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Elevator Line Up

mike newall

Well Known Member
Sponsor
Hung the elevators - the two horns don't match across the center bearing by about 1/4".

Leave as is or manipulate one horn down to keep straight ?
 
Step 6: With both elevators in the "trail" position there will most likely be a
mismatch in position between the bottom end of the WD-605-L-1 Elevator Horn and the bottom end of the WD-605-R-1 Elevator Horn;

Mine were off a tad, maybe 1/4" difference, I lined up elevator balance and TE.
 
Are you talking about the hole that you drilled for the center bearing or the bottom end of the horns?

I have that same confusion. If he is talking the center bearing, he should be sure the hinge bearings are lined up, single straight line through all. If the horns don't line up after that, it's Ok because the pivot hole you drill will match and the horns will at least rotate in position relative to each other.

Then, as mentioned elsewhere, line up the trailing edges, though you might have to compromise to get the counterbalances to look right. More important to get the TEs lined up so you don't have a roll moment there. Normally you won't see both counterbalances in a position to notice a slight mismatch anyway. Once you have them lined up, you can drill both at the right vertical distance and a fore/aft location that gives both horns edge clearance even if there is some difference between them. When adjusting the stops, only one horn needs to make contact but it's not much more work to modify the stops so both horns make contact at the same time, and probably will wear longer.

In practice, even if the horns don't match up perfectly, the control surfaces will move in unison, which is the most important thing.
 
It is the initial drill I was asking about - the centre bolt.

It is so long since I did it on our 7 and 8, can't remember.

Skin clearances are perfect, counterbalance gaps are perfect, just the horns are about 1/4" out in vertical alignment. One horn is higher than the other.

I figure - drill and leave alone rather than introduce stress in the assembly. I can check TE lineup when I drill the pushrod attach.
 
Lock your elevators together and move them through the range. If the horns keep the same relative positions to each other throughout, you are good to go for drilling through the bearing. It is normal to have some variance in the weldments.
 
Note this.

When all is said and done, the trim tabs don’t travel equally, by design. They’re not supposed to. There’s a definite difference in their travel, by design.

Regards,
 
Follow up...

Took everyone's advice :)

Set the drill bushing up ..... 3mm hole - wtf ? Ran it through on the lathe to #30 and I am Britsh G..D...It.... I hate metric ;) Unless it helps...

Drilled the centre pushrod hole on one horn, then the other - perfect. The horns were about 1/4" out but Vans say to expect it.

Locked the counterweights onto the ends of the HS and sighted down. My word, I am not blowing smoke but you would not fit a RCH down it as out of true.

So onto phase 2 - drilled the aftermost horn, fitted a block, drilled through, opened up, de burred, bolted...

Still as straight as a straight thing !

Nice one chaps (chappesses are also lauded)

Now let me tell you about the rolling of the forward skins - OMG ! New thread.
 
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