Popping sound

[oldwahoo54]

I have a Mac 10t with a 36V em3ev framepack battery, 6 fet controller. and CA V3. We are in our 3rd year and now have ~2700 miles on the bike. I have been running the max PAS speed at 23 mph and the max PAS watts at 800. I occasionally get this noise from somewhere and I'd like to diagnose it and fix if possible. You can hear the noise about half way through this video as I resume pedaling: https://www.youtube.com/watch?v=Z_tU4KH42p4 (video is 30 seconds long). It always seems to occur as I resume pedaling. Not sure it's ever occurred at other times.

I put the Lyen tester on the phase wires and got all three blinking when I turn the rear wheel in reverse, but I don't get anything when I test the Halls, turning the rear wheel either way. Does that help?

thanks

 

[Ykick]

I don't have a Mac but if I had to venture a generic "geared hub" motor guess, I say it was the clutch momentarily slipping?

Other folks will probably want to chime in so here's your video embedded (16sec) - [youtube]Z_tU4KH42p4[/youtube]

 

[teklektik]

+1
Ya - It's your clutch being over-torqued and 'slipping' - with 100% certainty.

Since you are riding an old build I'm guessing it has old CA firmware. Upgrading to the new CA V3.0 production release is recommended as a start. (Get an updated V3 Guide as well.) This more recent V3 firmware removes a power jolt that can occur when PAS is re-engaged, which will quite likely remedy your issue. The sudden momentary power application is likely overloading the clutch and causing a brief hissy fit.

If this doesn't fix it, you can try increasing ThrO->UpRate or reducing PLim->WGain to 10-15 to soften the getaway. Either of these will add some throttle lag, so going with the newer firmware is the preferred first step.

That said, your clutch shouldn't be doing that at your power levels. If the firmware fix works, you are good to go for some time, but if the clutch begins making with any frequency that machine gun auto-fire sound on getaways, going up hills, or on rough road impacts when under power, you might consider replacing it. The best bet is to get both a new clutch and new gears from EM3EV and replace the whole gear cluster. There are a couple of good threads on this here on ES. Also, see my build thread about gear replacement for the BMC (the motors are essentially identical). So - not trying to scare you into a clutch replacement - just some info if the problem becomes acute. In any case, as bad as the sound is, it cannot harm the rest of the motor - just scares pets and children... (maybe adults, too)

 

[oldwahoo54]

yes, teklektik, the CA has whatever build came with it 2 years ago. So I'll check into that first.

I tried messing around with a few of those parameters a while back trying to reduce the lag before re-engage. That is, starting up a hill after the motor had cut off going down, I didn't want it slow down so much before kicking back in. I sort of solved that by raising the max PAS speed, but I may not have reset the parameters I changed. I have to say I had a hard time noticing any effect from the changes I made.

Anyway, I'll get this upgrade and see if I can figure out what I changes and set them back to what they were. With any luck, I recorded them somewhere.

 

[teklektik]

Sounds good.

Check out the newer Guide regarding throttle ramping ( section 4.8 ). This section was improved a slight bit since the version of 2 years past and may be more helpful...

 

[oldwahoo54]

Well, I've looked high and low for my TTL-USB cable and can't find it anywhere. Anyone know of a supplier closer to the east coast than ebikes.ca?

teklektik, after looking at the manual, the param settings on my bike seem way too high. Can you confirm?

thrO->Uprate: 10 V/sec
->DownRate: 20 V/sec
->FastRate: 20 V/sec
->FastThrsh: 3.00 Amps
->minOut: 1.30 V
->maxOut: 3.65 V

I don't remember if those were original or if I set them that way, but it seems like the top 3 should be lowered down into single digits.

 

[teklektik]

thrO->Uprate: 10 V/sec
->DownRate: 20 V/sec
->FastRate: 20 V/sec
->FastThrsh: 3.00 Amps
... it seems like the top 3 should be lowered down into single digits.

Ya - the UpRate and FastRate are way too fast - sort of a clutch-eater. Downrate is a matter of taste, Mine is set even faster (larger) than yours...

I would recommend setting FastThresh = 0 to deactivate FastRate to start, then tune UpRate for the gentlest getaway you can tolerate responsiveness-wise.

Either leave FastThresh that way, or if you want to minimize freewheel re-engagement time at speed:
Lift the drive wheel and note your no-load current draw at WOT. Add maybe 25-35% and set that as FastThresh. Set FastRate 2x or more UpRate so it runs up to speed quickly but doesn't give a jolt when it engages. You will need to mess around, but that should get things running -- more or less.

FWIW:

• The new 3.1b2 firmware has flags showing the xxRate limits at work - which is pretty helpful -- but since you're happy with the existing 3.0 stuff and 3.1 requires re-entering the whole setup from scratch, it's probably not worth the effort unless other features look attractive. The 3.0 production software is compatible with your old settings and not in the same 'not-yet-prime-time' category as 3.1b2....

As far as the cable goes - Grin doesn't sell them via Amazon - which is too bad.
But - I just checked eBay and HPC has a bunch of CA cables for $10+shipping - a super bargain:
http://www.ebay.com/itm/like/181560421368?lpid=82&chn=ps&ul_noapp=true

 

[oldwahoo54]

OK, I got my cable. lsusb yields

Bus 001 Device 008: ID 0403:6015 Future Technology Devices International, Ltd Bridge(I2C/SPI/UART/FIFO)

as the location of the cable, but the choices in the Read Setup menu don't match, or it's not obvious which one is the match. Any hints?

Running Ubuntu BTW

 

[oldwahoo54]

Apparently it's /dev/ttyUSB0, but I'm getting the following error:

Failed to read setup from Cycle Analyst! Please make sure you have selected the correct COM port and that your Cycle Analyst is turned on and properly connected, then try again.

Battery is on, CA is on. Not sure what the problem is.

 

[teklektik]

Yahoo! Good to have a cable in hand...

...I'm getting the following error:

Failed to read setup from Cycle Analyst! Please make sure you have selected the correct COM port and that your Cycle Analyst is turned on and properly connected, then try again.

I've never run the Linux version so no help here. There is a comms issue in the Windows version that can cause the messaging error you report, but I'm unsure if it is also manifest in the Linux build.

I think you best bet is to contact Grin directly so Justin or Michael can give you direct advice to get connected.

Meanwhile - are you running Setup Utility v1.31?
If not, you will need it and can download it from the Grin V3 page.

 

[oldwahoo54]

Yes, I just downloaded it a few days ago. Will contact the Grin folks.

 

[oldwahoo54]

Apparently just some sort of permissions issue. Ran the startup script as 'sudo' and all was well.