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Page 09-24 step 9 and page 09-25 step 5 - clevis pin fit

iamtheari

Well Known Member
In doing some test-fitting in preparation of installing the pitch trim servo, I dug out the hardware and found a problem. I am waiting for paint to dry on the metal components, but I test-fit the clevis pin into the trim servo and it does not fit through the hole on the actuator rod. The pin should be an MS20392-1C11 according to the plans. That is the part number from the parts bag. It also does not seem to fit through the NAS1149FN432P washers, although it was getting late and there is a chance I grabbed the wrong washers so I will have to test that again.

Am I supposed to just push harder to install the pin through the trim servo actuator rod or get a different pin? I know from searching the forums that a loose fit is bad (some reports of the trim tab being loose due to wear in the trim tab horn holes, requiring a bushing to correct) but I don't want to hurt something by force-fitting things.
 
I recall running a drill (#30 I believe) through the actuator rod. Not sure if it had some plastic flash but the clevis pin wouldn?t go in easily. Smooth after.
 
I had to drill as well. Didn't measure but it needs very little material removed. Same on the Roll servo which, if I remember correctly, is the same model.
 
A #30 on the servo pushrod did the trick. The clevis is a little looser fitting (not dangerously so) once it is in, so I think the end of it is enlarged. Meanwhile, the metal pushrod assembly still doesn't allow the clevis through after drilling it to #30. That tells me that the clevis really is the problem, which also explains the lack of fit through the washers it's supposed to go through. And I don't want to drill things to #27 as that's just way too big. The odd thing is that both of the clevises from the kit (the longer one C11 for the servo end of the pushrod and the shorter one C9 for the trim tab horn end) have the same issue, and getting two faulty clevises seems improbable to me.
 
Update: I used the small 3M wheel to debur the cotter pin holes in the clevis pins and they perfectly fit through the washers and all other necessary holes. Builders of the future: Try that before drilling anything, if you read this in time.
 
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