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PostPosted: Mon Mar 17, 2008 9:15 pm
by Shannon
Thanks Russell but the F-9 doubler and "L" brackets were something my Dad incorported on his plane back in '81. Much like what you have there he was rebuilding a damaged front assembly and came up with his way of improvement.

Have you given any thought to using 2 bolts rather than 3 ? You can just make out the circles I drew around the rivets in the enlarged image. The factory solution apparently was to put bolts where rivets are so you wouldn't be going outside the box by using a couple of bolts.

PostPosted: Tue Mar 18, 2008 4:59 am
by mickbroom
Thanks for the tip on the rivets, no marks found yet so they are non structural or polished off but might explain why they cause trouble.
I am very concerned that I get the replacement parts of both the bracket and rivets made in the correct material ( or better) so any information or sorce for this would be appreciated.
At the moment my prefered route would be to slightly thicken the bracket as is and replace two of the outer rivets with steel ones as the assembly is coming off.
I assume the factory went for bolts so they could be fitted without taking it all apart.
Nicely made bracket, looks like the build quality is very high over your side of the pond, lots of time in the garage I suspect B).
The picture is G-MNRD which is the other local Lazair (15 miles down the road, we work on shorter distances than you lot which suits the plane) Its based at Sywell near Northampton in the middle of the country and is the one which might be used for experiments in electrical power.
I don't like the extra tubes on our plane but its what we got and when I can understand what they are for might remove them.
You advised the compression tube through-bolt motor mounts but I am not clear what this is or requires.
Will post a picture of the trim lever later today hopefully.
Thanks again.
Dave in the Shadow at a competition for those that are interested.

PostPosted: Tue Mar 18, 2008 5:49 am
by mickbroom
Mechanical pitch trim as fitted to the Lazair

PostPosted: Tue Mar 18, 2008 5:53 am
by mickbroom
The other side if you can see it against the rest of the stuff in the showroom

PostPosted: Tue Mar 18, 2008 9:06 am
by russell
Mick, the rivets on my seriesI have one dot, but that's not to say it is on yours.

Shannon, that suggestion is workable for me.

PostPosted: Tue Mar 18, 2008 10:13 am
by Shannon
Welcome Russell, glad to have your participation as there seems to be shortage at the moment.

Mick you can take a preliminary look at the compression tube motor mounts here on George's plane : ... #entry5919

Thanks for the compliment on the work. That plane is a cobble together project using several damaged parts planes and this-that from here-there. It came together well but as you suspect after many hours.

I'm definitely intrigued at the mechanical trim system. Will surely be asking more questions about that later ! WOW !, I thought G-MNRD and G-MVGZ were the same plane with different registration letters. They look almost identical !

I pulled out some old front assemblies and found the rivets to have a single dimple. As Karl earlier mentioned the craftsmanship that went into these assemblies seems really low. I've noticed some rear tail attach Y assemblies that look shabby as well.

PostPosted: Tue Mar 18, 2008 2:08 pm
by Shannon
Here's what I'm talking about. Factory new never installed rear "Y" fitting. Look at the hap-hazard work.

PostPosted: Wed Mar 19, 2008 3:05 am
by mickbroom
I am sort of getting used to it a bit now but every time you send a photo it does not look like the bits I have and it makes me think. Before all I thought I had to do was repair as is and go fly!
The rivet pattern on mine is not the same as yours and as you say the workmanship does seem to be over a big range.
I had a look at the wing last night and see the oppertunity for the through bolts and tubes for the engine mount and will use the idea as while I cannot see any evidence of deformation in the area I still cannot find a reason for the damage to the leading edge which was just under one side of the engine mount. Any idea's?
The two planes in the photo's are I believe simular because they were owned and built by two brothers! We have removed a few things as we have proceeded as they did tend to fit lots of extra bits from strobe lights to the spats ( lots of mud in the UK summer).
Picture of leading edge below engine mount which I intend to remove and ease out from the inside while having a good inspection of what I cannot see at the moment.

PostPosted: Wed Mar 19, 2008 4:58 pm
by russell
Uh-oh, not only is there dents, but it appears that there is also a crease. Hammer it out for sure, but the crease will most likely fracture, although not visible to the naked eye. You should without a doubt take Shannon's advice and install the skin doubler. Don't fly it without at least doing that, we need to keep all the Lazair owners we can.

PostPosted: Thu Mar 20, 2008 4:42 am
by mickbroom
Thanks for the observation and I note your point. I will approach this with a lot of care and the big worry for me is I still don't know what happened.
The plane finished on its back and the damage is under one of the engine mount sides but there is no evidence visable to show deformation near the engine mount holes.
Hopefully there will be more clues inside but if anyone else has an observation please let me know.