Nope! Still got it
I think it may be the chain. It's not the bottom bracket as I replaced it a while back, agreed its very irritating....Alien Gents Special II - Improvments and Modifications
- Thread starter NRG
- Start date
I think it may be the chain. It's not the bottom bracket as I replaced it a while back, agreed its very irritating....I don't think there's any magic solution other than increasing volts or if you are brave then you could try and convert your motor to delta wired........ Not seen any magic cure for increasing speed yet though......
Carry on chaps
The parameter designer software lets you set a battery current limit and a phase current limit. Various people's comments suggest that the phase limit is done by an approximation from the controller watching the same shunt as used for the battery current limit sensing but knowing the current PWM and possibly sampling it at specific times in the PWM cycle.
The question is what happens when these limits are exceeded. Does the controller smoothly cut PWM until either or both drop back under the limits. You say above that it's more like a drop to zero.
This relates to two things.
- Strategies to set the two values. Logically, the battery limit should be set according to what the battery/motor can cope with. So say 2C on a 10AHr battery and so 20A. The Phase current limit should be set mainly by the FETs and heat sink. The 2.5* rule of thumb is just a recommendation based on a circuit layout, FET choice and heat sink. So a typical 6 FET, 20A controller can tolerate 42A Phase limit
- Normally these controllers relate throttle position to average voltage via PWM. This makes the throttle mainly a speed controller as the motor will try and speed up to near whatever it's no-load rpm is for that voltage. Can we turn the throttle into a torque control by having it set the battery current limit? eg Use an external circuit or a modified CA to set a battery current limit from the throttle control and then drive the controller's throttle input to set the PWM to stay below this.
As i am understanding it....the throttle signal makes the controller reduce PWM smoothly, but also sets a threshold of current limit which does block current flow...hence the pulsing of the on/off current limit i am experiencing with my lastest controller. I have no way of adjusting this (software or otherwise) on my controller, the amount of limiting is set by throttle signal voltage. What i would suggest you do if you want reduce current to increase range is have a method of limiting throttle signal voltage and see for yourself the current limiting happening.
Unfortunately hall effect throttles don't have enough control over battery power. It's either on or off or a bit inbetween which is why i am trying to make mine more responsive. Like i have said already. It is possible to controll the throttle signal with external circuitry, but it looks to me that current limiting is already a feature of controllers. The problem (it seems to me) is the hall effect throttle. Unless you want to get more power out of your controller then it seems a programmable one is the way to go.
I'll just add this as it might be interesting for you.
On my throttle i have fitted a 200ohm potential divider (the signal current is only 350ua , so i figured a low value would give me the adjustment i needed to experiment)
Each test is with a turnigy power anaylser on the battery feed
Controller voltage without the resister is 3.663V WOT, current is max(i don't what as i have not measured it yet)
Reduce the maximum WOT signal voltage to 3.60V, current peak is 9.78A (on/off pulsing noticed and leds green and orange flickering at same frequency)
Reduce the maximum WOT signal voltage to 2.7, current peak is 5.62A (on/off pulse very noticable and ledsflickering but only the green one because volt sag not so high).
At the moment i am riding my bike with current limit set at just under 10A. What i am going to soon is make an adjustable limiter that i can set for different terrain while riding but using the controllers current limiting features instead of making my own.
Unfortunately hall effect throttles don't have enough control over battery power. It's either on or off or a bit inbetween which is why i am trying to make mine more responsive. Like i have said already. It is possible to controll the throttle signal with external circuitry, but it looks to me that current limiting is already a feature of controllers. The problem (it seems to me) is the hall effect throttle. Unless you want to get more power out of your controller then it seems a programmable one is the way to go.
I'll just add this as it might be interesting for you.
On my throttle i have fitted a 200ohm potential divider (the signal current is only 350ua , so i figured a low value would give me the adjustment i needed to experiment)
Each test is with a turnigy power anaylser on the battery feed
Controller voltage without the resister is 3.663V WOT, current is max(i don't what as i have not measured it yet)
Reduce the maximum WOT signal voltage to 3.60V, current peak is 9.78A (on/off pulsing noticed and leds green and orange flickering at same frequency)
Reduce the maximum WOT signal voltage to 2.7, current peak is 5.62A (on/off pulse very noticable and ledsflickering but only the green one because volt sag not so high).
At the moment i am riding my bike with current limit set at just under 10A. What i am going to soon is make an adjustable limiter that i can set for different terrain while riding but using the controllers current limiting features instead of making my own.
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It seems to me that the two current limit settings in the controller software are hard safety limits similar in approach to LVC. And I've never seen anything about these being settable on the fly.
The throttle control is a much finer control of PWM pulse width. It should be smoothly and infinitely adjustable between 0-100% If it's hard to do that with the throttle that's a problem with the throttle not the controller response to throttle input voltage.
What's not clear is what happens when load and speed are such that 50% throttle hits a current limit. And most likely this is low speed, steep hill when the phase current rises dramatically due to the lack of back EMF from the motor so it's phase current that hits the controller's programmed limit.
I don't really see where the pulsing you're experiencing is coming from unless it's in the controller's response to over-current limiting. Perhaps it's on a slow hysterisis cycle.
The CA Manual specifically talks about implementing a current throttle, where the throttle controls the CA current limit, and the CA sends a variable voltage to the controller throttle input to keep the battery current below that set. This could only work if reducing the PWM sufficiently reduced the battery current.
The throttle control is a much finer control of PWM pulse width. It should be smoothly and infinitely adjustable between 0-100% If it's hard to do that with the throttle that's a problem with the throttle not the controller response to throttle input voltage.
What's not clear is what happens when load and speed are such that 50% throttle hits a current limit. And most likely this is low speed, steep hill when the phase current rises dramatically due to the lack of back EMF from the motor so it's phase current that hits the controller's programmed limit.
I don't really see where the pulsing you're experiencing is coming from unless it's in the controller's response to over-current limiting. Perhaps it's on a slow hysterisis cycle.
The CA Manual specifically talks about implementing a current throttle, where the throttle controls the CA current limit, and the CA sends a variable voltage to the controller throttle input to keep the battery current below that set. This could only work if reducing the PWM sufficiently reduced the battery current.
Yes that is what the pulsing is...the controllers response.
Reading about them, it appears the CA ramps down the throttle signal voltage so there is less on/off pulses (hysterisis) and much smooth control.
I ran into trouble with my current limiter because i was unware that the controller was also trying to do the same thing. When my circuit clamped the throttle signal the controller also cut the current completely so the response was on-off-on-off and very jerky....took me a while to figure it out.
This thread has helped.
Reading about them, it appears the CA ramps down the throttle signal voltage so there is less on/off pulses (hysterisis) and much smooth control.
I ran into trouble with my current limiter because i was unware that the controller was also trying to do the same thing. When my circuit clamped the throttle signal the controller also cut the current completely so the response was on-off-on-off and very jerky....took me a while to figure it out.
This thread has helped.
See here. Endless-sphere.com • View topic - **Important** reality check on motor, voltage, current etc. Jeremy seems to be saying that the current limiting circuits in the controller are significantly slower than the PWM frequency but probably faster than the phase frequency. So PWM is not being reduced on each PWM pulse but maybe during and before a single motor phase is complete. I think this is still much faster than the sort of pulsing you're seeing. The other factor is the block time parameter (default to 1sec). If it was that causing the pulse then I'd expect a 1 HZ cycle on your pulsing, but it sounds like you're getting a faster flicker than that.
Are you sure this pulsing is not just an artifact of your current limiter over-ride? Perhaps the gain and damping of your circuit is making it oscillate round the target values. The CA manual talks about this in their equivalent current limiter.
Are you sure this pulsing is not just an artifact of your current limiter over-ride? Perhaps the gain and damping of your circuit is making it oscillate round the target values. The CA manual talks about this in their equivalent current limiter.
NRG, I had a couple of questions about this controller that perhaps you can answer.
1) What is the wiring/connection for the 3 way speed setting? Is it some kind of binary on the voltage on 2 wires (eg 0-0 = slow, +5-0=medium, +5-+5=fast), or is it a voltage range on one wire (eg <1v=slow, 1-3v=medium, 3-5v=fast).
2) What options are there for pedelec vs throttle control? I'm assuming here that the pedelec is an on-off switch and the the cadence doesn't affect anything.
I have it in mind I want an option of using pedelec+throttle control together. So Pedelec is an on-off switch for motor drive, and the throttle controls the motor speed once on. The logic is to set the controller to fast, use a CA as a current limit on the throttle. And finally to have a 3 position switch on the CA-throttle control for low-medium-high current. Getting assist would still be the very natural act of pedalling or not. And the amount of assist would be set by the CA current limit setting.
1) What is the wiring/connection for the 3 way speed setting? Is it some kind of binary on the voltage on 2 wires (eg 0-0 = slow, +5-0=medium, +5-+5=fast), or is it a voltage range on one wire (eg <1v=slow, 1-3v=medium, 3-5v=fast).
2) What options are there for pedelec vs throttle control? I'm assuming here that the pedelec is an on-off switch and the the cadence doesn't affect anything.
I have it in mind I want an option of using pedelec+throttle control together. So Pedelec is an on-off switch for motor drive, and the throttle controls the motor speed once on. The logic is to set the controller to fast, use a CA as a current limit on the throttle. And finally to have a 3 position switch on the CA-throttle control for low-medium-high current. Getting assist would still be the very natural act of pedalling or not. And the amount of assist would be set by the CA current limit setting.
Hi Jbond,
1) its a grounding scheme AFAIK, for contact points SL, X1 and X2 using the switch. Depending on pad is grounded tells the controller what value to read as set in Parameter designer
2) the two seem to work together, I can use the throttle to get going, start pedalling and then the pedelec sensor takes over. There is some cadence control but its a very short steep ramp between starting the motor and reaching full motor speed.
I'm travelling at the moment so can't go and check but I think the pedalec overrides the throttle...if you can wait until the weekend I'll check it....
1) its a grounding scheme AFAIK, for contact points SL, X1 and X2 using the switch. Depending on pad is grounded tells the controller what value to read as set in Parameter designer
2) the two seem to work together, I can use the throttle to get going, start pedalling and then the pedelec sensor takes over. There is some cadence control but its a very short steep ramp between starting the motor and reaching full motor speed.
I'm travelling at the moment so can't go and check but I think the pedalec overrides the throttle...if you can wait until the weekend I'll check it....
No problemo, I'll happily wait.
The puzzle is that I think when the pedelec kicks in, the controller supplies whatever mode you're in as if the throttle was fully open. But to use the CA as a current limiter it needs to be able to control the throttle voltage and that's being ignored.
The slightly different controller on the Aurora has a pedelec-throttle switch that is either/or not and. I suspect all it does when in throttle mode is to disconnect the pedelec. I'll have to trace the wiring and see. To do my CA scheme, I'd need nothing till pedalling, and then throttle as well to control how much.
Unless there's another way round this, like the Cytronex approach. Buttons, plus cruise control, plus brake interlocks perhaps.
The puzzle is that I think when the pedelec kicks in, the controller supplies whatever mode you're in as if the throttle was fully open. But to use the CA as a current limiter it needs to be able to control the throttle voltage and that's being ignored.
The slightly different controller on the Aurora has a pedelec-throttle switch that is either/or not and. I suspect all it does when in throttle mode is to disconnect the pedelec. I'll have to trace the wiring and see. To do my CA scheme, I'd need nothing till pedalling, and then throttle as well to control how much.
Unless there's another way round this, like the Cytronex approach. Buttons, plus cruise control, plus brake interlocks perhaps.
OK I've had a play. There is definitely a cadence ramp using the pedelec but it is very short, the gearing would need to be significantly higher to make use of it. On the flat it's nearly impossible to control the bike speed by cadence, it can only be done if there is a gradient holding the bike back, then there is a degree of control.....something to push against otherwise on the flat you end up pedalling air.....
The throttle in this situation overrides the pedelec sensor, so if climbing a gradient and you find yourself in the wrong gear for instance, as long as the speed is below the limit set by the three way switch and cadence is below the maximum for full motor speed, opening the throttle causes the motor to try and pick up speed. If however, the cadence is high enough to cause the motor to turn at full RPM under normal conditions as set by the speed switch the throttle does nothing. IE: you can't use it to slow down or provide fine control, the throttle seems to only override the pedelec if cadence is below the max limit for full motor speed and then only to increase speed.
Hope this helps.
The throttle in this situation overrides the pedelec sensor, so if climbing a gradient and you find yourself in the wrong gear for instance, as long as the speed is below the limit set by the three way switch and cadence is below the maximum for full motor speed, opening the throttle causes the motor to try and pick up speed. If however, the cadence is high enough to cause the motor to turn at full RPM under normal conditions as set by the speed switch the throttle does nothing. IE: you can't use it to slow down or provide fine control, the throttle seems to only override the pedelec if cadence is below the max limit for full motor speed and then only to increase speed.
Hope this helps.
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Ho-hum. This is going to take some more electronics then. No way to make the controller's current limit variable. No way to make the speed control variable when pedelec is active.
Perhaps I could replace the throttle with a latching push button (with the brake cutout as well) Or perhaps a momentary push button with a latching circuit.
Or maybe I'm just barking up a tree that doesn't contain a 'coon.
Perhaps I could replace the throttle with a latching push button (with the brake cutout as well) Or perhaps a momentary push button with a latching circuit.
Or maybe I'm just barking up a tree that doesn't contain a 'coon.
Just bringing my mods to the Alien GSII up-to-date:
Fitted a 4" stem riser recently to give a more relaxed riding position. The front brake cable had to be replaced with a longer one and I also replaced the front and rear gear cables as although long enough I'd been a bit of a brute with them and the pinch bolts had squashed the ends.
The brakes have continued to nag at me. Despite replacing the cables previously and upgrading to Avid 20R rim pads the front brake still felt weak, squealed like mad and also juddered badly despite my attempts to adjust them.
So I bit the bullet and bought some Avid single Digit 5 V brakes from Chainreaction as they where on offer.
I also replaced the cables (again!) with some Clarke's supa doopa black ones, can't recall the name. Anyhow, the feel and performance improved noticeably but there was still a slightly soft feel to them and the flex could be seen when operating the levers.
So back to Chainreaction and I bought some BrandX brake boosters....wow! Super smooth feel, no juddering at all and dead quite....result.
Fitted a 4" stem riser recently to give a more relaxed riding position. The front brake cable had to be replaced with a longer one and I also replaced the front and rear gear cables as although long enough I'd been a bit of a brute with them and the pinch bolts had squashed the ends.
The brakes have continued to nag at me. Despite replacing the cables previously and upgrading to Avid 20R rim pads the front brake still felt weak, squealed like mad and also juddered badly despite my attempts to adjust them.
So I bit the bullet and bought some Avid single Digit 5 V brakes from Chainreaction as they where on offer.
I also replaced the cables (again!) with some Clarke's supa doopa black ones, can't recall the name. Anyhow, the feel and performance improved noticeably but there was still a slightly soft feel to them and the flex could be seen when operating the levers.
So back to Chainreaction and I bought some BrandX brake boosters....wow! Super smooth feel, no juddering at all and dead quite....result.
Hiya
Yeh! I lifted my aurora bars by fitting a quill extender here quill_extender Photo Gallery by david chilvers at pbase.com
Looks a bit unusual the way the bars are much higher than the saddle but it fits in with my back position just right (anymore upright and my spine feels the bumps and anymore laying forward and it puts me in the awkward angle (like leaning over the car engine syndrome and with extra battery and power the upright position doesn`t detract from performance. Lifting the bars certainly makes for a relaxed ride now that spring is in the air.
Dave
Yeh! I lifted my aurora bars by fitting a quill extender here quill_extender Photo Gallery by david chilvers at pbase.com
Looks a bit unusual the way the bars are much higher than the saddle but it fits in with my back position just right (anymore upright and my spine feels the bumps and anymore laying forward and it puts me in the awkward angle (like leaning over the car engine syndrome
and with extra battery and power the upright position doesn`t detract from performance. Lifting the bars certainly makes for a relaxed ride now that spring is in the air.Dave
Been meaning to add a Watts Up meter to the Alien for ages so finally got my finger out and added one.
Didn't want it on the handle bars as there's already enough 'stuff' on them and I don't need to keep watching a real time display so decided to fit it on top of the controller box.
4 holes some super strong double sided padded tape and it was attached to the box. Couple of connectors and it was up and running.
I need to seal it fully around the wires and display but it will do for now.
What prompted me to fit one after all this time is a feeling my battery is now getting on a bit and also I've been messing about with the controller parameters to try and see how low I could tweak the power before I noticed any effect on hills.
Currently I've set the battery current to 9amps, the true draw is 12amps so out by +3 on this controller, and the phase amps to 35...this is as low as I can set the controller although there is a 30amp setting the Parameter designer s/w throws a fit if I choose it...
Given 12amps x 36v power draw is 430w and on full charge (41v) 490w. Given some losses in the controller and wiring (say 20w) and motor efficiency of about 70% at half no load speed when climbing hills...I estimate the motor is making around 290w to 330w electrical power.
I've only test around the block and on a gentle hill and it feels no different to before but I'm sure when I seek out some 14% hills I'll notice it....
Didn't want it on the handle bars as there's already enough 'stuff' on them and I don't need to keep watching a real time display so decided to fit it on top of the controller box.
4 holes some super strong double sided padded tape and it was attached to the box. Couple of connectors and it was up and running.
I need to seal it fully around the wires and display but it will do for now.
What prompted me to fit one after all this time is a feeling my battery is now getting on a bit and also I've been messing about with the controller parameters to try and see how low I could tweak the power before I noticed any effect on hills.
Currently I've set the battery current to 9amps, the true draw is 12amps so out by +3 on this controller, and the phase amps to 35...this is as low as I can set the controller although there is a 30amp setting the Parameter designer s/w throws a fit if I choose it...
Given 12amps x 36v power draw is 430w and on full charge (41v) 490w. Given some losses in the controller and wiring (say 20w) and motor efficiency of about 70% at half no load speed when climbing hills...I estimate the motor is making around 290w to 330w electrical power.
I've only test around the block and on a gentle hill and it feels no different to before but I'm sure when I seek out some 14% hills I'll notice it....
D
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Nice looking mod. Shame you can't see it while you're riding. I thought you'd have done the remote shunt mod. Looks much better like this :
To save me re-reading the whole thread, could you remind me what controller you've got, where it came from and how much it costs.
. I thought you'd have done the remote shunt mod. Looks much better like this :
To save me re-reading the whole thread, could you remind me what controller you've got, where it came from and how much it costs.
I think a cell or cells in my Alien battery are getting a bit weak.
I've been getting some strange behaviour recently with the bike performing well fresh off charge but then suddenly cutting out for no reason, however, not completely....the motor still turns with no load and provides some assistance but very weakly. Resetting the controller brings the motor back to life and I can continue to ride.
Charged the battery yesterday, took about 3 hours and stopped at 40.7v...a bit down on what I was expecting. Plugged the charger in and out a few times but the green light came on after a few seconds.
So left it overnight and just tried the charger again this morning, its been on for about an hour and has just finished, reading is now a more healthy 41.7v
Think I'll have to pull it apart and check each cell individually.
I've been getting some strange behaviour recently with the bike performing well fresh off charge but then suddenly cutting out for no reason, however, not completely....the motor still turns with no load and provides some assistance but very weakly. Resetting the controller brings the motor back to life and I can continue to ride.
Charged the battery yesterday, took about 3 hours and stopped at 40.7v...a bit down on what I was expecting. Plugged the charger in and out a few times but the green light came on after a few seconds.
So left it overnight and just tried the charger again this morning, its been on for about an hour and has just finished, reading is now a more healthy 41.7v
Think I'll have to pull it apart and check each cell individually.
My Alien has grown horns!
Took a leaf out of Old Timers book and fitted some bar ends and also replaced the solid grips for some soft comfy ones from Specialized.
The grips have made a difference, less jarring on the wrists etc and the bar ends have improved the riding position no end. The bike feels more comfortable and strangely seems to handle better...anyhow I should have done this ages ago.
I also took the opportunity to replace the twist throttle (the new grips made it impossible to keep the old) with a thumb throttle. I'm not a fan of thumb throttles but as I only ever use it for assistance when pulling away from rest its not a problem.
Instead of pulling out the old wires and replacing with the new throttle wires I simply pulled both throttles apart, unhooked the wiring and hall sensor and swapped over the mechanical bits. The LED wires from the old throttle I cut off but left enough wire to rejoin if necessary.
Fitting all this lot was a bit of a pain as the new grips where quite a bit longer than the old ones and I had to trim 10mm of each one in the end so everything would fit.
In fact after taking the pictures I realised there was no room for my auxiliary light so the bell was moved to the left hand bar end and the cycle computer moved over creating some space. Sure looks busy now.
Still need a mirror and I have some new XCM forks to fit to replace the very basic Zoom's
Took a leaf out of Old Timers book and fitted some bar ends and also replaced the solid grips for some soft comfy ones from Specialized.
The grips have made a difference, less jarring on the wrists etc and the bar ends have improved the riding position no end. The bike feels more comfortable and strangely seems to handle better...anyhow I should have done this ages ago.
I also took the opportunity to replace the twist throttle (the new grips made it impossible to keep the old) with a thumb throttle. I'm not a fan of thumb throttles but as I only ever use it for assistance when pulling away from rest its not a problem.
Instead of pulling out the old wires and replacing with the new throttle wires I simply pulled both throttles apart, unhooked the wiring and hall sensor and swapped over the mechanical bits. The LED wires from the old throttle I cut off but left enough wire to rejoin if necessary.
Fitting all this lot was a bit of a pain as the new grips where quite a bit longer than the old ones and I had to trim 10mm of each one in the end so everything would fit.
In fact after taking the pictures I realised there was no room for my auxiliary light so the bell was moved to the left hand bar end and the cycle computer moved over creating some space. Sure looks busy now.
Still need a mirror and I have some new XCM forks to fit to replace the very basic Zoom's
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