New build, BHT mid-drive "direct", custom frame

Discussions related to motors other than hub motors.
This includes R/C motors, botttom bracket, roller and geared drives.
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Overclocker   10 kW

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Re: New build, BHT mid-drive "direct", custom frame

Post by Overclocker » Oct 14 2019 2:53am

IMG_20191014_131629 (Medium).jpg
IMG_20191014_131629 (Medium).jpg (246.81 KiB) Viewed 1645 times
so here's the BHT after being dunked in water multiple times :lol: i really need to seal it up. but the windings seems fine, they could probably take 80A

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nutnspecial   1.21 GW

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Re: New build, BHT mid-drive "direct", custom frame

Post by nutnspecial » Oct 20 2019 2:33pm

Do it! I've been running 66a @ 24s for awhile now. Previously 16 and 18s, ~100a and ~80a respectively. I try to always gear for around 35mph max speed (and am happiest with 24s -charges quick @ 14a.)

Just cracked my bht open today and looks similar. Needed sprocket change which is welded, so upon cutting welds I gave throttle while holding sprocket.
Bad idea- no smoke but just grunts now and don't spin.

Just came on here to see what's up with bht's lately and maybe troubleshoot windings- glad yours is holding up bro. Post a link if you decide to refresh either bearing? I'll be doing the front except might just swap to spare.

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Re: New build, BHT mid-drive "direct", custom frame

Post by Overclocker » Oct 21 2019 2:04am

IMG_20191021_113127 (Medium).jpg
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IMG_20191021_095044.jpg
IMG_20191021_095044.jpg (101.17 KiB) Viewed 1556 times
so here's my smaller 11t. basically i bored a hole through a standard motorcycle #420 sprocket then welded a shaft through it. keyway cut w/ a hacksaw :lol: will ride it later, expecting a bit more thrust w/ less top speed

yeah that front bearing is rusty and getting a bit rough so i replaced it. easy to find, not an exotic size. i also changed out the stock grease from the bearing w/ a quality EP grease. the back bearing is fine so i didn't replace

PS hope you get your BHT working again. have you tried running it in sensorless mode? just to make sure it's not a hall issue...

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nutnspecial   1.21 GW

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Re: New build, BHT mid-drive "direct", custom frame

Post by nutnspecial » Oct 28 2019 4:48pm

Well done with keeping the bolt and key/keyway. I hadn't had any issue with the quick-lazy of welding it, till I also tried quick-lazy with removing it lol.
Turns out my bht is just fine, But will have to see about fixing or another >84v >18fet controller

Will you upload a vid of yours in action when you turn it up? They are such a fun setup with some juice and proper gearing imo!

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Re: New build, BHT mid-drive "direct", custom frame

Post by Overclocker » Oct 28 2019 10:27pm

nutnspecial wrote:
Oct 28 2019 4:48pm
Well done with keeping the bolt and key/keyway. I hadn't had any issue with the quick-lazy of welding it, till I also tried quick-lazy with removing it lol.
Turns out my bht is just fine, But will have to see about fixing or another >84v >18fet controller

Will you upload a vid of yours in action when you turn it up? They are such a fun setup with some juice and proper gearing imo!

will do! when it stops raining :lol:

the yuyangking YKZ7280 is here. wasn't expecting it to be this huge. the KLS7230 is already a chunky controller the YKZ manages to make it look tiny :lol: but all that size for just 80A max, the kelly is 120A max
IMG_20191028_134900 (Medium).jpg
IMG_20191028_134900 (Medium).jpg (167.73 KiB) Viewed 1477 times
(L to R: kt 6fet, YKZ7280, kelly KLS7230, cheapo 18fet)

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Re: New build, BHT mid-drive "direct", custom frame

Post by Ianhill » Oct 29 2019 8:53am

Just cut the same Kelly shell to bits to give my vesc a heatsink deffo the same one the holes on top were offset the same till I cut it, I had it given to me blown up so it's had some use at least.
viewtopic.php?f=35&t=97557&start=50

That controller is huge shouldn't be any issues getting airflow over that, best of luck hope it goes well.

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Re: New build, BHT mid-drive "direct", custom frame

Post by Overclocker » Oct 30 2019 5:16am

IMG_20191101_173656 (Medium).jpg
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yyk overdrive.jpg
yyk overdrive.jpg (33.92 KiB) Viewed 1423 times
so there it is ziptied to the bottom of the saddle. the "overspeed" mode gave me back all the lost speed when i moved to 11t motor sprocket (from 13t). so i got a very nice increase in thrust due to the gearing change, further boosted by the increase in controller amps (from 55a to 80a). bike feels a lot more lively now.

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Re: New build, BHT mid-drive "direct", custom frame

Post by Overclocker » Nov 01 2019 10:21pm

IMG_20191102_111009 (Medium).jpg
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jszh vs ga vs 26f.png
jszh vs ga vs 26f.png (55.85 KiB) Viewed 1369 times
the higher amp controller needs better cells. i'm taking a gamble w/ these cheap (PHP95 or USD1.86 per piece, landed) chinese cells made by JSZH (jiangsu zhihang new energy). i've cycled a cell and got 97.8% after 152 cycles :shock: that's pretty good cycle life!

here's the raw data from the cycle test. in retrospect i set the LVC too low at 2.5V :lol: if you look at the discharge curve it begins to fall off the cliff at around 3.2v. but this didn't seem to hurt the cell at all :lol:

Code: Select all

JSZH 18650 2600mah TEST!
charging time: 2:06 == 126 mins
rest: 0:05
discharging time: 0:54
rest: 0:05
TOTAL: 190 mins == 3.16~hrs per cycle

1.5a charge, 3.0a discharge, 2.5v cutoff

1 cycle: 2711mah
10: 2704
14: 2681
18: 2726
22: 2710
27: 2690
33: 2685
36: 2690
39: 2688
42: 2702
45: 2696
48: 2701
51: 2693
54: 2678
57: 2665
60: 2700
63: 2666
66: 2677        
69: 2690
72: 26xx
75: 2659
78: 2661
81: 2658
84: 2644
87: 2671
90: 2666
93: 2665
96: 2655
99: 2668
100: 2665
101: 2663
104: 2660
107: 2661
110: 2656
113: 2651
116: 2660
119: 2657
122: 2649
125: 2619
128: 2636
131: 2609
134: 2643
137: 2650
140: 2645
143: 2646
146: 2643
149: 2646
152: 2651

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Overclocker   10 kW

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Re: New build, BHT mid-drive "direct", custom frame

Post by Overclocker » Feb 24 2020 1:38am

qs120vt.jpg
qs120vt.jpg (55.12 KiB) Viewed 598 times
just ordered this motor+controller... the BHT is just too small...
Last edited by Overclocker on Feb 25 2020 5:48am, edited 1 time in total.

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macribs   1.21 GW

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Re: New build, BHT mid-drive "direct", custom frame

Post by macribs » Feb 24 2020 12:01pm

That should be well worth your time. What controller do you pair it with?

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Re: New build, BHT mid-drive "direct", custom frame

Post by Overclocker » Feb 25 2020 5:52am

macribs wrote:
Feb 24 2020 12:01pm
That should be well worth your time. What controller do you pair it with?

QS is bundling it w/ the votol EM100. this motor is an IPM internal permanent magnet motor so to be safe i ordered the controller as well. the votol as an option to use SPM or IPM
vtipm.jpg
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macribs   1.21 GW

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Re: New build, BHT mid-drive "direct", custom frame

Post by macribs » Feb 25 2020 3:46pm

Ok, not familiar with that votol controller. If QS pair'd the motor with that controller I am sure it will work well.
If not, you can always look at the controllers from vasiliSk, the nucular controllers. I've heard those work very well with that motor. In fact I think the nucular inventor actually got that qs motor in his test bench....

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