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PostPosted: Fri Dec 12, 2008 11:57 pm
by tony_jl2005
You got it Steve. It's the T26 pushrods. For some reason I thought they were solid nylon given the small diameter holes in the F32 guides. You say 117 inches long. Do you know the exact diameter?
Tony

PostPosted: Sat Dec 13, 2008 6:24 pm
by ozzie
quarter inch tube. they are not solid rod

PostPosted: Mon Dec 15, 2008 1:23 am
by Chappy
Tony,

I finally found my mis-located notes today from when I built my series 1 Lazair in early 1980. The T26 Pushrods supplied with my kit were 0.250 OD X .049 wall X 117.25" long each, made from 6061-T6 aluminum tubing . I don't remember having to trim the length. Do not substitute a softer, weaker 5000 series aluminum for the high temper 6061-T6!

The tubing needs to be well lubricated where it runs through the nylon guides, as they get brittle with age and binding could cause them to fail. Unfortunately, the lube will pick up dirt and grit that will cause not only wear on the guides, but also on the tubing. Clean the old lube off and redo it to keep them clean depending on how dusty your area is.

The larger aileron pushrods used nylon insets that were threaded for rod-end bearings. The inserts are Pop riveted in place. The expanded bulb of the rivets can eventually crack the inserts causing them to fail, and allowing them to pull out of the tubing. I suggest giving them a pull to check, or replace them with aluminum inserts like later Lazairs used. (Incidentally, very early series ones didn't come with aileron pushrod tubes in the wings, they used dual cables.)

Also, you might consider upgrading the T-26 tubes to the 1/2" pushrod setup used on later Lazairs.

Chappy

PostPosted: Mon Dec 15, 2008 3:50 am
by ozzie
I measured mine in situ so they are a aprox only. thread one end, fit a rod end and connect it to the mixer head and set the stick up as per the assembly manual, block the ruddervators to the stab and get the length exact. you get a bit of adjustment from the control rod ends as well.
i found this diameter and wall thickness in stainless steel when i made up some steam lances a few weeks ago. i'd consider this material when i change these in future. the alloy ones where fast in dusty conditions
i can't find the reciept for the 6061 tube think it was about

steve

PostPosted: Mon Dec 15, 2008 9:38 pm
by tony_jl2005
Thanks Chappy, ozzie and all who posted.
:rolleyes:
Does anyone have a supply of the F32 nylon guides & the N3/BE couplings plus pins that screw into the ends of 1/4 inch T26 ruddervator pushrods for Series 1.

I have the nylon guides but they look pretty brittle. Don't have any couplings for either end of pushrods though.

Tony

PostPosted: Tue Dec 16, 2008 1:50 pm
by lazairiii
Tony,

I have a brand new set of guides and rod ends...BUT, since you are where you are, I'd suggest that you convert them over to the 1/2" pushrods and not look back.

George

PostPosted: Wed Dec 17, 2008 5:46 am
by tony_jl2005
Hi George,

The only problem with going 1/2" pushrods is that I will then need 1/2" guides & rod ends. Are any available?
ozzie suggested 1/4" stainless steel rods. These would be beefier than the aluminium I should think and not much heavier.
I have seen a photo of a Series 1 with chrome steel sleeves over the 1/4" aluminium on the sections that slid through the guides. I guess this was to save a wear problem.

Tony

PostPosted: Wed Dec 17, 2008 8:23 am
by russell
These are aluminum, but put a halt on the wear of the smaller tubing.