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Need help to fix problem with a trailing link gear strut

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Need help to fix problem with a trailing link gear strut

Old 10-12-2016, 05:03 PM
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mun_iz
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Default Need help to fix problem with a trailing link gear strut

Hi all,

I am facing a problem with the main struts on my CARF Ultra Flash and would appreciate advice to get it fixed. The struts are from a reputable manufacturer but somehow, it failed to work for me. I had written to the manufacturer since Monday but had yet to receive any replies and the weekends are coming =(. I hope to get it fixed so that I can get more flights this weekend.

I had the maiden flight for my Ultra Flash last weekend.The landing was smooth with no bounce, hard impact, etc..
However, I noticed after the maiden flight, both main strutsremained jammed in the bent position and will not straightened out. Please see photos.

I removed the spring on one of them to check and found the twolinks to be very tight. I also removed the set screw from the bottom link(the one that holds the wheel). There seem to be a lot of rubbing (either between the 2 links or between one of the link and the pin that holds them together)causing them not to move freely. The struts has no damage on them at all butthe links are somehow tight.

I am not able to dismantle the two links as I found thatthe links are held together by a pin (and not a bolt which I can undo). I am not sure if I can knock out the pin with a mallet and was concern about doing damage on it.

Can someone with experience dismantling such struts advice please?

Many thanks.

Isaac



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Last edited by mun_iz; 10-12-2016 at 05:06 PM.
Old 10-12-2016, 06:43 PM
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Crazy4Flight
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check first if there is any clearance between the link and strut, it may be binding there
remove the set screw from the link, then you drive out the pin, use a drive pin punch (flat on the end)
the hole in the link should be slightly bigger than the pin .002-.004"so it can pivot
Old 10-12-2016, 11:23 PM
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Dave Wilshere
 
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The Aluminium on Aluminium surface can pick up especially in humid or large temperature change countries. As said you can knock the pin out after the set screw is taken out. But just teflon oil should free it up if you work it back and forth without removing the pin.
The Intairco Wheels to AT legs always need a 6mm washer between the brake unit and leg to give tyre clearance.
Once free, ground handling is better if you wrap the leg and spring with insulation tape, 4-5 layers. The spring will still operate under the tape, you can also tie the brake line to the rear outside edge of the leg with an additional wrap of tape.

Dave
Old 10-12-2016, 11:56 PM
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mun_iz
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Hi all,

many thanks for the replies. I also received a reply from the manufacturer this afternoon. Apparently, he replied me a few days earlier but for some reasons I did not received it. I was told the problem may be due to oxide build up as I do live in an area which is highly humid.

Anyway, I hope lubrication and working it back and forth will work... will have to try it tonight.

Cheers
Isaac
Old 10-14-2016, 05:42 AM
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lov2flyrc
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Issac,
I suggest using a "Dry" lube (sometimes referred to as PTFE Lube) for all of your strut joints. This will provide the lubrication needed without attracting dirt/dust to the joint. Cleaning and reapplying every 25 flights or so should keep things in good shape.

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