Neumotor 8057/75 middrive project, belt drive, adding halls, 10kW+

Electric Motors and Controllers
User avatar
fechter   100 GW

100 GW
Posts: 14716
Joined: Dec 31 2006 3:23pm
Location: California Bay Area, USA

Re: Neumotor 8057/75 middrive project, belt drive, adding halls, 10kW+

Post by fechter » Feb 23 2020 6:56pm

If the hall sensor is located exactly at the middle of the magnet you could have no flux in the direction of the sensor axis (fail). If the sensor axis is off a little from the middle of the magnet, it should work fine.

If you powered a sensor and watched the output while trying different positions you could verify a good signal.
"One test is worth a thousand opinions"

coleasterling   100 W

100 W
Posts: 254
Joined: Sep 21 2010 3:37am

Re: Neumotor 8057/75 middrive project, belt drive, adding halls, 10kW+

Post by coleasterling » Feb 24 2020 12:46am

It is tested and switching well. The slots are slightly longer than the sensors to allow moving them across the thickness, but I didn't end up needing it. Controller testing will happen tomorrow or Tuesday and we'll see for sure. I'll probably throw the scope on it, too.

coleasterling   100 W

100 W
Posts: 254
Joined: Sep 21 2010 3:37am

Re: Neumotor 8057/75 middrive project, belt drive, adding halls, 10kW+

Post by coleasterling » Feb 24 2020 8:23pm

I realized it was somewhat difficult to tune the hall position due to some dumb dimensioning. I reworked the part today for more adjustment range (On gap? Middle of tooth? Somewhere in-between?) and better centering. Don't quite get the relationship between initial hall position and termination yet, other than being 30 degrees different.

Anyway, I made the ID of the ring smaller than the motor mount's hole (instead of larger) and turned a tight-tolerance insert that allows me to tune the hall position without worrying about concentricity until the mounting screws are tightened.The screw in the end of the insert lets me pop it off when tuning is done. I didn't get it fully wired up today since I made the design revisions, but will have it running tomorrow.
Attachments
MVIMG_20200224_185526.jpg
MVIMG_20200224_185526.jpg (464.94 KiB) Viewed 851 times
MVIMG_20200224_185857.jpg
MVIMG_20200224_185857.jpg (406.85 KiB) Viewed 851 times

coleasterling   100 W

100 W
Posts: 254
Joined: Sep 21 2010 3:37am

Re: Neumotor 8057/75 middrive project, belt drive, adding halls, 10kW+

Post by coleasterling » Feb 25 2020 2:46pm

Made yet another revision, this time to allow building of the hall-sensor module off of the motor, and for much better wire routing.

This is after tumbling it to deburr in our 4-foot diameter vibratory tumbler with polyester tetrahedrons.

Edit: I can't change the orientation of the image for some reason.
Attachments
MVIMG_20200225_131547.jpg
MVIMG_20200225_131547.jpg (395.18 KiB) Viewed 826 times

User avatar
nowholeself   100 mW

100 mW
Posts: 42
Joined: Sep 28 2019 12:58pm
Location: Los Angeles
Contact:

Re: Neumotor 8057/75 middrive project, belt drive, adding halls, 10kW+

Post by nowholeself » Feb 25 2020 3:33pm

coleasterling wrote:
Feb 25 2020 2:46pm
Made yet another revision, this time to allow building of the hall-sensor module off of the motor, and for much better wire routing.

This is after tumbling it to deburr in our 4-foot diameter vibratory tumbler with polyester tetrahedrons.

Edit: I can't change the orientation of the image for some reason.
I want one!

User avatar
nowholeself   100 mW

100 mW
Posts: 42
Joined: Sep 28 2019 12:58pm
Location: Los Angeles
Contact:

Re: Neumotor 8057/75 middrive project, belt drive, adding halls, 10kW+

Post by nowholeself » Mar 05 2020 12:59am

My Neumotors 8025 has just arrived. It is so small! My original plan was to attempt to at least match, if not beat, the power of an ASI BAC800 controlled BBSHD. But can something so tiny really do that!?!? Maybe I should have gone with the 8038...

User avatar
fechter   100 GW

100 GW
Posts: 14716
Joined: Dec 31 2006 3:23pm
Location: California Bay Area, USA

Re: Neumotor 8057/75 middrive project, belt drive, adding halls, 10kW+

Post by fechter » Mar 05 2020 9:00am

If you apply a steady current to a pair of phase wires, the rotor will align to a certain spot and this will be exactly where one of the halls should be right at the switching point. By jiggling the rotor a little, you should be able to dial in the position so the hall signal toggles, indicating the timing is neutral. This would be a good starting point for the timing.
"One test is worth a thousand opinions"

coleasterling   100 W

100 W
Posts: 254
Joined: Sep 21 2010 3:37am

Re: Neumotor 8057/75 middrive project, belt drive, adding halls, 10kW+

Post by coleasterling » Mar 05 2020 11:00am

Ah, makes sense. Manual version of setting a digital encoder or resolver.

This solution works quite well...when the halls are functioning. Twice now, I've had the bike running well, then come back and the halls were all shot. Not sure why. They definitely aren't touching anything and there's no physical damage to the halls, mount, or hall harness. It wasn't getting hot enough to kill them, either. Color me confused.

Anyway, nowholeself, if you did want one, I'm happy to send the last one I took photos of to you. I realized there wasn't enough clearance to the stator windings with it, so it couldn't move as much as I wanted. I think the easy solution if you did want it is to just bend the legs slightly out. I haven't been able to tell any difference in function with a bit of angle on the halls. I can't really envision the 3d flux path that makes it work in the first place.

User avatar
madin88   1 GW

1 GW
Posts: 3069
Joined: May 27 2013 2:02am
Location: Austria

Re: Neumotor 8057/75 middrive project, belt drive, adding halls, 10kW+

Post by madin88 » Mar 05 2020 5:51pm

coleasterling wrote:
Mar 05 2020 11:00am
Twice now, I've had the bike running well, then come back and the halls were all shot.
Thats weird. hope you find out what the problem is.
It wasn't getting hot enough to kill them, either.
The holder is made of aluminum so there will be eddy currents, but i hardly think that this small surface area behind the halls would heat up so much to toast them.

coleasterling   100 W

100 W
Posts: 254
Joined: Sep 21 2010 3:37am

Re: Neumotor 8057/75 middrive project, belt drive, adding halls, 10kW+

Post by coleasterling » Mar 06 2020 12:02pm

madin88 wrote:
Mar 05 2020 5:51pm
The holder is made of aluminum so there will be eddy currents, but i hardly think that this small surface area behind the halls would heat up so much to toast them.
Thanks, they definitely weren't significantly heating. I really don't know. Now, I'm not running resistors, but I never have on ss411a's and they've been just fine, even with this exact controller. Strange deal. I'm out of halls now, but might buy more and wire the resistors just to check.

Post Reply