[Adam Oke]

So before I go ahead an bend up my trim tab beyond repair, I wan't two know why everyone has built two?

It seems that this is a pretty common part to screw up on. I've read a lot of sites that give little guidance on the procedure -- just a pictures of a nice result. I'm looking for tips on how you built it and how to prevent blowing it the first time around.

 

[Bob Axsom]

Sorry

I only built one with a lot of care and there was no problem. There may be a message there, perhaps not.

Bob Axsom

 

[SeanB]

prep counts

Make sure and use hardwood for the blocks.

Make sure the blocks can't move. I used double sided carpet tape and drove a drywall screw through the blocks. Even used a clamp.

Pics at: http://websites.expercraft.com/sblair/index.php?q=log_entry&log_id=49697

Make sure to consider there will be a bend radius introduced around the blocks, so move the skin accordingly.

Don't forget to dimple the tabs for CS4-4 rivets prior to assembly.

Not too bad a job if you take your time and use a good setup.

 

[roee]

What's all the fuss?

Adam,

If it seems like it's "a common part to screw up" or that "everyone has built two", it's primarily because only people who mess it up have a reason to write about it. Everyone else, probably a large majority of the thousands and thousands of builders here, got it right the first time without too much trouble.

I'm not putting down people who messed it up and had to redo. We've all had to redo something at one time or another, that's par for the course. No big deal, and even better if it's something as small and inexpensive as a trim tab.

The point I was trying to make is that there's no real problem with the trim tab and no magic to building one. But rather that the percpetion of it is a common problem with this type of forum in general -- that it naturally tends to amplify the perception of a problem where the reality is a lot less dramatic.

So don't sweat it. Build the trim tab carefully, and most likely you'll get through it just fine.

P.S. just wait til you get to the canopy...

 

[Adam Oke]

I'm away from the shop for a bit and have been doing some more reading. It seems that it is also pretty common to just fabricate a riblet to avoid any issues all together. It actually looks like a pretty good idea, and wondering around the airport every certified aircraft is done this way. Having said that, the web on all certified aircraft I have looked at is "inboard" on both control surfaces.

If I were to go the riblet route, why is everyone putting the web outboard vs inboard? Is there something I am missing here? It looks like it would be simple to put the web inboard and squeeze the rivets. There must be some reason....

I'm leaning more and more towards something like Terry's but fliping the rib so the web is inboard

ref: http://www.mykitlog.com/users/display_log.php?user=frazitl&project=61&category=1026&log=13674&row=11