MAC 6T Suddenly has Regen??!

[GMUseless]

Well, all of a sudden my MAC 6T has regen. I had the bike on the stand and noticed it wasn't freewheeling properly. Then when spinning the cranks to check out the freewheel...I noticed the CA lighting up with no battery connected.

I'm guessing this is the clutch. I'll open it up soon.

Anyone else had this failure?

 

[Spicerack]

Nope but I'd say you're right on the money.

 

[neptronix]

Clutch.

 

[GMUseless]

Ok, I removed the wheel and popped the side cover. I then removed the circular retaining clip just above the clutch assembly. But, I can't seem to get the clutch pulled from the axel. Is there a trick to this? Shouldn't it just slide up and off?

 

[DAND214]

Being new it will be pretty tight on the shaft. the key is still snug too.
Need a puller if it's too tight.

I pulled mine out the gear side to use a couple levers to pull the clutch. A puller would work better and safer.

Dan

 

[GMUseless]

Thanks Dan. I'm not sure I have a puller that will work. If not I'll try some levers. I've seemed to I've misplaced my freewheel tool as well, so I'm trying to do this with the freewheel side intact. I just wanted to make sure that wasn't an issue.

 

[DAND214]

No need to remove the freewheel. mark you cover locations before removing them. It shouldn't make any differance as they should be all machined in mass not per motor but that is what all of post I read say to.

Dan

 

[miuan]

I've had this happen many times on both MAC and BPM motors.
Usually caused by a burst of torque after landing from a curb etc...
Always went away after a mile or two.
Never bothered to open the suckers up.

 

[Ypedal]

pics of an eZee.. but they are very similar.

http://ypedal.com/ezee.htm

 

[GMUseless]

Thanks Y. I've got an eZee as well, so that's good to know they're very similar.

Well, I went to pry the clutch assembly off with three composite tire levers: one between each planet gear. As I pried on one side I heard a fairly loud click and noticed the clutch assembly move perhaps a milimeter. And just like magic, the freewheeling is back.

Any ideas on what is going on here? I had noticed that when it wasn't freewheeling (or the one way bearing was acting like a two way bearing) there was a few degrees of slop/play upon reversal until the gears would start turning again.

The keyway looks fine, and I didn't noticed it move. And there was nothing loose that I could see inside.

Anyone who's completely torn these thing apart have a guess as to what causes this? Should I do some kind of preventive actions before buttoning it back up?

 

[Ypedal]

I've often wondered about locking up the freewheel intentionally to get regen, given my riding style ( throttle always on unless i'm on the brakes ) .. not sure how the gears would react to reverse forces however.

 

[Spicerack]

mark you cover locations before removing them. It shouldn't make any differance as they should be all machined in mass not per motor but that is what all of post I read say to.

Dan

Yes, they are machined in mass, all off centre just a tiny bit, so it really does make quite a difference! Ask me how......

I use a centre punch on each cover and the corresponding part of the hub.

 

[GMUseless]

I could of used that tip earlier today!

Anyway, this is what it looked like right after popping it back in place:


Everything else inside looked fine. Although, upon disconnecting the leads for removal, I noticed the Anderson's had melted / fused close a bit. Looks like I'm under gauged / need bigger connectors. I"m running 12s LiPo, with 1.8kw peaks.

 

[DAND214]

I'm still running the 30amp ones on 15s with no problem yet. It's only a 8t on both bikes. I guess I don't abuse it as much as others.
26" with 2.3 tires and they are still good.

I only have 6" out of the hub to 12g to the controller with 4mm bullets there. I like the plugs just incase I need to remove the wheel. Less hassel matching colors.

Last thing. I would get ahold of Cell-man and get a spare clutch. Or go to http://ebikessf.com/node/218
Dan

 

[veloman]

How long do you pull 1800w for? That's 40amps on 12s, right?

I have my controller set to 35amps and haven't had a problem with my 30amp andersons yet. I don't pull move than 1500w for a few seconds though.

 

[Spicerack]

I run 1800-2000 most of the time, with 5mm bullets for the phases. I'm on 15S(62V)

 

[d8veh]

If your clutch sticks, before going to all that trouble of taking your wheel off and dismantling the motor, you should try the simpler method to free it:
Whack the tyre in the forward direction with a tanjential blow from a big hammer, or you can practice your best Karate kicks on it if you're into that sort of thing. The impact will free it unless it's really stuck. Sometimes, jumping off a kerb or doing a bunny-hop is all that's required. My one took a big whack to free it the first time, and then each time thereafter it got a bit easier until finally it stopped sticking after about 500 miles.

 

[GMUseless]

How long do you pull 1800w for? That's 40amps on 12s, right?

I have my controller set to 35amps and haven't had a problem with my 30amp andersons yet. I don't pull move than 1500w for a few seconds though.

I don't pull on it more than a few seconds: acceleration from stop, starting on an incline, etc. It's the stock 1000w setup from Cell_man, with the controller settings as shipped.

After about 200 miles on this setup I broke everything down and checked the connections ( I've ridden through some torrential downpours, so I was mainly looking for water damage/corrosion.) Everything look fine. Right after this, I've moved and am currently working from home..so I'm not commuting right now. I've taken maybe 5 small rides after the last check, and now I've found the connectors fried.

I'm wondering if it had something to do with losing the freewheel and the resulting regen. I would think not since there shouldn't be any real regen current happening: that is I don't think it's charging the batteries...just powering the controller and 5v rail.

Also, one night during the move the bike was racked on my car, and we had 6 inches of rain overnight. So maybe some water got in at the point and I had some arcing / corrosive resistance at the connectors.

 

[GMUseless]

If your clutch sticks, before going to all that trouble of taking your wheel off and dismantling the motor, you should try the simpler method to free it:
Whack the tyre in the forward direction with a tanjential blow from a big hammer, or you can practice your best Karate kicks on it if you're into that sort of thing. The impact will free it unless it's really stuck. Sometimes, jumping off a kerb or doing a bunny-hop is all that's required. My one took a big whack to free it the first time, and then each time thereafter it got a bit easier until finally it stopped sticking after about 500 miles.

Thanks man. Next time I'll definately just beat it back into submission. But you know..curiousity...you've got to open it up and take look at least once.

 

[Ypedal]

sounds like a thin brass spacer or shim could be handy in those..