Removable method of securing motor's axle nuts

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thunderstorm80
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Removable method of securing motor's axle nuts

Post by thunderstorm80 » Feb 07, 2018 2:49 am

Hi,
The lock-nuts on my H3525 come loose all the time because of the very powerful torque it can provide + changing between forward torque&regen + the road vibrations due to the high tire pressure.
I have tried applying a special glue for holding metal-to-metal but it also eventually came loose.
I know I can put some locktite, although I have doubts if it will hold up to the task, but I was aiming to find a removable solution:
Locktite-ed nut can be set free with torque wrench in case I have a flat on the road, but afterward I have to apply it again: Clean the threads, apply, let it dry, etc...
I was thinking of something like a rubber/tefelon strips I can put between the threads and the nut, which can be reused or replaced very easily in case of a flat in the middle of the road.
Has anyone tried something like this?

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Re: Removable method of securing motor's axle nuts

Post by amberwolf » Feb 07, 2018 3:29 am

Nordlock washers on the nuts

torque arms. (if you already have torque arms then they aren't good enough and you need better ones)

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Re: Removable method of securing motor's axle nuts

Post by Punx0r » Feb 07, 2018 3:49 am

Clamping torque arms
Disable regen unless you really need it

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Re: Removable method of securing motor's axle nuts

Post by thunderstorm80 » Feb 07, 2018 6:20 am

amberwolf wrote:
Feb 07, 2018 3:29 am
Nordlock washers on the nuts

torque arms. (if you already have torque arms then they aren't good enough and you need better ones)
I use Grin's torque arms. One on each side. One is preloaded in the forward torque direction and one in the reverse.
And still - I note that the motor's axle is slowly "digging" through them, by striking back and forth.
Are they meant to be replaced once in a while? I actually remember now that the axle of the H3525 was a bit smaller than the torque arm's matching cavity, and perhaps it's the reason for this slow creeping?
The problem is that not all motors have equal axles: Another motor of mine (TC4080) has a bit thicker axle and that one fits just right to the torque arm, so they have to make it universal, and for most axles there would be that kind of rotational freedom tolerance.
These are the best of the best torque arms. What else can be done?
Maybe using a crescent wrench as a torque arm, and filing it so it SNUGLY fits the axle?
Or another kind of torque arm which you recommend?

Regarding the nordlock washers: I have tried spring-washers and they failed, but I didn't try those.
Considering that my dropouts are made from aluminium, I guess should place such washer between the nut and the torque arm so I don't wear out the fork with each service opening?

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Re: Removable method of securing motor's axle nuts

Post by captain387 » Feb 07, 2018 6:47 am

You might find a few options in this thread 8)

https://endless-sphere.com/forums/viewt ... =2&t=26444
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Re: Removable method of securing motor's axle nuts

Post by thunderstorm80 » Feb 07, 2018 7:27 am

captain387 wrote:
Feb 07, 2018 6:47 am
You might find a few options in this thread 8)

https://endless-sphere.com/forums/viewt ... =2&t=26444
I saw this thread and many more similar ones. I don't have the proper skills/knowledge/good access to laser cutting/metal shaping facilities and to plan such a plate correctly regarding to all the stresses/weaknesses. For example, whenever I create aluminium plates with holes in specific places, I am always wrong by about 1mm, not to mention parallel lines because I can't measure that right (for example the exact location of the eyelets), or I (or the person that cuts for me) doesn't drill/cut it right.
I did liked Dogman's pinching idea with the 2 plates and the 2 bolts, as you don't need to be exact to create it. However, I worry if such pinching plates (even if made from thick steel) can withstand the (rocking back and forth) spreading forces with usage.

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Re: Removable method of securing motor's axle nuts

Post by Alan B » Feb 07, 2018 8:46 am

Nordlock washers will keep the nuts tight if properly used. They must be between the nut and the torque arm. No other washers can be mingled to interfere with the wedge locking operation. Read about how they work. The Nordlock washer pairs are hardened and must bite into the nut and the torque arm. Tighten them daily after wheel removal, after a few days they settle in, stop moving and don't loosen again.

The 12mm axles are too small, a design flaw of that hubmotor, creating excessive forces. Thicker torque arms, clamping dropouts or a custom larger diameter axle such as 14mm with 10mm flats could solve it. Reducing motor current and thereby limiting torque could help also.

Drilling and safety wiring the nut might work also.

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Re: Removable method of securing motor's axle nuts

Post by John in CR » Feb 10, 2018 7:53 am

Clamping torque arms for the win, though clamping dropouts are best. I don't even bother with axle nuts anymore except sometimes as decoration. Zero issues in 9 years.

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Re: Removable method of securing motor's axle nuts

Post by 0gri » Feb 12, 2018 8:48 am

Make your own torque arms from old circular saw blades. Hardened steel will not deform when subjected to torque forces as long as they're accurately filed to fit snuggly.

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Re: Removable method of securing motor's axle nuts

Post by Alan B » Feb 12, 2018 8:28 pm

Using hardened steel will prevent the torque arm from deforming but allow it to slice through the soft axle steel instead.

A torque arm must have enough area to spread out the forces so they won't deform either the axle or the arm.

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