From the V is for Voltage Archives
A003 Name: Chain Wheel Motor My1018
No-load Voltage: 24V
Rotation Speed: >=2800r/min
On-load Voltage: 24V
Rotation Speed: >=2400r/min
Used in electric scooter of various size
Shanghai Masston Co., Ltd.
Posted:Oct 3 2006, 04:56 PM
This thread will detail adventures met training a 250W Unite Motor MY1018 to scream like a banshee without dying like a kamakazee.
By force-cooling of the armature, we'll uprate the motor's heat tolerance but not electrical efficiency, to live as if it were a 600 to 900W motor. No more charred windings.
That's the main goal.
Second goal: a fast (25mph) cruiser bike I won't have to pedal home from a ride.
Also planned: to advance the brush timing--for better top-end power.
MY1018 weighs only 5 pounds,bolts on and is very easy to service.
TNC Scooters will be stocking the MY1018 24V gear motor begining this month--
Good for bottom bracket drives and rear hub drives.
ban blue smoke
Posted: Oct 3 2006, 11:06 PM
This motor is availble from the maker, wound for 36V. Even so, I prefer the 24V version. The 36V version will give the same performance specs. at 36V, as the 24V version does on 24V
(so says the published specs--theory notwithstanding)
The Currie line of cheap ebikes use the 24V version, so that's what I work with.
By adding another 12AH battery I got 36V, and a 33% boost in torque and top speed, both of which were exhilarating.
A gearmotor has great advantage over typical BL hubmotors, (I write for new readers now), in that it has great torque from a standing start. Hubmotors (except for the Giant Ampeaters) do not do much to scoot you up to speed from a stop.
The gearmotor whisks me and my 100lb StupidHeavy (formerly known as Currie) bike, right across a busy intersection--no real need to pedal.
But... running a 24V MY1018 at full throttle for more than a few miles at a time will char the windings and stop things right then.
After seven miles of a motor destruct test:
Posted: Oct 3 2006, 11:19 PM
What you see is the end result of over-baking the wire enamel. The gray stuff is either smoke condensate, or, more likely, enamel going to ash. The black area over by the thumb and over at the seven o'clock area is where the turns shorted badly, charring the enamel. As you see, the entire thing was pretty hot--most of the visible wire evidences heat damage.
The putty is some sort of heatproof stuff that the factory employs for dynamic balancing.
Enamel can withstand, what? Probably four or five hundred degrees without appearing to burn or make ash or smoke stains (I should go as at a motor forum).
This motor was probably dissipating about four hundred watts of electricity as waste heat in the armature. Being sealed in a small housing, that much heat inevitably burns wire--the temperature rise will be steady and almost without limit--except that the motor burns out first.
Short runs at high speed (overload is the same thing) will not cause this. A long, lugging haul of a grade would also do this in time.
Cooling would prevent it all, just like that. Simple. Convective and radiant cooling is not enough here.
By forced air cooling it should be possible to avoid this from happening to the new motor which just arrived today. _ _ _ taught me how best to do this. Brushed DC motors particularly benefit from air-over cooling
Think of AC electric drills and saws and the like...
More later after system construction is in progress.
Posted: Oct 4 2006, 07:25 AM
Great posts. Keep 'em coming.
Posted: Oct 9 2006, 02:21 PM
Beginning to mod the Unite MY1018 today.
Figuring out things as I go along.
Good surprise: the housings are diecast zinc. This means that it drills very easily and cleanly.
I won't have to remove, pry out/disturb the brush plate in order to Swiss cheese its cover (there's a few mm. of air gap between the inside of the cover and the brush holding plate). Diecast makes no curlycues of metal which could otherwise lurk and remain under the brush plate, to go adrift later on and cause mischief.
Pictures to be taken later today or tomorrow will make all of the steps clear.
Swiss cheese the brush cover plate? Yes, to some extent. This'll be the easiest way to put air into the motor.
I will recycle the old motor's brush cover plate--using it as a plenum cover. That is, it fits, Oreo-style, over the existing cover. Spacers of a few mm. thickness... and a nipple for the air hose? That'll mount in the former ball bearing's space in the recycled cover.
The finished result will look like stock, but protrude a half inch or so more from the bike. It will have a copper nipple press-fitted and epoxied into the center of the cover.
I'll probably paint the whole thing with a light coat of Krylon flat black, to further maximize radiant cooling.
The stock motor is painted silver. The silver paint yields quickly to paint remover.
So it's bare as a baby right now.
Next step--ventilate the brush cover.
I'll also be advancing brush timing by about 7 to 10 degrees (roughly) by re-indexing the new motor's brush plate/cover assembly. This requires drilling just four new holes.
The old cover plate will guide my hand drill.
Pictures later, having too much fun right now. Gee, what if this all works out?
Well, if it doesn't--if I burn up this motor too in torture testing to come, I'll buy a new one from TNC scooters. They should have stock of this MY1018 very soon.
I consider it to be a consumable item (not like a BL $$ hub motor).
So, to have a spare, ready to slap on, it a good plan.
And if it doesn't burn up on 36V and flat-out running, after this force-cooling mod?
How long will it last? I'm curious to find out.
Next posting will show pictures more or less self explanatory. I'll caption them only as needed.
Posted: Oct 9 2006, 06:47 PM
The inside of the diecast motor cover carries the brush plate: phenolic board standing about 3mm off from the inside surface of the cover. This plate has a 3mm air gap. It stands on four lugs, one of which is noted by the white cursor. The lugs are swedged a bit to hold the phenolic. Removable by prying, but I didn't wish to disturb things--there is no need to do so because the metal drills so cleanly.
The cover has already been ventilated--air will pass around the perimeter of the brush plate and also around the center hole, hitting the commutator and brushes with cool air.
On the right is the very same cover as above. See the phenolic board peeking through the air holes. Note the other cover--the gear-end cover of the motor has twelve air exit holes. These will be baffled to prevent ingress of water splash, no worry about that.
Here are the major parts of the MY1018. So simple. OK: the extra (leftover) brush end cover from the old motor is to be used as a plenum cover; that's it laying atop the new motor's brush plate cover. It will get a 3/4" copper elbow fitted to its center, next step.
I will grind off its flange and attach it with self tapping screws to the ventilated cover. Air will be forced into the plenum, go through the holes, around the brush plate, through the motor, carrying off waste heat generated in the armature.
This is all done to allow the motor to live longer at high loads, high
speeds. As a sealed motor, it gets to be like a miniature oven inside. The modification will make it like an oven with an open door, and a fan blowing on the turkey. It should be less liable to roast turkey this way. I am, of course, the turkey, if the armature...roasts!
Note how cleanly the diecast zinc drills. This was a great troublesaver, to not have to pry out the brush plate.
Note the little gear case? That is to be packed with grease, per usual. I will vent the case, though ,with a couple of small holes. When a case is packed full of grease and then the gears are run, thermal expansion plus the churning, forces excess grease out through the "sealed" beaings *there is no such thing, really*.
The bearing behind the output sprocket is of the metal shielded type. It will pass excess grease readily, until the excess is relieved. The bearing behind the drive pinion (integral with the armature) is of the rubber "seal" type. This type passes less grease, so relatively little grease gets into the armature housing.
Anyway: by making two small grease holes remote from one another I can "change" the grease in the compartment from time to time, if thought needed, without opening the case up.
Two small self-tapping screws will seal the holes when they aren't needed.
Next step: mate the fake cover to the real cover and begin air flow tests (that is, guess whether I've got a free enough passage for the air pressure the blower will provide. If less restriction is called for, more holes will be drilled, no sweat.
So it goes...
Posted: Oct 9 2006, 07:15 PM
I'm following this with interest.
Because I just recieved my own MY1018.
Not the geared one, a different one.
Voltage: 24VDC Rated speed: 2500 RPM
Rated current: 16.5A Output: 300W
Jx JX Motor Co.,Ltd"
Was picked up off E-bay $.99 + S&H of $20.00 Black body, Silver end caps about 4" Dia, and 3.4" long Has 4 bolt mnt plate built on Shaft= 15/32", with a .393" dbl flat sided sprocket mnt under 19/64" threaded end also has dbl flat spots on main larger shaft area about 3/8" across flats 11T #25 chain size sprocket came on it. ZERO air cooling as no holes at all front end plate has 4 screws, rear has nothing Spins either way with 12 VDC to wires, (cw or ccw). When shorted, (wire held together) the motor is harder to turn. This is a test we, (R.E. people, aka windmills ect,ect..) do with DC motors to see if worth picking up when found in travels.
I was working on building a mini E-scooter or something like maybe the "Sparky II". So watching what you do to help cooling will be of interest !!! The "Solar Scooter" I was given has gotten me bitten to have a faster E-Ride Toy. The ss has a motor with built in jackshaft like the newer MY1018's have. All belt drive, but limited speed as being a "old fart" type, 15 MPH, but hey, I't do wheelies if rode standing and being in turbo speed, (button on) when starting from dead stop just do like on a bike, pull back on handle bars a bit as motor starts to push it forward! Would be great for parts if it wasn't a working E-ride. I should just mod on it but hate to ruin it. Still thing it would be cool chopped out.
Posted:Oct 9 2006, 08:22 PM
Good! I'm glad that the general principle here is of interest to folks.
We are hot rodding mini motors.
The perversity of manufacturers...
The ball bearing, as a -general rule- should be a light press fit on
It should not be a slip-on fit or the shaft may at times spin in the
bearing's ID bore,
making wierd noises that come and go, and eventually possibly causing
Unite had the bearings set up as a bare slip fit on both of the two
motors I've seen now.
A small sin in my opinion, but a sin nonetheless.
So, just as good, even better than press fit here, is to slip the
bearings back onto the armature shafts
using a locking agent. "Stud and bearing mount" is another name for
this thick red anerobic cement.
Use it sparingly--a dab'll do ya.
Now, the other side of the coin: as a -general rule- the ball bearing's
outer race should be a bare slip fit in the supporting cover's bore.
This allows for thermal expansion. IF both ID and OD of the ball
bearing are press fit-tight, there's no relief for strains engendered
when the motor heats or cools.
Shortened bearing life may result.
Radial load ball bearings like these are not meant to take much of a
On the other hand, the castings are thin and somewhat flexible/springy,
to a couple of thousandths of thermal growth----differential of
dimensional growth between armature shaft length and housing length.
Unite provides (correctly) a spring washer behind the brush-end ball
bearing, to keep it all lightly pressed forward, to prevent end shake
rattles that could otherwise occur
(and prevent the -wear- to the castings' bearing bores that woud
If the OD bore is worn or slopped, it -might be OK- to apply a bit of
silcone rubber type of glue.
If the parts are grease free... the silicone rubber is elastic enough
and yielding enough to allow thermal strain relief, while also
immobilizing the OD of the bearing from chattering or spinning out in
the bore (so long as the bearing runs without internal failure, ie:
grinding up. Then somthing's gonna give and you'll know it by loss of
power and terrible noises, probably.
See that Unite uses a rubber "sealed" pinion-end bearing here.
This is to better exclude gearcase grease.
However, such bearing seals are only rated to keep ball bearing grease
-in- the ball bearing.
They cannot prevent grease or oil migration shoving or leaking
-through- the bearing from an adjacent grease-packed case.
But, as noted in a prior posting, the output shaft bearing is only
metal "shielded", and so,
leaks excess grease to the outside world, in preference to the grease
going back into the motor.
So, no problemo.
If it were a critical application, an "umbrella seal" would be called
Here there is no room for, nor any real need for an umbrella seal (It's
a sort of flanged rubber compression seal).
Bearings cemented in place for silent running
Posted:Oct 10 2006, 09:19 AM
I must have missed a post somewhere -you finally got a proper
With all your cool plans -this motor should be a rocket!!
I was surprised when i put my controller(which never felt like it got
warm ever) in my battery bag -the bike cut out after a few minutes
Took me a while to work out it needs air running over it -even a small
Posted: Oct 10 2006, 10:07 AM
Yeah, Currie at last sent a new motor.
I was just humbled by my ignorance again:
-motor partly assembled (sans output gear),
I ran it from a 12V battery, holding the brush cover in place.
Rotating the cover anti-motor rotation, the armature spins faster,
Ooooo (I thought!) More power at speed!
Then I smelled smoke. Glanced at the clip leads.
Melting vinyl. I pulled off the brush cover pronto to prevent the
neighborhood from burning up.
Stufu just learned: advancing the brush timing much past (presumed
neutral?) factory setting,
increases no-load current draw enormously.
I will forego timing advance for now.
My fingertips are blistered! (not really)
I hate the smell of blue smoke.
Break---finish it later today.
Grow Less Stupid
Currie seals the controller in an airtight cubby.
I don't know how they get away with that.
It's just above the b.b.; a totally closed box,
designed to hide the controller and...retain rain water.
Posted:Oct 10 2006, 07:27 PM
At this writing the brushes are running-in on a 12V feed, no load.
The plenum cover will be screwed on with sealant
and the unit painted with Krylon satin black for appearance and for
that little extra bit of cooling afforded by a thin coat of black paint
(black is a cooling color).
The 3/4" copper elbow is an interference fit. The slight protrusion
inside the cover is riveted over;
nicked with a chisel and cemented with red bearing locker.
It should hold OK. Don't want it to fall out, ever.
I've decided to mount the motor in a new orientation:
the big circle hanging down instead of up.
It'll look a little neater.
The blower will get mounted next
to the underside of the existing seatpost rack.
It is a 24V blower. The bike is 36V.
It was discussed here on forum, and determined earlier, that the
simplest way to drop 12V
for the blower is to run a 12V 1A auto lamp in series with the blower
The blower will be fed in parallel with the motor.
Therefore, its action will be entirely automatic, in sync with motor
The two long, protruding RH screws are temp. caps for the grease
input/output holes I just drilled into the gear case.
They'll be replaced with stubby screws. By this means I can regrease
the gear case as desired without stuffing it over-full.
It has occured to me that I -could- engineer a grease pumping
system--grease pumped by the pinion and driven gear, recirculating, and
shot out into the mesh of the pinion-to-driven gear.
That's for the next motor. This one I just want to run asap even before
installing the blower.
I'll just keep the speed down for now until the blower gets fitted,
holding my speedgreed to 17 or 18 miles per hour; it'll be OK at that
Once blown? Full bore and 25 per!
Posted:Oct 10 2006, 10:38 PM
Here's a blowup of the Currie Izip cruiser motor drive
back when it was bone stock (Aug 13th)
Now it's time to test the blower. "24V 10W", it cost about five bucks
from Marlin Jones electronics
The motor, even idling on 12V grows warm to the touch.
Next I lashed up the blower.
It's so quiet on 24V that I think it's wiser and better to
run it full power all of the time.
After five minutes the motor case was cool to the touch
Quite a breeze is going through the motor.
The motor was stone cool after five minutes of blower operation.
The two units are running--the frash flozen motion.