Aileron Pushrod length question

Desert Rat · #1 12-10-2019, 05:47 AM

On the old 2006 vintage wings I bought, the print says to cut the tube 65 25/32" The new preview plans I have call out a longer dimension, presumably to deal with the problem I've read about on here where people were finding them to be too short.

The callout on the new preview plans as pretty fuzzy and isn't any better on the electronic version, but I believe it says 66 26/32"

Can somebody verify that from a set of full sized new-ish plans? I get that the idea is to make it about an inch longer than it used to be, but it just seems weird that they would increase it by 1 1/32"

wirejock · #2 12-10-2019, 08:31 AM

65-25/32" on my plans. I cut them 3/8" longer. 66-5/32".

Desert Rat · #3 12-10-2019, 09:38 AM

Thats odd. These wings are from 2006 and the 15A print that came with them definitely shows the old 65 25/32 dimension.

However when I look at my new preview plans they show the bigger dimension, even though the title block shows that it hasn't had a revision since 2003.

I put a screen shot of the new callout in my build log.

https://eaabuilderslog.org/?blproject&proj=7WxtkKls2

Z-EDD · #4 12-10-2019, 10:46 PM

Quote:

Originally Posted by Desert Rat

On the old 2006 vintage wings I bought, the print says to cut the tube 65 25/32" The new preview plans I have call out a longer dimension, presumably to deal with the problem I've read about on here where people were finding them to be too short.

The callout on the new preview plans as pretty fuzzy and isn't any better on the electronic version, but I believe it says 66 26/32"

Can somebody verify that from a set of full sized new-ish plans? I get that the idea is to make it about an inch longer than it used to be, but it just seems weird that they would increase it by 1 1/32"

I don't think vans have changed this, I think your blurry copy of the plans actually reads 65 25/32. As you point out 1 1/32 is an odd increase, but it is also way too much to resolve the minor discrepancies that have been reported. Mine were slightly short at the dimension shown on the plans, but I was planning on adding around 1/4 to resolve this. 1 inch could almost make them too long. Another clue is that 26/32nds should resolve to 13/16ths. Don't think Vans would make this kind of error.

Desert Rat · #5 12-11-2019, 05:07 AM

Quote:

Originally Posted by Z-EDD

I don't think vans have changed this, I think your blurry copy of the plans actually reads 65 25/32. As you point out 1 1/32 is an odd increase, but it is also way too much to resolve the minor discrepancies that have been reported. Mine were slightly short at the dimension shown on the plans, but I was planning on adding around 1/4 to resolve this. 1 inch could almost make them too long. Another clue is that 26/32nds should resolve to 13/16ths. Don't think Vans would make this kind of error.

You may be right, but it sure looks like 66 26/32 doesn't it? As for that dimension making them too long, I suspect you're right.

I called builder support when they opened for business yesterday morning and they thought it looked like the bigger dimension on their end as well. Their suggestion was to measure the rod ends and then do the math to determine what tube length was actually needed to get to the overall dimension of 69 9/32. When I did that, I discovered that a 66 26/32 tube is would cause the rod ends to be bottomed out on the jamb nuts to achieve this, leaving me with the ability to adjust it longer, but not shorter. Who knows, maybe that's what they intended?

I need one of these tubes at least temporarily installed to check clearance for my pitot lines. I have a heated pitot with a min length requirement for the hard lines coming off of it and the previous owners of these wings cut the hole for the pitot mast 1 bay inbd of the bell crank. The skin is just clecoed on, so now is the time to change this if there's interference with the tube.

At this point I'm just going to finish one end so I can do a trial fit for clearance and leave them long with the cockpit side unfinished until I mate the wings on down the road and can determine a real world length.

CubedRoot · #6 10-03-2020, 11:30 AM

I’m about to cut my pushrods and was wanting to know if any of you guys had any issues with cutting longer?

Larry, did your dimensions work out ok?

wirejock · #7 10-03-2020, 02:09 PM

Quote:

Originally Posted by CubedRoot

I’m about to cut my pushrods and was wanting to know if any of you guys had any issues with cutting longer?

Larry, did your dimensions work out ok?

Sorry. They haven't been connected yet.

Desert Rat · #8 10-03-2020, 04:08 PM

I left them long with only one end done. Figured it really wouldn't be a problem to wait until the wings are on and then finish the other end.

CubedRoot · #9 10-03-2020, 05:49 PM

Is that tube stock used for anything else in the build? If not! I’ll just cut both really long and leave one end unfinished till I bolt the wings on

agent4573 · #10 10-03-2020, 09:26 PM

That tube is only used for the pushrods. My plans that shipped this year still called out 65 25/32" and they were too short. Vans support said their plans showed 66 and something but it was too blurry on his computer to read it. We had the same drawing revision so I don't know how we had different numbers. I had to reorder the tubes and ended up at 66 1/8".

Edit: the total dimension for eye to eye length is correct, it's just the tube call-out that's too short. Find a way to hold the rod ends the correct distance apart (like drilling a hole into your workbench and using a long bolt) and then cut the tube to fit.