THE ACCURATERELOADING.COM OPTICS FORUM


Moderators: Canuck
Go
New
Find
Notify
Tools
Reply
  
Sako Optilocks backing off?
 Login/Join
 
One of Us
posted
I know this is a touchy subject but here goes: Has anyone else noticed the screws on their optilock rings backing off after application. I can torque them on tight and come back in an hour and get an eighth to a quarter of a turn more. What gives?
 
Posts: 3073 | Location: Pittsburgh, PA | Registered: 11 November 2004Reply With Quote
one of us
posted Hide Post
I don't suppose I've ever tightend a screw so tight that I couldn't get another eighth turn out of it if I gave it enough muscle. Of course, if you do this a couple or three times, the screw is going to break.

As to waiting a while then retightening, all screws will stretch (that is, they are somewhat elastic). A screw of a certain size and tensile is typically specified to be torqued a certain amount. If you overtourque it, it will react by stretching excessively, thus allowing you to turn it some more by applying the same torque again later. So, even a screw with the proper tensile can overstretch if overtorqued -- that is, until it breaks or strips. (BTW, bolts on airplane engines are manufactured to both a certain tensile and exact length. Rather than using a torque wrench to set them, the mechanic uses a caliper and torques them until they have stretched to an exact greater length.)

On the other hand, if a screw is too soft, then it will stretch excessively under what would otherwise be proper torque. This COULD be the case even with a quality manufacturer like Sako, since Sako almost certainly outsources things like common screws and your mounts might have sub-spec screws.

My suspicion, however, is that you're placing too much torque on them.
 
Posts: 13239 | Location: Henly, TX, USA | Registered: 04 April 2001Reply With Quote
one of us
Picture of Bobby Tomek
posted Hide Post
No matter what some will tell you, I am here to say that the ring screws for these mounts are among the softest I have ever encountered.

For the cost of the set-up, Sako should incorporate higher quality screws. The mount itself is well-designed.

The company is aware of and admits to the problem (and yes, it IS a problem) but apparently has chosen to do nothing other than try and sell you another set of screws for $4 per screw.

But this is a touchy subject, and if you do a search, you'll see that some posters will say it's all a matter of technique, tools, etc. to make these screws work properly. I say it's a matter of quality and customer service, and to this end, Sako has failed miserably.


Bobby
Μολὼν λαβέ
The most important thing in life is not what we do but how and why we do it. - Nana Mouskouri

 
Posts: 9344 | Location: Shiner TX USA | Registered: 19 March 2002Reply With Quote
One of Us
posted Hide Post
The screws on my optiloks suck. They are about worn out after just one mount job. A buddy turned me on to a push and turn technique that I got a little more accomplished with, but you really have to push hard while you are turning to keep the head from turning all the way out.
 
Posts: 175 | Location: Oklahoma | Registered: 11 January 2005Reply With Quote
One of Us
Picture of bulldog563
posted Hide Post
Sako screws are pretty horrible if you ask me. And then they charge you $4 EACH to replace them.
 
Posts: 2153 | Location: Southern California | Registered: 23 October 2005Reply With Quote
one of us
posted Hide Post
Sounds like Sako is accepting too-soft screws from its supplier. I would suggestion complaining to their American importer, Beretta, USA. It may not do any good, but as many as seem to be having trouble with them, there should be a ruckus made over it.

In the meantime, has anyone tried finding an alternate source for these screws? After all, they must be a fairly standard thread, and the head dimensions can be custom machined, if necessary.

Of course there may be a reason that Sako is supplying soft screws with the mounts: They don't want harder screw threads to strip what might be excessively soft threads in the rings themselves. If that's the case, then Sako ought to have those gawdawful expensive rings shoved up Beretta's corporate wazoo.
 
Posts: 13239 | Location: Henly, TX, USA | Registered: 04 April 2001Reply With Quote
one of us
Picture of Bobby Tomek
posted Hide Post
They are not a standard size and not a standard pitch rate, which simply adds more fuel to the fire.


Bobby
Μολὼν λαβέ
The most important thing in life is not what we do but how and why we do it. - Nana Mouskouri

 
Posts: 9344 | Location: Shiner TX USA | Registered: 19 March 2002Reply With Quote
one of us
posted Hide Post
Oh no - not this again! It's already been almost thrashed to death here - see the following:

https://forums.accuratereloading.com/eve/forums/a/tpc/f/...=898101054#898101054

While on the subject, though, perhaps somebody can answer a question I have asked a number of times, on several different forums:

Is it the stainless steel 'Optilock' screws that are said to be too soft, the blued steel ones, or both? (or does the Sako factory provide ONLY stainless ones these days?)
 
Posts: 160 | Location: New Zealand | Registered: 26 July 2002Reply With Quote
One of Us
posted Hide Post
Redrover: I don't think "I'm beating your dead horse" again. The earlier post has nothing to do with my question. I was asking about "back off". We all agree the screws are crap and unavailable for replacement. Why are they backing off?
 
Posts: 3073 | Location: Pittsburgh, PA | Registered: 11 November 2004Reply With Quote
one of us
posted Hide Post
LJS: No, I agree that your original question was not addressed in the previous thread, but the subsequent bickering about whether or not the screws are too soft, and whether or not they are a ‘standard’ size certainly was.

I can’t claim to know exactly what is causing the ‘backing off’ you describe. I haven’t seen any problems with the stainless Optilocks on my son’s Tikka 270. These were first installed about three years ago, then the screws were loosened and re-tightened once a year or so later to re-position the scope slightly. They are still quite snug, and the scope has not shifted.

I have noticed (with these Optilocks and with other scope rings with two screws each side) that it isn’t quick and easy to tighten all four screws perfectly uniformly. Tighten, say, the rear left and rear right screw in one of the rings to what you think is the correct torque, do the same to the front left and front right screws, then re-check the rear pair of screws and they seem to be on the loose side. Tighten them some more, then re-check the front pair, and they seem to be slightly looser …

Could you be tightening the screws so hard that the plastic inserts in the rings are getting severely compressed?

How many times in succession can you induce this apparent ‘backing out’?

If it is due to the screws stretching, even after ‘once-around’ you should be able to detect the elongation of them with a micrometer or good callipers. (assuming your Optilocks are like my son’s, with both ends of the screws accessible when installed) If the elongation keeps occurring one time after another, at one hour intervals, then after a while you would probably be able to measure it with a carpenter’s rule …
 
Posts: 160 | Location: New Zealand | Registered: 26 July 2002Reply With Quote
one of us
posted Hide Post
LJS, When I get back to the house I'm going to check some of mine to see if they have backed off a bit. I'm thinkin' that either they are stetching a bit as mentioned earlier or the backlash in the threads is allowing them to loosen up a bit.
But hey at least with your handy-dandy Brownells 2.5mm bits you can get them as tight as you want without any problems!...... stir..... Smiler Smiler..... stir.....................DJ


....Remember that this is all supposed to be for fun!..................
 
Posts: 3976 | Location: Oklahoma,USA | Registered: 27 February 2004Reply With Quote
  Powered by Social Strata  
 


Copyright December 1997-2023 Accuratereloading.com


Visit our on-line store for AR Memorabilia