[Tumper]

I have seen several methods of marking pushrods for the end rivets and none of them seemed very easy or accurate to me. I had this idea and it has worked great for me, so I thought I?d share it.

For this method you will be required to use a little math, but don?t be nervous it will be OK. The equation for the circumference of a circle (distance around the push rod) is the diameter of the circle times 3.1416. All you have to do is determine the circumference and divide by the number of rivets to get the distance between the rivets.

Here is an example: the pushrod has a diameter of 0.750? so I multiply that times 3.1416 to get a circumference of 2.256?. There are six rivets around the end so divide by six to get 0.393? between the rivets.

Now take a piece of tape and apply it to a flat surface. Mark off a zero line and then measure 0.393? using your handy digital calipers. Then multiply 0.393? times 2 and mark that distance off. Continue to add one to your multiplier until you account for all the rivets. Next, draw a line parallel to the edge of the tape the distance the rivets are supposed to be from the end of the pushrod.

Then pull up the tape and apply it to the end of the pushrod being careful not to stretch the tape when you apply it. There you have it; all your holes are evenly marked and the correct distance from the end of the pushrod, ready to be punched and drilled.

And to speed up the process apply a second piece of tape next to the first and mark both at the same time so you work both ends of the pushrod simultaneously.

 

[Mel]

Or if you don't like math....

Just wrap the piece of tape around the tube and mark the point of overlap. Remove the tape and divide the distance by the number of rivets you want. Mark it, put it back on the tube and drill.

 

[Ironflight]

Just wrap the piece of tape around the tube and mark the point of overlap. Remove the tape and divide the distance by the number of rivets you want. Mark it, put it back on the tube and drill.

To avoid any math AT ALL, once you unwrap the tape, use a rivet fan to mark the number of rivet holes - just remember that the two ends are the same rivet.....

 

[Rick6a]

Always mathmatically challenged, I developed an almost self-explanatory technique to easily lay out a series of evenly spaced holes on a round tube and posted it here in April, 2007. The way I chose to describe the technique in that thread was influenced by a monthly cartoon feature called "Wordless Workshop" that ran in (Popular Mechanics?) when I was a kid. Very recently, the EAA indicated they may use that tip in an upcoming edition of Sport Aviation Magazine:

http://www.vansairforce.com/community/showthread.php?t=16846

 

[BSwayze]

Another non-math method

Not that I don't like math. Or accurately measuring. There are a lot of ways to skin this cat. This was just so fast and easy. Wrap a 2" wide piece of paper around the tube and cut to length so the ends just meet. Then fold the paper in half, then quarters, then eighths. Unfold, and you have all the fold marks for the rivet spacing. You can then mark a line on the paper for the edge distance, and tape it back on the tube for drilling. So simple. And dead-on accurate. It's just as easy for the smaller forward tube which has six rivets. Fold in thirds first, then in half for six rivet spacings.

Turned out great!

 

[RV7Guy]

???

Man, that is a short pushrod, where's it go?

It's not that you divide it but how you divide it.