J-arm for PVS-14; a constant struggle

[ace4059]

My J-arm for the pvs-14 has lasted about a year and is finally shot. I have searched for better replacements, quick fixes, and everything in between. Besides paying big bucks for a wilcox dovetail, I am on a journey to see if I can upgrade my j-arm. I'm open to ideas, but I think I have a way to better enhance the design.

The j-arm operates on a ball and socket principle. It's a common issue that the plastic knobs wear on the j-arm and no matter how much tension you tighten the plastic knob, the j-arm is free swinging.

As you can see the plastic balls looks like they have been ground on, and will no longer positive lock into the sockets.




here you can see the screw that puts tension on the mount. Notice all the holes in the base. This is the "sockets" that the balls align into and it holds it in place.


Here a pic of the fit up to give anyone that's not familiar with the j-arm setup an idea of what I am talking about with the ball and socket adjustment.



The j-arms aren't very expensive but if I bought a new one it would do the same thing. So I am going to use this thread to document any fixes that I do. Hopefully it is as clear as the Red River.

[ace4059]

I ground down all the knobs for a flat surface. I am wanting to drill holes into the arm and put in straight walled, constant pitch compression springs with ball bearings to act as the ball and socket method so I can still have the movement.

I have not been able to find and compression springs, or ball bearing that are small enough. Anyone have any ideas where to get them? I was trying to find them locally but will more than likely have to order them online, which the only problems is ordering the correct size.

I did try using retaining pins to see if it will work. It looks like it should work but it would then be in a "fixed" position and I would have to really loosen the mount to adjust it. I would like the ball bearing setup best.

Another idea that I had would be to use a star washer, but that would be my last resort.

[ace4059]

I was never able to find small enough springs and ball bearings so I had to go with my second idea.

I measured the holes that act as the "sockets" and they measured 1/16". I found some RCBS depriming rods that were a perfect fit in the holes. So I marked where each hole lined up on the plastic j-arm and I used a 1/16" drill bit and drilled the holes. I cut the depriming rods to the correct length and pushed them in the holes. They are a tight fit and hold by themselves. These are almost the same as the factory, except the "balls" are now metal instead of plastic. These will no longer wear down and should last. The j-arm is now a nice tight, snug fit with no wobble. This is how it should have been from the factory.

Hopefully this will help someone in the future fix there j-arm for their pvs-14.


The 1/16" holes that I drilled in the j-arm. I smoothed over the plastic after drilling the holes.



The rods that I used


Rods once I started installing them into the plastic j arm.


I pressed the rods in so it will act like the factory "ball and sockets"



I installed a total of 7 rods in the arm and it fits up very well. Nice snug fit with no wobble nor play. On my j-arm, its about 12 months old and I noticed the newer ones are designed a little different. Mine had the plastic "balls" that the arm rotated on. The newer one I saw had little rods like I installed, but they were made of plastic. I imagine the plastic rods will also wear out like the plastic balls. I think the best idea is the metal rods like I installed.

[ace4059]

Here is the final fit up of the j arm

[Eurodriver]

Last I checked, a PVS14 cost just on the wrong side of $3,000. Even if it's agency or unit issued, you'll still have to pay up if it goes missing. (When your entire battalion police calls Ali Al Salem airbase in Kuwait looking for a Peq15 it's not fun)

Why not dump the $200 for the Wilcox? You don't have a lanyard, and while it would be pretty obvious that a PVS-14 fell off your helmet 99% of the time, that 1% of the time it does fall off and you don't notice it will be when you are most likely to need it and you don't have time to go looking for it.

I mean, you've already got the TNVC Twist mount for it ($180). PVS14s are pretty rugged, but dropping one on concrete from 6+ feet is not going to prolong the life of it. It looks like a good repair, and I'm sure it's solid. I just don't think high end equipment like that is the place for skimping - on anything.

[ace4059]

It would be pretty obvious that it feel off the helmet so I'm not worried about loosing it. The reason for no lanyard to keep it striking the ground, Have you tried to quickly switch it from the active state on your helmet, to a passive state on your gun?
The Wilcox mount is snug and I've never had a problem with it before. I must not be familiar about the Wilcox setup you're talking about, because as for all the ones I have seen take the j-arm mount. Now if it was the cheap Rhino mount, now that would be secured with a lanyard since those are loose.

Edit: The lanyard we get to secure the pvs-14 is the standard "shoe lace" so to speak. We do not have the quick detach mounts/clips. But I would have to agree that it would be smart to have a safety chain attached.

[thopkins22]

I must not be familiar about the Wilcox setup you're talking about, because as for all the ones I have seen take the j-arm mount. Now if it was the cheap Rhino mount, now that would be secured with a lanyard since those are loose.

http://tnvc.com/shop/wilcox-pvs-14-a...to-off-switch/

[Eurodriver]

It would be pretty obvious that it feel off the helmet so I'm not worried about loosing it. The reason for no lanyard to keep it striking the ground, Have you tried to quickly switch it from the active state on your helmet, to a passive state on your gun?
The Wilcox mount is snug and I've never had a problem with it before. I must not be familiar about the Wilcox setup you're talking about, because as for all the ones I have seen take the j-arm mount. Now if it was the cheap Rhino mount, now that would be secured with a lanyard since those are loose.

Edit: The lanyard we get to secure the pvs-14 is the standard "shoe lace" so to speak. We do not have the quick detach mounts/clips. But I would have to agree that it would be smart to have a safety chain attached.

My "you don't have a lanyard" comment wasn't implying that you needed one, simply that because there isn't one it means you must make extra sure your equipment is good to go so it doesn't fall off. I have never used a lanyard, but I have switched from active to passive and a lanyard would make that practically impossible, especially at night. I agree, that losing it if it falls off is very unlikely, but that J-arm breaking isn't impossible. To avoid that, I'd just swap J-arms especially if you're using your NVGs frequently.

thopkins posted what I was referring to. Seems like cheap insurance to me. Your repair looks pretty good to go, but for how long is anyone's guess.