Excessive wear to gimbal/cam mechanism

[WedgeSD]

Hello, I own two VKB gunfighter Mk3’s. I utilize one of these bases with the 200mm extension and KG12 grip in my sim rig. I use this with one #40 and one #50 on both pitch and roll axis. I also use the avia-s cams on both axis.

I have owned this joystick for a little over a month and when I went to use it today noticed a grind on my roll axis when rolling right.

I have disassembled the gimbal and found that the screw that acts as the pivot for the roll axis has bent and the cam is actually grinding against the gimbal body itself. At this point the gimbal is borked and I have a $300 paper weight. I have included images of the damage.

[fallout9]

I don't think the screw is bent, just that you haven't tightened the nut properly - I can see the spring washer is extended.

[WedgeSD]

Yes, upon disassembly it was found the screw and lock washer had worked loose. This in itself is a bit concerning as the nut was torqued to 50 in-lbs and measured utilizing a Mk10 3i force sensor in conjunction with MR55-20 torque sensor.

The unit has seen aprox. 100 hrs of use since the torque was set. I went ahead and checked the pitch axis as well and while it had not loosed to the point of the lock washer no longer being under full compression, it was not at the 50 in-lbs I had torqued the nut too.

Unfortunately the cam was damaged by the grinding along the gimbal, but fortunately the damage to the gimbal is limited to cosmetic only. I had only actuated the stick maybe 3 or 4 times however to cause this level of damage. If this had occurred during a flight and I had not noticed until after I am sure the gimbal would have been destroyed as well based on the amount of material that was removed from just the few actuation's.

Long story short, it would seem that these sticks are actually fairly maintenance heavy without a few design changes. I will be ordering stainless steel locknuts with embedded nylon inserts to replace the lock washer and nut configuration. As can be seen in the article linked below and many more like it, typically a lock washer offers very little in the way of additional lock security beyond the initial set torque. In fact, the spring nature of the split washer can actually promote the fastener loosing faster once the initial fastener torque has been broken.

https://www.boltscience.com/pages/helicalspringwashers.htm#:~:text=Helical%20spring%20lock%20washers%20have,for%20well%20over%20100%20years.&text=Junker%20originally%20showed%20in%20his,both%20material%20and%20human%20loss.

[WedgeSD]

So I went ahead and just reassembled the gimbal while I waited for the new parts to come, about an hour into flying I hear a pop and my roll axis started to feel very odd with notching in the translation of the stick. Upon disassembly it looks as if the outer race of the roll axis bearing has shattered!!!

[fallout9]

Please fill up a service ticket for that.

[WedgeSD]

Ticket submitted.

As an FYI to anyone who may encounter this issue. The bearing is just a standard 684ZZ 4mm X 9mm X 4mm double shielded. I ordered a 10 pack of ABEC 5 replacements on amazon for a whopping 9 bucks with free next day shipping. Installed and everything is back to normal!