question regarding nut plate for flap and aileron??

[sjt]

Can anyone tell me if this is what is meant to be used in this location?
It does not seem to be very substantial.
k1000.jpg
Also it does not look the the drawing.


Is it seated into plate backward and then a locking nut goes on back side?


stan p284

[rodsmith]

Yes a K1000 works and is installed as per the drawing. Once the flaps and ailerons are covered there is no access to the back side. Some builders have installed the hinges before covering, hoping they will never have to replace one.

[sjt]

So, checking one more time, the K1000 are small things, and bob drew something that looks like a 1/4 inch nut,
But, I should assume the drawing is an exageration of what a K1000 actually looks like?

Also, it means that I would use locktite on the 10-32 bolt to keep it from coming loose in the K1000.

[rodsmith]

The K1000s are self locking

[Pbruce]

I used larger nutplates than that, for use with AN3 bolts. 20 came with my hardware package from Wicks, which Avipro specified for me. I also used a bunch of single-arm nutplanes too since they afforded more clearance for tools near the corners in some places. At Mark Goldberg’s suggestion I also used a few steel countersink cherry pull rivets. (CCC 32 I think). This helped a great deal. When you think about it, the rivets really only stop the nutplates from spinning and align them over the hole, so it makes sense. Accuracy is everything. I found out the hard way to make sure that the bolt-holes in the aluminum control surfaces have a little bit of clearance around the bolts (only a couple thousands needed). If the bolt holes grasp the threaded bolt, the bolts tend to cross-thread into the nutplates. Not sure if locktite is required since the nutplates pinch the bolts, but I guess it can’t hurt. Also lubricates the bolt as it goes in which would help avoid cross-threading.

[rodsmith]

You always want to drill your screw holes oversize where the screws pass thru. Most tap/drill charts give a drill size for tapping the screw as well as a clearance hole size.

[Pbruce]

Yet another detail I wish I knew prior to building a plane but ended up learning during the process! The knowledge base on this forum is pretty amazing. It would be wonderful if more of it could be captured in a a step-by step manual. Personally, I think that could cause an explosion of Bearhawks. This is in no way a criticism of anyone. I knew the deal when I signed on, and when I complete this project, I will owe my success to the generosity of Mark Goldberg and the members of this forum. Thank you all.

[Gerhard Rieger]

I will also use AN3 bolts with ni-lock nut plates, one side the one with two holes next to each other and the nut on the end and the other side as in the photo

[sjt]

Are you saying that you are using 4 of them total for each doubler plate / hinge?

[Gerhard Rieger]

Yes, 2 left and 2 right, a total of 40. I will take photos tomorrow and put it on with part numbers

[sjt]

I looked up that part on aircraft spruce. It does have additonal protection for an3 10-32 backing out.

I think I can still use the K1000 and use safety wire on bolts to keep them from coming out.
If I still do not like it, I can follow the suggestion of additional stainless rivets.



I think it is the same size as a K1000.

[Gerhard Rieger]

If you go and look up on youtube- Desert Bearhawk- he also used the K1000 like you have

[sjt]

I have watched all of his videos. I just wish I could go back in the past and grab the camera and point it in another direction

[sjt]

This is what I think I am suppose to do.

I was suprised at how small the K1000 part is.

I just wanted to make sure that there was not a much stronger part.

I guess it does not matter. Assuming the 2024 doubler fails at about the same time as the 10-32 pulls loose.




doubler.jpg

[Pbruce]

Yes, that looks like it. I do highly recommend getting some of the single arm nutplates for locations which are too close to the ribs to get a bucking bar or rivet-set on, or to get more edge clearance. also, Mark G’s suggestion of using the odd countersunk pull rivet in some of the nutplate holes really helped. The nose of the pull-riveter didn’t fit everywhere either, so sometimes I had to resort to placing a long bucking bar on one end, a short one on the other, and hammering with a rivet gun on one of the bars. I was trying to keep the inboard end of the flap in line with the inboard wing rib, (not really required, I guess) and that may have skewed my hinge locations away from the ideal, closer to the flap and aileron ribs.

the bolt heads are going to visable during pre-flight inspection, and since the nutplates pinch fairly reliably, I’m not going to lock wire. The bolt is not subject to rotation, after all. I might think about locative though, if I think any feel too loose

[Bcone1381]

Can anyone tell me if this is what is meant to be used in this location?
It does not seem to be very substantial.
k1000.jpg
Also it does not look the the drawing.


Is it seated into plate backward and then a locking nut goes on back side?


stan p284

Would it calm your mind if the Spruce Anchor Nut photo appears smaller than the unit Spruce sells to me? Below is a photo what I get from them.

I feel good about the Mil Spec aircraft grade product and don't question its ability to hold as well as a standard nut. The threaded hole is slightly oval in order to squeeze the bolt's threads as it penetrates the nut plate. They lock so well that some folks run a tap through them. I never do. They are good...weigh less than a nut, and has more surface area to hold than a nut.

Would locktite on this produce work better than applying it to a anchor nut with a nylon insert? I dont know.....I think maybe.
Screen Shot 2021-06-17 at 7.43.14 AM.png

[Gerhard Rieger]

[sjt]

I will probably pick up some of those one arm versions.

I also left some room on my 4130 material for hinges. Maybe I can put a hole in it for a safety wire attach point.