Norotos AKA2 + J-arm = not locking up - Page 1

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[ARCHIVED THREAD] - Norotos AKA2 + J-arm = not locking up

Posted: 4/18/2017 5:07:23 PM EDT

What am I doing wrong here? My J-arm locks up fine on an L4 G11, but does not on my AKA2 with the PVS14 mount.

Posted: 4/18/2017 5:14:50 PM EDT

[#1]

Possible conflict with magnet. Remove the magnet, anyways. The auto-off feature is garbage.

If this does not fix it:

Possible incompatibility with J-Arm. Try another J-Arm or lightly sand the bayonet lug where it hits the socket.

Posted: 4/18/2017 5:51:13 PM EDT

[#2]

Quote History

Quoted:
Possible conflict with magnet. Remove the magnet, anyways. The auto-off feature is garbage.

If this does not fix it:

Possible incompatibility with J-Arm. Try another J-Arm or lightly sand the bayonet lug where it hits the socket.

View Quote

I tried taking the magnet off. Are you saying to sand the center of the "V" in the lug to make it deeper? I can't tell if its not going in the socket far enough to lock up, or if the release is just not lining up correctly to lock it in place.

I don't have another J-Arm.

Posted: 4/18/2017 5:58:47 PM EDT

[#3]

Quote History

Quoted:

I tried taking the magnet off. Are you saying to sand the center of the "V" in the lug to make it deeper? I can't tell if its not going in the socket far enough to lock up, or if the release is just not lining up correctly to lock it in place.

I don't have another J-Arm.

View Quote

No - I am saying to lightly sand the outer edges so the bayonet lug can penetrate deeper into the socket.

Posted: 4/18/2017 10:13:42 PM EDT

[#4]

IM sent.

This annoyance is what drove me to dovetail mounts.

Posted: 4/18/2017 11:41:57 PM EDT

[#5]

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Quoted:
IM sent.

This annoyance is what drove me to dovetail mounts.

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I don't doubt that you guys are having problems but I have a half-dozen RHNO IIs and 25 J-arms and I have not seen this so it is not as widespread as some imagine.

Posted: 4/18/2017 11:47:25 PM EDT

[#6]

Quote History

Quoted:
IM sent.

This annoyance is what drove me to dovetail mounts.

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Thanks for the offer, I sent you my info.

I think the AKA2 has a dovetail interface as well and I'm returning an L4G11, so I might see if I could make the change.

Posted: 4/19/2017 1:46:20 AM EDT

[#7]

I ended up crossing the streams and using a G24 with a dual dovetail adapter. I'm hoping to go to a dual tube eventually, hence the G24.

Posted: 4/19/2017 7:12:18 AM EDT

[#8]

Quote History

Quoted:
I ended up crossing the streams and using a G24 with a dual dovetail adapter. I'm hoping to go to a dual tube eventually, hence the G24.

View Quote

Nice. I'd like dual tubes, but I think thermal and/or a second IR setup will come first.

Posted: 4/19/2017 8:49:53 AM EDT

[#9]

Quote History

Quoted:
I tried taking the magnet off. Are you saying to sand the center of the "V" in the lug to make it deeper? I can't tell if its not going in the socket far enough to lock up, or if the release is just not lining up correctly to lock it in place.

I don't have another J-Arm.

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Quote History

Quoted:

Quoted:
Possible conflict with magnet. Remove the magnet, anyways. The auto-off feature is garbage.

If this does not fix it:

Possible incompatibility with J-Arm. Try another J-Arm or lightly sand the bayonet lug where it hits the socket.

I tried taking the magnet off. Are you saying to sand the center of the "V" in the lug to make it deeper? I can't tell if its not going in the socket far enough to lock up, or if the release is just not lining up correctly to lock it in place.

I don't have another J-Arm.

Sand the $25 J-Arm, NOT the $350 mount...

And do it incrementally checking fit with the mount as you go. I had the same issue with a JArm and a TATM.

Posted: 4/19/2017 11:06:23 AM EDT

[#10]

Whoever is making the J arms must be making them a lot tighter than previously. This has come up a couple times lately.

Posted: 4/19/2017 11:20:36 AM EDT

[#11]

Quote History

Quoted:
Whoever is making the J arms must be making them a lot tighter than previously. This has come up a couple times lately.

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As a side note, some of the PVS-7s have been found to have a locking tooth either further forward or further rearward. The bayo lug is coned, so it's not so much a matter of tighter and looser as it is further forward or rearward.

I suspect many of the eBay specials to be genuine USGI contractor out of spec fallout.

I have also seen people that thought they had a problem that just did not press the lug hard enough. I would rather have to crank the thing in there and know that I got max stability then have it be sloppy like a RHNO I. I personally thought I had a fitment problem when I got my first RHNO II.

Posted: 4/19/2017 11:34:47 AM EDT

[#12]

Quote History

Quoted:
Sand the $25 J-Arm, NOT the $350 mount...

And do it incrementally checking fit with the mount as you go. I had the same issue with a JArm and a TATM.

View Quote View All Quotes

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Quote History

Quoted:

Quoted:
Possible conflict with magnet. Remove the magnet, anyways. The auto-off feature is garbage.

If this does not fix it:

Possible incompatibility with J-Arm. Try another J-Arm or lightly sand the bayonet lug where it hits the socket.

I tried taking the magnet off. Are you saying to sand the center of the "V" in the lug to make it deeper? I can't tell if its not going in the socket far enough to lock up, or if the release is just not lining up correctly to lock it in place.

I don't have another J-Arm.

Sand the $25 J-Arm, NOT the $350 mount...

And do it incrementally checking fit with the mount as you go. I had the same issue with a JArm and a TATM.

That's what I meant. If you turn the J-Arm vertical, you have a sort of "V" where the "base plate" and the lug portion with the release lever that goes into the mount meet. I had originally thought it was bottoming out, but now I'm thinking the lug may just be too wide and/or tall for the space. You want very low tolerance to reduce wiggle and make the lock up tight, but I have two AKA2s and it doesn't lock into either.

As mentioned, it locks fine in the G11 which I was going to return for some credit against other stuff, but now I'm rethinking that. Depending on how things work out, I might keep it and just buy a dovetail mount and adapter for the AKA2 and use the G11/J-Arm on another helmet.

Posted: 4/19/2017 12:01:22 PM EDT

[#13]

My J-Arm slot for the spring loaded locking latch measures 0.395" and my socket locking tooth measures 0.325" so I have 0.070" clearance - and basically zero chance for that problem.

You want the system to "bottom-out" right at the point of locking, for stability. The tooth does not need to kiss the locking latch slot for the system to be stable.

Posted: 4/19/2017 3:31:11 PM EDT

[#14]

That's as far as I can get it inserted. You can see the release lever is in the "down" position because it hasn't cleared the tooth yet.

Posted: 4/19/2017 3:54:54 PM EDT

[#15]

That is close. Try loosening the four screws at the corners of the base of the socket. That should tell us if it is an Up/Down fitment issue which I suspect... and get rid of the damned magnet. I don't think Left/Right fitment problems are common. That bottom plate should give resistance but it should give way under force. It is spring-loaded.

Posted: 4/19/2017 4:45:14 PM EDT

[#16]

Quote History

Quoted:
That is close. Try loosening the four screws at the corners of the base of the socket. That should tell us if it is an Up/Down fitment issue which I suspect... and get rid of the damned magnet. I don't think Left/Right fitment problems are common. That bottom plate should give resistance but it should give way under force. It is spring-loaded.

View Quote

No joy.

I even tried taking the socket all the way off and I can't get it to latch to the lug at all.

Posted: 4/19/2017 4:58:26 PM EDT

[#17]

use a q-tip to coat a light film of grease at the bottom of the mount, install the J arm, then remove it and see if the grease transfers to the end of bayonet. You could also grease the ridges of the bayonet insert the J arm and remove it to see how far the grease tracks go into the mount.

Posted: 4/19/2017 6:24:41 PM EDT

[#18]

If you took the bottom plate all the way off of the socket and you still could not get the lug to lock on the tooth then it sounds like a Left/Right fitment issue.

EDIT: Let's all have a moment of silence or the poor bastards that have this happen with their AN/PVS-7s. The lug is built into the housing.

Posted: 4/21/2017 2:38:21 PM EDT

[#19]

Fuck me....now I have two AKA2 mounts w/PVS-14 adapter and 2 J-Arms that do not lock up with either mount.

I think these are my options:

1) I can try shaving down the J-Arm lug. This risks fucking up the J-Arm for use with other mounts.
2) I can keep the L4 G11 and use it. The Norotos are nicer, but they were free and I've already paid for the G11.
3) I can return the G11 as planned and buy a dual dovetail adapter + Norotos PVS-15/PVS-18 socket. The G11 credit would also let me get some 4D pads.
4) Anything else?

Posted: 4/21/2017 4:15:03 PM EDT

[#20]

Sorry, between your avatar and the first two words my brain drifted a bit...

Your lost of options all make sense. Personally, the 4D pads are very nice so I'd lean that way.

Posted: 4/21/2017 11:46:37 PM EDT

[#21]

i've sanded a few J-Arms down so they would fit into my Rhino II's. just go slow.

Posted: 4/21/2017 11:59:07 PM EDT

[#22]

Quote History

Quoted:

I can try shaving down the J-Arm lug. This risks fucking up the J-Arm for use with other mounts.

View Quote

If you are part of a team then swap J-Arms with team mates until one fits. If you are not part of a team then don't worry about being compatible with every other lowering arm on the planet. The most important part is that it works for you. Practice on a crappy, beat up, used one if that generates less stress for you. Used ones can be had for cheap. I bought a batch of 15 used ones for $50.

Posted: 4/22/2017 12:01:50 AM EDT

[#23]

Quote History

Quoted:
i've sanded a few J-Arms down so they would fit into my Rhino II's. just go slow.

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Quote History

Quoted:
i've sanded a few J-Arms down so they would fit into my Rhino II's. just go slow.

Sandpaper or file?

Quoted:
If you are part of a team then swap J-Arms with team mates until one fits. If you are not part of a team then don't worry about being compatible with every other lowering arm on the planet. The most important part is that it works for you. Practice on a crappy, beat up, used one if that generates less stress for you. Used ones can be had for cheap. I bought a batch of 15 used ones for $50.

No team, just a dude. I'll give it a shot. I have a few more days to get the G11 back to TNVC.

Posted: 4/22/2017 11:09:51 PM EDT

[#24]

Quote History

Quoted:

Sandpaper or file?

View Quote

i used sandpaper. i think i started with 220 grit then when it was close i went to 800 or something fine to leave it smooth. i'd rather have it tight then too loose. and always use a lanyard.

Posted: 4/23/2017 11:48:51 AM EDT

[#25]

Quote History

Quoted:
i used sandpaper. i think i started with 220 grit then when it was close i went to 800 or something fine to leave it smooth. i'd rather have it tight then too loose. and always use a lanyard.

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Quote History

Quoted:

Quoted:

Sandpaper or file?

i used sandpaper. i think i started with 220 grit then when it was close i went to 800 or something fine to leave it smooth. i'd rather have it tight then too loose. and always use a lanyard.

I agree - sandpaper on a flat surface to get a flat cut. Files tend to rub and bite erratically on the plastic instead of evenly cutting through the surface. I can tell from the photo that the system almost fits. Take it slow. You do not need to take very much off of the lug.

[ARCHIVED THREAD] - Norotos AKA2 + J-arm = not locking up

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