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Firearms and Gear => CZ Handguns => Topic started by: Ecthelion on June 01, 2019, 05:17:01 PM

Title: Slide to frame tolerances.
Post by: Ecthelion on June 01, 2019, 05:17:01 PM
Just got a CZ 75b Omega and I'm wondering whats a normal amount of play is. I have +/- 0.40mm of side to side play and about 0.15-0.20mm up and down play. Because of this it of course rattles a lot and I'm wondering if this is within spec?
Title: Re: Slide to frame tolerances.
Post by: Bart Noir on June 05, 2019, 06:24:30 PM
Respectively, I believe you are asking about clearances, not tolerances. 

Tolerances are the designer's plus or minus values, as in having a part being machined to, for instance, 1.5 inches +/- .03 inches.
Bart Noir
Title: Re: Slide to frame tolerances.
Post by: PappaWheelie on September 11, 2019, 06:05:29 PM
Respectively, I believe you are asking about clearances, not tolerances. 
Ya, the clearances are a function of the tolerances, with a minimum clearance required for function (i.e., movement) at "Maximum Material Condition," and the clearance at "Least Material Condition" being that of MMC plus the total tolerances of both (assuming a two-component stackup) components. Tight tolerances allow for a "fug snit" but only at expense of manufacturing cost, the difference between a production firearm and a "race gun" like the Czechmate at $3,416.00!
https://cz-usa.com/product/cz-75-ts-czechmate-9mm-black-2x20-rd-1x26-rd-mags/ (https://cz-usa.com/product/cz-75-ts-czechmate-9mm-black-2x20-rd-1x26-rd-mags/)
The play you describe does sound a bit* large, but the dynamics of discharge tend to load the clearances in a consistent manner shot to shot.

*do you really mean +/- 0.40mm, i.e., 0.80mm (1/32"!!!) or 0.40mm total relative motion?