Page 8 of 8

Re: Electric kart

Posted: Oct 28 2020 12:49pm
by nuxland
hallkbrdz wrote:
Oct 27 2020 12:59pm
Nuxland - Nice! I would have like to have made the support all aluminum, but metric tube supply here is - difficult. Oh well, maybe the next time.
I had to buy 6m lenght tube and I only used like a 1m from that :roll:
Finished welding and aluminium is lighter than original.
LeftSidePodAluminium.jpg
LeftSidePodAluminium.jpg (257.95 KiB) Viewed 572 times
I have to cut out parts and make battery base plate also lighter. Actually I do not need the middle part at all, it is there for correct distance between front and rear fixations. So will be making big holes there :)
BatteryBasePlate.jpg
BatteryBasePlate.jpg (109.98 KiB) Viewed 572 times

Re: Electric kart

Posted: Nov 02 2020 12:06pm
by nuxland
Left SidePod holder and battery baseplate holder is now finished and compared to my old tony frame the new is 520g lighter :)
OldvsNewSidePod.jpg
OldvsNewSidePod.jpg (424.42 KiB) Viewed 526 times
Made my battery baseplate also 580g lighter :)
OldvsNewBatteryBasePlate.jpg
OldvsNewBatteryBasePlate.jpg (225.99 KiB) Viewed 526 times
So together I was able to make left side about 1100g ligther compared to my old frame.

Re: Electric kart

Posted: Nov 09 2020 6:01am
by nuxland
Finally completed new motor cooling sideplate. Comparision to my old one, the new one is like 1,17kg heavier :twisted:
MotorCooling.jpg
MotorCooling.jpg (171.87 KiB) Viewed 472 times
In initial test with cardboard box and hole inside in front of the opening old fans where able to push 20m/s wind through hole and new ones 23m/s. So not so big improvement but it's still more air through motor and every m3 counts :)

Here is motor weight together with baseplate and cooler plate.
MotorWeightWithCooling.jpg
MotorWeightWithCooling.jpg (164.3 KiB) Viewed 472 times
In my calculations I will save that 1,17kg from lighter controller heatsink 8)
There was also extra aluminium plate in old tony frame that will not be in the new frame.

Re: Electric kart

Posted: Nov 09 2020 6:11am
by Solexelec
hi Nuxland

have you ever thought about using water spray?
I tried on outrunner it works well.
they were outdoor misters for the terraces.

Re: Electric kart

Posted: Nov 12 2020 12:21pm
by nuxland
Solexelec wrote:
Nov 09 2020 6:11am
have you ever thought about using water spray?
I tried on outrunner it works well.
they were outdoor misters for the terraces.
When I had closed motor with oil inside, I thought to cool with compressed nitrogen (these little bottles that airguns are using) and to spray it through some misters to motor fins. But it did not go nowhere.

Almoust finished controller baseplate and heatsink. Baseplate is fixed to the frame with 2 x M8 bolts. Right now there is regular bolts, but there will be countersink bolts, because space between heatsink and holder is like 5mm only.
ControllerBase.jpg
ControllerBase.jpg (117.65 KiB) Viewed 434 times
Then heatsink is fixed to baseplate with 4 x M6 rubber holders that you can see in controllerbase image
ControllerHeatsink.jpg
ControllerHeatsink.jpg (124.89 KiB) Viewed 434 times
And then controller is fixed with 4x M6 bolts to the heatsink. (there is also contactor fixed to the heatsink)
ControllerFromAbowe.jpg
ControllerFromAbowe.jpg (140.19 KiB) Viewed 434 times
ControllerFromBelow.jpg
ControllerFromBelow.jpg (145.97 KiB) Viewed 434 times
At first will try with heatsink only (and it should be enough considering my test with watercooled controller)
But if it is not enough then I have this little 5mm spacer that I can install between controller and heatsink.
And then make little holes through controller heatsink and add watercooling to the setup :)
Vahejupp.jpg
Vahejupp.jpg (333.57 KiB) Viewed 434 times

Re: Electric kart

Posted: Nov 13 2020 9:13am
by hallkbrdz
Nice heatsink/mount design, and now with quattro ventole cooling for the motor. :thumb:

Re: Electric kart

Posted: Nov 16 2020 5:52am
by nuxland
Weighted new controller parts, new is 6,51kg lighter and that with contactor.
ControllerBaseWeight.jpg
ControllerBaseWeight.jpg (230.06 KiB) Viewed 385 times
Old watercooled with big heatsink and without contactor
WaterCooledOldControllerWeight.jpg
WaterCooledOldControllerWeight.jpg (195.4 KiB) Viewed 385 times
Also installed accelerator unit and cable
Accelerator.jpg
Accelerator.jpg (415.7 KiB) Viewed 385 times
It's 3 degrees celcius outside, so can not work more than 1h in a row :evil:

Re: Electric kart

Posted: Jan 08 2021 3:19pm
by nuxland
Finally could move to garage and finish up all the wires in the new frame. As this so called "turbo" button on the wheel (that actually activated profile 2) was very hard to use in races (you have to look and then keep it pressed). Then now I installed 2pcs of tumbler switched instead ON-OFF-ON. So the right one will be configured Down-Profile 1 and Up-Profile 2, in the middle - Base Profile. And Base will be configured max 5000 rpm and max 60% of torque. Profile 2 like now 6000rpm and 100% torque. And Profile 1 to 4000rpm and 40% of torque. Then it is easier before the corner to switch to profile 2 and exiting the corner already full power available to pass someone in front of me :)
But have not figured what to configure to left switch (I have wired there actually one Digital Input and one Analog input so if needed just change switch to something else in the future)
Made also a little video about the progress: https://www.youtube.com/watch?v=gAUEnLZVcoc

Re: Electric kart

Posted: Jan 12 2021 6:50am
by louis raaijmakers
nice to folow this build and see the updates!

congrats to the great work! just for comparising, howmany cc 2stroke karts are no problem to beat?
250cc shifter karts?

keep up the good work! :bigthumb:

Re: Electric kart

Posted: Jan 12 2021 8:56am
by hallkbrdz
Agreed - great build as always.

Louis - 250cc shifter - is that a vintage kart engine? 80cc, 125cc, 175cc - but I've never seen a 250cc engine.

Re: Electric kart

Posted: Jan 12 2021 12:11pm
by nuxland
In Estonia there is no 250cc shifters (they use these in big tracks in other countries and their top speed is over 200km/h).
But we have 125cc three versions 1. without gears (rotax max) 2. with 2 gears (rotax dd2) 3. 6 gears (KZ2).
Also ProKart events there are also old soviet karts both 125cc, 1. 4 gears Minsk and 2. 6 gear CZ
(some use old soviet frames with old soviet tires and others have put these motors to modern kart frames.

If we compare my kart lap times then we have to take account that I have not raced with new tires (always used) so there goes at least 1s lap time :) Then My driving skills are not very good and there goes another 2s lap time.
Last test we did in Põltsamaa "Kuningamäe" kart track with a driver who races KZ2 as pro. He got lap time 37,79 (in 7th lap with used green vega tires and there was no rubber in asphalt as there is in competitions). Also that was the first time he raced with that kart and I think he could driven better if the accelator wire would not have broken :).
He got to drive 4 minutes and 24 seconds only: https://youtu.be/rShP1MLI-p0
The same track track all time records are following:
Rotax max - 35.783
DD2 - 35.706
KZ2 - 34.297
Retro Minsk - 38.616
Retro CZ - 36.441
So 2 second slower than regular 125cc no gears and under 4s slower than KZ2 kart track record (you have to take account that record is from pro driver who knows how his kart acts and so one)

But if you take some Prokart Estonia competition then for example in kz2 races 4th place best time was 37,247 (about the same as we got)
DD2 winner best lap time was 36,343 so a little over 1s better.
https://speedhive.mylaps.com/Events/1418497

So I think that when I finish moving to a new frame then a good driver with brand new tires can drive lap time close to track record :)

Re: Electric kart

Posted: Jan 13 2021 4:09am
by louis raaijmakers
cool!

thats you need some serious power to beat 125 shifters. cool to see.
looking forward to the new frame and a new track time!

curious to see a few seconds of the lap time

greetings louis

Re: Electric kart

Posted: Jan 16 2021 6:13am
by nuxland
Made myself a wheeled table to configure motor and controller in the livingroom. Can't took the whole kart there :)
So now the second controller should be also configured to that motor. Had to change configuration laptop time to year 2017, because sevcon license is only for a year (I do not understand how this can be as I have bought it for quit a big sum of money) and you have to email and ask for a license every year. I had working official license from 2016 to 2017 so changing computer date works in my case.