h0ts1lk

ACM 16 Wobble "Play" Before Acceleration Help

24 posts in this topic

Before I take this thing apart, I'm wondering if you guys can give me some insight on what this "wobble" or "play" is so that I know what to watch out for and what I'm getting into.

How dangerous is this?

I've attached a video, but I'm not sure if it will display properly.

Gotway ACM 16 Wobble Play VLC Android SD High.mp4

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Have a good look at the hall sensor wires, I'd bet it's them causing this behaviour. Those are the 5 small wires next to the main motor wires coming out of the motor.

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Posted (edited)

Looks very much like loose axle/axle nuts to me. The behavior is consistent with that, a short "loose" phase before the nuts grip and the wheel behaves as normal. Everytime you change direction/re-accelerate, it repeats itself.

Good thing, you can check this by just opening the side panels and look at the axle and nuts on both sides (possibly while repeating the stuff in your video to see it in motion). No serious disassembly required.

New wheel, or started to happen with existing wheel?

Edited by meepmeepmayer
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4 minutes ago, meepmeepmayer said:

New wheel, or started to happen with existing wheel?

I've had it for 2093km.  I noticed it when I first got the machine, but it was very slight, and I asked on Facebook or this forum (I forgot) and the answer was, "Welcome to Gotway."

It wasn't very noticeable until 2000km.

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If it got gradually worse, that is also consistent with the nuts getting loose over time.

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Just now, meepmeepmayer said:

If it got gradually worse, that is also consistent with the nuts getting loose over time.

I will check tomorrow.  Thanks, Meep.

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I'm no expert but your video looks exactly like the axle is not gripping perfectly, so that's why I think it must be this.

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On 5/16/2017 at 3:15 PM, h0ts1lk said:

Before I take this thing apart, I'm wondering if you guys can give me some insight on what this "wobble" or "play" is so that I know what to watch out for and what I'm getting into.

How dangerous is this?

I've attached a video, but I'm not sure if it will display properly.

Gotway ACM 16 Wobble Play VLC Android SD High.mp4

if I am not mistaken your left pedal is loose. At least it looks like it is shifting in the video.  I believe that is your problem. Hopefully it has not worn into the aluminium material. You might have to add a piece/strip of metal to fill up worn area on the clamping bars.

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On 5/16/2017 at 11:46 PM, meepmeepmayer said:

I'm no expert but your video looks exactly like the axle is not gripping perfectly, so that's why I think it must be this.

I removed the cover and it doesn't seem like the nut is the problem.  Maybe I'm wrong.  Can you take a look at the video?

Test Video2 Android HD.mp4

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On 5/16/2017 at 4:21 PM, Slaughthammer said:

Have a good look at the hall sensor wires, I'd bet it's them causing this behaviour. Those are the 5 small wires next to the main motor wires coming out of the motor.

I agree, think it's a hall sensor problem.

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Posted (edited)

2nd video would still make me believe there might be something loose/broken inside (because it only happens when changing directions/starting from 0, but not in continuous motion), but if the dealer says it's a hall sensor problem, trust the dealer;)

There was a similar thread where a wheel was malfunctioning due to hall sensor problems. Turns out, just the connector plug on the mainboard was bad, one of the 5 wires wasn't connecting properly. Have a look and maybe you see something that helps you.

Or just contact your seller and ask.

Edited by meepmeepmayer
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Here's a video where you can see the axle assembly really well.

 

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On 5/18/2017 at 11:39 PM, Jason McNeil said:

I agree, think it's a hall sensor problem.

Hm.. I am looking at them, but what am I really looking for?  The connector is white glued (silicon?) to the board.  Shall I remove it and reinsert?

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1 hour ago, h0ts1lk said:

Hm.. I am looking at them, but what am I really looking for?  The connector is white glued (silicon?) to the board.  Shall I remove it and reinsert?

That link shows a pin on the hall sensor cable that was defective and not seated all the way in.

 

IMG_7450.thumb.JPG.804b22cae76b69e9135db46f200c906f.JPG

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On 5/18/2017 at 1:33 AM, Carlos E Rodriguez said:

if I am not mistaken your left pedal is loose. At least it looks like it is shifting in the video.  I believe that is your problem. Hopefully it has not worn into the aluminium material. You might have to add a piece/strip of metal to fill up worn area on the clamping bars.

I took a look at the pedal and it wasn't loose.  Thanks for mentioning this.

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18 hours ago, Carlos E Rodriguez said:

That link shows a pin on the hall sensor cable that was defective and not seated all the way in.

Here I pulled the hall sensor off of the board and inspected it.  I moved the cables around and everything seems to move freely.  I reinserted the cable and the problem still exists.  This is a picture that I took before reinsertion.

 

 

20170520_175620 50 percent.jpg

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Posted (edited)

2 hours ago, h0ts1lk said:

Here I pulled the hall sensor off of the board and inspected it.  I moved the cables around and everything seems to move freely.  I reinserted the cable and the problem still exists.  This is a picture that I took before reinsertion.

 

 

20170520_175620 50 percent.jpg

Pin 2 and pin 5 from left to right look damaged like the link o posted earlier on similar issue on a different wheel. 

The pins should not move up and down.  Inside the connector. 

Remove all the glue very carefully.

then tug on the wire one by one with say about 1lbs pound of force then push in. The pins should not move. If it does that need to be corrected. 

A hobby shop for RC planes helicopter drones model train shop should be able to fix for you. 

Edited by Carlos E Rodriguez
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38 minutes ago, Carlos E Rodriguez said:

Pin 2 and pin 5 from left to right look damaged like the link o posted earlier on similar issue on a different wheel. 

The pins should not move up and down.  Inside the connector. 

Remove all the glue very carefully.

then tug on the wire one by one with say about 1lbs pound of force then push in. The pins should not move. If it does that need to be corrected. 

A hobby shop for RC planes helicopter drones model train shop should be able to fix for you. 

Oh wow, yep.  They all move.  Thanks, Carlos.

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My MCM4 seems to be doing the same exact thing and its my second day riding it.  Bought it off a seller on E bay who is a dealer in NYC.  Very frustrating to have to repair my wheel after not even riding for 2 miles. 

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13 hours ago, Carlos E Rodriguez said:

@h0ts1lk @Acturbo  

have you solved the issue?

So I did not have a new connector, but I did have the pins and tools to change at least the pins out.  I turned it back on, ran calibration, but still the same problem.  

I started to disassemble the wheel, but someone, probably me, a long time ago, used red loctite on the six large screws holding in one side of the shell.  Two of those screws came out fine, but the other four are stripping the head and are there for good.  I cannot remove the shell any further without causing permanent damage.  I can however, reassemble the entire wheel as-is and ride it, but that leads me to question:

How dangerous is this wobble/play?

As the wheel and shell lay on it's side, I wiggle the shell, and it is reproducing the same effect though minor than in the video, and is leading me to believe that after +2000km of hard riding, the plastic shell/chasis may be showing wear and tear, thus giving the "wobble" and "play."

But again, I am no expert, and a solution is still in the air.  

As far as I am concerned, there are two possible outcomes to both our hypothesis: either the hall sensor is bad and it's decently safe to ride though serious failure is imminent, or the shell is showing wear and tear which eventually, will result in catastrophe - especially at the speeds that I ride.  Both of these scenarios are reason enough for me to say that this wheel is done.  

For now, I would only feel safe riding this wheel with majority of its parts replaced.  

What do you think Carlos?

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16 minutes ago, h0ts1lk said:

As the wheel and shell lay on it's side, I wiggle the shell, and it is reproducing the same effect though minor than in the video, and is leading me to believe that after +2000km of hard riding, the plastic shell/chasis may be showing wear and tear, thus giving the "wobble" and "play."

The pedal brackets are screwed to the motor, the shell is screwed to the pedal brackets, and the board is screwed to the shell AND the pedal bracket (but probably, the board moves with the shell, not the bracket).

You're right, a loose shell might confuse the gyro sensor while the hall sensors are ok. In that case you'd need to replace the shell (and move the board to the new one) which unfortunately means opening and redoing the motor connectors.

So either find out more (find out exactly what is wrong) and do the repairs, or go for a new wheel.

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1 hour ago, meepmeepmayer said:

The pedal brackets are screwed to the motor, the shell is screwed to the pedal brackets, and the board is screwed to the shell AND the pedal bracket (but probably, the board moves with the shell, not the bracket).

You're right, a loose shell might confuse the gyro sensor while the hall sensors are ok. In that case you'd need to replace the shell (and move the board to the new one) which unfortunately means opening and redoing the motor connectors.

So either find out more (find out exactly what is wrong) and do the repairs, or go for a new wheel.

on this model the board is screwed to the pedal bracket. like mentioned abouve.

. With a small drill bit say 1/8, start a shallow pilot hole abpout 1/16 deep and no more.  With a thicker drill bit but smaller that the screw diamater drill into the screw 1/16 or 2/16 or inch deep.

MAKE SURE YOU DO NOT DRILL INTO THE SCREW HOLE WALLS. Only drill into the screw itself. Then buy a screw remover tap set. they are very inexpensive at your discount hardware store.

I believe ACETONE/nail polish remover should help soften the locktite. Put some drops and keep wet for 5 minutes.  

Use the screw remover tool and the screw should come right out.

 

with the sheel out you can pull the pedals  in opposite directions. if you feel movement, that is a problem. if the nut has locktite then the nut might feel tight but it could still be loose because the vise clamping component has worn out somehow. due to it might not have been tight enough originally. all it takes is the slightest inperseptible play and it will get worst with time until it becomes a problem.

Edited by Carlos E Rodriguez
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4 hours ago, Carlos E Rodriguez said:

with the sheel out you can pull the pedals  in opposite directions. if you feel movement, that is a problem. if the nut has locktite then the nut might feel tight but it could still be loose because the vise clamping component has worn out somehow. due to it might not have been tight enough originally. all it takes is the slightest inperseptible play and it will get worst with time until it becomes a problem.

Perfect.  I'll give this a try in my evenings.  Thanks, Carlos.  I will update by next week.

 

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