Cruise Control minimum engage speed LCD3 w/Kt Contoller

[AHicks]

Easy question. Right now, the only way the cruise will engage is to be going 20+mph. Has anyone figure out how to lower the minimum engagement speed to something more convenient - like maybe 10mph?

Thanks for any insight you may have.

 

[aroundqube]

The set-up manual says that the cruise function begins to work above 17 kph ( 10.6 mph ? ) . I imagine it calculates based on the wheel size chosen in the set-up procedure.

 

[Johne-bike]

I have an all KT setup.. KT 45amp Sinewave controller, KT-D12L PAS kit, and KT LCD6 display driving a Mxus 3000w motor. The PAS locks in after the LCD6 shows 15kph or over. I have the wheel size set to 28" on my 26" Fatbike.
My Daughter's 20" Fatbike is also an all KT setup, and the PAS also locks in after the LCD3 Display shows 15kph or higher.
I also think you may have your wheel diameter set incorrectly in the KT setup parameters.

 

[AHicks]

Well, my instructions show 7kmh as minimum engagement speed, and this is how both of my previous (similar) conversions worked.

I had actually, figured out how to set the wheel size to match my 26" wheels. Pretty basic....

The biggest difference in the installs I've done successfully previous to this one, is regarding the PAS sensors, and the newest install is a 1500w motor where the previous were 1000w. The previous installs used 8 magnet sensors (probably KT manf/supplied) and ran well with C1 set on 01. This newest has a 12 magnet setup (that was already on the bike) that would not work with C1=01 as the previous bikes did. PAS was completely inop. when set that way

So I set it using the "reverse 12 signal" as it has 12 magnets, using C1= 07. With no other changes made, PAS was now fully functional, or it seemed that way at least.

When I started messing with the cruise, I didn't think it was working at all, so I double checked to make sure it was enabled (C7=1), which it was. It wasn't until it occurred to me to try engaging it at higher speeds with the rear wheel held off the ground that I discovered the cruise worked fine - starting at 20mph - WAY over the suggested 7kmh minimum.

Because of the difference in the PAS sensors I was using, I tried C1=05 (thinking 6 magnet signal may help), with no difference. PAS worked, but minimum cruise engage still 20 mph. On a lark, I tried C1=06 (reverse 10 signal), and my minimum engage speed dropped to 15mph, leading me to believe I was getting close to the actual issue, but I have yet to get it any closer.

I am not sure of the "forward signal" vs. "reverse signal" significance to the controller. Forward signal uses 00, 01 (which we know leaves PAS disabled), and 02 for parameters. Reverse signal uses 05 through 07.

I'm also not sure of what is meant by a PAS "locking in". Are you talking cruise will engage at those speeds? My PAS is working as soon as I start pedaling.

Thanks much for the input/ideas. It's surely appreciated.

 

[wturber]

I don't think the number of PAS sensor magnets has anything to do with wheels speed. After all, how does the controller know what your gearing is. I think the controller understands rpm and hence speed by the signals that come from the hall sensors. Maybe you don't have the right Hall sensor config for the new and different motor?

 

[AHicks]

Current logic is that if changing C1 ( power assist sensor parameter) from 05 and 07 (which allowed cruise engage at 20 mph), to 06 (which allows it to engage at 15), I must be on the right track? Or at least it seems that way to me. Further, this is the only piece of hardware that different when comparing this bike to the 2 previous bikes. I does seem weird that this is affected the way it is, as the pedals aren't even turning when I'm testing. The bike is stationary w/rear tire in the air....

Re: hall sensors, I wish I knew more about this. I can share that all 3 motors are set up the same way/using the same parameters, with P2=0 (wheel speed sensor) and C2 =0 (Motor Phase Classification Coding Mode). These settings both advised by the e-bay seller.

If I'm missing something else, I'm here to learn. All ears. It's a mystery to me.

Sure would be nice if somebody more knowledgeable would/could expand on the "chinglish" interpretations that define the LCD3 parameters in the pdf manuals - OR - if somebody knows somebody that has done that, a link to that would be a godsend about now!

Thanks for sharing your thoughts!

 

[wturber]

I shoulda looked up the C an P settings B4 posting. It just seemed like you were fiddling with PAS settings.

I'll see if I can find time tonight to go over the docs and see if anything jumps out at me.

 

[wturber]

Current logic is that if changing C1 ( power assist sensor parameter) from 05 and 07 (which allowed cruise engage at 20 mph), to 06 (which allows it to engage at 15), I must be on the right track?

Assuming that something else didn't change and that you have the cause and effect correct, I'd guess that is a quirk of the system and that you are not on the right track. The PAS settings should have no relationship to the cruise control speed.

Or at least it seems that way to me. Further, this is the only piece of hardware that different when comparing this bike to the 2 previous bikes. I does seem weird that this is affected the way it is, as the pedals aren't even turning when I'm testing. The bike is stationary w/rear tire in the air....

Right. I don't see how/why there would or should be a connection. Also, there is another hardware difference, the motor.

Re: hall sensors, I wish I knew more about this. I can share that all 3 motors are set up the same way/using the same parameters, with P2=0 (wheel speed sensor) and C2 =0 (Motor Phase Classification Coding Mode). These settings both advised by the e-bay seller.

If I'm missing something else, I'm here to learn. All ears. It's a mystery to me.

If I were to change anything, it would be the P2 number. I'd be inclined to assume that the seller has the right P1 (rotor magnets) and C2 (motor phase) numbers correct if this came as a kit.

My problem with the logic of changing P2 is that it would seem to me that the speedometer might be off as well if the sensor count was wrong. But I'm not really sure. It would seem to me that there should be no need for a P2 if P1 is correct.

It just seems to me that something is interpreting the motor speed incorrectly.

Anyway, those are my thoughts. Not sure if it will be of any help.

 

[AHicks]

<<<"It would seem to me that there should be no need for a P2 if P1 is correct.">>>

From what little understanding I have, that seems to be the consensus - and the reason P2/wheel speed sensor is set to 0 (which I'm interpreting as "off"). My thought is, the P2 setting may come into play if an external wheel speed sensor has been installed.

Thanks so much for having a look at it for me. Much appreciated.

 

[wturber]

<<<"It would seem to me that there should be no need for a P2 if P1 is correct.">>>

From what little understanding I have, that seems to be the consensus - and the reason P2/wheel speed sensor is set to 0 (which I'm interpreting as "off"). My thought is, the P2 setting may come into play if an external wheel speed sensor has been installed.

Thanks so much for having a look at it for me. Much appreciated.

On the surface, the notion of an external sensor makes sense. But the settings are for one through six impulses. I think you generally only install one wheel sensor for speed monitoring purposes. Either way, I'd try fiddling with P2. It seems less likely to mess up any other functions.

 

[AHicks]

More messing around-
P2 set to anything but 0 disables the speedo function. Sounded hopeful, but that look's like a dead end.

P1 set to anything but 46 skews speedo calibration accuracy. Set to 92 for instance, it dropped cruise engagement to my target 10 mph (indicated), but the bike was actually going well over 20mph (as measured on butt meter dyno).

 

[wturber]

More messing around-
P2 set to anything but 0 disables the speedo function. Sounded hopeful, but that look's like a dead end.

P1 set to anything but 46 skews speedo calibration accuracy. Set to 92 for instance, it dropped cruise engagement to my target 10 mph (indicated), but the bike was actually going well over 20mph (as measured on butt meter dyno).

Your butt meter dyno is probably about right, but you could use a GPS to confirm speedo accuracy to be sure.

Here's a shot in the dark - try some different settings on C11 - meter protocol.