Small Pitch Axis Issue - And Solution

[KurtV 9]

@tutmeister

I wanted to call your attention to an issue that evolved with my Fulcrum One -- I have had the yoke several months now and remain very happy with it.

The pitch movement had developed a slight hitch, or bump in it, it was very slight just coming off its center point.  So minor it almost felt like some pet hair had found its way into the mechanism, but that is not what I discovered.

When I opened up the case and moved the axis I noticed that the flange that the front bearing in the carriage is mounted to, (This is the flange with the large bolts that take a 5mm allen key), was moving on the left hand side up and down slightly.   I recentered the shaft and snugged up that bolt and all is fine now.

But what I wanted to suggest is that since this wasn't loose on arrival, it clearly worked loose over time, you may want to consider using some thread locker on that bolt in your future units.

Also, I noticed that the rail for the pitch axis had become sticky, this would have been whatever lube you were using at the time (back around Apr/May 2022 I think).   I cleaned that all up and re-lubed with the WD40 Dry lube as suggested in your other post.  And all is good for now.

Edited February 2, 2023 by KurtV

[Ron Attwood 3,464]

How nice. A useful post. Not that I'm having trouble but it a good one to file away. 👍

[tutmeister 695]

17 hours ago, KurtV said:

@tutmeister

I wanted to call your attention to an issue that evolved with my Fulcrum One -- I have had the yoke several months now and remain very happy with it.

The pitch movement had developed a slight hitch, or bump in it, it was very slight just coming off its center point.  So minor it almost felt like some pet hair had found its way into the mechanism, but that is not what I discovered.

When I opened up the case and moved the axis I noticed that the flange that the front bearing in the carriage is mounted to, (This is the flange with the large bolts that take a 5mm allen key), was moving on the left hand side up and down slightly.   I recentered the shaft and snugged up that bolt and all is fine now.

But what I wanted to suggest is that since this wasn't loose on arrival, it clearly worked loose over time, you may want to consider using some thread locker on that bolt in your future units.

Also, I noticed that the rail for the pitch axis had become sticky, this would have been whatever lube you were using at the time (back around Apr/May 2022 I think).   I cleaned that all up and re-lubed with the WD40 Dry lube as suggested in your other post.  And all is good for now.

Thanks for the update! I will pass that along and we will probably thread lock them just in case. It is not something we have seen but it may be that yours was not as tight as it should have been when we assembled it.

Regarding the rail, we have changed our process for making sure all the shipping oil is removed. When those linear rails arrive, they are coated in a shipping oil that is rather viscous. We clean this off and flush it out of the bearing blocks and then lube with a teflon spray. We have had a couple of reports of sticky pitch and this it turns out was due to this oil not being fully flushed out during assembly. A small amount was left inside and was diluted by the light lube and over time it evaporated and caused it start sticking. Since those reports we now fully strip the bearings and flush everything out fully before reassembly.

Now you have re-lubed it I dont think you will have any more issues.

[KurtV 9]

9 hours ago, tutmeister said:

A small amount was left inside and was diluted by the light lube and over time it evaporated and caused it start sticking. Since those reports we now fully strip the bearings and flush everything out fully before reassembly.

Now you have re-lubed it I dont think you will have any more issues.

Yeah, I cleaned that all out with acetone, so I'm quite sure whatever it was is gone forever.  Waited for that to dry and then dry wiped it and went in with the dry lube.

it's more slippery than a greased doorknob now.

[jannickz 0]

Thank you for sharing your experience with the Fulcrum One yoke and the issue you encountered with the sticky pitch axis. Your detailed description, including the cause and your solution, is valuable information for both myself and other users who might face similar problems.