Mother's Day Short Reset Disco Installation, SP-01 Tactical

[PappaWheelie]

It's been a lengthy wait since PeachBoy son's Christmas SP-01 Tactical Trigger Job
http://www.czforum.com/forum/index.php?topic=5438.0
and associated CGW 1485-T2 Disconnector Installation in CZ 2075 RAMI BD
http://www.czforum.com/forum/index.php?topic=5442.msg22980#msg22980,
hoping he'd find time to install the CGW 1485-T2 Disconnector in his SP-01 Tactical, but he's been exceedingly busy with his Hotlanta business startup.

When an unexpected opportunity to "blow dis pop stand" and once again visit him over Mother's Day weekend appeared, Wifey and I jumped on it and boogied on down.

While the Short Disco installation remained on the to-do menu, it came down to Mother's Day Sunday as crunch time to "git 'er done" after enjoying such diversions as shooting at Adventure Outdoors (where the dinky P365 could be handled https://drive.google.com/open?id=1mgcsB09RSoHBZQe9eOUH2MWHSSDsls4J), long walks with the dogs, visiting motorcycle shops, and a delightful Blue Ridge Mountains trip to Amicalola Falls https://en.wikipedia.org/wiki/Amicalola_Falls_State_Park, Fort Mountain State Park, Elllijay and Jasper.

After yet another B.O.B. Sunday morning message at Northlands* and a delicious LCHF lunch, it was prime time: get out the gunsmithing stuff and "get with it."

PeachBoy, being quite "handy," took less than a half hour to swap out the Short Disco, but we soon discovered that his SP-01 Tactical was one of the few that CGW warns won't reset without a bit of rework. The new CGW Short Reset Disco held the trigger bar just rearward enough that it wouldn't pop up into place (its vertical sear foot pushing face not quite able to get up past the sear foot) if depressed by the cycling of the slide. It was very close; with the slide removed it could be popped up into engagement with finger pressure, but the trigger bar lifter spring by itself couldn't pull it off.

We examined the four polishing location options: 1.) the perfect geometry CGW Disco, 2.) the already-polished sear foot pushing face (reference Christmas Trigger Job link above for images), 3.) the sharp-cornered sear foot, and 4.) the Disco contact notch of the trigger bar. The choice was obvious, i.e., the latter, which displayed the worst-by-far geometry, having evidently been "cleaned up" (using the term VERY loosely) by hand filing before hardening.

SP-01_Tactical_Disco_Notch_Bottom_Before
https://drive.google.com/open?id=1QN_dnd3HwRBYT9pjfin9bgTp5b09Gcan

SP-01_Tactical_Disco_Notch_Bottom_Before_2
https://drive.google.com/open?id=1_YRJs1Vh6rMOhFlN8tNDFxZHqowslI4Y

PeachBoy used 400 grit wet-or-dry backed by a 1/8" thick machinists parallel to "de-texture" the otherwise crude geometry of the disco notch bottom of the trigger bar.

SP-01_Tactical_Disco_Notch_Bottom_After
https://drive.google.com/open?id=1XFCQq_TDMZ5B_hZ4NtIXbpWKUjturUCG

SP-01_Tactical_Disco_Notch_Top_After
https://drive.google.com/open?id=1aMarnkbIvVmWy3Arx28RfQbCnWMlPpLt

After this removal of high spots (but not fully cleaning up low spots), the pistol's normal functionality was attained, with the "for your troubles" benefit of virtually zero (!) reset freeplay.

The new SA trigger position is shown here:
https://drive.google.com/open?id=1wz1TyuUjyTBmh_cDQRJxlpPHOATE16m1

* https://www.youtube.com/user/NorthlandsMedia (trigger warning; Gospel Truth!)

[THarbison]

I too have fell victim to this problem. Were there any ill side effects caused by using this fix?

[PappaWheelie]

I too have fell victim to this problem. Were there any ill side effects caused by using this fix?

Hi THarbison,
Not exactly sure what you mean by "problem" and "fix." Clarify, please?
Here's more: https://czfirearms.us/index.php?topic=98302.msg800735#msg800735

[THarbison]

I put the RRK package in my phantom and it will not reset at all in single action. You are the only person I found that looks to have had this problem and remedied it theirselves. On your son's SP-01 it looked like you removed material from the trigger bar to give it enough travel ro reset. Did this remedy work?

[PappaWheelie]

Yes, THarbison: if you study the images and carefully read the text again in both this and the above-linked September 14, 2019, 12:43:49 PM Reply, you'll come to understand that the problem is a too-rearward pusher face on the Disco-located trigger bar, such that the sear foot can't engage it. The rounding of the trigger bar's Disco-engaging horizontal "knife edge" is the logical location to reduce interference, rather than try to modify the whole trigger bar-engaging vertical face of the Disco (as CGW does per a post I saw somewhere). Using a just-under 4mm wide backup blade* and ~400 grit wet-or-dry to "dull" the "knife edge" (if a ~90 degree corner can be characterized thusly) adds clearance fairly quickly so go slowly, with frequent reassembly to check results. When you're close to target you'll be able to pull the trigger bar up into place with a finger. I recommend a pitching action to the knife edge lowering abrasion so that you produce a radius instead of a flat.
If you haven't done so yet, the vertical pusher faces of the trigger bar https://drive.google.com/file/d/1Gp5pnN7QD9cJf5ivdBwR-XUy4p7RpZuY/view are usually in condition for flatness-improving polishing (also a clearance-increasing activity) before going after the Disco/knife edge interface. Making a Trigger_Bar_Polishing_Tool that spans both surfaces will keep them parallel; if of thick enough stock to avoid bowing longitudinally like my box cutter blade job as pictured did, it would facilitate improved flatness in the vertical direction.
No ill side effects.
*ideally stabilized in roll mode with a T-top as described