor ($$).

The testing will be to make sure the new design is at least as robust as the old one. I'll definitely be giving it a real operational vibration test with quickly varying loads. Should go to initial sample manufacturing soon. :D

Hillhater   100 GW

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Re: EKartGo Project

Post by Hillhater » Mar 11 2021 6:06am

It seems a big gamble to go with an unproven motot / controllet set up...
.. i hope it is very cheap and a bulletproof warranty !
Do you have any performance specs for the Hawk versions ?
This forum owes its existence to Justin of ebikes.ca

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hallkbrdz   100 W

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Re: EKartGo Project

Post by hallkbrdz » Mar 11 2021 9:26am

I don't see it as a gamble as there are many Formula SAE teams that use their motors for racing competition without any complaints. They seem to actually meet the specs they claim, unlike many of the axial-flux motors several teams have tried. Cost wise, I'm not sure what they will eventually sale for as I will be alpha testing this motor for them. My guess would be about half the price of a Hawk motor.

There is no other water cooled motors available I am aware of that are even close to the specs of the older Hawk motors in terms of power output vs weight and size, which is why I originally bought one (or so I thought) off Ebay. Unfortunately that one turned out to be a magnet-less display model they had originally sold to a motorcycle company and someone had acquired and sold as "new". DHX was very helpful in inspecting it at no cost and providing a statement so I could get a full refund from Paypal.

Hawk60 specs

Max kW: 55.3
Cont kW: 34.5
Peak Tq Nm: 120
Peak RPM: 7200
Weight: 12.88 kG <- very high power to weight

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hallkbrdz   100 W

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Re: EKartGo Project

Post by hallkbrdz » Mar 17 2021 12:43pm

Since it's rather dead at work this week (spring break), I decided to sign up for an on-line class on EV safety. Should prove helpful for anyone working with EVs:

https://continue.weber.edu/professional ... ng/phaseI/

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hallkbrdz   100 W

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Re: EKartGo Project

Post by hallkbrdz » Mar 24 2021 7:02pm

It's an EV, so it's going to need some screens...
20210324_driver_seat1.jpeg
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Oh yes, screens...
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