MPA Wedge Lock Action Screws installation

[eric1911]

Just saw the video about the MPA Wedge Lock Action Screws installation.

I used to just torque down MPA action screws at 65 inch/lb. Never thought I need to verify the impression.
I still don't get the idea of how to verify it after torquing the screws down at 65 inch/lb.
After I loose the screw and heard the 'pop', what should I do? leave it or tighten the screw again?

 

[jcmullis2]

Leave it.

 

[Tony1320]

Just saw the video about the MPA Wedge Lock Action Screws installation.

I used to just torque down MPA action screws at 65 inch/lb. Never thought I need to verify the impression.
I still don't get the idea of how to verify it after torquing the screws down at 65 inch/lb.
After I loose the screw and heard the 'pop', what should I do? leave it or tighten the screw again?

Looks to me like you are checking if it pops when you loosen the screw at 65 inch lbs if not increase the torque value and try again until it pops. Once it pops you know the correct torque value tighten it down again to that number

 

[eric1911]

Looks to me like you are checking if it pops when you loosen the screw at 65 inch lbs if not increase the torque value and try again until it pops. Once it pops you know the correct torque value tighten it down again to that number

if my torque wrench is accurate enough, do I still need to verify it?
if this is true, I would like to torque screws at 70 inch lb and no bother to verify it,since MPA says 65-80 inch lb is safe

 

[Tony1320]

if my torque wrench is accurate enough, do I still need to verify it?
if this is true, I would like to torque screws at 70 inch lb and no bother to verify it,since MPA says 65-80 inch lb is safe

I don't think you are verifying the torque value. You are verifying if 65 inch lbs is enough to make it pop I'm guessing every action / chassis is a bit different.

Only takes 2 seconds to verify that pop.

 

[jcmullis2]

Just to be clear on this. You tighten to your 65 in/LBs. The “pop” is just a way to verify it was properly engaged. If you verify you’ll need to retorque the screw.

 

[eric1911]

Just to be clear on this. You tighten to your 65 in/LBs. The “pop” is just a way to verify it was properly engaged. If you verify you’ll need to retorque the screw.

OK, then it comes back to the original question, how to verify it.
If I need 70 inch/lb to hear that 'pop', there are three options for me after the 'pop':
1) leave it, 2) hand tighten the screw, 3) use a torque wrench to tighten it to 70inch/lb, and then leave it.

I guess 3) is the correct one?

 

[Dthomas3523]

OK, then it comes back to the original question, how to verify it.
If I need 70 inch/lb to hear that 'pop', there are three options for me after the 'pop':
1) leave it, 2) hand tighten the screw, 3) use a torque wrench to tighten it to 70inch/lb, and then leave it.

I guess 3) is the correct one?

Yes. Whatever in/lb it takes to hear the pop is now the value you will torque the screws down to.

 

[Dthomas3523]

It’s explained at the 2:18 mark in the video.

 

[1moaoff]

Those washers are nothing new. They do work great.
They are on nearly every piece of machinery built in Europe that i install here in the US. The video doesn't show that there are also engagement cuts where the 2 washer faces meet also. They are a different cut, and can be confused. The reason for the POP is the washer digs into the surfaces. When removing you habe to overcome the interference fit created.

Then you have to retighten.

This is not the same thing that some people do when they are testing action screw torque for accuracy.

From experience I dont use them on things being taken apart frequently. They are great for set it and forget it.

Until you loose 1 of the 2 pieces of washer.

 

[fili.herrera]

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