Bafang rear geared brushless test

[mingonn]

Hi Doc,

I measured the current draw on my Bafang 36v 20" hub tonight, it pulls a measly .8 amp at 48v full throttle unloaded and spinning hard. That is less than my DD motor!

Something is definitely amiss with your set up if you are pulling 12A with the wheel off the ground.

Derek

 

[docnjoj]

Hi Doc,

I measured the current draw on my Bafang 36v 20" hub tonight, it pulls a measly .8 amp at 48v full throttle unloaded and spinning hard. That is less than my DD motor!

Something is definitely amiss with your set up if you are pulling 12A with the wheel off the ground.

Derek

Hey Derek

I hope not but it is the geared version. I'll know 4 sure when I get the new Kewin/Knuckles controller. It's on its way! I too was surprised at the high no-load, but its still possible the Crystalyte controller isnt correct. I played the matching game for all 36 combos, and 3 worked "fine". The motor started right up and rotated the right way, and during use it seems to run OK with minimal heating!?!?!?!?! So we will soon see. I will be real impressed if it exceeds its current (no pun intended) operational working capacity. Hope springs eternal!
otherDoc

 

[mingonn]

Doc,

Mine is definitely geared, I got Keywin to send me 2 extra sets of planetary gears just in case. Can't believe how smooth this thing is and the freewheel is great compared to my DD motor. Fingers crossed it performs in situ.

Derek

 

[docnjoj]

Yours is geared??????? And only pulls 0.8 amps free??? Gulp! I guess something is amiss, to say the least, with my setup Alright, experts (Fecther, Knuckles, et al) I waz humbly WRONG! If the controller doesnt change amp draw, I gotta do surgery on the motor!
otherDoc

edit again: Maybe those startup howls arent supposed to be there!?????

 

[mingonn]

Is you controller for a 120 degree phase? My bafang runs on 120, I tried on the other setting (60 degrees I think) but it would barely run.

No startup howls either just smooth and quiet all the way. Hope the controller does the trick.

Derek

 

[docnjoj]

The old Crystalytes only run 120 deg. I believe! And it runs kinda OK! If I didnt accidentally try the unloaded run, I might not have known anything was wrong, except for the startup growls! I figured this was just breaking in of the gears! Oh well! Live and learn!
otherDoc

 

[dnmun]

doc, have you had any trouble with loose spokes or breaking spokes on your 20" rim? how long are the spokes for a single cross in a 20" rim like you have set up? did you consider 13 or 12 gauge spokes, and how tight would they be in the bafang flange spoke holes?

i am gonna try to lace up a front hub in a 20" rim on an actionbent lowracer. what brand of rim did you use? how steep is the angle at the rim and did you have to drill them at all? is that why you went with the single cross?

thanks a lot, dm

 

[Knuckles]

I tested the Bafang PMGR no-load at 88V on the 45 amp Infineon. It was drawing almost 5 amps but was spinning so fast I thought it would fly off the upside down bike! This was ludicrous speed test but still NO WHERE NEAR 12 amps. It was truly a sick test at 88V. Rotor RPM must have been several thousand RPM. I've never seen a motor spin so fast! YIKES!

-K

btw ... spare gears here ...

 

[John in CR]

Knuckles,

My question is, did you flip it over and ride it at 88v? Dare I run mine at 90v when it gets here, or do I just feed it with it's own 72V and go with 90V on the speed DD hub in front for some thrills?

John

 

[docnjoj]

To answer dnmun: Since I dont believe in spoke breakage, Ive been able to use lighter and high quality spokes. I use 14 ga (2mm) forged or stainless from either Danscomp or Gaerlan Cycles. I have never had a spoke break on any bike I have ridden. Yes, sometimes I ride hard! After dealing with those inferior 12 ga from various Chinesemanufacturerers and drilling and filing< I chose not to play! I lace in 1x and use my LBS to true rims. I try to use Alex or Sun rims. This is for 20 and 16 inch wheels, as I havent ever done a 26 or 700C. Knuckles measured 138 mm spokes om AutoCad, but i had 140s so I used those and they are fine. The Bafang holes are a little big, so spoke washers might be a good idea for higher power. I wont need to go above 48 volts for my trike.

To Kmuckles: The motor seems fine except for minor probs like takeoff, and is riding 8-10 miles 4 times a week pushing 300 lbs! The Infineon is coming! Im sorry my free running amps are more than your amps! In regular use the amp draw is normal!!! Im only running 42 volts!
otherDoc

 

[Knuckles]

Knuckles,

My question is, did you flip it over and ride it at 88v? Dare I run mine at 90v when it gets here, or do I just feed it with it's own 72V and go with 90V on the speed DD hub in front for some thrills?

John

NO WAY JOS'E

Heck ... The Bafang is only 6.7 lbs! It can do 30 MPH. But really! It is just an AWESOME LITTLE MOTOR! And BETTER at low RPM torque than a DIRECT DRIVE.
But a geared motor is DIFFERENT than a DD motor. They perform differently and do different tasks!

IMHO

 

[Knuckles]

To answer dnmun: Since I dont believe in spoke breakage, Ive been able to use lighter and high quality spokes. I use 14 ga (2mm) forged or stainless from either Danscomp or Gaerlan Cycles. I have never had a spoke break on any bike I have ridden. Yes, sometimes I ride hard! After dealing with those inferior 12 ga from various Chinesemanufacturerers and drilling and filing< I chose not to play! I lace in 1x and use my LBS to true rims. I try to use Alex or Sun rims. This is for 20 and 16 inch wheels, as I havent ever done a 26 or 700C. Knuckles measured 138 mm spokes om AutoCad, but i had 140s so I used those and they are fine. The Bafang holes are a little big, so spoke washers might be a good idea for higher power. I wont need to go above 48 volts for my trike.

To Kmuckles: The motor seems fine except for minor probs like takeoff, and is riding 8-10 miles 4 times a week pushing 300 lbs! The Infineon is coming! Im sorry my free running amps are more than your amps! In regular use the amp draw is normal!!! Im only running 42 volts!
otherDoc

Are you running the new controller yet?

I can't wait. Is there a Hall problem? Maybe I am cross-posting here.
Gosh. I want to know if there is happyness of Sadness!

-K

 

[John in CR]

Knuckles,

My question is, did you flip it over and ride it at 88v? Dare I run mine at 90v when it gets here, or do I just feed it with it's own 72V and go with 90V on the speed DD hub in front for some thrills?

John

NO WAY JOS'E

Heck ... The Bafang is only 6.7 lbs! It can do 30 MPH. But really! It is just an AWESOME LITTLE MOTOR! And BETTER at low RPM torque than a DIRECT DRIVE.
But a geared motor is DIFFERENT than a DD motor. They perform differently and do different tasks!

IMHO

Knuckles,

Okay, how to do you suggest I set up my 2wd with DD front and Bafang rear, batts and controllers? I'll supply 80-90V at full charge for running the DD. A simple solution, at least in my mind, is to use just one big pack, 2 controlers, and 2 throttles. Then I just need to always get off of the Bafang throttle at 30mph or less, using the only the DD at higher speeds. Typically use only the Bafang on hills, so I don't push wasteful amps and heat up the DD unnecessarily. Then on flat road acceleration use the throttle to fit my mood, though I have little doubt that much of the time I won't be able to resist goosing it with both throttles. If this rig ends up as a permanent setup, then I can use dual CA's too, and protect the Bafang using a speed limit for it.

Is it just the high speed that could be destructive for the Bafang? How is it laid out on the inside? Are the magnets essentially lining the inside of a spinning metal cylinder like a DD, or are the magnets spinning inside the circumference of the windings with epoxy holding the magnets from flying off and hitting the windings? The reason I'm asking is that I want to understand the point of weakness at high speed. I obviously don't want to destroy the Bafang, but since I'll have an extra set of gears, I don't mind being the guinea pig and exploring the limits if its the gears that will fail before anything else gets hurt. I firmly believe that my 2wd on demand rig using each motor only for what it does best to create intermittent use for both, will be a significant weapon in the war against that ever present enemy, heat.

John

 

[docnjoj]

To answer dnmun: Since I dont believe in spoke breakage, Ive been able to use lighter and high quality spokes. I use 14 ga (2mm) forged or stainless from either Danscomp or Gaerlan Cycles. I have never had a spoke break on any bike I have ridden. Yes, sometimes I ride hard! After dealing with those inferior 12 ga from various Chinesemanufacturerers and drilling and filing< I chose not to play! I lace in 1x and use my LBS to true rims. I try to use Alex or Sun rims. This is for 20 and 16 inch wheels, as I havent ever done a 26 or 700C. Knuckles measured 138 mm spokes om AutoCad, but i had 140s so I used those and they are fine. The Bafang holes are a little big, so spoke washers might be a good idea for higher power. I wont need to go above 48 volts for my trike.

To Kmuckles: The motor seems fine except for minor probs like takeoff, and is riding 8-10 miles 4 times a week pushing 300 lbs! The Infineon is coming! Im sorry my free running amps are more than your amps! In regular use the amp draw is normal!!! Im only running 42 volts!
otherDoc

Are you running the new controller yet?

I can't wait. Is there a Hall problem? Maybe I am cross-posting here.
Gosh. I want to know if there is happyness of Sadness!
-K

Thanks Knuckles! Still on the Crystalyte and it is still running OK. The Infineon just cleared HongKong! Cant wait! Prolly gotta get a bigger than 25 amp fuse

 

[dnmun]

doc, i am looking at the Alex DA24 20" rim, is that the one you used? does sun make the rhyno lite in a 20"?

i think you have the hall sensors miswired if you are pulling 12 amps unloaded, where is the thread where someone figured out the wire colors? was that knuckles who did that? that may be why you get the noise at start up, but someone else mentioned on another thread that the shudder could be from the controller shutting down rapidly when it detects overcurrent, resetting repeatedly, and the rapidity appears as the shudders of the motor. just observing from a distance though.

 

[docnjoj]

Thanks dnmun! Ill look at the wiring AGAIN! Yes to Sun 20" rims. They make several! Gaerlan Cycles has em and obviously other places!
otherDoc

 

[docnjoj]

Wiring same as I AM OZ but different motor and controller. Bike really runs well and is in daily use so I need the "known good" at this point to rule out the controller. Infineon (known good) is on its way, but I will be stunned silly if there is a controller/halls fault at this time! Unfortunalely I have been stunned silly before!
otherDoc

 

[John in CR]

Doc,

I'd suggest more than "looking". Try all 6 combinations. I thought I had my hub motor wired right when it spun well with a little groaning on acceleration, but the wiring was wrong. On the other hand, with Infineon in route, you get it handed to you on a silver platter with no trial and error, just patience. I get my Bafang and Infineon at the same time...lucky me.

John

 

[docnjoj]

Thats what I needed to hear! Thanks, John!
otherDoc

 

[Knuckles]

I wait with baited breath!

 

[docnjoj]

U mean uve been eating worms?
otherDoc

 

[docnjoj]

Just and update! The Infineon has just left Jamaica, NY to head south! Yippee!
otherDoc

 

[Knuckles]

On the other hand, with Infineon in route, you get it handed to you on a silver platter with no trial and error, just patience. I get my Bafang and Infineon at the same time...lucky me.
John

NOT TRUE!

ALWAYS USE THIS METHOD!

http://endless-sphere.com/forums/viewtopic.php?f=16&t=3484#p81888

YOU MUST ALWAYS ALWAYS ALWAYS ALWAYS ALWAYS ALWAYS ALWAYS ALWAYS ... DO THIS!

The only exception is if you buy a MOTOR and CONTROLLER from me together.

Then I do it for you.

(btw John ... I did NOT tweak the hall connector (I forgot) so YOU must ALSO do it TOO! ... Oops ... My Bad! :wink: )

Do it Baby! Do it till your Satisfied!

-K

 

[John in CR]

On the other hand, with Infineon in route, you get it handed to you on a silver platter with no trial and error, just patience. I get my Bafang and Infineon at the same time...lucky me.
John

NOT TRUE!

ALWAYS USE THIS METHOD!

http://endless-sphere.com/forums/viewtopic.php?f=16&t=3484#p81888

YOU MUST ALWAYS ALWAYS ALWAYS ALWAYS ALWAYS ALWAYS ALWAYS ALWAYS ... DO THIS!

The only exception is if you buy a MOTOR and CONTROLLER from me together.

Then I do it for you.

(btw John ... I did NOT tweak the hall connector (I forgot) so YOU must ALSO do it TOO! ... Oops ... My Bad! :wink: )

Do it Baby! Do it till your Satisfied!

-K

This is just a joke, right? You really can't tell me the color codes to match the motor and controller you sell? Since it's a geared hub with freewheel, there's only one correct combination, unlike direct drive hubs that can have 2 depending which way you mount it. Are they at least consistent from the factory, so I can share the color code once I figure it out? Not only should you guys provide the color codes, but the next step would be matching connectors and testing before shipment, so it's plug-n-play upon arrival. It's not a big deal for some of us, but for most it is. You have to keep in mind what it was like to be a noob, and part of our responsibility as pioneers is to make it easier for those who follow.

John

 

[Knuckles]

John,

You have different motors ... YES?
You have DD and geared now from different manufacturers

So how can I know what controller you will choose with what motor!
When I sell a "kit" they work in harmony.

But you now have a menagerie of goodies so colors don't mean sh*t any more.
You can mix and match all you like. That is OK. Just remember what combo works for what motor!

Hell ... X-Lyte is the same thing! THERE IS NO STANDARD! DON'T SHOOT THE MESSENGER BRO!

Good Golly Miss Molly! Don't you get it yet?

SHEEEET!

Just ask me first. I will solve any problem you have in like 5 seconds. DON'T MOD ANYTHING! Just check with me first! OK? 8)

BLDC Controller Prayer "OH Lord ... They Know Not What They Do"