Question for CM84e specialists

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ken4all
Posts: 80
Joined: Mon Jun 09, 2008 3:02 am
Location: Belgium

Question for CM84e specialists

Post by ken4all »

I had to quit a match yesterday after raising the pistol for more than 200 times :-(

Most of the time the trigger wouldn't go off. Sometimes it worked for a few shots in a row. When the trigger wouldn't work, I removed the bullet, closed the breech and the trigger worked fine. Even if I continued to dry fire for 10 times. After replacing the bullet most of the time it still didn't work. Very strange.

I replaced the battery but that didn't help. I also taped off the sensor in the trigger guard and that didn't help either.

Do you guys have any idea about what this could be or what and how to check?

This ruined my season because it was a selection match for the nationals.


Many thanks,
K.
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conradin
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Location: Basement.

Post by conradin »

If the trigger is completely non responsive, take it apart and see if the solenoid works. If the trigger works and the firing pin moves (it should, because of the solenoid) then it is time to clean the firing pin and its casing. Finally you may want to consider other brands of ammo. If the solenoid does not work, check whether your batteries are securely placed. also make sure the battery unit is securely connected to the trigger electronic unit.

Adjust the trigger if needed.

I don't have all the answers, but that was my experience when it comes to the CM84E, as I have completely dismantle it and put it back together, clean and adjust before. It is very tricky to clean the firing pin area because the space is so tight. Dirt and other junk stuck inside the trigger casing and is hard to get it out. I een have to send it to Pilk to have it clean once, I don't have all the proper tools.

Of course, don't forget to check the firing pin.
FredB
Posts: 537
Joined: Sun Sep 05, 2004 6:43 pm
Location: Northern California, USA

possibility?

Post by FredB »

Here's a strange possibility that actually happened to me. I experienced very similar symptoms. Luckily it was not during such an important match - what a bummer that must be for you! Anyway, on disassembly I found that the solenoid shaft had broken in two. The shaft is a loose fit inside the solenoid, so when the 2 halves lined up just right, the gun fired, but more often than not they didn't line up. Replacing the solenoid shaft was relatively easy.

HTH,
FredB
David M
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Joined: Wed Mar 24, 2004 6:43 pm

Post by David M »

You need to determine the problem area, try this...

1/ Without cocking the pistol, turn on the battery and do a battery test.
Push the test button and cycle the trigger. If the battery and circuit is good you should hear the solinoid and see the battery light recover, and be able to hold a shot cycle per second.
Now you know the battery and circuit work.
If not working change battery, check circuit, check wiring check switch and adjust if required.

2/ Now cock the pistol and fire. You should hear the firing pin drop. If not recock and feel for sear engagement, some times the sear does not set and the firing pin follows the cocking lever back down. You can feel this as increased spring tension on the lever on closing.If the sear not setting, full strip, clean, inspect and replace sear or pin as required.

3/ If cocking but not firing, sound of solinoid but no sear release then it is a weak solinoid, sticky sear or dirty. Full strip, clean and inspect. Can also be caused by corroded wiring or high resistance/dry solder joints.
This should help determine the area to look ...good luck.
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ken4all
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Location: Belgium

Post by ken4all »

I'll check all those possibilities this weekend and will keep you informed.

Thanks for all the help.
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ken4all
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Joined: Mon Jun 09, 2008 3:02 am
Location: Belgium

Post by ken4all »

I dismantled it completely and couldn't find anything broken or even dirty.
I gave everything a good clean and reassembled.

In dry fire everything works fine, even when cocking.

Next I'll try on the range.

Something I was thinking of and the only remaining possibility is the following. I made myself a trigger in stainless steel and it's a bit shiny. Maybe there is some kind of reflection on the beam of the optical sensor. Is that possible?
David M
Posts: 1685
Joined: Wed Mar 24, 2004 6:43 pm

Post by David M »

How to prove it, refit the origional trigger and see if it works, is there a difference ?
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conradin
Posts: 1999
Joined: Sun Apr 29, 2012 1:18 am
Location: Basement.

Post by conradin »

Or intentionally tape up the optical glass.
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ken4all
Posts: 80
Joined: Mon Jun 09, 2008 3:02 am
Location: Belgium

Post by ken4all »

I finally can reproduce the strange thing...

When I increase pressure realy slowly on the trigger, nothing happens, it just won't fire (even in dry fire).

When I speed up increasing the pressure on the trigger, it works fine.

Any ideas what it could be?

I cleaned everything, changed battery, taped of both sensors.
With the quick increase of pressure it always works, unfortunately I'm used to increase the pressure realy slowly :-(
flolo
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Joined: Thu Mar 19, 2009 11:43 pm
Location: munich, bavaria

Post by flolo »

when did you have the gun serviced the last time? and how many shots did shoot you since then?
i think of two possibilities:
1.if your trigger is tilted, maybe the safety circuit is still activated( that's what happened to me) . maybe the tape you used isn't shielding enough.

2. the solenoid shaft is worn out(also happened to me). when i had service, they wondered that the gun was still firing. after replacement, everything worked fine again.
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ken4all
Posts: 80
Joined: Mon Jun 09, 2008 3:02 am
Location: Belgium

Post by ken4all »

I have seemed to cleared the problem by pushing the contacts of part 084092 more together. It's the part where you slide the electronics in.

I can't reproduce the problem anymore (for the moment).
David M
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Joined: Wed Mar 24, 2004 6:43 pm

Post by David M »

OK, it may be that the trigger switch is not resetting properly.
Unlike the airpistol this is a break switch with a optical circuit.
Make sure the contacts and the optics are clean.
A very light trigger or a stiff trigger may stop the trigger resetting full forward.
Try increasing the trigger weight up to 80-100g and check that the trigger is not touching the grip or frame when released.
Test (pistol unloaded - dryfire) by loading the trigger forward, then move aft to click. Check with both the optical circuit open then blocked. It should not click open but click when blocked.
northpaw
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Location: Nordrhein-Westfalen

CM 84E headspace adjustment?

Post by northpaw »

The receiver of my CM 84E closes with quite some resistance, even when chamber is empty. Is this intensional/normal for the CM 84E?
I would prefer less resistance, due to potential wear of the parts in the receiver, - i e increase headspace. But then how?

At page 7, an exploded drawing:
http://docplayer.net/33197841-Morini-cm ... -data.html
Note screw # 084007, it enters from below at 45 degrees at front of receiver. This scre appears to be part of the barrel fixture, along with two bolts at each side of the metal panels at front of the receiver. (Not able to see any identification numbers for these bolts).

I wonder, could the barrel be set forward, say 0,1 to 0,2 mm (not inch) by a thin shim around the barrel? I think the barrel bottoms at a "shoulder" inside the front part of the receiver.

Does anyone have acsess to a listing of parts for the CM 84E, with description? Regrettably, there is no parts list in the owners manual.
Btw, my gun has the new polygon barrel.
David M
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Joined: Wed Mar 24, 2004 6:43 pm

Re: CM 84E headspace adjustment?

Post by David M »

northpaw wrote: Fri Aug 21, 2020 9:41 am Note screw # 084007, it enters from below at 45 degrees at front of receiver. This scre appears to be part of the barrel fixture, along with two bolts at each side of the metal panels at front of the receiver. (Not able to see any identification numbers for these bolts).

I wonder, could the barrel be set forward, say 0,1 to 0,2 mm (not inch) by a thin shim around the barrel? I think the barrel bottoms at a "shoulder" inside the front part of the receiver.
Screw # 084007 (45 deg) engages in a cut-out in the barrel to hold it in place against a shoulder in the frame.
The two side plate screws are permanent holding the frame side plates to the frame body. Do not touch.
A shim on the barrel shoulder will reduce the head space. I would start with a shim of 0.05mm to 0.08mm only.
Do not over tighten the 45 deg screw or it will damage/distort the barrel.
Also look at the cam action of the locking block, it may just require a little stoning.
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