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Locktite for a bolt that is not torqued down

Bill D

Diamond
Joined
Apr 1, 2004
Location
Modesto, CA USA
I have an adjustment bolt on my wood working router that needs to be held in place with locktite. It is not tightened all the way down. Rather it is tightened down then backed off a bit to allow a controlled rotation of the turret knob it holds down as an axle for the knob. It should have been a shoulder bolt I suppose. I guess super glue would work but it might lock up before I have time to get it adjusted. Or the glue may squeeze out and prevent the turret knob from turning.
There is very little force needed when it is adjusted correctly. The screw vibrated out and fell on the floor the other day. As did another lockdown screw which I can use regualr locktite on.
Bill D
 
Take a look at ND Industries' Vibra-Tite VC-3, which amounts to a brush-on lockpatch.

Or, as a less-expensive alternative you can wrap the thread with enough PTFE tape to fill the clearance between the internal and external threads.

Or, another alternative would be to add a locknut.
Plus 1 on Vibra-Tite. The bolt needs to be snug, not tight and may need to be re-adjusted occasionally to compensate for wear.
 
Take a look at ND Industries' Vibra-Tite VC-3, which amounts to a brush-on lockpatch.

I use Vibra-Tite on the the lower adjustment knob of rifle bipods. They are loose allowing the rotational drag to be adjusted. With no Vibr-Tite they come loose. With Vibra-tite they will remain at any position you turn it too.
 
I prefer a slight dent at the nut face, basically creating a lock nut, but you get to decide how much resistance by location and amount of deformation at the threads.
 
Take a sharp cold chisel and make a slight indention in the screw threads.
Your idea reminds me of a tool maker I worked with in NZ, ejector pins were to short on a impeller mold which resulted in a protrusion on the surface which was unacceptable. His solution was to peen the sides of the ejector pins and increase the length. Much like your idea just not a good idea at all.
 
Agree with AlfaGta (post -10) Nylock screws are great for snugging an adjusting screw.

Sometimes one can put a fairly deep center drill hole in the bolt end, then cut a hack saw slice in the threaded end. Then drill from the head to go into the deep center dill so a screw will pull a center drill shape wedge to expand the threaded end enough to lock up at the adjust position.

Making this device it is good feel/test the threaded end in a nut because the slicing may let the threaded end get tight, for that one would run the threaded end in and out of the nut with a little lapping compound to correct the thread size.
 
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Your idea reminds me of a tool maker I worked with in NZ, ejector pins were to short on an impeller mold which resulted in a protrusion on the surface which was unacceptable. His solution was to peen the sides of the ejector pins and increase the length. Much like your idea just not a good idea at all.
ROFLMAO! That ranks right up there with one of the most subtle put-down’s ever! Chapeu!

Seriously, if it’s a router chances are that there is no separate nut that can be replaced with a lock nut. Since it has to be adjusted by hand, loctite is probably not a good option. A very, very slight deformation of the threads should achieve what the OP wants. Here is an example.

IMG_0476.jpeg
 
The buggered up thread seems like it may work, but. This threads into a pot metal casting. When it fell part the lock ball spring got lost so I need to find something to replace that before I worry too much about the screw. A section of ballpoint pen retract spring may be about right.
Another thought is to drill out the slip hole bigger and slip a sleeve over the screw. This would have to be exactly the right length to work.
Bill D
 
A few decades ago I built a machine that I had built many multi-spindle gearboxes for - on the cheap.
The units were tight as we were trying to git the smallest distance between spindles as possible, so I was using needle bearings and 3 pc thrust bearings, held together with 1/4-20 SHCS's.

I loaded the bolts up with 271, and only snugged, or maybe snugged and backed off one RCCH.
Worked fine, and was still just able to remove.

In similar cases I may just smack the bolt threads a bit to create a "lock-bolt" situation.
That seems to work purty good too.


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Think Snow Eh!
Ox
 
Loctite 609…it is a retaining grade but will keep that assembly locked up without it being tightened. Loosen with heat if necessary. Good luck!
 
I ended up buying blue thread locker from Horrible Fright. Made in USA. We will see how that works. I just found out my local Ace hardware sells small shoulder bolts that may work using washers as shims etc.
Bill D
 








 
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