Drilling rudder pedal bushing blocks

I'm about to drill the forward longeron/stiffener to match the rudder pedal bushing blocks. I looked at Dan C's site, and I like the way he did it (marking the stiffener and then removing it and drilling on the bench), so I'll probably do that, but I have a question about the lateral positioning of the blocks...

As you move aft along the stiffener, the distance between the stiffeners (and the skin) gets greater due to the curvature/angle of the fuselage as a whole. So do you drill such that the distance between the *blocks* is constant (which would successively reduce the edge distance on the stiffener), or do you drill such that blocks are always in the same position on each stiffener (which I would think would allow the rudder pedals to "slop" side-to-side once installed in an aft location)?

I think the first is the case, but then...

Option 2

I'm at the same stage on my RV-9, and my plan is to keep the bolt holes centered in the longerons (your option 2). The end blocks fit tightly, and the center block will be tight as well once the bolts are in, so I don't think the rudder bar will be moving side-to-side in any of the locations that you set up.

...Joe

Edge distance

For an AN-3 bolt, the holes would need to be centered in the flange of the angle to have the required edge distance. Thus, I chose your option 2.

Also, I haven't seen anyone else do this, but if you use the center-to-center spacing of the center block for all three blocks, it makes laying out multiple mounting locations much easier.

See this page for a description.

Option 2 it was...and laid it out so as to reuse the aftmost hole at the forward position as the forward-most hole in the aft position, then split the difference evenly for a "mid" position.

As for side-to-side slop, the suggestion was to just insert a spacer or washer into the holes for the tubes, if needed, when in the mid or aft position. Don't know why I didn't think of that!

Next up...mount and drill the 6118 brace, and so help me, if I end up with a hole problem at the various positions I'm going to scream

Renewing this thread.

Big gotcha in the plans. Didn’t see that I should have made the holes at a slight angle to accommodate the angle of the fuselage. Now my holes don’t line up. Probably going to order new blocks vs new stiffeners. I could sand down one side of the block to get it to fit as well. Any suggestions?

I split the side blocks into top and bottom, with a washer in between, like the center bushing block. Made getting the pedals in/out easier.

John Tierney said:

I split the side blocks into top and bottom, with a washer in between, like the center bushing block. Made getting the pedals in/out easier.

Click to expand...

Please please do this, especially for the next guy

To make it easier, I also put a temporary bolt in place and superglued the washers to one side, so you don't have to keep multiple plates spinning in the air while trying to reinstall the rudder bars in a completed airplane. You can user oversized washers, since they are really just spacers to take up the saw kerf you removed. I supposed you wouldn't need them if you were making new blocks, and sawed them in half first, then hole-sawed where the bars go into the block?

Untainted123 said:

Please please do this, especially for the next guy

To make it easier, I also put a temporary bolt in place and superglued the washers to one side, so you don't have to keep multiple plates spinning in the air while trying to reinstall the rudder bars in a completed airplane. You can user oversized washers, since they are really just spacers to take up the saw kerf you removed. I supposed you wouldn't need them if you were making new blocks, and sawed them in half first, then hole-sawed where the bars go into the block?

Click to expand...

Or avoid the spacer completely......

After you cut the block in half, bolt the 2 pcs. together and re-drill (clean up) with a drill press using a spade bit to make a round hole again and no spacer is needed.

nohoflyer said:

Renewing this thread.

Big gotcha in the plans. Didn’t see that I should have made the holes at a slight angle to accommodate the angle of the fuselage. Now my holes don’t line up. Probably going to order new blocks vs new stiffeners. I could sand down one side of the block to get it to fit as well. Any suggestions?

Click to expand...

The blocks are bored at a slight angle to accommodate the angle of the fuselage. Fit them to the cross tubes on the bench first to confirm proper position before drilling and installation.