CGW Type 3 Disco fitting fun.

[Tok36]

   I have learned allot about the mechanics of CZ75 pistols and what is possible through DIY and custom shop upgrades over the last year. There are still many things i have to learn. One of the things i still wanted to explore was the potential of a hand fitted Disconnector in a non-Fring Pin Block (FPB) CZ.

   I finely got around to fitting a CGW Type 3  Disco. I decided to fit this disco to my SP-01 Safety model. Before doing this work i had already added many of the available custom parts and done a full polishing job on the internals. I then put about 2000 rounds through this SP-01, after which it sat it the safe for a few months while my attention was held by other guns. While my SP-01 was sleeping California Single Shot Exemption (SSE) went away. I managed to acquire quite a few off list pistols while SSE was still running, all of them were CZ's. The CZ addiction at work.  I am quite happy and lucky to have gotten as many of the pistols i wanted before time ran out, but.... there were a few that got away. One of which was a CZ75 SP-01 Shadow. So i decided to see how close i could get my SP-01 Safety model to a Shadow, using my CZC CZ75 Shadow Custom as a comparison.

   As i mentioned above my SP-01 already had allot of the available upgrades, but was still FPB equipt. So the first thing i did was pull the FPB plunger out of its slide and replaced the FPB lifter with a spacer. I then went to work fitting the CGW type 3 disco.  I had a great guide and reference in this thread: http://www.czfirearms.us/index.php?topic=61135.15
 
  It took 6 disassembly / reassemblies to fit my T3 disco. (Edit Note: It is a good idea to test your T3 disco right out of the package, in some cases they require very little to no fitting, every pistol is different). Things got faster as i went.  By the end of this process i could put everything back together in around a minute. I also picked up on some of the nuances of the disco trigger bar interaction in a CZ. While some things about this interaction are still unclear to me, in general it is a little less mysterious. It was also allot of fun. I am interested in playing around with fitting some of the other parts in my CZ's. It seams there may be something to gain from adjusting the lower leg of the sear or the FPB lifter arm. I plan on fitting another disco and a few other parts for one of my FPB CZ's to see how short i can get the reset.

   In the end i am quite pleased. My SP-01 ended up with less SA pre-travel than my CZ75 Shadow Custom. On SA reset the trigger of this SP-01 stops dead in its tracks. I love tinkering with these pistols. At my current level of skill, i cannot take full advantage of many of the upgrades in my CZ's, so i do it for the enjoyment of completing the work my self and learning more about the design and function of the CZ 75 variant platform. With the available parts provided by the great custom shops that support CZ's, allot can be accomplished and much fun can be had.


Here are a few pics and a video to illustrate.

The T.3 Disco fitting was accomplished with a Dremel and a diamond cutting bit. (Covered in the thread i linked above)



The fitted T.3 Disco, at this profile my SP-01 would reset in SA. In the guide i linked above a vise was used to hold the disco while it was being fitted. I did not have access to a vice so i made due and held the disco in one hand and the Dremel in the other. A vise would have made the job of maintaining a flat face on the disco easier. Painting the face of the disco before you cut is also a good option for achieving a flat disco face (mentioned in the guide linked above).



Edit: to add pic from later in the thread.


A CGW T.2 Disco for reference. (for FPB CZ's) The type 2 Disco is thinner than a type 1 or 3, allowing for the function of a FPB and designed to work with the CGW Short Reset System



A stock CZ75 SP-01 Disco for reference. The stock disco is thinner again than any of the CGW discos and is designed to work with the stock FPB lifter arm.



Stock Disco, Trigger bar interface - Side View for reference.



Stock Disco, Trigger bar interface - Top View for reference.
Note for Non FPB CZs: The thicker the disco is, the less SA Pre-Travel there will be. Too thick and the disco will not allow the trigger bar far enough forward to slip under the foot of the sear and the action will not reset. The goal is to leave the disco as thick as possible, while still allowing enough trigger bar travel for a consistent reset.



75 Shadow Custom at rest SA trigger position.



My SP-01 at rest SA trigger position.



A short video comparison. (watch the volume, my fans are loud, don't get blasted)
SP-01 with T.3 Disco first. CZ75 Shadow Custom second.
https://www.youtube.com/watch?v=ElWs2aJpjoA

[emjei]

If you change those 85 triggers to the OLD thick style the reset and pre travel will feel even shorter ...... great job !!!

[cntrydawwwg]

Awesome Tok. There's nothing quite like doing your own work IMO. [emoji6] I'm curious to see what difference you find once you fit one of your FPB CZ's.

[GRB5111]

Thanks, Tok, great photos, video, and explanation. I have a full CGW kit upgrade to do on my P-09 (which I've been procrastinating on for a couple weeks), and while there are differences, these posts are extremely helpful in providing a better understand of the CZ inner workings.

[BDG]

Nice job TOK.
Way to up your Gunsmithing game.

[jinn707]

Awesome work Tok!  I did something very similar to my SP01, except with a CGW T1 disconnector.  Results are quite similar to yours.

[Tok36]

Thanks guys. Now i have to get the SP-01 to the range to see if i broke it.    Things are so tight in there atm i need to prove out live fire function. I also need to install and set the over-travel set screw in the trigger to tighten up the reset distance.


GRB5111: I have my P-09 parts sitting here as well, if you haven't see Jo L's P series videos they are worth checking out. The clarity of his videos are impressive.
Jo L's P series Videos: http://www.czfirearms.us/index.php?topic=63210.0

[Towns]

Tok,  You have inspired me.  I have done a bunch of CGW mods to my guns, but not the SRS.

I just emailed CGW asking about getting the firing pin lifter that goes with the SRS, as well as the type 2 disco.  Your video sold me.

[schmeky]

Tok36,

I am really glad you posted this thread and very impressed with your skills.  I have been telling folks for close to 4 years a basic SP-01 with the FP block is an outstanding platform.  Without the FP block, the SP-01 "is" a Shadow in virtually every respect in accuracy, trigger pull and reset.  For less money.  So what's the difference between a red Corvette and a black one, I say? 

Even with the FP block, some of the best shooters in the country tell me a 1mm difference in reset (on average) between an SP-01 with a FP block and Shadow is not a factor in the real world.  I agree.

The best news is CZ shooters have many outstanding platforms to pick from, so whether you go with the Shadow or the standard SP, you will have a great shooter.

Hats off to you my friend!!  And thanks for demonstrating what I have been preaching.

[emjei]

No to mention that the Tanfoglio "Unicorns" have a FPB and the reset / SA pre travel is not as great as CZs 

Mj

[copemech]

Good pics but I wish you could show exactly where you had to grind and fit!

[Tok36]

Tok,  You have inspired me.  I have done a bunch of CGW mods to my guns, but not the SRS.

I just emailed CGW asking about getting the firing pin lifter that goes with the SRS, as well as the type 2 disco.  Your video sold me.

Good to hear, i have the T.2 Disco and SRS in a few of my FPB CZ's i find them to be well worth the investment. Installing them is the most fulfilling part.

Tok36,

I am really glad you posted this thread and very impressed with your skills.  I have been telling folks for close to 4 years a basic SP-01 with the FP block is an outstanding platform.  Without the FP block, the SP-01 "is" a Shadow in virtually every respect in accuracy, trigger pull and reset.  For less money.  So what's the difference between a red Corvette and a black one, I say? 

Even with the FP block, some of the best shooters in the country tell me a 1mm difference in reset (on average) between an SP-01 with a FP block and Shadow is not a factor in the real world.  I agree.

The best news is CZ shooters have many outstanding platforms to pick from, so whether you go with the Shadow or the standard SP, you will have a great shooter.

Hats off to you my friend!!  And thanks for demonstrating what I have been preaching.

Thanks schmeky, for your comments and for expanding the enjoyment of DIY gun smiting with your fine products. I make an effort not to comment on things beyond my skill level but at least from a novice shooters point of view my CZ85B with the drop in T.2 Disco/SRS dose everything i need it to do, and some things i cannot take advantage of yet. It is also one of my favorite CZ's to shoot. As you mentioned the value of 1mm in a reset is debatable. Through time a grade i hope to find a more definitive answer as it pertains to my own shooting. At the very least, as Jo L. might say, "This is Fun".

Good pics but I wish you could show exactly where you had to grind and fit!

Here ya go. I have not established the perfect profile if there is one, more experimentation is needed and things will be different depending on the specific pistol. I tried to cut mine a little thinner toward the bottem to allow the reset and a little thicker up top so things would tighten up as the trigger bar kicks up into place in front of the foot of the sear. I am under the impression that things could also be made too tight to reliably function through extended use. I will be keeping a close eye on mine as i put rounds through it and if needed ill go back in and loosen things up a hair.

I also included a link in the original post to the guide i used. Here it is again, i found it to be quite helpful and would have been much less likely to attempt the fitting with out it.
http://www.czfirearms.us/index.php?topic=61135.15

[copemech]

Tok, I figure David probably sells about one per year of them disco blanks to the general public for those like yourself. The rest he keeps to himself for custom fitting.

It seems to me the guns tolerances vary a bit from one to another, and not just by a small amount when you are talking in thousandths or less.

Those Discos are EDM cut and precise to very close tolerance to get things tightened up on an average pistol. Yet still have slop because of the different guns. And on my stainless, I had to send it to him because it had a timing issue with a T2 disco, and he somehow fixed for free, but a pain for all. Still wish I knew exactly what he did? But I am not gonna look a gift horse in the mouth. He is a great guy and has these things figured out, which WE do not! He EARNS his money!

I have recently applied the SRS and other stuff to my P09 and 07, same principal applies it seems, because for whatever reason there is a notable difference between the two on reset and takeup in SA. Yet as David states, a mm or even more makes no notable difference in the real world.

[Tok36]

No issues so far. I need to replace this pistols night sights with comp sights, night sights are no fun for target shooting. A little more work is needed to tighten up the trigger as well, this SP-01 has a little play in the sear cage to frame fit. More on this latter....

3 Consecutive groups, 5 Shots each, Aprox. 7 yards, Standing, Slow fire


4 Consecutive groups, 5 Shots each, Aprox 7 yards, Standing, Slow fire
I threw a shot on the 4th group its hiding behind the gun. 

[andrewtac]

I did mine tonight, thanks for the inspiration.  If you've done any work on the gun I wouldn't fear this, quite easy.  Lessons learned below.

tips to speed up the assembly/disassemble; had them figured out after about the 4th time.
1.  Take the sear group out with the hammer all the way forward and the hammer spring in.
2.  Put the sear group in with the hammer all the way forward and the hammer spring out.
3.  leave the pin that holds the hammer pin out until you are done.
4.  When putting the hammer spring in for testing, put the bottom pin in about half way; so you can remove it by hand when you have to take the hammer back out.

others.
1.  somewhere it was mentioned to use a marker.  I would color the disco use it to ensure the cut was level and to gauge how much I was taking off; just a little past the marker.
2.  Once the gun would reset most of the time I did the rest of the cutting with 600 grit sandpaper to keep from cutting off to much; this probably slowed me down but not to much.  I think I had it out two maybe three times after I had transitioned to sandpaper.  After I was sure it worked 100% I finish polished with 1200/2000 and then dremel polishing. 

overall much better than the type 1.  This was in a SP01 shadow; I guess now I have nothing left to do.  I would like to eliminate some of the DA takeup and stay USPSA production legal.