DarylMc
100 mW
Just reversed the motor direction and it dropped the current right back 
Fisher and Paykel motors
- Thread starter TylerDurden
- Start date
DarylMc
100 mW
Hi whatever
It has standard windings and 240V controller.
240V and 0.7A per phase on the motor right now.
There is a massive difference in current depending on the direction of rotation which I assume is due to the positioning of the hall sensor.
I've been using FP motor in a centrifuge for the last 8 years.
It spin dries a large basket of washed lettuce leaves at 600 rpm for one minute.
Previously I couldnt find a suitable brushless DC drive and I was running it without hall sensors from a VFD with careful tuning to allow it to grab sync at startup.
With that arrangement it had virtually zero torque at startup but once it started moving it was fine.
Despite one drive failure during that time it worked really well but I never could get it to run on anything other than the very early motor with small magnets.
I found this brushless DC drive and wanted to give it a go with a more readily available motor.
Baldor BMC6A04 http://www.baldor.com/products/motioncontrol/dc_speed_controls.asp
(dead url, drive not appearing on website anymore)
All seems good now with the standard FP hall sensor.
Fantastic low speed torque and more than enough for its task.
Fingers crossed it will give a good working life.
Thanks for the reply.
It has standard windings and 240V controller.
240V and 0.7A per phase on the motor right now.
There is a massive difference in current depending on the direction of rotation which I assume is due to the positioning of the hall sensor.
I've been using FP motor in a centrifuge for the last 8 years.
It spin dries a large basket of washed lettuce leaves at 600 rpm for one minute.
Previously I couldnt find a suitable brushless DC drive and I was running it without hall sensors from a VFD with careful tuning to allow it to grab sync at startup.
With that arrangement it had virtually zero torque at startup but once it started moving it was fine.
Despite one drive failure during that time it worked really well but I never could get it to run on anything other than the very early motor with small magnets.
I found this brushless DC drive and wanted to give it a go with a more readily available motor.
Baldor BMC6A04 http://www.baldor.com/products/motioncontrol/dc_speed_controls.asp
(dead url, drive not appearing on website anymore)
All seems good now with the standard FP hall sensor.
Fantastic low speed torque and more than enough for its task.
Fingers crossed it will give a good working life.
Thanks for the reply.
whatever
100 kW
- Joined
- Jun 3, 2010
- Messages
- 1,297
thanks for reply, if you ever want to go to low voltage ( 48v) (you can use ebike controllers....dirt cheap) but requires reconnecting windings into parallel ( a bit of a job) thats very interesting your using it on high voltage with low amps ( exactly what it was designed for)
DarylMc
100 mW
If anyone is interested.
With the particular Baldor drive and a FP 42 pole stator with 14 segment 56 pole rotor, I hit a limit of 430 RPM.
Rewired the stator from star to delta and now I have much more rpm available.
Still running an acceptable 1A per phase @ 600rpm with the small load of the centrifuge.
I also tried a later model FP 36 pole stator 48 magnet rotor motor expecting it to have higher rpm but it had less.
I now put this down to back emf not allowing enough current to flow in the windings.
The later model 36 pole motor with rounded iron poles was much quieter but I didnt try connecting it in delta.
Another thing I learned was to calculate the RPM of the motor, I needed to use the measured hall switch frequency and the number of magnetic poles of the rotor which for the 14 segment rotor is 56 poles and for the newer motor which has 16 segments is 48 poles.
Hope that is of interest to someone.
With the particular Baldor drive and a FP 42 pole stator with 14 segment 56 pole rotor, I hit a limit of 430 RPM.
Rewired the stator from star to delta and now I have much more rpm available.
Still running an acceptable 1A per phase @ 600rpm with the small load of the centrifuge.
I also tried a later model FP 36 pole stator 48 magnet rotor motor expecting it to have higher rpm but it had less.
I now put this down to back emf not allowing enough current to flow in the windings.
The later model 36 pole motor with rounded iron poles was much quieter but I didnt try connecting it in delta.
Another thing I learned was to calculate the RPM of the motor, I needed to use the measured hall switch frequency and the number of magnetic poles of the rotor which for the 14 segment rotor is 56 poles and for the newer motor which has 16 segments is 48 poles.
Hope that is of interest to someone.
whatever
100 kW
- Joined
- Jun 3, 2010
- Messages
- 1,297
yes its of interest, one thing I noticed was you can adjust the rpm another way, you know the big plastic thread that locks the magnets onto the original axle? you can wind it out a bit and get higher rpm, as the magnets come off the stator the rpm increases, you probably loose torque but its an interesting effect
DarylMc
100 mW
That sounds reasonable.
Less magnetic influence on the windings from the spinning rotor giving less back emf.
http://en.wikipedia.org/wiki/Counter-electromotive_force
Less magnetic influence on the windings from the spinning rotor giving less back emf.
http://en.wikipedia.org/wiki/Counter-electromotive_force
opearn
100 µW
- Joined
- Oct 11, 2018
- Messages
- 7
Hey guys
I'm keen as to convert a smart drive motor I have laying around. Can anyone please help me with a few questions,
Does it matter which hall sensor is connected to which hall sensor pin from your controller?
I've seen the mindchallenger page where they get custom made magnets, so I've chiseled out the magnets (they measured 56x30x4mm), I was hoping to copy them but use the cheaper stock rectangle 30x10x3mm neodynium magnets with 4mm spacing instead & not worry about copying the arc of the motor. Is there anything I should be considering when sizing these magnets?
I was going to file back the stator to reduce cogging but would twisting the ends be a better idea considering I will be using rectangle not angled magnets?
How are people attaching their bmx freewheel to the axle? Just welding or anything easier to remove for bearing services?
Thanks heaps for your help
I'm keen as to convert a smart drive motor I have laying around. Can anyone please help me with a few questions,
Does it matter which hall sensor is connected to which hall sensor pin from your controller?
I've seen the mindchallenger page where they get custom made magnets, so I've chiseled out the magnets (they measured 56x30x4mm), I was hoping to copy them but use the cheaper stock rectangle 30x10x3mm neodynium magnets with 4mm spacing instead & not worry about copying the arc of the motor. Is there anything I should be considering when sizing these magnets?
I was going to file back the stator to reduce cogging but would twisting the ends be a better idea considering I will be using rectangle not angled magnets?
How are people attaching their bmx freewheel to the axle? Just welding or anything easier to remove for bearing services?
Thanks heaps for your help
whatever
100 kW
- Joined
- Jun 3, 2010
- Messages
- 1,297
yup you need to match correctly the hall wires too controller.
Also you need to have correct voltage hall sensor setup to match controller ( usually 5v for ebikes or 1 to 4v more acurately). I cant remember what voltage the hall sensors are on the fp motors.
What is the use for the motor? It would probably be much much easier simpler to just use an ebike hub motor,
because the scooter type ( moped type) ebikes are banned in oz, you can find them at recycle centres as people just throw them away ( usually when the batteries die). See if you can find one or even on gumtree .
Also you need to have correct voltage hall sensor setup to match controller ( usually 5v for ebikes or 1 to 4v more acurately). I cant remember what voltage the hall sensors are on the fp motors.
What is the use for the motor? It would probably be much much easier simpler to just use an ebike hub motor,
because the scooter type ( moped type) ebikes are banned in oz, you can find them at recycle centres as people just throw them away ( usually when the batteries die). See if you can find one or even on gumtree .
opearn
100 µW
- Joined
- Oct 11, 2018
- Messages
- 7
Bit limited with access in Tassie, not so much good gear about but something might turn up. Going to put this project on the backburner until i can get some funds together for battery+magnets+controller ect probably take a fair while but I'll still just convert this old motor i have when i get the chance.
As far as replacing the hall sensor, I found there's an arrow on the stator & the hall sensor clip to line them up by.
I've found some better wiring descriptions for chinese controllers, looks like thick/thin wires are same colour to make matching phase to halls easier, so can match up hall A/B/C/+/- with f&p wiring harness fairly easily, Now if i can just identify which phase is A/B/C coming from the motor? is it just A=M1/B=M2/C=M3 according to your previous wiring diagrams? working from the wiring diagrams you previously posted it would appear that the 8 AA cells are arranged in series so the hall sensors will only require between 1.2-1.5v which is in line with ebike hall voltages so I'm going to try to just run it off the cheapo chinese controller.
probably take a fair while but I'll still just convert this old motor i have when i get the chance.As far as replacing the hall sensor, I found there's an arrow on the stator & the hall sensor clip to line them up by.
I've found some better wiring descriptions for chinese controllers, looks like thick/thin wires are same colour to make matching phase to halls easier, so can match up hall A/B/C/+/- with f&p wiring harness fairly easily, Now if i can just identify which phase is A/B/C coming from the motor? is it just A=M1/B=M2/C=M3 according to your previous wiring diagrams? working from the wiring diagrams you previously posted it would appear that the 8 AA cells are arranged in series so the hall sensors will only require between 1.2-1.5v which is in line with ebike hall voltages so I'm going to try to just run it off the cheapo chinese controller.
Unfortunatley it's common for these things to have different (random) wiring order for those colors, so having them match isn't all that likely.opearn said:
There is a thread How to Determine The Wiring for a Brushless Motor that has multiple ways to do it if you find it doens't work in matching order.
8 AA cells in series is 1.5v * 8 = 12v.
Ebike controllers output 5v, and have a 5v pullup inside the controller on each hall signal wire, so if the halls on the motor are already powered by 12v, you'll need to either disconnect the 12v supply, and connect only the controller's 5v supply, or leave the 12v supply, and not connect the controler's 5v supply to the halls at all (just the green, yellow, blue, and black, NOT the red). (it doesnt' matter if the halls are powered by something different than the pullups on the output are).
You can look up the p/n on the hall sensors to find the spec sheet for what votlage range they'll take, if you're not sure.
Most hall switches can take up to 24v.
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