ira wrote:Nylocks are really only useful if the bolt extends at least one thread past the nut. You need to use a longer bolt.

Ira

Nylocs have a maximum retention value when used as Ira quotes, but for this application the current build works and cured this issue over 2 years ago.

While it might work, it's not inspectable, so someday when all the tolerances go wrong, you'll get a loose one again. What is the point of not using the correct length bolt? Not to be a jerk, but you're misusing something and hoping for a desired outcome, why not just do it right?

Ira

Ira,

What's the extra thread length do? Does it make the item inspectable? Does it grip the bolt better? Both?

BTW bolts or nyloc nuts are extremely inexpensive. I just ordered the smallest quantity of M6 nyloc nuts I could find (30 pieces) for under $4 USD delivered.

The nylon deforms around the thread in order to prevent vibration from rattling it off. If you can't see to verify that each bolt has at least one complete untapered thread exposed past the edge of the nut, then you don't know if the nut is even doing its job.

Note: I removed some posts that violated the site's Guidelines for productive online discussion. Please folks, let's keep it civil and factual. Thanks.

I posted about this back in 2013..
I still have the original screws in mine just really snugged down tight...

On the discussion about Nylocks the screws don't IMHO have to be longer than nuts, just as long will do..
I worked at ESNA (Elastic Stop Nut Corporation of America) for a few years many many years ago..
Longer would give you move time to notice it's loose but not stop it from loosening..
You just need the screw in the nylon of the nut..

I like what Tom wrote about leaving at least a thread past the nylock so you can visually inspect. Since I've never used nylocks I don't know if the nylon fitting itself to the thread will be sufficient to keep it in place or whether it must be watched. The thick white plastic that's attached to the cooling arm is soft, so it creeps, and this can reduce the snug fit of fasteners that are tightened against it, as happened with mine. For all I know the high strength thread locker I applied to my standard bolts and nuts may be sufficient to keep them in place, but I'm going to check and make sure all fasteners are accounted for after I've emptied the cooling tray.

A nylock on first use with a bolt extending the proper amount, 1 full thread as I recall, will meet its design spec, some might be rated for a small number of removal install cycles. On an airplane those tend to be use once and throw away, on a coffee roaster it will likely work fine with much less engagement, but the only way to insure sufficient engagement is to be able to see that the nylon is deformed and the easiest way is require protrusion. A roaster probably has almost no vibration of a level able to loosen that nylock or the thread locker you used on its own. Testing thread locker is an interesting problem because if you move it while testing you should replace the thread locker since you've broken the bond.

Ira

JK wrote:I posted about this back in 2013..
I still have the original screws in mine just really snugged down tight...

Yeah, I remember that post of yours and torqued everything down as soon I got my roaster way back then. Thx of the heads up.