CAv3 Max speed way too high (Phaserunner, GMAC 8T)

[cnrd]

Hi

I installed my new CAv3, Phaserunner and GMAC 8T yesterday, everything have been running smoothly for the long test run I took today, except for one thing, the max speed (MaxS) is significantly too high, for this run it said 143 km/h.

It seems like when I throttle from a standstill, the speed shoots up, after about a turn of the wheel the speed settle down to the correct value.

I have configured the CA to 6 magnets and set the wheel circumference to the correct value.

Anyone who knows how I can fix this?

Thanks!

 

[amberwolf]

You probably are getting electrical noise on the speed sensor line, induced from the phase wires.

If your hall sensor cable is separate from your phase wire cable, try physically separating them, and make sure the hall sensor cable from motor to controller doesnt' run directly along the frame, and the CA cable from controler to CA doesn't either.

If that works, then you can probably just put a small spacer /wrap between the frame and the cables above, and leave it at that.

If it doesn't, it may require a small (0.1uF to start with) capacitor on the speed sensor line on the CA connector where it plugs into the controller. You'd use a nonpolarized type, which would be wired with one leg to the speed sensor wire and one leg to the ground (battery negative) wire.

 

[momus3]

I just saw that. Thanks.

 

[amberwolf]

This is the first time on here that I've seen a post where someone was wanting their bike to go slower.

Then you still haven't seen such a post, because their post doesnt' say they want to go slower.

They're just troubleshooting an issue with the speedometer readout.

 

[cnrd]

If it doesn't, it may require a small (0.1uF to start with) capacitor on the speed sensor line on the CA connector where it plugs into the controller. You'd use a nonpolarized type, which would be wired with one leg to the speed sensor wire and one leg to the ground (battery negative) wire.

Thanks for the reply.

I'm using a Phaserunner_L10 and a CAv3_WP, so everything is connected with water resistant connectors.

Some time after asking this question the problem suddenly disappeared by it self for no apparent reason. Which meant I had no reason to look further and forgot everything about this question.

I recently had to swap some of the bearings in the motor and after putting it back to together the problem has returned. I have no idea why it disappeared and I have no idea why it reappeared.

Looking at the capacitor to fix this, it looks like what I should be making is a low pass filter, which seems to be a resistor + capacitor, any idea what value the resistor should be?

Also any guesses as to why the problem would reappear?

 

[rheo]

If it doesn't, it may require a small (0.1uF to start with) capacitor on the speed sensor line on the CA connector where it plugs into the controller. You'd use a nonpolarized type, which would be wired with one leg to the speed sensor wire and one leg to the ground (battery negative) wire.

Thanks for the reply.

I'm using a Phaserunner_L10 and a CAv3_WP, so everything is connected with water resistant connectors.

Some time after asking this question the problem suddenly disappeared by it self for no apparent reason. Which meant I had no reason to look further and forgot everything about this question.

I recently had to swap some of the bearings in the motor and after putting it back to together the problem has returned. I have no idea why it disappeared and I have no idea why it reappeared.

Looking at the capacitor to fix this, it looks like what I should be making is a low pass filter, which seems to be a resistor + capacitor, any idea what value the resistor should be?

Also any guesses as to why the problem would reappear?

Isn't it a bug in the ca3 firmware?

Sent from my Pixel 3a using Tapatalk

 

[amberwolf]

Some time after asking this question the problem suddenly disappeared by it self for no apparent reason. Which meant I had no reason to look further and forgot everything about this question.

I recently had to swap some of the bearings in the motor and after putting it back to together the problem has returned. I have no idea why it disappeared and I have no idea why it reappeared.

That kind of issue indicates a wire or connection problem, most likely in a connector between the motor and controller, since those are what would probably be disconnected and reconnected for the work performed.

It might not be the pins failing to make good contact, but rather where the wire enters the back of the contact, either broken or partly broken, or not fully soldered or crimped, etc. Can't see this in the overmolded water-resistant types of connectors, unfortunately, so have to use a multimeter to check resistance from tip of pin of connector to the point where the wire at the other end of the cable solders to something else.

While unlikely, it could even be in a wire between M & C, where it isn't broken, exactly, but it's a poor connection, from a type of splice I've seen several times now. The splice is done by teh company that makes the actual cabling, during the process before the outer jacket is molded over it, where htey just loop the end of the old spool of that color to the start of the new spool and continue feeding all the different colors into the cable-maker. Depending on the signals passed thru the cable, it may never be an issue...but if it was humid when the cable was made, it might trap some in the wire and corrode it slightly...or if the finger oils of the splicers got onto the conductors during the splice, etc. It's very rare...but it happens.

 

[cnrd]

Here is a reply I got from grin some time ago:

Thank you for the pictures.
Have you got the chance to set the DS Gain under the CA Speed Limit Setting to 0? It's a known issue with the GMAC where there is a lot of noise at low speed/high current that causes the speed signal to go crazy. The speed signal still won't be normal after setting the DS gain to 0, but the CA won't do any speed limiting and there won't be any loss of power.

It seems like they are working on a solution

We are working on this issue. Unfortunately, we have been quite busy over the past year and this problem is defiantly on our engineering team bucket list.

Also before I got the phaserunner + CAv3 I used the GMAC with a KT controller where I saw the same problem.

Seeing as the only thing that is constant is the GMAC my guess is the problem is somewhere there?

If it is a noise problem, do you think a low pass filter would help? I can easily cut up a short 8pin extension add the filter to the speedo wire and add that between the Phaserunner and CA. I just don't know what values I should use or if using only a capacitor is enough?