Reaming

[PapuaPilot]

If the bushings are a little loose I would suggest using Locktite 609. This is used in Continental engines and elsewhere on certified aircraft.

[Shadowrider]

How loose should the bushings be before trying to “press them in”? I have ran the reamer through multiple times and by hand I can barely get them started. I just don’t want to get them stuck like I have read others have? I was thinking of using a c clamp to push them in but don’t want to distort the brass or get them stuck.

[PapuaPilot]

I would say they should be no more than .002" tight fit. Zero to .001" tight would be ideal.

Here are a couple of tricks that will help get them in. You can do both.

1. Put the bushings in the freezer to make them contract, and carefully heat the airframe, but be careful that you don't overheat it causing the powder coating to melt.

2. Use a bolt that fits through the bushing that is about 2" long, a nut & two washers. Put one washer on the bolt, then the bushing, insert the bolt through the airframe bushing, then the other washer and nut on the other end. Keep the parts centered and straight, tighten the nut to draw the bushing into the airframe. This method gives you a good mechanical advantage and will draw bushings in with little effort if they are not too much oversize.

[Delta Whisky]

I turned my bushings down (mounted on a bolt and sanded while turned on a drill press) to a 0.0015 interference fit and then "cooled" to really cold with - of all things - butane. Clearly not to be performed anywhere near an open flame or heat source. Actually, I was surprised at how really cold this technique will get and how easy it made inserting the bushing. I used a wooden block and a leather mallet and didn't have any problem with insertion. I will admit though that I couldn't convince myself that the bearing loc was needed and didn't use any. Once everything warmed up to room temperature I attempted to move the bushing with the mallet and block trick and it wouldn't - no way, no how. Keep a rag handy to wipe of the ice build up before inserting. The wooden disc on the butane is the "trigger". None of the above is a recommendation, it is just what I did.

[efwd]

Good Lord. put that in the tips for builders section. I could of used this info back then.
Eddie

[Rodney]

R-134 works really well too and I don’t think it’s explosive

Rodney

[Flyboy66]

I turned my bushings down (mounted on a bolt and sanded while turned on a drill press) to a 0.0015 interference fit and then "cooled" to really cold with - of all things - butane. Clearly not to be performed anywhere near an open flame or heat source. Actually, I was surprised at how really cold this technique will get and how easy it made inserting the bushing. I used a wooden block and a leather mallet and didn't have any problem with insertion. I will admit though that I couldn't convince myself that the bearing loc was needed and didn't use any. Once everything warmed up to room temperature I attempted to move the bushing with the mallet and block trick and it wouldn't - no way, no how. Keep a rag handy to wipe of the ice build up before inserting. The wooden disc on the butane is the "trigger". None of the above is a recommendation, it is just what I did.

I think the butane is an excellent idea. The liquid can be used to cool the bearing, and the gas( if used near open flame) can expand the bushing. It’s a win, win.

[Flyboy66]

I think I have the opposite problem compared to what I am reading here. The bearing slides into the bushing and out the other side. I wrapped copy paper around it 1.5 turns and it still has play. Two turns would probably snug it up. No, paper is not my answer, just my measuring tool.

[jiott]

Maybe I don't understand your problem Flyboy, but the bearing is supposed to rotate fairly freely in the pressed-in bushing. That is your rotation surface. The bearing is NOT supposed to rotate on the bolt. You will notice that the bearing is slightly longer than the bushing; this is so that when you clamp the bearing in the elevator tabs with the bolt, it will NOT rotate with respect to the bolt. Maybe you already know all this, but FYI just in case.

[Flyboy66]

Sorry, not writing clearly. I was in a hurry while typing. Horizontal Tail Assembly page 11. Part number 93021 goes into the elevator hinge mount. It goes into hinge mount and has air space around it except for where it settles to the bottom of the hinge mount. I misread the words on the diagram under “detail A” while typing. I am using the correct part (93021) into the hinge mount. Is the part in the photo supposed to have free play between it and the powder coated tube it is in?

Does the liquid lock go on outside of 93021, to lock it in the hinge mount?