Does your X5 Hub Motor Hop At Speed?

This poll specifically concerns the X5 Crystalyte hub motors. These are also known as "X-lyte" and "Pheonix" motors. I'm especially interested to hear from those that are running 48 volts and higher. This is a multi-part question;

- When you stand next to your bike, lift the wheel off the ground and throttle the hub motor, does it wobble or shake violently?

- Which model/winding are you using?

- What pack voltage/chemistry are you running?


-S

- When you stand next to your bike, lift the wheel off the ground and throttle the hub motor, does it wobble or shake violently?

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I haven't spun-up the motor unloaded since assembling the bike ; I never noticed anything like you're describing. During normal, loaded operation, mine has always "groaned" and vibrated through about the 30-60% range of the powerband. It's smooth as glass above and below that range; the vibration's never caused any problems; and I recall some folks at the old V noting similar behavior with theirs'. I voted that mine rolls smoothly because this vibration doesn't result in any sort of hop or unbalanced behavior.

- Which model/winding are you using?

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Earlier 100mm wide 5304.

- What pack voltage/chemistry are you running?

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74 volt low, 84 volt high, 33 amp-hour lithium pack consisting of 300, 2.2ah, 18650-sized cells in a 20s15p configuration. The controller is the 35 amp crystalyte.

Stevil, I always associated you with the cool, one-off scooters, did you just buy an x5 and it's not performing right?
Is this motor to which you refer having balance problems when you're on the bike or scooter?

Oops. I voted "no" by accident. I was reading the post, not the voting question. So take one of the no's and move it to a "yes".

When you stand next to your bike, lift the wheel off the ground and throttle the hub motor, does it wobble or shake violently?

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No, it spins up quickly and quietly with no wobbling or shaking, groaning or anything else. It's smooth as silk the whole way.

Which model/winding are you using?

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5304

What pack voltage/chemistry are you running?

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Normally a 44V nominal lithium-ion pack. But I've tried it with a 48V SLA pack as well.

patrick_mahoney said:

Oops. I voted "no" by accident. I was reading the post, not the voting question. So take one of the no's and move it to a "yes".

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Done :wink:

xyster said:

Stevil, I always associated you with the cool, one-off scooters, did you just buy an x5 and it's not performing right?

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Well thanks for saying so, Xyster 8)

Yep, I bought a brand-spanking-new (5304), unspoked, silver X5.
After the bench-test and runout measurements.. I was a little upset/depressed.

xyster said:

Is this motor to which you refer having balance problems when you're on the bike or scooter?

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No. I clamped a front fork into my vise stand and fit the bare motor for a test spin. After I connected the throttle to the controller, motor leads and hall sensors, I introduced the controller to a 6 pack of SLAs. POP! Don't you love the sound of discharged capacitors getting a gulp of electrons? My cat, Hobbes doesn't get into it as much as I do :lol:

At ultra-low speed, I could hear/count the fields firing. On throttle-up, the clicks turned into a growl. A little more throttle and the stand began to undulate. :?

I pulled my ear away from the motors' axle and twisted the throttle a bit more.. up to 75%. The whole stand was shaking considerably meow
At WOT, the shaking subsided.
The unsprung weight was totally expected.. but this had me thinking *really* hard about taking THIS motor to 60 MPH.

This is my first BLDC motor, but I have experience with a certain high performance hub-motored motorcycle. That motor shook violently at unloaded -and certain dynamic mid-speeds.. but was mostly smooth at ~45MPH (in the 1/8 mile).

This is the conundrum that I need to understand.

Patrick Mahoney- thanks for your input as well. I knew that the disconnect between static (unloaded) and dynamic (loaded) performance would trip somebody :wink: ..sorry.

How long have you had your X5?


-S

P.S. I used 6 different emoticons (and one meow) in this post. Is that a record

P.S. I used 6 different emoticons (and one meow) in this post. Is that a record

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Well #@$% me @#$%%@^ :? 8) :lol: :x :wink:

It used to be...

Arf.

The bar moves ever higher.. phew!

Meow am I supposed to take an X5 motor -with .035" of runout- into the 50MPH club?

Meow I am seriously considering taking this motor apart to balance it.

I would really like to understand meow these motors can be SO far out of tolerance, but roll smoothly at speed. Meow that works is waaay over my head.


-S

What's with the meows?

On a computer forum I frequent, the admin set in place olde english word philters, so "you" becomes "thou", "your" become "thy", ect.


And +1 to blueprinting the X5, go for weight reduction at the same time?

Meows? Hmm, sorry Mathurin.. must be the Canadian language filter.

All seriousness aside- have you seen the movie, Super Troopers? -S

Thanks for fixing my mistake, knight.

How long have you had your X5?

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I got it in May of last year.

Stevil_Knevil said:

Meows? Hmm, sorry Mathurin.. must be the Canadian language filter.

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I thought Mr Rogers and Henrietta Kitten had returned from the Land of Make Believe in the sky...

Meow I thought it was a Super Troopers thing?

http://www.imdb.com/title/tt0247745/trailers

Ah well, I obtained the said movie overnight, so I ought to be able to watch it at a buddie's place later today. BTW, you know what handyman's secret weapon is, right?

Mathurin said:

BTW, you know what handyman's secret weapon is, right?

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Butt Crack Putty?

Stevil_Knevil said:

The bar moves ever higher.. phew!

Meow am I supposed to take an X5 motor -with .035" of runout- into the 50MPH club?

Meow I am seriously considering taking this motor apart to balance it.

I would really like to understand meow these motors can be SO far out of tolerance, but roll smoothly at speed. Meow that works is waaay over my head.


-S

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How to balance the thing?
What if the magnet ring has run-out in more than one plane w/regard to the stator?

I guess I'm a fan of trial and error kludging; how the heck can you balance it if it's got run-out?

Trial and error?


ruff!

Reid Welch said:

How to balance the thing?
What if the magnet ring has run-out in more than one plane w/regard to the stator?

I guess I'm a fan of trial and error kludging; how the heck can you balance it if it's got run-out?

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Oh man, I only wish I knew. My suspicion is that the side covers are fukt..



..and this is the GOOD side. There is .035" of runout on the other side. I would call this motor defective.. but I've heard from the most reliable source that this is within "normal" manufacturing tolerance for Crystalyte.

It was too expensive to heave out into the yard, so I better open a can of turd polish.

Does anybody know the best way to take these motors apart? -S

Also, can someone please explain motor "run out" and how it affects balance? A cursory web search yielded zilch.

Stevil, how would this 5304 perform if you were riding on it normally? Would it be like riding on an elliptical wheel?

have to respect a guy with a dial indicator.
i returned 4 of 8 wheels for my 72 vette. 0.100" 0.065" out.
0.035" is pretty good, i accepted those, but they were cheap wheels $50 each.

HINT: rotate the tire, it is not true either. 2 wrongs in the right position can be acceptable. new cars have a lazer machine do this at the factory

Sure Xyster, it works like this-

I attached the X5 into the fork, which is clamped into my vise stand.
Then, I mounted a dial indicator which is attached to an adjustable fixture on a magnetic base (pictured above).
For this measurement, I set the tip of the indicator against the side cover and turned the motor slowly, by hand, until the needle registered its lowest reading. Once I found that, I turned the outer bezel (the numbers turn with the bezel) to indicate "0". This was my starting point for measuring the lateral "runout".
Then, I slowly turned the motor until the needle indicated the highest point. In this case, I found .020" of runout.

For gather more raw data, I measured both sides of the spoke flanges. There is .015" of runout on either side.

Information only: Radially (outer hub measured in the center), there is .007" of runout.

It sounds like y'all have X5s that roll smoothly. I'm inclined to reject the sloppy manufacturing tolerance claims of someone who's opinion I respect.. and ask for a replacement. The sticky part is that -even though it's wobbly as sh!t- it still "works".


-S

xyster said:

Stevil, how would this 5304 perform if you were riding on it normally? Would it be like riding on an elliptical wheel?

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Oops. Sorry, I missed that point. Here is my theory-

Unsprung weight is a bitch to work with.
Mounted in the center of this rotating mass is the majority of the wheels' weight. If the hub has a little lateral runout, the spokes can be adjusted to cancel that wobble, rendering a "true" wheel.
However, if there is enough radial runout to make it hop violently in static bench-testing.. that reaction will be amplified during dynamic road-testing.

My concern is that a machine with this particular hub motor laced into its wheel will become unstable at 50-55MPH.

I'm not a daredevil. I prefer the term "calculated risk taker" :lol:


-S

Thank you for the excellent explanations, Sir Stevil. Now I understand.

My concern is that a machine with this particular hub motor laced into its wheel will become unstable at 50-55MPH.

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You probably know, unless your planning to curl up into a ball or use a fairing, it's going to take some serious voltage to get a 5304 above 50mph -- possibly higher than a 72V crystalyte controller can reliably handle. Laced into a 24" wheel, mine goes 44mph at 80 volts. What'r yur plans, man?

Stevil, you might try unbolting the side cover and turn it a few holes and bolt it back down again. There might be a cumulative error in both sets of holes that could be partially cancelled out. Another possible approach might be to enlarge the holes just enough to allow some adjustment of the centering.

You could also add weights to the hub to balance it. Even if there was no runout, it might not be balanced. If you put the axle on a pair of parallel, level knife edges, it should roll easily enough to balance. You'd have to manage the wires so they don't affect the balance.

If you can balance it weight wise, the runout can be corrected by the spokes.

xyster said:

Laced into a 24" wheel, mine goes 44mph at 80 volts. What'r yur plans, man?

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I'm going BIG.





-S

I know very little about such things, but couldn't you correct rim-based wobble from motor runout when you lace the spokes? The motor would wobble a bit, but it's near the center. If the wheel spun true wouldn't that mostly fix the problem?

Not that I'm suggesting you should have to respoke/retune to fix a manufacturing problem, but hypothetically, could you fix this by adjusthing the spokes though?