C-lyte Centertap motor useless?

I've got me one of these 4012/408 Crystalyte motors with the 20 amp controller, and at first, thought it was the greatest invention Since sliced bread. (I'm curious what the greatest invention before sliced bread was) Now that I have a Watts Up meter, and can start to quantify some of the preformance, I'm starting to change my oppinion.

My first test was amp draw, The 4012 setting doesn't go as a fast as the 408 setting, as would be expected. However, the 4012 pulls the same amps at full speed, 16mph, as the 408 does at the same speed. the 408 then goes on to more than double the Amp draw rate by it's top speed.

So I figured, almost naturaly, that this just ment the 4012 was making more torque at lower speeds, like being in low gear. They advertise the higher winding motors to be so. Texas is flat. I have almost no hills to test this kind of thing on, so I had to just assume this was right. I made it a practice to use the low setting for intersections and to take off with, and the high for crusing at speed.

But yesterday, I decided to actualy test this. After riding around for a while in just the 408 setting, I couldn't tell that the 4012 accelerated any better from a dead stop, or gave me any more efficent acceleration.

So I found a steep part of a walking trail that comes up from a green belt to a parking lot. Its roughly 100 feet of switchback to get up a 15 foor embankment. I marked a starting point at the base, and with no pedal help, rode up the path from a dead stop. both the motor settings did it, in roughly the same amount of time, and neither seemed to have an advantag untill I was almost at the top, and above 12 mph, were the 408 setting seemed to be able to keep pulling up in speed, were the 4012 seemed to be peaked.

So, does this mean the 4012 is useless? Is this a problem others are finding? is everything I know about windings VS torque on brushelss motors wrong?

well, the 4012 is clearly the "go far" mode. it is a "slow" gear, not a max torque gear. makes sense to me.
i guess IF u have a throttle pot and a speedometer, u don't need it.
But who has the pot? knoxie, me and?

I have similar experience, last year I swapped my 408 out for a 4011, and increased voltage to give a reasonable top speed (30mph at 84v), but found that hillclimbing was only very slightly improved, while power consuption at any speed remained the same. The downside was the increased backemf, that limits power on the 4011 at higher speeds. Also means freewheel speed can never exceed the hub no load speed (no load speed was only slightly higher than loaded speed). The 408 on the other hand, at lower volts and higher amps (same watts) pulls as hard than the 4011, maintains power through a greater percentage of its speedrange, and has a no load speed much higher than the loaded speed.
All in all, i'm happier with a singlespeed 408. Possibly, the ideal solution is the puma BMC motor, but I'm still waiting to try one...
Best invention before sliced bread was probably the breadknife...
Jozz

The crystalyte motors come in all sorts of flavors.. but assuming 36/48v

404 = 16"wheel
405 = 20"wheel
406 = 20 to 24" wheel
407 = 24 to 26" wheel
408 = 26" +
409, 4011, 4012 = 26" +

Depending on what you want and need, choice of battery, etc..

Uppping the voltage makes the RPM's go up.

Upping the amps ie: 20 or 40 amp controller .. creates more torque

Reading on Justin's site, http://www.ebikes.ca he states that all clyte motors produce the same torque, but at different RPM levels.


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That said.. my 406/409 is used 90 % of the time in 409 mode at 72v in a 20" wheel.. only on occasion do i use the 406 setting as it's just tooo fast.

Some combinations work well. some don't.. using a 406 in a 700C wheel will be FAST.. but the amp draw won't drop below the controller's allowed limit until you reach 30 mph. =- hard on batteries.

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Personally i like the high-voltage systems. using a high-wound motor to slow things down.. and a smaller wheel to provide more torque. The brushless hub motors are smoother at high-voltage than at 36v.

It all comes down to personal preference.. :wink:

Does anyone know how accurate the Ebikes.ca simulator is for the 4XX hubs? It seems like a lot of the combinations I tried don't get very high on the efficiency curve for some reason.

Interesting. That Ebikes site has some great information. I think I need to look at the watt readings along with the amps were they are equil, and see if its also the same.

Jozz, did you notice any diffrence between the 408 single speed, and the 408 setting on your dual speed? If I'm right, the dual speed is going to have a higher resistance.

Afraid I don't have a dual speed, nut 2 single speeds.

The riding experience with the 2 motors volted up to run at the same speeds is very different though.
Justins calculater was within about 10% for my 4011 at different voltages, whilst the 408 was spot on accurate (from 48 to 84v, 20 and 30 amps).
THeres a long thread somewhere on the powerassist forums about the windings/resistance in dual speed compared to single speed motors...

i had a 408/4012 for awhile and i was very disappointed in the performance at 36-48v, but that is true of all the hub motors i have tried. The first controller they sent me was defective and was part of the problem, but even with a new controller i found the differences between the two settings to be disappointing. When I switched to 72V and higher it became a different world altogether. The 4012 screams up hills and cruises at 30+ and the 408 is about 10-15 mph. faster. At the higher voltage I almost never used the 408 tap except to show off.

you will also noticed a bigger difference if you switch to a higher current controller. the major torque benefits of the 4012 require lots of current and 20A is just not enough. While it is true that all the xlite motors can do basically the same thing given enough volts/amps, it is not practical to use >40A, so choosing the right motor for the job will result in a more efficient system. The higher voltage is the real key, though, as it takes a lot of volts to push a lot of amps through the 12 turns.

the lead-in wire is very small on these motors, so all the conductors can fit in the inlet port, but the wire inside is the same 1 mm size as used in all the motors, with one difference. On the tapped wind motors the resistance of the 408 winding will be higher than on a single wind motor, because they use fewer strands of wire for that winding on the tapped motors. This results in some loss of efficiency when using the 408 setting compared with the performance of a single wind motor.

In general I think the tapped wind motors are highly overrated and probably are only useful in a 20" wheel on a trike pedicab or something like that where the two extremes of torque and speed are required. I think 99% of us would be just as happy with the properly chosen single wind motor. Justin agrees with me on this and does not sell them.

BTW the simulator data on ebikes.ca is taken from actual dyno data and i have found it to correlate quite well with my own experience for the 408,409, and 4012 motors i have used.

-bob

The fun is just starting at 40 amps though... 60 is a good balance.

Lowell said:

The fun is just starting at 40 amps though... 60 is a good balance.

Click to expand...

For the 5 series.. yes...

So in the lower winding mode, not all the turns are used???
That seems silly.

It would make much more sense to have a delta - wye switch and use all the copper in both modes.

If relays were used for switching, they could be located inside the hub, so only 3 fat wires would need to come through the axle, plus the halls and a skinny pair to run the relays.

Another one of those "I'll have to do it myself because the manufacturer is dense" things.

As far as I can tell, the motors are in the wye configuration. I'm not sure what the equivalent number of windings would be for the delta configuration. If you had a 4012 and reconfigured the windings to a delta, I guess it would be somewhere near a 404. This might be too much of a difference to be of practical use. I'll have to double check my math. Maybe they're not so dense after all. Not.

The dual speeds can be had in any combination spanning no more than 4..

ie: 404/408... 405/409.. 408/4012 !!..... 406/407... etc...

The dual speed motors have a purpose in life.. i agree that they are not useful for most.. but if you are building something that needs either reduced speed.. or increased speed at times.. they are a nifty option.

I have mine rigged with a 3PDT relay and a single speed controller for switching.. so far so good.. followed Steve H's dirt-Monkey lead !

bobmcree said:

i had a 408/4012 for awhile and i was very disappointed in the performance at 36-48v, but that is true of all the hub motors i have tried. The first controller they sent me was defective and was part of the problem, but even with a new controller i found the differences between the two settings to be disappointing. When I switched to 72V and higher it became a different world altogether. The 4012 screams up hills and cruises at 30+ and the 408 is about 10-15 mph. faster. At the higher voltage I almost never used the 408 tap except to show off.

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the lead-in wire is very small on these motors, so all the conductors can fit in the inlet port, but the wire inside is the same 1 mm size as used in all the motors, with one difference. On the tapped wind motors the resistance of the 408 winding will be higher than on a single wind motor, because they use fewer strands of wire for that winding on the tapped motors. This results in some loss of efficiency when using the 408 setting compared with the performance of a single wind motor.

...

BTW the simulator data on ebikes.ca is taken from actual dyno data and i have found it to correlate quite well with my own experience for the 408,409, and 4012 motors i have used.

-bob

Click to expand...

So if I understand you correctly, if I run a big amp controller at 72 volts, I would be able to notice more torque out of the 4012, as opposed to the 408?

As for efficiency, are we talking an decrease in distance per watt type inefficancy? My understanding is that the smaller diameter wire would be less powerfull, less fast, but More efficent.

As for the Ebikes, how close did you find the centertapped version to be to the 408 they have listed?

Does anyone make a 35 amp center tapped controller? Or will I need to modify one?


As for now, I've found a use for the switch. at top speed in 4012 mode, I can do 25 miles, in 408, I can do 13. The switch has become a speed limiter. Not worth the $30 price tag just to govern my speed, but it was worth the expeiriment. I've lost more money in failed battery mounts so far.

So you got almost twice the distance using the 4012 than the 408?
What speed were you going on each setting?
Any idea what what the distances would be for each setting at at the same speeds?

A power meter would show you the problem quickly.

I suspect you like to run " WOT " ( Wide Open Throttle !! ) ..

Your 20 amp controller in the 408 setting.. likely allows 20 amps all the way up to 30 mph + before it drops.. and by this point unless you have the wind at your back.. and a strong gust at that.. you still need mucho-amps to move along !!..

This is where that motor in a 20" wheel would rule !

Exactly as you mentioned, in 4011 you actually manage to get up to the motor's running speed and the amp draw settles down below the max limit imposed by the controller.

It's fun to go fast. but it's alot more economic to slow down ! hehe.

( As of this writing , crystalyte dual speed controllers only come in 20 amp. 72v x 20 amp = 1500w ( plus or minus depending on operating volts ) this is as much as you want to pass in the gauge of wire used !! )

Also.. about the meter.. when you can monitor the amp draw, using partial trottle you might find a sweet spot between the 2 modes of the motor. keeping the throttle in this spot and pedaling along in top gear can bring some extra miles !!!

To answer Kyle's question, - Yes. twice the range on the motors.

and to Ypedals, - Yes, I'm a Redneck. Its all or nothing, "Hold meh beer and whatch This" style driving for me: WOT, or I'm on the brakes.

I've got a meter, and my latest readings done at 15mph on both motors show they both pull the same amprage, 6.3 amps. There is no diffrence in efficancy between the two, within the same speed band. However, the 4012 maxes out at 6.5 amps draw, and the 408 maxes out at 12.5. thats at wot, after reaching top speed.

As for 30mph, never seen it, but then I can only pull higher amps during acceleration. 22mph seems to be the max norm, with rare breaks into the 23+ range under ideal conditions, but its a mountian bike.

For now, the switch locks me into a max 16mph, at 6.5 amps. Thats much faster than I would be going if I was pedaling, but still in the reasonable speed range for riding through parks or down sidewalks around people.


So whats the guage on these wires compared to the single speeds? Whatsthe max amp rating on them?

http://www.ebikes.ca/hubmotors.shtml


The torque that is produced by one of these motors varies in direct proportion to the total current flowing around each pole. So in the above case, a 406 motor with 15 amps flowing through the winding has a total of 90 amps around the pole. The 409 motor would need just 10 amps to have 90 amps around the pole and hence the same torque output.

One false and oft-repeated conclusion is that therefor the 409 is a higher torque motor than the 406 because it can produce the same torque with fewer amps, or likewise more torque with the same amps. This is not the case. All 400 series motors can deliver exactly the same torque at exactly the same efficiency. The lower winding count motors just need more current to do this, but because they have fewer turns of a shorter length of heavier gauge wire, they can handle high currents with minimal loss. To use a concrete example, lets compare a 406 with a 412. The 412 has twice the number of turns than the 406, so the copper wire in the windings has 1/2 the cross sectional area and twice the length, for a total of 4 times the winding resistance of the 406. For a given torque output, the 412 needs only 1/2 the amps, but because it has 4 times the resistance the net electrical loss (I2R) is exactly the same.

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I read that, but unfortunatly, most of that goes right out the window with the center tapped motors.

An normal 406 would have thicker winding wires than a 4012, with essentualy the same mass. For a simplified example, lets say the 406 is wound with 6 windings of 10 guage wire. The 4012 would have 12 windings of 20 guage wire. And in a case like this, the math on Ebikes works.

The problem with the center tap motor is the 406 would be using half of the 4012's wire, and therefor have 6 windings of 20 guage wire. esentualy half the current capacity, but half the resistance, and half the inductance for back emf to act on.

The math works when comparing 2 motors of equil coil mass, but these centertapped motors are a diffrent animal.