Snap bushing for rudder cables

Gents,

I am installing my rudder cables and first installing the snap bushing in my RV-7A.

I had purchased additional SB625-7 and SB625-8's for my electrical wiring runs so I have two 5/8 OD bushing to work with.

I just found a bag #1945 from my fuselage kit with 39 SB625-8 bushing in it. However the plans call out SB625-7 for the rudder cable snap bushings.

The SB625-7 have a smaller ID and a "larger shoulder" for the cable to rub against. I prefer to follow the drawing so I don't want to use the SB625-8 bushing without checking to see if I just have a bag of incorrect bushings. Or did Van's change the bushing used and not updated the drawings?

For those with a fuselage kit in progress, please check your snap bushing bag #1945 and see what snap bushings are in the bag (they are clearly marked) and please post your findings.

The downside to using the SB625-7 is that you must first squeeze the snap bushing past the end of the cable and then install the bushing in the hole. This will make removing the cable very difficult if needed to do so.

So for those who have already installed their rudder cables if they had to pre-install the bushings on the cable then please respond as well.

Thanks for the help,

Paul

paul

I just ran out to the shop and the part number in my bag #1945 is SSB625-7. This is a March 07 kit. Remember that from time to time these bushing will need to be replaced, so a bushing with a little better clearance would be better. I'm two weeks behind you.Keep it up!

Rudder Cables

I just installed my rudder cables a couple days ago. Yes, you do have to squeeze the bushings to feed the cable through, and yes, it would be very difficult to remove the cable later. The only reason I can think of to remove the cables, would be if one broke or was frayed, in which case you could just cut the cable to remove it, since it wouldn't be reusable anyway. And yes, that means you would have to remove the snap bushing in order to feed a new cable through them. Since I didn't read up on this process before I did mine, I had to go through and remove all of my snap bushings before I installed my cable. Yes, I was one of those fools who thought I should pre-install all the snap bushings.

My 2 cents worth: Go ahead and install them with what you have, and worry about it later if, by small chance, you have to redo them.

Another consideration is to use two snap bushings for the rudder cables. Many of us have found that another smaller bushing will snap into the bigger one. Don't ask me what size. Maybe someone else will remember. Van's had an article in the RVator not long ago. Anyway, you need to saw a slot in the smaller one with a Zona saw (very fine tooth Exacto saw). Then you can open it up and slide it over the cable. the smaller one snaps into the bigger one. It acts as a sacrificial bushing and falls apart before the cable eats into the big one. Then you can replace the little ones and save the cable and the big bushings from wear.

Trial fit some of the snap bushings into each other. I'm sure you will find the ones that fit. I did.

Roberta

cable protection

What I did was buy some cable sleeves at the overpriced boating supply store, West Marine. They sell white nylon(?) tubes that are split and you can slide them over the rudder cables. Makes the system a whole lot quieter and provides protection for your snap bushings. They cost about $2 per 6 foot section and I used 4 sections of 5/32" ID. You can see it in the picture below:

Wrong snap bushings in bag

From the responses I received I have the wrong bushings in bag #1945.

I will call Van's and get some of the right bushings sent.

Roberta,

Thanks for the idea of a sacrafical bushing.

Paul

Pmerems said:

From the responses I received I have the wrong bushings in bag #1945.

I will call Van's and get some of the right bushings sent.

Roberta,

Thanks for the idea of a sacrafical bushing.

Paul

Click to expand...

I had the same problem... they bagged up the wrong bushings. Van's sent the correct ones at no charge.

Rudder Cable Snap Bushings

Here is a hint...Seems to me I heated the snap bushings with a heat gun, squeezed them oval shaped while still warm, inserted the rudder cable ends through the now oval bushing then popped them into the bulkhead holes and they cooled off round again. Made the job fairly easy.

Dick DeCramer
RV6 N500DD flying
RV8 Wing kit
Northfield, MN

You don't really need to heat the bushings. They will deform and allow the cable to slide through easily. I've inspected quite a few RVs with well over 1000 hrs. and have yet to see worn out bushings.

Which snap bushing to replace (if worn)

I image the snap bushings that will wear more then the others is where the rudder cable run is not straight. That is most likely to occur in the baggage bay. This area is also covered by a pop riveted panel in my RV-7.

Paul

Not sure where you are talking about that you can't access them. The rear ones can be accessed by removing the baggage bulkhead, and the front ones can be accessed by removing the flap covers, both of which are done at annual condition inspection.

What about the ELT bracket interference?

What suggestions do you folks have for protecting the cables where they run behind the strobe/ELT brackets (sold by Vans)?

smithhb said:

What suggestions do you folks have for protecting the cables where they run behind the strobe/ELT brackets (sold by Vans)?

Click to expand...

Stop by your local sailboat shop, they have a split covering for cable protection... same product Scott Will is using. Works GREAT!

Per post #10 of this thread, how do you replace the snap bushings if they wear, but are positioned such that you can not get to the back side of the bushing to press the release catches and push it out? The example mentioned in post #10 refers to the f-724 and f-706 bulkheads behind the aft baggage side cover that is blind riveted in place. Perhaps this is is one of those items you just work out after a couple of thousand hours of flying?
Tom.

If you need to replace a bushing or you want to add the smaller bushings, pop it out and cut it with side cutters. Inspect the cable. Take a razer blade and slice one side of the new bushing and slip it over the cable and snap back in.

I did add the smaller bushing inside the stock bushing. I then cut a 2 inch piece of tubing and bevel the end and cut a groove lengthwise to slip over the cable to pop out the smaller bushing when needed. Over 10 years and no sign of any wear on the bushings. The smaller bushing has greater surface contact with the cable.

I was talking to a friend of mine today and he said why not just cut off the tabs of the inner bushing and sikaflex it in place, then cut off the Sika in the future of you ever need to replace it. This got me thinking, so I decided instead to just round off the teeth that normally would grip the edge of the hole you are pushing it into. There is enough force from the spring arms to still hold the bushing in place, but not so so much grip that you can't get the bushing out. You just put a thin blade screwdriver or knife under the front face and flick it out of the hole. I've just tried it and it works a treat, so I am doing this to the bushings I can not access the back of like at the rear baggage bulkheads and the main spar.
Tom.