BIG BLOCK alternative Motor

The first page of this thread contains photos of the motor opened up, and quite a lot of information posted by Crossbreak and BZH.
From memory (don't trust me.. check for yourself) it has 12 magnets on the rotor, 18 coils in the stator = 3 phases of 6 poles each, so is a 6 pole motor.
One day soon I will have time to get mine going. When that happens I will be sharing impressions and data on this thread and my own build log.
Regards,
Drum
 
Drum said:
it has 12 magnets on the rotor, 18 coils in the stator = 3 phases of 6 poles each, so is a 6 pole motor.
Click to expand...
The fundamental frequency relates to the rotor poles. With 12 magnets, it's most likely that it has 12 poles (6 pole pairs).
 
Miles said:
Drum said:
it has 12 magnets on the rotor, 18 coils in the stator = 3 phases of 6 poles each, so is a 6 pole motor.
Click to expand...
The fundamental frequency relates to the rotor poles. With 12 magnets, it's most likely that it has 12 poles (6 pole pairs).
Click to expand...

This is probably correct in this case, however it is worth knowing about so-called Fractional Pole PMSM configurations (more common in hub motors):

https://hal.archives-ouvertes.fr/hal-00623643/document
 
Sure. The usual reason for the number of magnets not equating to the number of poles is that the poles are segmented (axially or circumferentially) to reduce the eddy current losses in the magnets from sub-harmonics in the MMF.
 
Old motor
https://drive.google.com/open?id=0B1RLHnDGi5iXdjZMbG1oSVZUY2M

New motor
https://drive.google.com/file/d/0B1RLHnDGi5iXSDQtWVFiUlpWelU/view?usp=sharing
 
Maybe I am too stupid, but how do I get the regular or the high pole ?
Or asked the other way round: What do I get if I order this one:

http://e-bike-diffusion.com/index.php?module=produit&prd_id=509&url_retour=http%253A%252F%252Fe-bike-diffusion.com%253A80%252Findex.php%253Fmodule%253Dcategorie%2526code_cat%253D24%2526page_start_num%253D1

Thanks for enlightening me :roll:
 
Yeah, Felix, I'm not sure if Cross meant that as an answer to your question or not, but basically:

BLDC BRUSHLESS DC MOTOR 48V 1000W
High efficient brushless motor for Electric car, electric motorcycle
Length (height): 114mm Diameter: 137mm
RPM 1600 weight 5.250Kg
Sporcket 8T type 420 Pitch 12.70mm

-Small Vehicle：E-bike, E-motorcycle, Golf car, Sport car, cleaning car E-car etc...

different types of assemblage
Click to expand...

From the two pieces of information you extrapolate that this is going to be 33-35kv. 1600rpm coming from 48v. At 72-96v the rpm goes up to a more commonly used range, I don't want to make the value judgement personally but a lot of people see it that way.

But I'm not sure I agree with that website calling it a "Sportscar" motor.
 
as posted earlier, the BHT 12pole 35kv can be used in delta with 48V as well. It runs fine like that as most motors. It then has 35*1.73= 60 kV. But you can only run it sensorless without fitting new halls. So if you want to run 48V-sensored you should ask someone to get you a 70kV motor or ask how exactly to order

about the rpm i can just tell my opinion. driving a 35kV with 48V just gives you 1600rpm no-load. you'd think about a 4:1 reduction chain so it gets you to 400rpm@wheel. this is 50kph for a 26" wheel. sound just fine for a off-road bike. but that's really low reduction for such a motor, you will experience low no-load loss but also not so many continuous-watts-output-power. It gets hot fast during acceleration. If you have a recumbent that shall use little energy and goes mostly on the flats, then this choice fits just fine (or even lower reduction), but if you want an off-road-bike with lots of torque then you should think about higher voltage or more kV. Which both - of course- comes with higher reduction ratio. Like 5:1 or higher

Higher reduction ratio leads to much reduced copper loss. It's a quadratic relationship. This means that a 4:1 reduction ratio will suffer double the copper loss (and thus double motor heat on hills) compared to a 4*√2= 5.64 :1 reduction ratio. 5.64 :1 is still realistic with the #219 chain, for example 14T:80T. Both 14T and 80T sprocket can be bought off-the-shelf for #219 chains

So what you will see is: with 5.64:1 reduction you will see just 5.64/4= 1.41 times the no load loss (or 1.5 times with eddy current loss that rises, too). 41% seem acceptable if copper loss is cut in half on hills/acceleration. Copper loss is major during hill climbing and acceleration. No load loss is important when going straight for long periods. hope i could help you on your motors and reduction choice as i dont even know what kind of bike you want to built :D

my proposal: make an excel sheet and compare three different reduction ratios and motors against each other. You can calc on loss using the equations miles gave us, if you have more questions just ask. then choose what fits your needs most. Choosing this is always a compromise on efficiency, torque, persistence and price
 
Thanks for the quick reply, but I am still not sure what I will get. There seem to be 2 types of this motor. An 8 magnet and a 12 magnet one (see picture for the 8 one and compare with the pictures of the 12 above). My current bike runs with a revolt 100Pro with halls and kelly kbx at 20s. Max.Speed is at 80km/h. 25% uphill is a piece of cake. Motor gets slightly warm. Pretty good so far.
The downside is, that when taking steeper hills or stairs or even steeper (which we have a lot here), the speed slows down rapidly and the motor gets hot, smoking hot to say. Long story short: That thing needs a 2 speed shifter which I would like to place into the motor. Plus...when CNC ing that thing anyway I would like to give the oil cooling from the beginning of the thread a try. I just want to make sure that, if I order the motor through the link above I will not get the 8magnet guy.
Or am I still too stupid :) Thanks !!
 

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either i still dont get what u want or u cant read. 1st post on page 1:

crossbreak said:
bzhwindtalker said:
If someone is searching for a big block GNG style motor, this seems to be a good solution (just received and mesured)
http://e-bike-diffusion.com/index.php?module=produit&prd_id=509&url_retour=http%253A%252F%252Fe-bike-diffusion.com%253A80%252Findex.php%253Fmodule%253Dcategorie%2526code_cat%253D24%2526page_start_num%253D1
Has 50mm long x 80mm diameter rotor, small lams (quite rusted on mine...) big phases to boot and 120mm inner case diameter
1899895_10152248703114617_2130819906_n.jpg


150€ shipped via air mail is not bad at all!
Click to expand...

Awesome, it has 12magnets! [...]
Click to expand...
 
I copied the picture above (incl order-link) some month ago from a thread somewhere here.
The link is identical to the one for the high pole version (1st post here).
Means: Same order link points to 2 different motors.

Reasonable question: Which version will I get ?

Unfortunately I don't find the post anymore, but if you check the LMX P2 thread (which uses the same motor) you will find a picture which looks like the 8 pole.
 
From the technical specs absolutely, would be a great thing, but no option for me. It is not a bit waterproof. :cry:
I will order one of those bht as a baseline for experimenting with the oil cooling and 2 speed.
Once I get it, I will launch a thread.

Does anybody more internal measurements ? Or Cad ? Or at least a good photo ? Diameter and length of rotor was 80 and 50.
So I could start with some 3d prints.

Thank's !!!
 
Can anyone tell me how many phase amps and Rated Current folks are running this (BHT) motor at?
I am using an 18 FET 4110 Low RDS Overclocker Ready LYEN Edition Controller
And 20s 9p 18650's.

Thanks!
 
+1
I can only say that 60amp at 72v constant is way too much :twisted:
I ran it at this for maybe 3/4 a mile testing it in a fat bike and it got too hot to touch.
I had to turn the amps up to get things to spin. :roll:
I since disassembled to use the motor in a cx450. building...

Just checking Allinv:
What was your Phase/Hall combo?
Are you spinning your motor clockwise or counter?
Are you using a Ca v3 with it? If so what did you set the shunt for the 18fet at?

To try and answer your question from what I have read on here though.
People have given this motor about 4500w peak capability and about 1500w constant capability.
I would (and this is what I'll do next time) start out lighter duty.
I would run battery amp level at the 1500w continuous and phase amps at the peak 4500w.
Since your 20s to me this means 80v.
So 1500w/80v=18.75 battery amps. I'd do 20amps.
Then 4500w/80=56.25 phase amps. I'd just do 55amps
(Which by the way is 1:2.75 close to the 1:2.5 ratio that some like and china has pretty much standardized in there cheap controllers.)
I'm not experienced enough to make a judgment call on the ratio one should use, and this application will have it's own unique circumstances, but I think I would/will start out with this, but turn the phase amps down to 50.

So then ride it at that power level and get one of those lazer temp guns to measure the case temp.
I am not even going to try and guess what the correlation between the case and the winding temp would be but hopefully some one will pipe up who knows something about it...
Then keep slowly turning up the battery amps till either it matches phase or it gets too hot.
(others feel free as always to pipe up if this seems like a bad idea)

A LOT Depends on your reduction ratio.
Some have run 4:1 with success but some have gone though thorough explanation on the advocacy for 5:1.
Wheel size is a factor too.
 
what hall phase combo are you using???
Just no loaded the motor with the 18fet at 21s.
Was seeing 5 amps on the CA v3 and it ran funny. shunt at 1.33
green and yellow switched around as well as halls.
 
Unloaded mine ran rough w/ colors matched on em3 infineon. I switched one phase (yel/ green) and when it still spun in proper direction (CW) I then started swapping halls. That was also yel/green. JohnCR has a better explanation in the wiki I think.
Don't overload it when testing or you could fry stuff! Also, maybe eliminate ca until it is running smoothly, although when running speed throttle shunt value shouldn't be a big deal. I left mine hooked up to monitor and did throttle direct to controller for testing.
 
Haha Oops!
So how I had it must have worked but poorly.
I matched all the wires hall and phase and it ran like a top.
Thing sounds cool as heck.
I don't think all infineons have the same color corresponding phases.
Can't wait to get it in the mongoose cx.
I might as well take it apart and get the shaft machined for a #35 sprocket 5/8 ID.
See if there is any burnt shellac coating too.
 
Diggler, thanks very much for the advice on the settings.
I'm in Ohio, so it will be a while before I can do some more experimenting (it finally got cold here [well, probably not as cold as Minnesota]).
Unfortunately, I don't have a CA.
With my Lyen controller the motor runs forward nicely (ccw viewed from the end opposite the shaft) with ALL the colors coordinated.
But since I am running it on the left side of my mongoose cx, I had to reverse it.
By trial and error I ended up leaving the phase green to green, and the hall yellow to yellow (swapped the others).
I am running an 8 tooth sprocket on the motor, and 30 on the 20" rear wheel, but I will be going bigger when I get back to working on it again.

I would also like to extend my swingarm and run a bigger wheel on the back.

Some pics:
IMG_1841_800.jpg
IMG_1844_800.jpg
IMG_1842_800.jpg
 
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