The Dremel Tool Special

motomech

10 MW
Joined
Sep 10, 2010
Messages
3,713
Location
Yuma and Punta Cana Baja Mexico
The bike is a 2003 model that had never been used. That model had a recall(under hard off-road usage, the chain stays could break)and it had been pulled from the showroom of a large bike shop and lost in the warehouse. I wanted something with Hyd. disc brakes and quality suspension components.
The geared Mini Might frt. wheel kit is from Hightekbikes and the 48V 8ah batt. and rack are from E-Bike CA(Excellent service from them). The rack is a nice piece of work, but I would caution those considering this type of rack to make sure the the frame seat post reciever extends high enough to facilitate the mounting clamps. The batt/rack's three-way switch(master on/off and batt. lock)is very convienent. The sm. controller is mounted entirely under the Schwinn touring seat and the excess wiring and connectors are stuffed into a sm. camera bag strapped to the frt. of the seat post reciever.
The title of this post refers to the mounting of the motor in the Marzocchi mag. alloy forks. In order to mount the extra thick Rev-3 torque arm, I needed as much of the motor axle to extend past the securing fasteners as possible. To this end, the flat washers were disgarded and c-washers were not used. Instead, I hand bored a flat surface in the sides of the drop-outs[removing the Laywer Lips] for the axle nuts to seat with the sm. Dremel standard cut-off disc, which has the exact same diameter as the nuts. Minimal metal was removed. These Italian forks[made for jumping] are high quality and I have absolutely no reservations of running this low-power motor in them. I also had to clearance(sounds better than grind)the hub and brk. caliper and spend time aligning the frt. whl.

The performance of this motor/controller has been well described here, suffice to say that it is no power house, but as an assist, it's perfect. The top speed is well matched to the bike's 44/11 sprockets. In general, I use 8 of the 9 available rear derailleur's gears.
Total weight is 47 pounds, 17 of which came from the conversion. The frt. to rear balance is excellent and I can easily carry it using the rear shock as a hand-hold. This was important to me as I live on an Island in the Carribean and needed to be able to carry it on/off the inter-island ferry boats.
I read and lurked here for days and it payed off, as I am very happy w/ the results. The only thing I would change is that I probably forgo The Cycle Analyst 2.2. It's quality unit, but I have no need for the limiting features it provides.
The tires are Continental Town and Country's.
I am not an accomplished cyclist and I really like the way the motor helps me out of noob situations. I can wait to down-shift at the bottom of the hill and use the motor power to ease the strain on the deraileur's gears as I down-shift. Also, the frame(a 20.5 incher)is somewhat tall for my 30" inseam and the motor helps to pull me out of "tippy" situtations and 0 m.p.h. starts.
Much thanks to all who provided their expertise and a special thanks goes out to Dogman. For awhile I was on the fence about using the frt. motor w/ the alloy forks, but his experience's moved me in that direction and I'm glad I did.
Now, if I can lose 40 pounds of excess rider weight, I might reward my myself with a rear mini-motor(dual motor set-up).
Motomech
 

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UPDATE!!!!!
Well, even my feble noob brain realized that 18 m.p.h. on 48 V wasn't too great, so I went and inspected my install(Probably a good idea for everybody, noob or not). The first thing I noticed was that the throttle lever was contacting the brk. ASM. mount. I quick adj. there and bingo!, 22 m.p.h.
Then I remembered reading here about the unused gray(loop) wire being a current limiter, so I wired it thru the supplied(w/the frt. whl. kit) on/off switch and WOW, it's like a nitrous button, 25 plus m.p.h. And I weight 250#!
So now I have a low power/high power switch(good if I let my girlfriend ride...she can crash at a lower speed).
On high power, the frt. tire will spin a bit if I'm not careful, but suprising to me, hill climbing ability is about the same. I suspect that when the revs drop, much efficiency is lost.
What I don't understand is, the C.A. tells me max current only jumps from 14A to 15A, low/high mode. Watt/hr.s jumped big time, from 20/mile to 30/mile, so maybe I should think of the low power mode as a batt. conservation mode. Cruising around this afternoon in cool weather, neither the controller or motor warmed up at all.
Bottom line, the Mini Might motor Rocks!
Can't recommend it enough.
 
Most likely the loop wire is not a current limit, but a speed limiter. Many controllers have this to adhere to various regulations for areas they may be sold in, where ebikes may not be allowed past certain speeds. That would explain why the current reading isn't much different.


Wh jumping up will happen if you ride faster; drag from wind and rolling resistance, etc, eats up power like crazy as you go faster.
 
<<<<Wh jumping up will happen if you ride faster; drag from wind and rolling resistance, etc, eats up power like crazy as you go faster.>>>

Yes, and I can hardly pedal fast enough to assist @ 25 m.p.h., even w/ the 44/11 gear combo.


"Absolute power corrupts absolutely"

Motomech
 
motomech said:
UPDATE!!!!!
Well, even my feble noob brain realized that 18 m.p.h. on 48 V wasn't too great, so I went and inspected my install(Probably a good idea for everybody, noob or not). The first thing I noticed was that the throttle lever was contacting the brk. ASM. mount. I quick adj. there and bingo!, 22 m.p.h.
Then I remembered reading here about the unused gray(loop) wire being a current limiter, so I wired it thru the supplied(w/the frt. whl. kit) on/off switch and WOW, it's like a nitrous button, 25 plus m.p.h. And I weight 250#!
So now I have a low power/high power switch(good if I let my girlfriend ride...she can crash at a lower speed).
On high power, the frt. tire will spin a bit if I'm not careful, but suprising to me, hill climbing ability is about the same. I suspect that when the revs drop, much efficiency is lost.
What I don't understand is, the C.A. tells me max current only jumps from 14A to 15A, low/high mode. Watt/hr.s jumped big time, from 20/mile to 30/mile, so maybe I should think of the low power mode as a batt. conservation mode. Cruising around this afternoon in cool weather, neither the controller or motor warmed up at all.
Bottom line, the Mini Might motor Rocks!
Can't recommend it enough.

I think the voltage is the limiter that keeps the amps at 14 -15 , I *think* when you add more volts it starts to draw more Amps as well. The Amps need to be limited to prevent over driving / pulling too many watts and over heating the motor.

So you you can tune your motor with higher volts and limited amps
 
motomech said:
<<<<Wh jumping up will happen if you ride faster; drag from wind and rolling resistance, etc, eats up power like crazy as you go faster.>>>

Yes, and I can hardly pedal fast enough to assist @ 25 m.p.h., even w/ the 44/11 gear combo.


"Absolute power corrupts absolutely"

Motomech

I was going to use a 53/39 road crank on the ebuild but it would not accept the PAS sensor so used a truvative mtb 44/34 crankset as it turns out with the nexus hub its about the ideal rpm to speed variation. Sheldons browns gear calculator gave good results , i still need to do gear testing as its not set up still waiting for a part.
 
I would say that is a real advantage of the Nexus hub. Had you been using a 11 sm. tooth cassette w/ that 44 T chainring, you would run out of leg speed around 20 mph.
On my Rocky Mountain, when I went to 24 inch wheels, I started getting pedal strikes when pedaling in the corners. To get rid of that, I replaced the entire crank w/ one w/ shorter crank arms and a 50 T chainring. It's an Octalionk and it took a couple of days searching to fine the one I needed. W/ this combo, I can pedal up to 23-24 mph. Like you, I also went w/ "low-profile" pedals.
100_0076.JPG
 
eCue said:
motomech said:
UPDATE!!!!!
Well, even my feble noob brain realized that 18 m.p.h. on 48 V wasn't too great, so I went and inspected my install(Probably a good idea for everybody, noob or not). The first thing I noticed was that the throttle lever was contacting the brk. ASM. mount. I quick adj. there and bingo!, 22 m.p.h.
Then I remembered reading here about the unused gray(loop) wire being a current limiter, so I wired it thru the supplied(w/the frt. whl. kit) on/off switch and WOW, it's like a nitrous button, 25 plus m.p.h. And I weight 250#!
So now I have a low power/high power switch(good if I let my girlfriend ride...she can crash at a lower speed).
On high power, the frt. tire will spin a bit if I'm not careful, but suprising to me, hill climbing ability is about the same. I suspect that when the revs drop, much efficiency is lost.
What I don't understand is, the C.A. tells me max current only jumps from 14A to 15A, low/high mode. Watt/hr.s jumped big time, from 20/mile to 30/mile, so maybe I should think of the low power mode as a batt. conservation mode. Cruising around this afternoon in cool weather, neither the controller or motor warmed up at all.
Bottom line, the Mini Might motor Rocks!
Can't recommend it enough.

I think the voltage is the limiter that keeps the amps at 14 -15 , I *think* when you add more volts it starts to draw more Amps as well. The Amps need to be limited to prevent over driving / pulling too many watts and over heating the motor.

So you you can tune your motor with higher volts and limited amps
With that first build, I used the KU63, a tiny square wave controller that truely was only 15 Amps max. Over the years, I used various controllers on the MUXS including a 22 amp Mini-Monster from Lyen and a 25 Amp Grineon (Infineon from Grin). The Mini-Monster is well-named, a real hard-hitter. I had to watch the throttle at times to keep the wheel from spinning. The 25 Amp Infineon was too much. It would "hammer" the gears/clutch and I removed it to keep from damaging internals. Neither high-powered controller added much in the way of speed, maybe a mph. The top speed of the MXUS 260 on 48V in a 26" whl. is RPM limited, not power limited. When I went to LiPoly, I played around w/ various pack Voltages, from 45V (12S) to 55V (15S). Going to 13S and then to 14S added a mph or so each and at 15S (22A X 55 V = 1220 W!), the phase wires started to melt and I went back to 12S, where it's stayed. I don't think one can get the MXUS 250 to do a sustained 25 mph plus without damaging the motor. My advice is to be happy at 23 to 24 mph or if one has to go faster w/ a mini-motor, use two (2WD).
As a side note, I burned out a hall sensor while using the Mini-Monster(not related to the controller) and the Lyen controller ran it very well sensorless. Unlike the Q100, the MXUS has a conventual pole count (8, I think) and a low 5:1 gear ratio, so it doesn't spin so fast as to cause a sensorless controller to have problems "sync'ing up.
 
A final note;
I used that motor for about 4 years and many 1000's of miles and aside from that one Hall incident, it never over-heated or gave me any problems. Eventualy, one of the wheel bearings started to get loose and rather than repair it, I gave it to a kid down the street and replaced it w/ a Q100H (260). We drag raced a number of times, switching bikes to off-set my greater weight. On the same Voltage and basicly same controllers, thge lighter and smaller Q100H would jump it off the line due to fact that it spins much faster (12:1 compound gearing), but every time, the MXUS would catch it in the mid-range and power away to a 1 to 2 mph higher top speed.
The MXUS mini is a great motor!
 
yeah it cant maintain its top speed over terrain its fun testing it out though , so far Im finding 32 to 34 kph to be a nice travel speed and easy for me and the motor to maintain in its mid 4th speed setting. It maintains 32 to 34 on level to slightly sloping ground with me kicking in off and on to keep it spinning fast when in throttle mode. In pas mode it seems efficient so far
 
I should stay at 48 volts ( I think I will ) Im not up to frying a motor especially for a potential 2 mph gain :D I see no point especially as the amps cost battery life or distance when misused for acceleration my plan is to be the starter motor and save the watt draw. Hope to make it a habit.

When I was setting up the LCD5 there is a setting under P1 called motor characteristic parameter setting (see below) I asked the seller what this was reply was to set it to 88

P1 = motor gear reduction ratio× number of rotor magnet pieces rounded to any decimal. P1 setting ranges between1-255

Divided 88 x 5 (the gear ratio) the pole count works out to 17.6 or 18 magnets.

I see the xof7 advertised with the 5:1 ratio


motomech said:
motomech said:
UPDATE!!!!!

With that first build, I used the KU63, a tiny square wave controller that truely was only 15 Amps max. Over the years, I used various controllers on the MUXS including a 22 amp Mini-Monster from Lyen and a 25 Amp Grineon (Infineon from Grin). The Mini-Monster is well-named, a real hard-hitter. I had to watch the throttle at times to keep the wheel from spinning. The 25 Amp Infineon was too much. It would "hammer" the gears/clutch and I removed it to keep from damaging internals. Neither high-powered controller added much in the way of speed, maybe a mph. The top speed of the MXUS 260 on 48V in a 26" whl. is RPM limited, not power limited. When I went to LiPoly, I played around w/ various pack Voltages, from 45V (12S) to 55V (15S). Going to 13S and then to 14S added a mph or so each and at 15S (22A X 55 V = 1220 W!), the phase wires started to melt and I went back to 12S, where it's stayed. I don't think one can get the MXUS 250 to do a sustained 25 mph plus without damaging the motor. My advice is to be happy at 23 to 24 mph or if one has to go faster w/ a mini-motor, use two (2WD).
As a side note, I burned out a hall sensor while using the Mini-Monster(not related to the controller) and the Lyen controller ran it very well sensorless. Unlike the Q100, the MXUS has a conventual pole count (8, I think) and a low 5:1 gear ratio, so it doesn't spin so fast as to cause a sensorless controller to have problems "sync'ing up.
 
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