MidMacMod (Mid-drive Mac motor Mod)

[j3tch1u]

damn. and i thought i had the coolest mac mid drive converted bike
that's a very nice piece of art. very well done. i'd like to ride it and compare it to my bike. how is motor noise (not the fans)? i'm REALLY happy with my motor (can't get it over 90°C even riding it at 2kW+ for over an hour) but the high pitch noise is all but stealthy. could you please post a video with the motor running alone, and one with the whole drivetrain + chain connected.

wow fantastic build hannes! the powder coating is top notch and i really like the cnc grille. i'd highly recommend my friend's FOC controller for your bike. we are still working out some bugs. the FOC runs fine on DD hub motors, but the "play" in mid-drive geared motor systems throws off the torque interpolation during start. got a fresh firmware build to test tonite that hopefully solves this issue

 

[j3tch1u]

The crank freewheel made from the MAC's internal freewheeling sprag clutch is brilliant. izemans MAC mid drive was using 3000W-ish and sometimes the clutch would get stuck (fixed in both directions). He lowered the power to 2,000W and it is reported to be running fine ever since. https://www.electricbike.com/hannes-crossbreak-style-mid-drive/

Regardless of the power used, I am interested in a silent freewheeling BB crankset. In the izeman/crossbreak configuration, the motor bypasses the crank freewheel, so using a high-powered but "clicky" and expensive ENO in the crankset would no longer be necessary, but...as the rest of a drive gets very quiet, it is a nice luxury to have an almost silent system. The MAC clutch being re-purposed for a freewheeling crank would be overkill for a crossbreak-style, but...they are only $25 (plus tax/shipping) http://em3ev.com/store/index.php?route=product/product&path=44&product_id=110

i wouldn't give up that easily. they might be getting stuck because the springs are getting wedged between the carrier and are unable to push the pawls back in place. in my clutch, i upgraded the 4mm long springs to 6.5mm springs (0.2mm wire, 1.4mm diameter) to increase the contact pressure, decrease the engagement time and prevent slippage from shock/vibration. they sound really gnarly when they slip. over time, slippage will damage the delicate springs and pawl carrier. the bearing surfaces will be fine. they are surface hardened and super tough (i know because i tried unsuccessfully to drill through them).

 

[izeman]

having a 2k+ post count and still not knowing what FOC stands for: could you please tell me and/or post a link? i also don't understand what 6-step stands for?! i guess than i could enjoy your build even more
i'm not sure that the noise comes from the controller. my motor sounds similar to yours. at the moment i'm using spinningmagnet's motor, and now that i know what to take care when doing the conversion i will start a new conversion soon with a new mac motor avoiding some issues i had.
i was discussing your build with a colleague at the office and we both couldn't find the right side bearing to support the bottom bracket axle. and the video shows it clear: there is NONE. are you sure that the sun gears can take the load without support on the right side? i'm not sure this will work for long. i hope i'm wrong and i just overlooked something ...
thanks for the thumbs up. every time i look at the paint job i'm amazed how good it is. and the whole job was €68.- taxes included. spray cans would have been more expensive.

 

[j3tch1u]

but...as the rest of a drive gets very quiet, it is a nice luxury to have an almost silent system. The MAC clutch being re-purposed for a freewheeling crank would be overkill for a crossbreak-style, but...they are only $25 (plus tax/shipping) http://em3ev.com/store/index.php?route=product/product&path=44&product_id=110

completely agree ron. if you are running a noisy infineon or kelly, i wouldn't bother. but if you had a nice quiet sinewave controller...then the clicking/whizzing would really be pronounced. can't beat the price of that Mac clutch. i could ask Paul to get them cheaper without the gears and pins. still a bit on the heavy side though.

 

[j3tch1u]

having a 2k+ post count and still not knowing what FOC stands for: could you please tell me and/or post a link? i also don't understand what 6-step stands for?! i guess than i could enjoy your build even more
i'm not sure that the noise comes from the controller. my motor sounds similar to yours. at the moment i'm using spinningmagnet's motor, and now that i know what to take care when doing the conversion i will start a new conversion soon with a new mac motor avoiding some issues i had.

hannes, too much to cover in one post, but this might be a good starting point:

http://endless-sphere.com/forums/viewtopic.php?f=2&t=62693&p=948608&hilit=field+oriented+control#p948608
http://en.wikipedia.org/wiki/Vector_control_(motor)

Field Oriented Control (sine wave) generally drives the motor quieter and smoother than 6-step (square wave or trapezoid). the noise will not be at the controller...it will come from the electrical pulses made inside the motor.

 

[j3tch1u]

i was discussing your build with a colleague at the office and we both couldn't find the right side bearing to support the bottom bracket axle. and the video shows it clear: there is NONE. are you sure that the sun gears can take the load without support on the right side? i'm not sure this will work for long. i hope i'm wrong and i just overlooked something ...
thanks for the thumbs up. every time i look at the paint job i'm amazed how good it is. and the whole job was €68.- taxes included. spray cans would have been more expensive.

everything is fully supported. the entire right side that rotates (BB spindle, output flange, crank, crank freewheel, chainring, internal clutch) are all locked together axially and supported by a large skirt bearing in the right cover. i had left/right mixed up in some of the prior posts so that might have thrown you off. the BB spindle is supported by a bearing in the stator bridge that is locked to the left cover. the rotor (and sun gear) are supported by the large bearing in the stator (unchanged). :wink:

 

[izeman]

so why don't you just say SINE WAVE? it was just the unknown acronym FOC. so you're building your own? maybe make it small enough that it fits into the infineon 9fet case and i'll buy one. 8)
can you give a estimate how much especially the MAC's noise is related to the controller type used? i know that DD motor profit a lot from it, but i must say i can't really hear my HS3540 when riding as wind and tire noise is much louder. i guess what you hear from the MAC is the spur toothed sun/planet gear set. what do you think? i hope it's ok to discuss this in this thread. i don't want to hitch hike your thread!

 

[j3tch1u]

i used to say sinewave until i was corrected by my friend. FOC is the correct term...not all sinewave controllers are FOC (buyer beware!) but usually FOC is outputting sine wave. it is around same length as 12fet infineon and twice the width. the controller was designed by my friend's company. i am just testing the prototype and helping diagnose bugs. i would say 90% of the sound is from the electrical phase pulses (not much from the clutch). the chain and clutch is quieter when it is under load (unlike in my video). i would say your mid-drive Mac driven by FOC would be quieter than your HS3540 driven by 6-step.

so why don't you just say SINE WAVE? it was just the unknown acronym FOC. so you're building your own? maybe make it small enough that it fits into the infineon 9fet case and i'll buy one. 8)
can you give a estimate how much especially the MAC's noise is related to the controller type used? i know that DD motor profit a lot from it, but i must say i can't really hear my HS3540 when riding as wind and tire noise is much louder. i guess what you hear from the MAC is the spur toothed sun/planet gear set. what do you think? i hope it's ok to discuss this in this thread. i don't want to hitch hike your thread!

 

[izeman]

that's a huge controller. what's the cont/max power it's designed to deliver? where would you place a controller that is double the wide of an infineon? too sad that i can't hide that somewhere on my bike. i wish i could try one out and see if it really helps, i guess coming to taiwan just for a test is a no-go.

 

[j3tch1u]

that's a huge controller. what's the cont/max power it's designed to deliver? where would you place a controller that is double the wide of an infineon? too sad that i can't hide that somewhere on my bike. i wish i could try one out and see if it really helps, i guess coming to taiwan just for a test is a no-go.

200A peak phase current, 150A peak battery current. it's very compact given its power output. this is their smallest model. the largest is 400A peak phase.

the actual dimensions are: 160mm (L) x 120mm (W) x 49.5mm (H)

 

[izeman]

sure, for this output it's super small. but all i need is a 45a cont battery and maybe 70a phase max. maybe i can find a FOC controller for that that is small enough.

 

[j3tch1u]

sure, for this output it's super small. but all i need is a 45a cont battery and maybe 70a phase max. maybe i can find a FOC controller for that that is small enough.

you could get an adappto mini-e or wait for justin's controller. it should be quite sweet:
http://endless-sphere.com/forums/viewtopic.php?f=30&t=56680&p=921618&hilit=field+oriented+control#p921618

 

[j3tch1u]

noise test 6-step commutation vs Field Oriented Control

pure 6-step:
[youtube]UWW8mDPNyuU[/youtube]

6-step start followed by FOC (kicks in after 10kph)
[youtube]0ld4kJQFGyA[/youtube]

 

[izeman]

there is really a noticeable difference. a lot quieter. thanks.

 

[waynebergman]

Wow thanks for posting that comparision with the Field Oriented Control test. Its hard for me to understand how all that motor noise can be silenced by a different controller like this, amazing. I will pass this on to the guy that bought my mac mid drive conversion so he can see his options should he want to silence the motor.

 

[j3tch1u]

Wow thanks for posting that comparision with the Field Oriented Control test. Its hard for me to understand how all that motor noise can be silenced by a different controller like this, amazing. I will pass this on to the guy that bought my mac mid drive conversion so he can see his options should he want to silence the motor.

the difference is even more noticeable when your are on the bike (human ears vs recorded audio). noise aside, the acceleration is way way smoother. once you try it, you won't ever wanna go back.

 

[j3tch1u]

where would you place a controller that is double the wide of an infineon? too sad that i can't hide that somewhere on my bike.

i will be using these on my Dogati and Duty Cycle (dual) production bikes (see my sig for the links). On the Duty Cycle, they will be bolted with their heatsinks back-to-back leaving a small air-gap for cooling. I will ask my friend for permission to post some pics of the controller.

 

[j3tch1u]

here is the final stage of this build.

using the drive mounting shell, i traced a cardboard template for cutting the frame. the motor drive is mounted slightly forward from the original BB axis so that i wouldn't need to cut off the cross-tube on the chainstay (and keeps the rear triangle aligned). the shell is also welded to the cross-tube for added rigidity.

i used the template to draw outlines on the tubes (on both sides) and joined them by eyeballing it at 90 degrees. i used an angle grinder to cut and shape the "fishmouths". this process was easier and quicker than i imagined.

before welding, i installed the bare hub shell and side covers to prevent the mounting shell from deforming. then i clamped the drive in a vice, squared up the frame and proceeded to tack weld. after it cooled, i welded the rest of the frame. no fixtures were necessary. went kind of overboard on the welds as you can see in the picture. ugly but very strong.

 

[j3tch1u]

some shots of the drive before it was mounted:


View attachment 5


mounted:

 

[spinningmagnets]

Wonderful design!...and very professional execution of the details.

 

[Hellscreeper]

I love it! That a real artwork E-bike.
I dont know if that possible, to get a patent for your invention.

 

[j3tch1u]

I love it! That a real artwork E-bike.
I dont know if that possible, to get a patent for your invention.

i don't believe in patents. they stand in the way of true innovation and are part of the problem of our cyclical consumption, artificial scarcity, monetary driven, socially divisive based anti-economy. i say anti-economy because it reinforces waste and there is nothing economical about it.

 

[liveforphysics]

I love it! That a real artwork E-bike.
I dont know if that possible, to get a patent for your invention.

i don't believe in patents. they stand in the way of true innovation and are part of the problem of our cyclical consumption, artificial scarcity, monetary driven, socially divisive based anti-economy. i say anti-economy because it reinforces waste and there is nothing economical about it.

Awesome!! Preach it brother!

 

[macribs]

I love it! That a real artwork E-bike.
I dont know if that possible, to get a patent for your invention.

i don't believe in patents. they stand in the way of true innovation and are part of the problem of our cyclical consumption, artificial scarcity, monetary driven, socially divisive based anti-economy. i say anti-economy because it reinforces waste and there is nothing economical about it.

I hear you bro! I totally agree. Luckily the next gen seems to be more open to the idea, and em young ones have strong feelings against patent trolls, and patents in general. And there is some companies that slowly turn around to the idea of sharing knowledge. Then there is companies that really are leading the way, like Tesla made all their patents available. Breweries are sharing their receipts and even yeast cultures. In time I think people will look back and view our time as the dark ages of waste and development.

Sharing is caring

 

[j3tch1u]

great 1000th post macribs!

I love it! That a real artwork E-bike.
I dont know if that possible, to get a patent for your invention.

i don't believe in patents. they stand in the way of true innovation and are part of the problem of our cyclical consumption, artificial scarcity, monetary driven, socially divisive based anti-economy. i say anti-economy because it reinforces waste and there is nothing economical about it.

I hear you bro! I totally agree. Luckily the next gen seems to be more open to the idea, and em young ones have strong feelings against patent trolls, and patents in general. And there is some companies that slowly turn around to the idea of sharing knowledge. Then there is companies that really are leading the way, like Tesla made all their patents available. Breweries are sharing their receipts and even yeast cultures. In time I think people will look back and view our time as the dark ages of waste and development.

Sharing is caring