Cost to Metalize

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6896
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Joined: Tue May 01, 2018 7:00 am
Name: ConsultEngr
Aircraft Type: Cessna 140
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Re: Cost to Metalize

Post by 6896 »

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6896
Posts: 105
Joined: Tue May 01, 2018 7:00 am
Name: ConsultEngr
Aircraft Type: Cessna 140
Occupation-Interests:
Contact:

Re: Cost to Metalize

Post by 6896 »

Down toward the trailing edge of the tip, the spacing between the upper and lower wing surfaces is very limited, so limited that you have to take care in using the right length machine screw so it doesn't protrude beyond the nut plate any more than it needs to (a couple of threads). If a screw is too long, it could touch the screw coming in from the opposite direction, depending on the placement of the original rivet holes in your tip. I made measurements to ensure I would not have an issue, but to be safe, I used a video borescope after installing the tip with screws to verify no interference.

What I did does take a bit of repetitive work, especially in laying out the rivet holes in the nut plate strip. However, if you have a nut plate drill jig for the #4-40 screw and an pneumatic rivet squeezer, the process goes smoothly.

My part numbers for the #4-40 and #10-32 mini-spacing nutplates were: MS21069L04 (I ordered 100), MS21071L04 (I ordered 25), MS21071L3 (only 4 reqd per tip-these are for the original #10-32 attachment screws). I needed both two lug and one lug nut plates. The one luggers I used in the corners.

For the most part, my screws were AN526C440R6. I looked at using the MS51957 CRES pan head screws instead of the truss heads, but they were just too small to work with for reliable screw driver bite into the Phillips head. There is a bit of wrist work to screw all of the screws onto the nut plates, and the last thing I wanted to do was to slip with a screwdriver and mar the wing skins.

I ordered all of my parts from WBParts Express since they stocked the mini nut plates in quantity and I needed a lot anyway.

I finished the sheet metal work on my wings back in 2016, but it was a several year project to restore them to new-like condition.
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