etard
100 kW
Great work, why is there 4 wires coming out of it? And why is RCGroups getting it before us? 
We are willing to ride on our toys! :lol:
We are willing to ride on our toys! :lol:
The perfect ebike motor!?
- Thread starter CNCAddict
- Start date
magudaman
10 kW
No one has really mentioned it but one concern I have always heard about and personally worried about when using RC sized motors is the shaft bearing size. A lot of time if we do end up doing some sort of reduction it will put quite a bit of side load on that shaft. Most of the brushless RC stuff is made for direct drive to a prop and usually uses smaller bearings.
I notice on the real high power motors like Eteks they have monster bearing supporting monster 7/8in shafts.
I notice on the real high power motors like Eteks they have monster bearing supporting monster 7/8in shafts.
MitchJi
10 MW
Hi,
Actually this issue was beaten to death either in this thread or an earlier thread. This motor is being designed specifically for Ebike use. One of the design parameters is big shaft and bearings.
Also being an inrunner there are bearings at both ends of the shaft.
magudaman said:
Actually this issue was beaten to death either in this thread or an earlier thread. This motor is being designed specifically for Ebike use. One of the design parameters is big shaft and bearings.
Also being an inrunner there are bearings at both ends of the shaft.
liveforphysics said:
I'm testing the motor on 50V with my Spin 200. I won't really be able to stress this motor very much with this setup, so I may have to invest in that new 400A peak Schulze ESC and some very powerful batteries for sure. The other problem is that my scooter is not very safe at these power levels. I can only lean forward so far
I'll send you a PM about those batteries!!magudaman said:
As Mitch said, this is a pretty beefy motor. The shaft is 12mm and the bearings are 28x12x8mm. The dynamic load rating on these bearings is 1200lbs.
etard
100 kW
Why six wires?
recumpence
1 GW
Two possible reasons;
#1 Configuration between a Delta and a Wye winding.
#2 To run two ESCs.
Matt
#1 Configuration between a Delta and a Wye winding.
#2 To run two ESCs.
Matt
voicecoils
1 MW
#3: Double them up for greater current handling to 1 controller?
Ypedal
100 TW
voicecoils said:
That was what i always assumed it was for... never considered other options..
liveforphysics
100 TW
O
M
G
6 wires to enable you to use a pair of ESC's is awesome!!!!!! I'm frothing to buy one of these things!!!
You are a hero David!
M
G
6 wires to enable you to use a pair of ESC's is awesome!!!!!! I'm frothing to buy one of these things!!!
You are a hero David!
Haha, no 2 esc's on this motor. Running 2 ESC's to a single motor may cause some serious problems with the zero cross detection...I will do some tests on a tiny motor to see if that's possible ( and it may be). I just haven't worked on this "yet".
I ran the motor yesterday and it works flawlessly, it runs extremely cool even without a fan. I need to redesign a few things on the case though to give the windings more room (it's way too tight in there)..and try to do higher powered testing, but my A123 pack is now completely screwed up with 3 or 4 damaged cells...so I need to get some high current cells ASAP.
I also have to do some 300A tests to see how it does..but my scooter can't handle this much power...so I need to get another test vehicle to ring it out. A bit of chasing my tail going on here...but it's kinda of fun breaking stuff in the name of testing
I ran the motor yesterday and it works flawlessly, it runs extremely cool even without a fan. I need to redesign a few things on the case though to give the windings more room (it's way too tight in there)..and try to do higher powered testing, but my A123 pack is now completely screwed up with 3 or 4 damaged cells...so I need to get some high current cells ASAP.
I also have to do some 300A tests to see how it does..but my scooter can't handle this much power...so I need to get another test vehicle to ring it out. A bit of chasing my tail going on here...but it's kinda of fun breaking stuff in the name of testing
MitchJi
10 MW
Hi David,
Why six wires?
If Luke ever gets his build on the road he might be a good person to help with testing:
http://endless-sphere.com/forums/viewtopic.php?f=28&t=8347
CNCAddict said:
Why six wires?
CNCAddict said:I also have to do some 300A tests to see how it does..but my scooter can't handle this much power...so I need to get another test vehicle to ring it out. A bit of chasing my tail going on here...but it's kinda of fun breaking stuff in the name of testing
If Luke ever gets his build on the road he might be a good person to help with testing:
http://endless-sphere.com/forums/viewtopic.php?f=28&t=8347
GGoodrum
1 MW
I'm guessing it is to allow for external selection of whether or not it is in the "wye" or "delta" configuration. Basically it gives one motor two different kVs and torque characteristics. One possibility, in theory anyway, is you could implement an electronic two-speed transmission. I don't remember which is which, but motor wired one way will have a kV that is a factor of something like 1.7 higher than if it was wired the other way. Where this could be useful is you can size the motor and do the gearing so that it is optimized for low-end torque, but might be limited in top speed. "Shifting" into the other configuration will spin the motor faster, at the same voltage, but will have less torque.
I know a couple of people, like Doc, are looking at trying this with hub motors, but I think I remember reading about some issues that came up. Doc is looking to get something like a 5305 and a 5302 in the same motor. The 5305 is a torque monster, but you need to really overvolt it to get a decent top speed. The 5202 has a pretty high top speed, at a lower voltage, but on a heavy bike, you'd just about have to start going downhill to get going.
-- Gary
I know a couple of people, like Doc, are looking at trying this with hub motors, but I think I remember reading about some issues that came up. Doc is looking to get something like a 5305 and a 5302 in the same motor. The 5305 is a torque monster, but you need to really overvolt it to get a decent top speed. The 5202 has a pretty high top speed, at a lower voltage, but on a heavy bike, you'd just about have to start going downhill to get going.
-- Gary
There are 6 ends of a 3-phase motor winding. Running these outside the motor is a cleaner solution in my book. My Astro had some problems with the y-connection so I decided it would be better to move it outside the motor case. This also allows someone to run a delta/wye switch instead of a 2-speed transmission.
I'm talking with Luke right now about some batteries....not sure about lending this motor out though, it's the only one i have..and I don't want to loose it :wink:
I'm talking with Luke right now about some batteries....not sure about lending this motor out though, it's the only one i have..and I don't want to loose it :wink:
liveforphysics
100 TW
I don't imagine I would ever send that motor back, but I would send back the empty box you shipped it in with a wad of cash and a note that says "another please sir"
I'm loving the though of some bad-ass solid state relays setup to do the phase switching to change from delta to wye. I would make it happen automatically from a micro controller tapping a leg of the motor to read RPM, then giving the signal to switch the FETs at the moment of intersection between the torque curves of the two winding types. That would make it feel seamless, and give the motor an incredible broad power band.
This is very very cool stuff! The 1/5th scale RC car guys would also be all over a motor like this with the ability to switch from delta to wye on the go. Awesome stuff!
-Luke
I'm loving the though of some bad-ass solid state relays setup to do the phase switching to change from delta to wye. I would make it happen automatically from a micro controller tapping a leg of the motor to read RPM, then giving the signal to switch the FETs at the moment of intersection between the torque curves of the two winding types. That would make it feel seamless, and give the motor an incredible broad power band.
This is very very cool stuff! The 1/5th scale RC car guys would also be all over a motor like this with the ability to switch from delta to wye on the go. Awesome stuff!
-Luke
liveforphysics said:
No doubt! I can imagine even the eBike folks would be too if it became a "conventional" possibility. Everybody knows how theoretically excellent transmissions are and add in the factor it's all electronic and shifting doesn't involve anymore expensive and difficult to install mechanical parts? Wow, a god-send.
I really hope David's motor comes to fruition.
The Wye/Delta switch is a great way to reduce the burden on the batteries and ESC. The motor will produce a certain amount of heat/unit torque no matter what configuration the winding. So both a 2 turn and 60 turn delta or Wye wound motor will heat up the same while producing a fixed amount of torque. So basically, a 2-stage transmission reduces the load on the Battery/ESC/motor while a Delta Wye switch helps out the Battery/ESC while the motor still has to face the heat.
I personally would still prefer a 2-stage transmission...this motor could produce a LOT of sparks if something is switched incorrectly, and it might take a separate bit of electronics to orchestrate all this so nothing blows up.
I hope Miles thread about transmissions comes up with something that works well
I personally would still prefer a 2-stage transmission...this motor could produce a LOT of sparks if something is switched incorrectly, and it might take a separate bit of electronics to orchestrate all this so nothing blows up.
I hope Miles thread about transmissions comes up with something that works well
recumpence
1 GW
liveforphysics said:
Huge Lehner motors are switchable. I almost went that route, except they are a two pole motor. I did not want that much RPM screaming in my recumbent at that time.
Matt
GGoodrum
1 MW
For constant torque, you are right, of course, but in an ebike application the torque required/demand is not a constant at all. For most of the ebike setups I've seen, a motor just doesn't have enough torque range so that you can have one motor that gives a satisfactory top speed, while providing good low-end acceleration, unless you use a very big motor. An overvolted 5304 can do both, but it weighes 25 pounds, and you need to run at least 72V and feed it close to 100A. With the smaler 40x series, and other similarly sized hub motors, the problem is much more pronounced. You can get decent low-end torque at say, 50V, but the top speed is more limited. You can get a higher kV wind that gives you the desired top speed, but not much low-end torque.
With our non-hub setups, the whole point to this is trying to achieve good performance on both ends, but with a lot less weight. We have the same issues, though. It is hard to get one motor to be able to have a kV high enough to give us the top speed we are looking for, while still having enough low-end torque. The result is that we really need more than one set of gears, one with a higher ratio so that the motor can spin faster for a given speed, and a second ratio that is lower so that the same motor speed will move the bike faster. The net result is if you double the ratio, you double the torque.
Switching issues aside, if you setup the gearing, etc., so that you get the lowend performance you want with a "normal" wye-configured motor, being able to switch it to a delta configuration would be exactly like having an "overdrive" that gives you 1.73 x more speed, at the same voltage. With my existing Cyclone setup, which uses a Nexus 3-speed hub, if I start out in 3rd, the motor groans and maxes out the current, and will slowly start to go faster. Once I'm at the top speed (a bit over 30 mph...), or close to it, the motor is quite happy, and draws a lot less current. If I start in 1st gear, it has almost too much low-end torque, and will just about flip me off the backend, but the top speed is only 18 mph. The difference in the ratios between 1st and 3rd is 1.86, not much more than the 1.73 ratio difference between the wye and delta configurations. My point is that we don't need much, in terms of a "gearing" change to widen the torque range enough for the motors setups we've all been playing with.
There's always tradeoffs, but in a most cases there are one or two factors that are less flexible. Because of costs, etc., pack voltage and current are usually the first limits you run into. Generally, you top speed is going to be limited by the pack voltage, and lowend torque will be limited by the max current that can be supplied. Given those kinds of limitations, it is just about impossible to have one motor/gearing setup that can do both. Driving through the crank, in order to use the existing gearing, is one solution, but again there's tradoffs. It usually means you end up screwing up the "stock" pedal ratios. Anyway, a direct drive solution is usually the least complex, but without a two-speed transmission, you have the same problem. You can optimise for lowend torque or for top speed, but not both. A switchable wye-delta configuration would be all that is needed, if it can be done properly.
-- Gary
With our non-hub setups, the whole point to this is trying to achieve good performance on both ends, but with a lot less weight. We have the same issues, though. It is hard to get one motor to be able to have a kV high enough to give us the top speed we are looking for, while still having enough low-end torque. The result is that we really need more than one set of gears, one with a higher ratio so that the motor can spin faster for a given speed, and a second ratio that is lower so that the same motor speed will move the bike faster. The net result is if you double the ratio, you double the torque.
Switching issues aside, if you setup the gearing, etc., so that you get the lowend performance you want with a "normal" wye-configured motor, being able to switch it to a delta configuration would be exactly like having an "overdrive" that gives you 1.73 x more speed, at the same voltage. With my existing Cyclone setup, which uses a Nexus 3-speed hub, if I start out in 3rd, the motor groans and maxes out the current, and will slowly start to go faster. Once I'm at the top speed (a bit over 30 mph...), or close to it, the motor is quite happy, and draws a lot less current. If I start in 1st gear, it has almost too much low-end torque, and will just about flip me off the backend, but the top speed is only 18 mph. The difference in the ratios between 1st and 3rd is 1.86, not much more than the 1.73 ratio difference between the wye and delta configurations. My point is that we don't need much, in terms of a "gearing" change to widen the torque range enough for the motors setups we've all been playing with.
There's always tradeoffs, but in a most cases there are one or two factors that are less flexible. Because of costs, etc., pack voltage and current are usually the first limits you run into. Generally, you top speed is going to be limited by the pack voltage, and lowend torque will be limited by the max current that can be supplied. Given those kinds of limitations, it is just about impossible to have one motor/gearing setup that can do both. Driving through the crank, in order to use the existing gearing, is one solution, but again there's tradoffs. It usually means you end up screwing up the "stock" pedal ratios. Anyway, a direct drive solution is usually the least complex, but without a two-speed transmission, you have the same problem. You can optimise for lowend torque or for top speed, but not both. A switchable wye-delta configuration would be all that is needed, if it can be done properly.
-- Gary
CNCAddict said:
The conditions specifying the "right time" to switch isn't too complicated or too narrow of a window, is it? That is, from an external circuit's point of view.
Would turning off the controller to the engine(turn throttle to nothing), electronically switching, and then revving back up the throttle one possible way without serious damage? I imagine this switching could take less than 1/5th of a second, all steps included, which wouldn't be noticeable. I could easily extend my current controller's supplemental circuit with this functionality, if needed.
Also, I'm curious, could someone explicitly state the probable gains of this delta-wye switching? What exactly changes? Does the Kv go up and motor's internal resistance go down(or vice versa)? Do they both go up(or down)? I'd like to know what the exact electrical properties are, as my simulator can produce realistic models with these two different parameters considered and so my expectations wouldn't be so lofty. It sounds like upping the Kv by ~1.7 times sounds like a definite difference assuming it was geared correctly.
GGoodrum
1 MW
There is an inversely proportional relationship between kV (rpm per volt...) and the torque constant (kT...), which is measured in inch-ounces per amp. Basically, voltage controls rpm, and current controls torque. Check out this AstroFlight PDF on the 3210 to see how these two factors are interrelated: http://www.astroflight.com/pdfs/3210.pdf. What this clearly shows is that if the number of turns is doubled the kV is cut in half, which means you need twice the voltage to get the same speed, but you only need half the current to get the same torque, because the torque constant is twice as much.
Using this Astro table as an example, assume you were using the 12T version in a standard wye configuration. Being able to switch to a delta configuration on the fly would be roughly like you switched off the 12t motor and turned on a 7t version. For the same max pack voltage, the 7t will spin 1.73 times faster, so assuming the same gearing, the bike will go that much faster.
-- Gary
Using this Astro table as an example, assume you were using the 12T version in a standard wye configuration. Being able to switch to a delta configuration on the fly would be roughly like you switched off the 12t motor and turned on a 7t version. For the same max pack voltage, the 7t will spin 1.73 times faster, so assuming the same gearing, the bike will go that much faster.
-- Gary
MotorSmoke
10 µW
- Joined
- Feb 22, 2009
- Messages
- 5
I do not know how switched off a controller has to be to allow a wye to delta switch but,
to do the switching is easy enough.
I have just made a drawing at home but do not know how to display it here but I can describe.
One just needs three components:
1. momentary switch(normally off) for logic control(indicate desire for a switch of wye to delta or the inverse).
2. A time delay relay/contactor, double poled for breaking the throttle(or power to controller).
3. A double latching relay/contactor for doing the switch from wye to delta.
The momentary switch is powered at all times. A push of it sets the relay, breaking the power to the throttle(for some short time), and energizes the latching
relay. The latching relay flips to the other side it was on, the timer elapses and the throttle is on again.
Tell me if I am missing anything.
to do the switching is easy enough.
I have just made a drawing at home but do not know how to display it here but I can describe.
One just needs three components:
1. momentary switch(normally off) for logic control(indicate desire for a switch of wye to delta or the inverse).
2. A time delay relay/contactor, double poled for breaking the throttle(or power to controller).
3. A double latching relay/contactor for doing the switch from wye to delta.
The momentary switch is powered at all times. A push of it sets the relay, breaking the power to the throttle(for some short time), and energizes the latching
relay. The latching relay flips to the other side it was on, the timer elapses and the throttle is on again.
Tell me if I am missing anything.
Doctorbass
100 GW
That discussion about Delta/WYE become really interesting!.. I can't wait to get my contactor and try it!
I know that in delta mode the current will increase alot.
My actual setup in oem WYE peak at 100A and do 70-80A continuous so i guess i need something like the kelly 220A controller (the one that toasted the 5305 of Methods..
)
Or an infineon 18 fets controller upgraded with 18x 4110!! that will rock!!.. I have 40 of these fets + their IR2101 driver in the mail for me from Bob..
.. i'll have 22 more in case i blow something.
Cuting the power to the controller while doing the switch will be easy.. I'll have to cut the EV200 contactor that control power to the controller, switch the WYE/DELTA contactor and re-activate the EV200..
I just wonder if while the controller have no power, if there is some little current that flow in the phase wire.. .. thru the fets diode.. or something like that? I just want to be sure that the controller does not draw any current to avoid spark when making or braking contact o the WYE contactor...
Normally i guess that it doesn't.. ?
I joined a pic of the Delta/WYE configuration for switching.
Doc
I know that in delta mode the current will increase alot.
My actual setup in oem WYE peak at 100A and do 70-80A continuous so i guess i need something like the kelly 220A controller (the one that toasted the 5305 of Methods..
)Or an infineon 18 fets controller upgraded with 18x 4110!! that will rock!!.. I have 40 of these fets + their IR2101 driver in the mail for me from Bob..
.. i'll have 22 more in case i blow something.Cuting the power to the controller while doing the switch will be easy.. I'll have to cut the EV200 contactor that control power to the controller, switch the WYE/DELTA contactor and re-activate the EV200..
I just wonder if while the controller have no power, if there is some little current that flow in the phase wire.. .. thru the fets diode.. or something like that? I just want to be sure that the controller does not draw any current to avoid spark when making or braking contact o the WYE contactor...
Normally i guess that it doesn't.. ?
I joined a pic of the Delta/WYE configuration for switching.
Doc
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