screw up

[steve canyon]

I got the bright idea that our pitch trim assy. needed some lube so I sprayed LPS 1 on it and now the cable is slipping on the pully. i'm going to try wiping acetone on groove in pully and cable. This stuff is all above a headliner that doesn't have long enough zippers to allow good access. Any suggestions would be welcome. This is a BC12-D

[Robert Lees]

Well done for admitting a screw up (it takes courage to do that publicly).

How far in can you get your hand, and is there access from above?

Acetone is a good solvent to remove lubricant, but you don't really want to wash out the lubricant internal to the cable that was used during its manufacture, so use sparingly (if you can). Use a rag, damp with your solvent, hold it against the cable and wind the trim back-and-forth (whilst keeping the yoke in a neutral pitch position).

Good luck! (Remember, winding the trim with the yoke against the panel is a no-no; apologies if this is teaching granny, but it can never be said enough to get the message across to those who don't know)

Rob.

[steve canyon]

Thanks Robert, I can Get my hand to the pully but no access from above. I will try your advice.

[PA1195]

High proof alcohol (ethanol or isopropyl-rubbing alcohol) will de-lube safer that toxic solvents. I prefer alcohol but sometimes use spray brake cleaner with a fine tip extension but only with gloves and a mask. The front and rear pulleys should be cleaned while you're at it as the rear pulley is nearby frequently lubed parts.

Gary

[Hank Jarrett]

Once you get all the excess surface lube off the cable make sure the pulley groove is clean too ans well as having a slight "V" shape (unlike a regular pulley which is more rounded. Then fins someone with a kid learning to play violin or a music shop and rub the cable with Bow Rosin. It is a sticky stuff that comes in a small block. Most violin shops will have little pieces that are worn out for a musical instrument but will work fine on our cables. Bow rosin will help the cable stick in the groove and not slip.

[Scott]

Perhaps your idea was spurred by sensing some tightness in the trim system?

Now the lube is simply magnifying the real problem ie binding in another part of the system?

Bottom line is, when properly setup, rigged, and lubricated, with no clearance issues around the pullies, cable or in the elevator, the trim should run smooth and easy. Tight quarters in the elvator area... easy to have a small rub or lube issue that can come to the fore when other "stars align."
s

[steve canyon]

Thanks all for the information. I will clean the rear pully also and find some bow rosin. The trim system does seem to be working better after cleaning the front pully and cable up there.

[Robert Lees]

Good news!

[Robert Lees]

Thanks all for the information. I will clean the rear pully also and find some bow rosin. The trim system does seem to be working better after cleaning the front pully and cable up there.

Sometimes called "violin rosin", it's what all stringed instrument users use, to allow the horse-hair bow strings to grab the strings of their instrument. Best source? Local school or private music teacher; they throw it away in a state that we can still use it!