KONA Entourage Build Thread - middrive (pic heavy)

next step was installing the big central bearing. this is more or less a conversion of the "new style mac stator" to the old version. the new version looks like the bafang motors and have two bearings in the yoke. the old version has one big bearing installed in the stator.
the bearing needs to be held in place. so i built a little disc. the disc is 70mm diameter an 2.5mm thick. to install it i had to mill a circular groove.
then i made the disc, and i didn't do as my father said: measure twice cut once. so i drilled the holes in the wrong place. :) so i made a second disc. funny thing is, that making the second part always takes only about a third of the time?!
the disc is held down by 3x m4 screws. looks good :)

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nice to see u managed to get those two MAC versions merged. Yep doing more than one part speeds things up a lot....

I try to run mine sensorless ATM (old version with single big bearing), that seems to be not so easy though. Looks like a sensored Kelly isnt the worst thing at the end of the day. Maybe i should have given my old version 6T to you :D
 
today i wanted to clean up the wiring and make it a bit less complex. well, a REALLY bad idea. at least if you forget to double check the polarity of your xt60 connectors. i installed the second one in my shunt setup reversed. connected it to the bike, and a lot happened :) fuse blew, contactor melted and the inrush limiters FETs exploded.
i didn't realize what the problem was, and checked AGAIN on my desk with my 12s lipo. hmmm. guess what: the 2nd inrush limiter went up in flames as well. not funny.

good news: v2.81 of lebowskis is a BIG improvement for the MAC. i runs quite well. some issues to sort out, but it's really nice already.

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John Bozi said:
sounds similar to the flame thrower my mate experienced a few days ago with the same connectors.
glad you are ok
thanks man! even if i put some smileys after my words it was quite frightning to see the switch go up in flames. the flames where coming from the heatshrink, but still ... smells really bad in the basement now. had to open all windows before the wife came down ;). i also observed the lipo very well. measured all cells, looked for swelling, heat etc. but i'm 100% it didn't take any harm. this was only a millisecond short.

and in the meantime i build a new inrush limiter.

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btw: did i ever mention, that soldering with soldering paste and a hot air station is really fun?! soldering smd components with the iron is ok, but putting on the paste which is not solder alone, but also keep the components in place, then adding heat and watch it melt. perfect soldering joints. i also added paste under the FETs to fix them on the pcb. much better for heat dissipation as well.
 
John Bozi said:
sounds similar to the flame thrower my mate experienced a few days ago with the same connectors.

glad you are ok

OMG! same thing happened in my case. the result was a dead controller and of course the connectors too (XT with antispark are not cheap).
looks like a curse rests on those connectors haha
 
OMG! same thing happened in my case. the result was a dead controller and of course the connectors too (XT with antispark are not cheap).
looks like a curse rests on those connectors haha
i hope i didn't burn the controller. so far all seems fine. i had a FUSE in the battery line, and the inrush limiter's FETs blew right away. so i guess there was no voltage going to the controller "behind" this circuit. i HOPE.
i now integrated 3x 5mOhm shunt in parallel directly into the GND wire. no way i can connect anything wrong now.
 
i swapped the yoke and the freewheel and now everything runs nice. noise is higher in the video than it's in real life.

[youtube]_oXQznH_OHo[/youtube]

in the bike it's dead silent. there needs to be some tuning in the controller be done, these are the funny sounds your can hear.

[youtube]4S1znVnt-6M[/youtube]
 
the new controller case came from powder coating. it now has an external push button for "setup", and a waterproof 5pin serial connector. LEDs for drive mode.
both side covers where custom made from 2mm aluminium. the fins where shortened at the edges for a "better" look. controller stays super cool at 120A phase. not even warm at the touch.
 

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Animalector said:
Nice work .. 120A phase hey. Nice...
i'll up that to 150A as soon as lebowskis firmware reaches it's next level :)

the mac is REALLY as MOTOR FROM HELL. very difficult for a controller to drive it seems.

150A is the limit of the current sensors, the IRFB4468 handles 190A. and as cooling is fine, and peak current is only needed for some seconds, it should be fine. total power limit is 2.000W, so it's 50A battery. something the FETs don't even may notice *ggg*

and phase current is REALLY needed for getting the bike to move. i see a difference between 100A and 120A. 150A may be even more noticeable.
due to the sine wave torque throttle characteristics the power delivery is VERY smooth. nice to handle, but on the other hand, not really "snappy".
it's impossible to lift the front wheel by throttle only. something that should work in the first gear with 2kW with ease.

the other lightning rod-style mid drive i have, that is driven by a 12FET infineon is wheely prone as hell. it's limited to 2.5kW and block time is set to zero. don't want to know what this bike does when a block time of 1-2s. ;)
 
short update: the rc lipo was replaced by 18650 lion cells. 150 of them. the pack is divided in two 15s5p packs. one on each side, and it's a perfect fit. capacity has grown from around 890Wh to 1620Wh. so a real range of 50km is doable.

here is the thread for the battery build: https://endless-sphere.com/forums/viewtopic.php?f=14&t=92611&p=1359481#p1354420

and here are some teaser pics:


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