# FB1-4001A Shaft Failure



## TheSGC (Nov 15, 2007)

So today I took apart my EV to replace some bearings in my transmission, which I should have done before I started my conversion.

Well I found the coupling to be loose and after removing it I found the shaft shot to hell along with the inner piece of my taper locking coupling:
















I have two theories on the failure: the first being misalignment and the second being a soft shaft. My dad (who is a mechanical engineer and helped design the coupling) has always thought this particular shaft was soft. 

Now I am not the first owner of this motor. It was sold by EV America back in 1996 to someone else who used it for 2-3 years then his EV died and he garaged it. I basically got it for free of Craigslist and put 10K on it on two EVs. 

I did kick up the current setting on my Zilla to 600 motor amps a month or so ago and I bet that didn't help.

Now I am in the market for a new motor and I'm about to start my research and I am going to try and locate a local motor repair shop if possible.


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## TheSGC (Nov 15, 2007)

I am going to get a new motor to replace this one to keep my EV running, but I was thinking about the rebuild on this one. 

First Idea: Get it rebuilt. I want to get a new shaft for it so does anyone know if there are any out there or should I get a machine shop to build one?

Seconds Idea: Get the shaft turned down to a smaller diameter, maybe 1" and a new keyway made.

Any other ideas?


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## major (Apr 4, 2008)

TheSGC said:


> I am going to get a new motor to replace this one to keep my EV running, but I was thinking about the rebuild on this one.
> 
> First Idea: Get it rebuilt. I want to get a new shaft for it so does anyone know if there are any out there or should I get a machine shop to build one?
> 
> ...


I was hoping someone else would chime in. It looks to me that this was caused by a loose coupler on the shaft and possible misalignment. I am unsure about a need for a pilot bearing and thought others might comment.

As far as fixing it, yes, you can turn it down. I'd get a taper lock coupler first and have it machined to fit then you don't need to cut a keyway.

major


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## TheSGC (Nov 15, 2007)

Yeah, with further investigating we think enough rust built up on the inner part of the taper locking coupling that wore away in the 2k miles I put on my new EV and that allowed it to loosen again a bit. So bascially it was never truly tight on this EV.

Later tonight and tomorrow my dad and I are going to breakdown the whole thing. 

For a replacement motor should I get another FB1-4001a or get a Warp 9? I do need to have it advanced for CW cause I have a Honda and I don't know if the new FB1s have adjustable timing.


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## ruckus (Apr 15, 2009)

Hello,

Sorry for your loss. A few things..

1. Soft might not be the right word. A 'soft' shaft will be more flexible and withstand misalignment better than a 'hard' shaft which will become brittle and break/fracture. 

2. Yes, misalignment or a loose coupling does cause these type of failures.

3. ADC vs WARP. I would strongly suggest you go with a Warp. I used an ADC on the 37 Jag because it was 'on sale' and have always regretted it. At EVCCON folks with an equivalent size warp were smoking tires while the ADC was 'working' (if you consider cringing while the motor brushes make a gkkkkkxxxzzz!!! sound as working). Also George is an upstanding fellow who stands behind his product. ADC... well, the warranty ran out before we even had it running or started finding chunks of the balancing putty in the engine bay... Go with WARP.

sorry, have to go.... more later.


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## TheSGC (Nov 15, 2007)

I am leaning towards the Warp, I sent a few emails trying to see who has one ready for shipping. 

Tomorrow morning I am calling a local motor repair shop that might be able to replace the shaft. I am hoping that they can replace the shaft for a decent price, but I need to redo other parts of the motor too. 

What is really interesting to us is that the key for the shaft is completely gone like it was vaporized.


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## major (Apr 4, 2008)

TheSGC said:


> What is really interesting to us is that the key for the shaft is completely gone like it was vaporized.


Fretting corrosion. The key turned into rust. But I don't understand. Taper lock couplings don't use keys. You photo doesn't look like taper locks I've seen.


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## ruckus (Apr 15, 2009)

Yes, 'fretting' or 'rabbiting'. There was another of the same thing not too long ago. On that one most of the shaft was powder.

I know someone who has an extra Warp 9 they are selling for less than book if you are interested. Where are you located?


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## TheSGC (Nov 15, 2007)

major said:


> Fretting corrosion. The key turned into rust. But I don't understand. Taper lock couplings don't use keys. You photo doesn't look like taper locks I've seen.


I designed and built this coupling and the taper piece I used as the base on the motor shaft had a key so we decided to use it. I'll separate the coupling later today and post more pictures.


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## TheSGC (Nov 15, 2007)

ruckus said:


> Yes, 'fretting' or 'rabbiting'. There was another of the same thing not too long ago. On that one most of the shaft was powder.
> 
> I know someone who has an extra Warp 9 they are selling for less than book if you are interested. Where are you located?


We definitely think its a misalignment so the next motor I get we are going to check the alignment better. 

I am near Boston, MA.


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## electro wrks (Mar 5, 2012)

Great project! Bummer this happened. This seems to be a recurring theme with many DIY motor couplers.

The type of QD(for '"Quick Disconnect"or "Dismount", pioneered by Browning) tapered bushing you're using has contraction slot(s) on the tapered portion only. If the tapered end of the bushing is hanging off the end of the motor shaft, it may try to squeeze itself off. Try using a bushing that has a slot cut through the bushing flange as well. They seem to grip better and more evenly along the shaft. The QD's usually have a keyway, too. 

Also, your trans. input shaft has a spigot for a pilot bearing. If you don't have a support for the spigot built into your coupler, that might explain(along with alignment issues)the problems with the input shaft bearing(s). 

I've got photos, but I can't seem to upload them. Can somebody walk a newbe through the process


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## TheSGC (Nov 15, 2007)

It's a pain, but definitely something I can avoid next time. Some modifications are going to happen once I get the new taper inserts in and on Monday I plan on ordering my new motor. 

I am about to go take my coupling apart and remove the flywheel to get a better look at it and take notes on the insert. The design seems fine, I think this was a result of installation error aka "want EV grin now" syndrome.

All I can say is that I did not buy this motor, I got it in a trade years ago and I am going to rebuild it in some fashion.


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## electro wrks (Mar 5, 2012)

Here are the two types of bushings:


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## TheSGC (Nov 15, 2007)

electro wrks said:


> Here are the two types of bushings:


I am using the one on the left. I have 4 on the way so I might experiment with some of them, they are cheap enough.


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## TheSGC (Nov 15, 2007)

Does anyone have a guess of what a machine shop would charge to rework the shaft?

I was quoted $615 to get a whole new armature straight from ADC/AMD and that didn't sound too bad to me. I did just order up a Warp 9 from EV America, who also quoted me the armature. 

I didn't order a new armature yet because I want to breakdown the motor and make sure all is well, I may have some bearing issues on it and the motor face may need some help as it has some wear marks where the bolts on my coupling hit it.


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## electro wrks (Mar 5, 2012)

TheSGC said:


> I am using the one on the left. I have 4 on the way so I might experiment with some of them, they are cheap enough.


Be sure to let us know how your next attempts at this setup work. Aligning the motor to the trans. is difficult to do correctly. The original ICE, aligned with dowels, is located within +or- a few thousands of an inch(about the thickness of two hairs).

This kind of precision is difficult to achieve without the skilled use of measuring and alignment tools. And, once properly aligned, dowel holes will have to be drilled and reamed through the motor plate and the trans. to maintain the alignment when the motor plate is taken off and put back on. Bolt holes alone usually are not precise enough.

Also, in your case with the motor mounted on stand-offs, you'll have to figure out someway to index the alignment between the plate and the motor. Bolts alone, as before, usually are not precise enough. Maybe dowel sleeves(around the bolts) can be used in 2 of the stand-offs and the stand-offs welded to the plate.

I can see an advantage with the stand-offs where you can keep an eye on the coupler and easily re-torque its bolts.


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## TheSGC (Nov 15, 2007)

electro wrks said:


> Be sure to let us know how your next attempts at this setup work. Aligning the motor to the trans. is difficult to do correctly. The original ICE, aligned with dowels, is located within +or- a few thousands of an inch(about the thickness of two hairs).
> 
> This kind of precision is difficult to achieve without the skilled use of measuring and alignment tools. And, once properly aligned, dowel holes will have to be drilled and reamed through the motor plate and the trans. to maintain the alignment when the motor plate is taken off and put back on. Bolt holes alone usually are not precise enough.
> 
> ...


I am having my coupling modified to use the pilot bearing. The plates are correct, we checked them with alignment tools. What I did not do is adjust the flywheel on the motor before it went into the transmission. I did have vibration issues when I first installed the clutch but went away. This time the motor is sitting on my bench until the flywheel is flush and aligned correctly.


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## electro wrks (Mar 5, 2012)

TheSGC said:


> I am having my coupling modified to use the pilot bearing. The plates are correct, we checked them with alignment tools. What I did not do is adjust the flywheel on the motor before it went into the transmission. I did have vibration issues when I first installed the clutch but went away. This time the motor is sitting on my bench until the flywheel is flush and aligned correctly.


 Could you explain and/or show what tools you used and how you used them? I'm always looking for a way to do the alignment and indexing of the parts with the minimum amount of contortions.


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## TheSGC (Nov 15, 2007)

electro wrks said:


> Could you explain and/or show what tools you used and how you used them? I'm always looking for a way to do the alignment and indexing of the parts with the minimum amount of contortions.


What I did was mount the plates and coupling together to the motor, then used a laser level to align the shafts of the motor and transmission. I then put it all together and did minor adjusts with the motor levels while clamping. I had the motor on a hoist to make things easy. I also did a spin test of everything to check for alignment before drilling holes with a DeWalt drill. 

This was all done with my automatic transmission, which had perfect alignment. It was a long process, if I remember it was a good 2-3 hours of adjustments, but after that I had removed the motor and reinstalled it over the years without any issue, until now when I changed to a manual transmission.


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