Nutplate Issue - Screw does not fit

tdavis1198 · #1 01-18-2021, 04:46 PM

I am trying to insert the screws that secure the pitch trim servo assembly onto the elevator. I can't get one of the screws to bind with the threads in one of the K1100-06 nut plates. I assume that there is a bit of distortion.

I assume that I will have to tap the nutplate. Is this correct and any suggestions what size and type tap I need to get?

abwaldal@gmail.com · #2 01-18-2021, 05:27 PM

Time to buy a tap/die set. But if it's not structural I will usually take half the pinch out of the nut so I don't snap the screw off. Been there done that.
Oh as for the call out on the tap. All the numbers are worn off both of my tapes for those.
Art

wirejock · #3 01-18-2021, 05:42 PM

Most common used on the airplane.
4-40, 6-32, 8-32, 10-32, 1/4-28, 3/8-16
Don't buy Harbor Fright. Buy quality taps.
Nothing worse than snapping off a hardened tap in a hole.

DaveWelch · #4 01-18-2021, 10:58 PM

After a similar experience with an installed nutplate that was a pain to replace, I vowed to run a boelubed screw thru every nutplate before riveting them in place. Preemptively Found a few more that would have given me problems.

CJK · #5 01-19-2021, 05:53 AM

Quote:

Originally Posted by DaveWelch

After a similar experience with an installed nutplate that was a pain to replace, I vowed to run a boelubed screw thru every nutplate before riveting them in place. Preemptively Found a few more that would have given me problems.

New builder here: I've seen a few folks recommend this, and it sounds wise. Is there a particular version of Boelube (paste, gel) that you recommend? Do you just leave it on the threads once you've checked them, or do you wipe it off before installing the fastener for the final assembly?

sf3543 · #6 01-19-2021, 08:35 AM

You'd be surprised how many times I have found the wrong size nut plate installed or where the threaded part got squeezed by the riveter.
If it is the incorrect size then drill it out and replace with the correct size.
If its the correct size for the screw, then what the others said.

stigaro · #7 01-19-2021, 09:41 AM

You may have the same issue a few of us have seen lately. No threads in the nutplate?

https://vansairforce.net/community/s...ighlight=wrong

wirejock · #8 01-19-2021, 11:21 AM

Quote:

Originally Posted by CJK

New builder here: I've seen a few folks recommend this, and it sounds wise. Is there a particular version of Boelube (paste, gel) that you recommend? Do you just leave it on the threads once you've checked them, or do you wipe it off before installing the fastener for the final assembly?

I prefer the paste blue stuff. Leave it. Unless you're really OCD like me.
Dime. Soak them after in a solvent. Dry. Spray with primer. I use NAPA 7220. I have a section of 1x2 with nails. Heads are cut off. I spray 40 at a time.
Totally unecessary but I do it anyway.