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Old 04-05-2017, 05:12 PM   #12
popgun pete
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Re: Ermessub Double Roller Trigger Test

A square cut tail notch produces no downwards force to wipe the free floating roller tooth out of the top of the side slots in the walls of the sear box, especially with the contra-curved slots. If the slots were curved the other way or sloped rearwards to match the sear lever rotation then the roller may be pushed down the side slots by the pressure from the shaft which acts only in the longitudinal direction. In a eurogun the pressure relayed from the bands via the shaft not only acts longitudinally, but at an angle downwards as the sear tooth is sloped, the sear box roof stopping the shaft riding up on the tooth. As the roof cannot budge the spear tail pushes down on the sear lever and creates a loading on the trigger-sear lever interface, which is actually the "sear". In square cut trigger mechanisms that trigger-sear lever interface loading only comes through the torques.

Such changes to the slot orientations may reduce the effectiveness of the roller tooth principle, but may still produce a good result, that is if you need it on a square cut tooth mechanism.

Last edited by popgun pete; 04-05-2017 at 05:29 PM. Reason: additional comment
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