Lazair 4

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Postby ozzie » Tue Jan 10, 2006 2:23 am

i have seen a crack in this area on the accident damaged rear spar that i replaced during my recent rebuild. it propogated from the hole that was drilled to fold the spar over . the hole was never deburred or cleaned up during the original assembly. the crack had at some stage been stopdrilled and had ceased going passed that point. the crack is half inch long. probably caused by engine vibration.

another small crack that is developing (but will be replaced) is in the Y fitting that holds the tail on. when the fitting was pushed into the fuse tube one side of the Y fitting is hard up against the fuse the other side is a couple of thou off the tube. the crack about 1/32" long not much (but it will grow) and has started where it touches the tube. again none of the components were deburred and the edges on the fuse is very sharp. just goes to show that a little extra effort when building will save lots of hassells later. might pay to check yours. ozzie
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Postby ola » Tue Jan 10, 2006 5:29 am

yes a couple of hard landings it is !,but i will first check for new materials.
i don`t belive in old aluminium w cracks.
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Postby pittsnut » Tue Jan 10, 2006 2:41 pm

Hello Ola,

Its Dale George, in Canada. I think the best way to deal with your cracks is to replace the parts yourself.

Dale Kramer was kind enough to tell us what materials he used, buy the aluminum and make the parts, use your old ones to make new ones, something like that.

I have repaired many a Lazair, they are very simple to make parts as long as you have the old "cracked" ones.

Just great that Dale gives us information, lets not bug him too much.

O' ya, I have all the covering materials, tapes etc, so just let me know what you need. I use 2 inch wide, clear, single sided, PVF tape for all the trailing edge seams and 2 inch wide aluminum 3M tape for the leading edges. I have them in stock.

Tedlar covering 60 inch wide X 100 feet, 3/4 inch PVF foam tape, 1/2 inch tedlar tape, 2 inch aluminum foil, 2 inch clear, single sided, PVF tape

Let me know what you need and your shipping and can work up a price for you.


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Postby Bill » Sun Feb 05, 2006 1:56 pm

I agree that making parts is not very hard to do... You really only need to know what material to buy and what thickness... When I was actively flying and building... we did come up with some parts that we improved ourselves for various reasons... mostly to make parts twice as strong to deal with landings... and some to deal with longterm vibration effects...

One item the tail y... we used to double it up... or make one out of material that was twice as strong...

The 2 seater had many strength enhancements that are worth looking at for heavier single seaters... floats... reduction drive or heavier engines... etc..

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