EKartGo Project
- Thread starter hallkbrdz
- Start date
thepronghorn
1 kW
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
100 W
thepronghorn said:
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
100 W
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).
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!
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.
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).
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!
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.
hallkbrdz
100 W
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.
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.
hallkbrdz
100 W
Here is the current "simplified" wiring diagram for the system. Doesn't even show all the cell tap wires! Wire management is key.
hallkbrdz
100 W
Top tip: To smooth out 18650 holes on the 3D printed part, I found a 47/64" drill bit works pretty good.
hallkbrdz
100 W
Rendering showing that battery configuration in it's packaging. Four variable speed BMS controlled 120mm fans for cooling.
hallkbrdz
100 W
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.
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.
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.
How are you going to attach the copper bus to the cells?
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?
I am also curious about the connection method. Right now it looks like compression to hold the bus onto the cell?
hallkbrdz
100 W
fechter said:
It uses compression to hold the stack together.
spinningmagnets said:
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...
Hillhater
100 TW
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 ?
The website is a little bare on details ?
hallkbrdz
100 W
Hillhater said:
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.
Hillhater
100 TW
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 ?
.. i hope it is very cheap and a bulletproof warranty !
Do you have any performance specs for the Hawk versions ?
hallkbrdz
100 W
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
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
hallkbrdz
100 W
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/programs/evtraining/phaseI/
https://continue.weber.edu/professional/programs/evtraining/phaseI/
hallkbrdz
100 W
It's an EV, so it's going to need some screens...
Oh yes, screens...
Oh yes, screens...
hallkbrdz
100 W
Short video covering the motor controller while still waiting on the motor...
[youtube]3G555q-qyrQ[/youtube]
[youtube]3G555q-qyrQ[/youtube]
hallkbrdz
100 W
While waiting on the DHX motor, I decided to pursue building a kidkart.
The goal is to build a kid kart that is initially "inexpensive", has the battery capacity to last all day on one charge, and a programmable controller to limit the motor to top-end Honda GHX50-ish power (what they run locally). It will be air cooled and IP65+ rated so it can run in the rain.
I’m currently looking for a “local” roller to start. I plan to employ my grandkids for the R&D testing, with my younger granddaughter being the top candidate (although slightly too young yet). I have a good handle on the motor, controller, BMS, and battery size.
Once the bugs are worked out, I will build at least two more so they can race as a class.
Motor and controller wise I think the pair used in the below video would be adequate for a kid kart and possibly cadet. This is an ME1717 with Kelly controller. Pair that with a BMS to make running and charging safe and a 2kWh battery and it should move.
I do have a cadet chassis, but would rather put this on a kid kart - still looking if someone has one (no motor required).
[youtube]xxSXxFqGbp8[/youtube]
The goal is to build a kid kart that is initially "inexpensive", has the battery capacity to last all day on one charge, and a programmable controller to limit the motor to top-end Honda GHX50-ish power (what they run locally). It will be air cooled and IP65+ rated so it can run in the rain.
I’m currently looking for a “local” roller to start. I plan to employ my grandkids for the R&D testing, with my younger granddaughter being the top candidate (although slightly too young yet). I have a good handle on the motor, controller, BMS, and battery size.
Once the bugs are worked out, I will build at least two more so they can race as a class.
Motor and controller wise I think the pair used in the below video would be adequate for a kid kart and possibly cadet. This is an ME1717 with Kelly controller. Pair that with a BMS to make running and charging safe and a 2kWh battery and it should move.
I do have a cadet chassis, but would rather put this on a kid kart - still looking if someone has one (no motor required).
[youtube]xxSXxFqGbp8[/youtube]
Latvians have ready made 7kw plug and play for kid's kart.
https://blueshockrace.com/electric-kart-power-units/#7kw
http://blueshockrace.com/wp-content/uploads/2020/11/PowerUnit_BSR2_0_7kw.pdf
But why ME1717 and not QSMOTOR QS138 4000W 90H or similar.
And why kelly and not Nucular 12F.
For battery why not use LTO, as you are only building 2kwh, then weight difference is not that big?
You gain better charging current and a lot more cycles.
https://blueshockrace.com/electric-kart-power-units/#7kw
http://blueshockrace.com/wp-content/uploads/2020/11/PowerUnit_BSR2_0_7kw.pdf
But why ME1717 and not QSMOTOR QS138 4000W 90H or similar.
And why kelly and not Nucular 12F.
For battery why not use LTO, as you are only building 2kwh, then weight difference is not that big?
You gain better charging current and a lot more cycles.
hallkbrdz
100 W
Thanks for the suggestions, I wasn't aware QS made anything but hub motors. And, I had never heard of Nucular controllers, so thanks for that as well.
BSR, yes I get an email from them every week after I looked at the specs for someone interested in buying one.
Of course either of these motors is overkill for the Honda kid karts. I'll have to greatly limit current and/or max RPM to keep the acceleration and speed down whatever I use (even with their motor and somewhat weaker controller combo). If I go that way I'll need to find someone who makes (or someone to make) a motor sprocket for #219 chain for that shaft type.
Here's footage of what a Honda powered kid kart does around the local track. The max speed is about 32 MPH, still pretty quick for a 5 year old (5-7 age group).
[youtube]3OXm-wde6Q0[/youtube]
BSR, yes I get an email from them every week after I looked at the specs for someone interested in buying one.
Of course either of these motors is overkill for the Honda kid karts. I'll have to greatly limit current and/or max RPM to keep the acceleration and speed down whatever I use (even with their motor and somewhat weaker controller combo). If I go that way I'll need to find someone who makes (or someone to make) a motor sprocket for #219 chain for that shaft type.
Here's footage of what a Honda powered kid kart does around the local track. The max speed is about 32 MPH, still pretty quick for a 5 year old (5-7 age group).
[youtube]3OXm-wde6Q0[/youtube]
hallkbrdz
100 W
On LTO... it looks like the weight difference is huge, much worse than LifePO4. Maybe I'm not finding the right cells?
As far as motors go, I'm pulling a guinea pig 135 Amp alternator tonight from a Ford Freestar for PMSM test conversion. If it's anything like the below older F150 model, this looks like it may be a very valid way to go forward for the kid karts. Remove the brushes, diode board, and rotor coils. Extend the lead wires, machine the rotor, add a magnet, add hall sensors, and a temp sensor as well. Should be interesting.
I'm also curious to try using a belt to transfer power to eliminate the grease mess.
[youtube]vp44tW1VDGg[/youtube]
As far as motors go, I'm pulling a guinea pig 135 Amp alternator tonight from a Ford Freestar for PMSM test conversion. If it's anything like the below older F150 model, this looks like it may be a very valid way to go forward for the kid karts. Remove the brushes, diode board, and rotor coils. Extend the lead wires, machine the rotor, add a magnet, add hall sensors, and a temp sensor as well. Should be interesting.
I'm also curious to try using a belt to transfer power to eliminate the grease mess.
[youtube]vp44tW1VDGg[/youtube]
hallkbrdz
100 W
nuxland said:
Apparently the wait time for a Nucular 6F is about 6-9 months?
From the descriptions the 6F (all I'll need for this sub 2kW build) looks reasonable, and it is definitely lighter and more compact. I'm willing to try one, but I've ordered a Kelly KLS6018N to get this going this month.
Magnets (ordered 3) are on the way. The alternator rotor will be dropped off at a machine shop tomorrow to have .5" removed from each side for the magnet.
hallkbrdz
100 W
I received a reply from Dima Bogdanchikov about the 6F wait-time:
Approx 7-8 months ( The big queue and the new casing in production).
Approx 7-8 months ( The big queue and the new casing in production).
