Wear and tear on cams; cams not hardened

[Tolovay]

Laides and gentlemens

I have Gunfighter Mk3 since august 2020. I had 2x#20A on pitch and 2x#10 on roll. Cams were also greased. And this is a result. Even tear of chrome. So that means, cams are not hardened enough or they are not hardened at all. And I even have aprox. average 7 hours per week of flying since purchase. This is very disappointing. Metal gimbal was one of major reasons why I have decide to buy VKB stick. I can not even imagine putting extension and spings 40 in cams...

Cams were attached as described in your video. And you can see ball bearing traces on cam are in parallel to cam. I must say in manual there is no limit of number and spring force that can be added to the cams. This is a big no, no.

I want a respond from VKB technical support why is wear so severe?

Kind regards, Gregor

P.S.: my serial nr. is attached

[fallout9]

There's a layer of Chromium on top which is NOT protective; the steel alloy is underneath. It shouldn't have worn out, but if it did it's most probably because you greased the cams too much and that made the ball bearing sliding along the cam instead of rolling.

[Hollister56]

Hello Fallout9,

Thank you for the tip about not to over greasing the cam.

Is there information about how often the grease should be replaced, meaning servicing them with fresh grease. The type of grease recommended by VKB and then amount to apply.

Thanks,

Ed

EDIT.....after reviewing the VKB video on how to change cams and springs, if you look at the screw that attaches the cam there appears to be a washer behind the head of the screw. In the video there is no washer under the head of the screw, but on the other side of the cam which would move the cam over to the right a little bit to align the roller to the cam. In the photo is seems like the left edge of the roller is causing the wear as it might not be perfectly centered on the cam because of the washer being on the wrong side. I could be all wrong on this, but just thought I would put that out here for further review.

[fallout9]

The grease on cams and on bearings is not necessary at all, unless you live in a very humid country or humidity in your room is always high; in this case only a very, very fine film of grease is advised.
The position of washers and split washers on the cams' assembly is pretty relaxed; the only rules are that the cam is aligned on the bearing on its whole range and the head of the screw or the nut won't block the bearing's cylinders.

[Hollister56]

Fallout9,

Okay thanks for the reply and all is noted.

Ed

[Tolovay]

Tnx for noticing this Hollister. I'll check that again. It is realy hard to watch that small video.

Anyway, I would realy prefer to have assembly manual because this video is really hard to watch how to assemble. Video can be only a help. Example of good praxise is on link below. See page 20 how Japanese makes thos thing perfectly. It is just a sugestion .

https://www.horizonhobby.com/on/demandw ... Manual.pdf

[Tolovay]

There's a layer of Chromium on top which is NOT protective; the steel alloy is underneath. It shouldn't have worn out, but if it did it's most probably because you greased the cams too much and that made the ball bearing sliding along the cam instead of rolling.

Thnx for the tip. I'll check all again.