Do the new MAC motors really have 0.27mm laminations?

[neptronix]

I've heard that the new MAC motors have 0.27mm laminations nowadays. This is rather juicy. No other hub motor has such thin laminations.
This would mean that it's more amenable to being spun fast - producing healthy amounts of power and less heat the quicker you spin it than the 0.33mm lamination version.

A new MAC in a 20" wheel would be doing 40mph at 669rpm at the wheel.
669 x the 5:1 reduction ratio gets your stator actually spinning at 3,345rpm.
3,345rpm x 16 poles = 53,520rpm, which is beyond the capabilities of a standard ebike controller..
But, pair it with something like a high rpm capable kelly and you've got a little 9.5lb rocket of a motor that could, most likely, sustain 40mph w/o overheating for quite a while.
Color me interested in that..

So that bears the question.. has someone here measured the laminations on a late 2016 motor yet?

 

[Lebowski]

Since you're talking about spinning a MAC at high speed, how fast can you spin one safely ? I've been playing with MAC internals (thanks Izeman !) and can tell you that 55 k-erpm is bloody fast... at what point is it no longer safe ? I had to tighten down my vice as from stop to 55k-erpm in 1-2 seconds was moving the vice in the counter-rotation direction...

 

[neptronix]

No idea, but i got a 2011 era one with 0.5mm lams up to about 45-47mph once in a 26" wheel with an EB3 controller.
The gears melted after 5 minutes, but i had the original white gears.
That would be about 585rpm at the wheel x 5 x 16 = 46,800 eRPM.
The motor continued to run flawlessly for years after replacing the gears. Despite it being on a hardtail bike with a then 270lb rider over bumpy roads.

The EB3 infineon clones had that typical on-off throttle response during that run ( 76v nominal ), indicating to me that it was starting to struggle.
The old EB2 controllers used to have that behavior with a MAC at far lower eRPM - forget setting it up to do more than 30mph.

But with these really thin laminations, i think that the best way to make power would be to have a 70,000+ eRPM capable controller, and spin the MAC motor up like you would with a RC motor. Chain drive it to the rear wheel, and have a blast.
Supposedly, the thermal path is better this time around, so you could possibly be making what.. 2000w continuous? just a guess.

The clutch and bearings all around are probably the limiting factor for this.

 

[cell_man]

Thinner laminations have been mentioned and i know there was some talk about trying them, but they are not a standard feature or anything like that. I'll speak to them and find out if they have any available and if they have done any testing, to compare performance. The boss at Mac has been away for several weeks, so I haven't checked in with them lately, to discuss the new stuff they've been working on.

The Mac has had a complete makeover externally and it looks much nicer and more modern. The stator design, remains the same. There is now also a cassette version rear. The new version front has cable entrance on the side, rather than through the axle.

 

[izeman]

regarding the stator design i must say that i DID change. i can't say when this change happened.
well, the pure stator stayed more or less the same. what really changed was the big central bearing that was replaced by 2 smaller ones, placed in the yoke. the overall dimensions of the two stators, as well as taps and stuff are the same.
this doesn't allow a 1:1 swap between the 2 stators. it is still possible, as i proofed in my kona build thread. it involves a bit of lathe/mill work though.

 

[cell_man]

regarding the stator design i must say that i DID change. i can't say when this change happened.
well, the pure stator stayed more or less the same. what really changed was the big central bearing that was replaced by 2 smaller ones, placed in the yoke. the overall dimensions of the two stators, as well as taps and stuff are the same.
this doesn't allow a 1:1 swap between the 2 stators. it is still possible, as i proofed in my kona build thread. it involves a bit of lathe/mill work though.

You are referring to the motor structure, stator support support etc. Yes, the structure has changed, the new/new versions are not interchangeable and there are various differences, but the actual stator and the magnets are unchanged.

I can still provide the original version inner structure, with the previous design/structure, but there are no more (or very limited supply) of the original version hubs, side cover etc.

 

[Triketech]

The Mac has had a complete makeover externally and it looks much nicer and more modern. The stator design, remains the same. There is now also a cassette version rear. The new version front has cable entrance on the side, rather than through the axle.

Cassette version...hmmm...tell me more....

 

[izeman]

You are deferring to the motor structure, stator support support etc. Yes, the structure has changed, the new/new versions are not interchangeable and there are various differences, but the actual stator and the magnets are unchanged.

100% agreed. i just wanted to make sure that ppl know that you can't swap parts directly. but when i think about it, most ppl won't do that anyway and will swap the whole internal unit (stator, yoke, axle) at once. and this CAN be done.
i just may add, that i really appreciate your great service you offered to me over years, especially by being able to fulfill my special spare part needs!

 

[Lebowski]

accellerating a MAC to 55kerpm forward, from around 30kerpm reverse:

[youtube]C-fbivN7BHk[/youtube]

I first apply throttle, then change direction to forward, then save settings by flicking setup switch.

some info:

hall sensored mode (but transitions to sensorless FOC at 1500 erpm)
57 V
50 A phase (peak), 30A fieldweakening (peak)
50 A battery current

erpm limits set (this is what limits the speed, and makes forward and reverse speed different):

a) erpm limiter (forward) rampdown start, range: 52.97, 2.99 k-erpm
b) erpm limiter (reverse) rampdown start, range: 31.99, 3.98 k-erpm

the info at the flick of the last switch:

 Chip status at button press:

status bits:               
drive LEDS:                ...3
time spent:                3.257 sec
throttle:                  99 %
wanted_i_torque:           40.8 A
wanted_i_fieldweak:        29.0 A
filter_i_torque:           6.7 A
filter_i_fieldweak:        28.3 A
filter_i_error:            0.3 A
Vout_real:                 94 %
Vout_imag:                 27 %
Vout_scaling:              0
speed_sensorless:          55.44 k-erpm
filter_speed:              0.00 k-erpm
accelleration:             1 %

The MAC is spinning with 98V of backemf here !!! (55 kerpm but nominal speed at 57V is 32 kerpm)

 

[irq]

The Mac has had a complete makeover externally and it looks much nicer and more modern. The stator design, remains the same. There is now also a cassette version rear. The new version front has cable entrance on the side, rather than through the axle.

Cassette version...hmmm...tell me more....

12T and 10T MAC Cassette User here, ask me anything you ever wanted to

 

[LewTwo]

... The new version front has cable entrance on the side, rather than through the axle.

That is a big plus.Now for a temperature sensor as well.

 

[ScooterMan101]

Are you saying that we can buy a new one, take out the old one's complete inner parts ( In one unit from the outter hub ) Axle and all and put the newer one into the hub that is already build up / laced up to a rim , in order to not have to buy a new rim/spokes and do/pay for a new wheel build ?

Without having to do any Mill/Lathe work ?

If so that would be excellent for someone like me that has a 2013 Mac that is a 6t.
It likes flat ground and small 100-200 foot hills , but does not like to go up mountains for a long period of time,
by doing a 15 minute complete inner swap I/we could switch over to a 10t or 12 t for times we want to go up mountain trails .

If so could that be done with the cassette version as well ?

Anyone who has taken a Mac up mountains, ( 1000 foot and more , 10 % grade and steeper climbs ) on single track at speeds of 6 mph or so), please tell me your experience/how the Mac handled such altitude climbs , and which T version you did it on.

You are deferring to the motor structure, stator support support etc. Yes, the structure has changed, the new/new versions are not interchangeable and there are various differences, but the actual stator and the magnets are unchanged.

100% agreed. i just wanted to make sure that ppl know that you can't swap parts directly. but when i think about it, most ppl won't do that anyway and will swap the whole internal unit (stator, yoke, axle) at once. and this CAN be done.
i just may add, that i really appreciate your great service you offered to me over years, especially by being able to fulfill my special spare part needs!

 

[izeman]

Are you saying that we can buy a new one, take out the old one's complete inner parts ( In one unit from the outter hub ) Axle and all and put the newer one into the hub that is already build up / laced up to a rim , in order to not have to buy a new rim/spokes and do/pay for a new wheel build ?

i'd say YES. don't know why it shouldn't work.

 

[ScooterMan101]

If so , I will keep my 2013 Mac 6T and at sometime in the future,
( when someone posts his doing this, with pictures ) Highly consider a swap out.
I have had good experience with a Mac, except when I road it up a 1,200 foot Mountain at 6-10 mph.
Because of that climb, I had to have someone repair/replace the Hall Sensors.
I had 800 miles on it up to that point.
What are the shipping costs to where you live ?
Here in the U.S. a Mac motor costs Apx. $ 75-$85 for shipping the motor.
$ 270 for the motor and then shipping on top of that, so apx. $ 360 total for just a motor , so I really want to
get some report on others who have done this first.
Lets keep this thread current.

 

[irq]

i dont think that a 6t is able to do such slow climbing on 10%, you want 10T or better 12T or even 14T. Torque capabilities which could cause fear, or lots of 8)

motor incl. shipping to europe, directly from mac motor shanghai (the 2016 cassette version) ended up in about ~300€ and additional danegeld for federal debt collector aka customs. but, if you ask the mac sales the right questions and point them into the right direction they will probably show a pretty easy way to reduce at least the danegeld amount for importing goods. i wont explain this further here, but i cant prevent you from sending pm

 

[ScooterMan101]

Here in the U.S. we do not have such taxes when getting something shipped from overseas. Unless perhaps you are a business buying a container load of stuff ? I am not in business so I only know about buying small items. No mater if it is a Bicycle Part like handlebar, brakes, frame, or even any electric bicycle conversion parts we/the consumer do not have to pay extra , at this present time.

The High Shipping cost of single Items from China , like the Mac motor from Em3ev , it all about the weight of the product.
so a 9.5 pound motor , plus box/foam is where that $ 75-80 comes from.

I was talking mostly about that cost of shipping as a way of hinting ..... well I will just go ahead and say it.

I wish that some vendor here in the U.S. would stock the Mac Motors, especially since the improvements on it. the cost of each motor in regards to shipping , and a little in price for bulk purchases, would bring the cost of the Mac Hub motor Down by 10-20 % when you include that it would cost at least $ 50 less in shipping.
shipping for a 9.5 pound hub motor from one place in the U.S. to another would cost about $ 12 ,
I am disappointed that more vendors , or any that I know of , sell the Mac Hub Motor here in the U.S.

I am guessing that Em3ev would love to have someone here buy a crate full from them, along with some other parts as well.

i dont think that a 6t is able to do such slow climbing on 10%, you want 10T or better 12T or even 14T. Torque capabilities which could cause fear, or lots of 8)

motor incl. shipping to europe, directly from mac motor shanghai (the 2016 cassette version) ended up in about ~300€ and additional danegeld for federal debt collector aka customs. but, if you ask the mac sales the right questions and point them into the right direction they will probably show a pretty easy way to reduce at least the danegeld amount for importing goods. i wont explain this further here, but i cant prevent you from sending pm

 

[izeman]

no sales tax, no import tax, no handling fee? wow. that sounds great. here in austria i pay 20% sales tax for everything imported from outside the E.U., and about $15 handling fee from FedEx, DHL, UPS etc for collecting the tax and if above a certain treshold you pay import tax as well.

 

[macribs]

<OT rant>

Yeah no wonder US health care is for the well funded and so many people in the US live in poverty. Low taxes is great for the money makers but they got their ways no matter what you try to tax em. Like Google, Microsoft, Face and all them other pirates. They hardly pay anything no matter what, and politicians and other smart people pet their backs (kiss their brown holes) and get fed a piece of the pie. So the rich getting richer and the poor... well we all know how that one goes. </rant>

 

[neptronix]

<OT rant>

Yeah no wonder US health care is for the well funded and so many people in the US live in poverty. Low taxes is great for the money makers but they got their ways no matter what you try to tax em. Like Google, Microsoft, Face and all them other pirates. They hardly pay anything no matter what, and politicians and other smart people pet their backs (kiss their brown holes) and get fed a piece of the pie. So the rich getting richer and the poor... well we all know how that one goes. </rant>

Uh.. guys.. how do we go from a technical discussion on a motor straight to first world problems in just a few days.. :lol:
Let's please contain your posts about how bad 'da man is treating us to the off topic section, ok?

 

[cell_man]

... The new version front has cable entrance on the side, rather than through the axle.

That is a big plus.Now for a temperature sensor as well.

I've personally been fitting a temp sensor in Mac motors for maybe 3 years. I'm sure Mac fit them for others too.

I spoke with Mac today, regarding the 0.27 lams and apparently they will receive the stators in about 3 weeks and built motors will be available sometime soon after that. There is no performance data yet. Apparently, Mac had a few 0.27 lam stators, but the material quality was not very good apparently, so performance data wouldn't be valid. The production stators are a better material grade.

I'm also very keen to see how the new stator effects the efficiency. Going from 0.5mm to the 0.35mm stator, improved peak efficiency by maybe 2-3% (off the top of my head). Will just have to wait and see how the 0.27mm version stacks up. It would be great if we saw similar gains, but I don't know enough to make any sort of prediction. I'll get some comparative data, once there are motors available.

For info, the slower wound motors have higher peak efficiency figures. At least, that is the case on the current versions.

 

[Lebowski]

Cellman, if you want I can do some no-load testing and give numbers for how much power it takes to spin at so and so many erpm. If the laminations make a difference for the no-load power consumption then it should show up... Best would be to do the test for bare internals as in the video I posted above.

All out of the goodness of my heart of course (am dreading the day Izeman wants his internals back )

About temp sensors, have you ever considered using digital sensors ? Like the DS18S10 ? Because they are digital there is no ambiguity about which type of temp sensors you use. With resistors there are so many types... (PTC ? NTC ? resistor value at room temp ? temperature slope ?)

 

[Samd]

I have to confess I nabbed a few 0.27 a few weeks back and kicked this off discussing with Nep via facebook. The purchasing dept has said they should only have 0.27mm coming in from about the 28th of Oct.

I plan to dyno a few with my 3077 fet based sine controllers that Barent and I cooked up.

It will be interesting to see the combined effect of sine and the lams. Huge deadspots for torque on the 4011 infineon that Mac shipped me. Hope I can get some torque curves for comparison guys.


Sent from my iPhone using Tapatalk

 

[izeman]

All out of the goodness of my heart of course (am dreading the day Izeman wants his internals back

keep it as long as it's needed

 

[neptronix]

Very nice, thanks for the info.

What would be really helpful is a measurement at no load at the same wind, at the same RPM for a 0.5/0.35/0.27 to see what the differences are.
I'd figure you of all people would have one of each laying around :lol:

I really think that the razor thin laminations will be a small benefit in a 26-27" wheel, maybe 50-100 watts less consumed at most at high load..

But when it comes to using the thing as an RC motor in a mid or rear chain drive, i believe it will be an absolute rocket with the right controller and high voltages in a 6T..

 

[neptronix]

I got some dyno data from MAC.

I asked specifically for information on the 6T winding at 60V to see how high RPM affects this motor..

0.5mm lamination version: 327.7W at 764 rpm
0.35mm lamination version: 243.0W at 749.7 rpm
0.27mm lamination version: 220.3W at 760rpm

The no load watts difference between the 0.27 and 0.35 would be about 10% if we take the RPM difference in to account.

Peak power tested on the 0.35mm was 2123W at 78.9% efficiency..
Peak power tested on the 0.27mm was 2146W at 80% efficiency..

I think they were wimping this motor out by testing it only to 35A. But i understand that it cannot hold 35A all day. At 80% efficiency, it would need to shed 450W of power. I believe that peak power delivery would be higher, but the thermal limit this motor has isn't going away.
In other words, i'm sure the 0.27mm can be pushed to deliver even more power to the wheel in bursts.. but it's ability to shed the heat hasn't improved... so despite the efficiency gain, you're still kinda up against a wall there.

For regular in wheel applications, i'd imagine that the new thinner laminations might make a 1-2% difference in efficiency/power in a 26" wheel or so. When it comes to a 20" or smaller wheel on high voltage, or a 2:1 reduction running the motor at ~850rpm ( 72v approx ) to the rear wheel, then you are going to see the thin laminations really start doing their thing. Then, this is more like a large RC motor.

We still want the BIG MAC, but this new style motor might have some interesting uses..