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Out of curiosity, on a somewhat related topic, have you tried nord-lock washers [1] in any of your applications? We looked at them for a small work boat we desi

Out of curiosity, on a somewhat related topic, have you tried nord-lock washers [1] in any of your applications? We looked at them for a small work boat we designed and built, but they were a bit pricey and it was just a prototype, so we ended up just using a dab of lock tight to avoid vibration. Was always curious to find someone who had practical experience with these things. I may use them on an upcoming autonomous boat project where there's nobody around to do rounds and tighten loose bolts that have shaken loose unexpectedly. 1. https://www.nord-lock.com/nord-lock/products/washers/ https://www.nord-lock.com/nord-lock/products/washers/

auxym 5y ago
When I worked on railway vehicles (bogies for passengers vehicles, more accurately), Nord locks (or equivalent clones) were standard on all structural joints. Especially on a prototype I'd recommend them. Prototypes are really expensive, a complete supply of Nord locks for your project is probably less than a single one-off CNC part. Note that Nord locks are specced to be single use. Not that I've never reused some on prototypes, but, well, I'd never do it on a life-critical joint that is meant to be taken apart often.
- mojomark 5y ago
  > Nord locks (or equivalent clones) were standard on all structural joints. > Especially on a prototype I'd recommend them. > I'd never do it on a life-critical joint that is meant to be taken apart often. Very good/helpful feedback. This thread is giving me much more confidence to make the extra upfront investment. Thanks!
blamazon 5y ago
I have used Nord-lock washers, they are demonstrated to be one of, if not the most effective thread locking washer devices under heavy vibration, but as you say they are quite pricey. I would certainly recommend them if you have the time/cost budget, especially for something like an autonomous boat where vibration is expected and routine inspection is challenging or impossible. When I’ve used them, it’s been for critical fasteners where ease of assembly was important, and could not be effectively decoupled from vibration, and where our recommended inspection/maintenance cycle was not guaranteed. You might also consider something like a pinned castle nut, or safety wire, etc. These are not as simple to specify or install but more cost effective. Also, I’ve seen safety wire used as a conductive link to detect failure in a remote application.
- mojomark 5y ago
  > I would certainly recommend them > When I’ve used them, it’s been for critical fasteners where ease of assembly was important, and could not be effectively decoupled from vibration, and where our recommended inspection/maintenance cycle was not guaranteed. Taken to heart - sincerely appreciate the insight!
- rsync 5y ago
  "I have used Nord-lock washers, they are demonstrated to be one of the most effective thread locking devices under heavy vibration, but as you say they are quite pricey." Which is odd, given their simplicity and ease of manufacture, etc. Can you get them stainless or just HDG ?
  - blamazon 5y ago
    You can get them in various stainless alloys. My understanding is they have a really defensible patent.
    - auxym 5y ago
      Their patent might have expired? Im not aware of the situation but these seem to be an identical product: https://heico-lock.us/ https://heico-lock.us/
smegsicle 5y ago
Their promotional video on the Junker test is pretty cool: https://yewtu.be/watch?v=IKwWu2w1gGk https://yewtu.be/watch?v=IKwWu2w1gGk
toss1 5y ago
NordLocks are excellent - I was told about them by a very experienced racecar engineer who helped me work on my racecars - he couldn't say enough good about them, and recommended them for anything close to critical importance (or that you just wanted to stay fastened). Another engineer friend had a biz providing racecar component kits (think brakes, suspension, etc.), and also enthusiastically all his kits with NordLocks. I've had less experience but never seem them fail. Good stuff

auxym 5y ago

When I worked on railway vehicles (bogies for passengers vehicles, more accurately), Nord locks (or equivalent clones) were standard on all structural joints. Especially on a prototype I'd recommend them. Prototypes are really expensive, a complete supply of Nord locks for your project is probably less than a single one-off CNC part. Note that Nord locks are specced to be single use. Not that I've never reused some on prototypes, but, well, I'd never do it on a life-critical joint that is meant to be taken apart often.

mojomark 5y ago
> Nord locks (or equivalent clones) were standard on all structural joints. > Especially on a prototype I'd recommend them. > I'd never do it on a life-critical joint that is meant to be taken apart often. Very good/helpful feedback. This thread is giving me much more confidence to make the extra upfront investment. Thanks!

blamazon 5y ago

I have used Nord-lock washers, they are demonstrated to be one of, if not the most effective thread locking washer devices under heavy vibration, but as you say they are quite pricey. I would certainly recommend them if you have the time/cost budget, especially for something like an autonomous boat where vibration is expected and routine inspection is challenging or impossible. When I’ve used them, it’s been for critical fasteners where ease of assembly was important, and could not be effectively decoupled from vibration, and where our recommended inspection/maintenance cycle was not guaranteed. You might also consider something like a pinned castle nut, or safety wire, etc. These are not as simple to specify or install but more cost effective. Also, I’ve seen safety wire used as a conductive link to detect failure in a remote application.

mojomark 5y ago
> I would certainly recommend them > When I’ve used them, it’s been for critical fasteners where ease of assembly was important, and could not be effectively decoupled from vibration, and where our recommended inspection/maintenance cycle was not guaranteed. Taken to heart - sincerely appreciate the insight!
rsync 5y ago
"I have used Nord-lock washers, they are demonstrated to be one of the most effective thread locking devices under heavy vibration, but as you say they are quite pricey." Which is odd, given their simplicity and ease of manufacture, etc. Can you get them stainless or just HDG ?
- blamazon 5y ago
  You can get them in various stainless alloys. My understanding is they have a really defensible patent.
  - auxym 5y ago
    Their patent might have expired? Im not aware of the situation but these seem to be an identical product: https://heico-lock.us/ https://heico-lock.us/

smegsicle 5y ago

Their promotional video on the Junker test is pretty cool: https://yewtu.be/watch?v=IKwWu2w1gGk https://yewtu.be/watch?v=IKwWu2w1gGk

toss1 5y ago

NordLocks are excellent - I was told about them by a very experienced racecar engineer who helped me work on my racecars - he couldn't say enough good about them, and recommended them for anything close to critical importance (or that you just wanted to stay fastened). Another engineer friend had a biz providing racecar component kits (think brakes, suspension, etc.), and also enthusiastically all his kits with NordLocks. I've had less experience but never seem them fail. Good stuff