EKartGo Project

[Upperfoot]

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]

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.

[hallkbrdz]

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.

[hallkbrdz]

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).

batteryparts1.jpg (51.52 KiB) Viewed 192 times

batteryparts4.jpg (140.61 KiB) Viewed 192 times

batteryparts3.jpg (100.63 KiB) Viewed 192 times

batteryparts2.jpg (64.15 KiB) Viewed 192 times

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 (246.93 KiB) Viewed 192 times

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 (271.98 KiB) Viewed 192 times

[hallkbrdz]

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 (298.84 KiB) Viewed 153 times

[hallkbrdz]

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 (1.62 MiB) Viewed 44 times

[hallkbrdz]

Top tip: To smooth out 18650 holes on the 3D printed part, I found a 23/32" drill bit works pretty good. The 47/64" one I used previously made the holes slightly loose.

[hallkbrdz]

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

20210306_kart_w_new_battery.jpg.jpeg (280.53 KiB) Viewed 24 times