Match drill nutplates or not?

RVG8tor · #1 01-06-2008, 12:36 PM

To you experienced builders,

I was dealing with my first nutplates, which are the K1000 that go on the rudder spar. The plans have you cleco them in place then match drill the holes in the spar. The nutplate holes are already big enough to handle the rivet size. It seems like having the nutplate in place does nothing, and it actually leaves open the possibility that you might mar the nutplate hole with the drill thereby removing some of the cad corrosion protection.

Would it hurt to leave the nutplates off for the match drilling part, what problems might this cause?

sprucemoose · #2 01-06-2008, 12:48 PM

Should not be a problem to leave them off. If, upon final assembly, you find that the holes don't quite line up, you can always match drill them then. With pre-punched kits, this is unlikely.

I think this is a hold-over from the old, non-pre-punched days.

Transporter · #3 01-06-2008, 01:13 PM

I just primered them (slid them onto a dowel and primered while rotating the dowel). The rivets fit fine during assembly. I would suggest you check the threads though-I had one bad one that cleaned up with a tap.

az_gila · #4 01-06-2008, 01:33 PM

Quote:

Originally Posted by Transporter

I just primered them (slid them onto a dowel and primered while rotating the dowel). The rivets fit fine during assembly. I would suggest you check the threads though-I had one bad one that cleaned up with a tap.

Careful here... remember the all metal nutplates have a "deformed" thread - which is the actual locking feature.
Running a cutting tap through them probably removes most of this locking.

A tight nutplate can usually be loosened up by using a scrap screw and Boelube...

The nutplates have a passivated finish and should not need priming..

gil A

Transporter · #5 01-06-2008, 03:43 PM

Gil,
Thanks-I didn't run the tap through completely (nowhere near the 'deformed thread'). Mine just needed a turn (with Boelube) to clean out some metal that was blocking the starting thread. I should have pointed that out. A bolt might have done the same job. Caution is well advised.

Priming is probably overkill, but hey, I had the gun out anyway

Mike

prkaye · #6 01-07-2008, 06:53 AM

When I first started building i was diligently match-drilling all my nutplates, being careful to record which nutplate goes iwth which hole, and the orientation. What a pain. I've since learned that that is totally unnecessary. When you get later into the project and have to drill nutplates that don't have pre-punched rivet holes (like if you want to make removeabale floors) the Avery nutplate drilling jig is a really fantastic tool. It really saves a lot of time (using a nutplate itself as a drilling jig can be fiddly and annoying).

http://www.averytools.com/p-892-plat...rill-jigs.aspx

Rick S. · #7 01-07-2008, 08:14 PM

Not to shoot down nutplate jigs but every nutplate I ever drilled without having the mounting holes matched drilled prior involved a 1" long screw with the same thread size run through the hole, hold the screw by hand to drill the first hole, clecoed then drilled the second hole. Also nutplate "threads" are not deformed, the exit end of the barrel is squeezed from round to oblong in manufacturing, this gives it it's thread locking capability, sometimes to a fault. I have found several nutplates with T.U. threads, I always run a screw into them, not all the way through, just enough to make sure there are threads and the screw will start, before mounting to make sure the are OK. Some didn't even have threads!

Not a good thing if you relying on them to function buried in the airframe at a later date in the build.

Mark Burns · #8 01-07-2008, 09:57 PM

Quote:

Originally Posted by Rick S.

Not to shoot down nutplate jigs but every nutplate I ever drilled without having the mounting holes matched drilled prior involved a 1" long screw with the same thread size run through the hole, hold the screw by hand to drill the first hole, clecoed then drilled the second hole.

That's how I do it also. It's fast and works great.

Mark

GAHco · #9 01-07-2008, 10:11 PM

As far as I know Van's only supplies the Steel nutplates that are Black Moly coated (after Cad Plating)and they are magnetic. Although the steel ones can be made with a yellow cad finish also they are just not as popular.

If you knock the finish off on the steel ones I recommend replacing it with a new one, especially if it is in a structural or difficult to replace area. If not maybe a q-tip primer job will work, but I would still rather have a new one.

Yes some nutplates are passivated, but only the Non-magnetic ones.They are made from A286 Stainless and may be Black Moly coated or silver plated. These are typically not mounted on aluminum structures.

I built allot of my project with the homespun nutplate jig by sacrificing a nutplate to make a simple tool, and the cleco bit on one side works even better than just holding it.

I also have been using a nut plate jig but I just had to mess with it. I started with one made for a regular fixed standard spacing #4 nutplate (you can always enlarge the screw hole) then I knocked the side alignment pin out. I the drill all my screw holes in the material. Next I go back and using the jig drill all of one side of the holes. Afetr that I use a c-3/32 cleco and secure the jig to each rivet hole while drilling out the other side. I don't even have to hold the jig, the cleco does the work. After each one is finished I just hop to the next hole.

One thing is for sure nutplates are one of the handiest pieces of hardware we work with.

If one were to consider the option of not using them, WAKE UP! WAKE UP!, oops I almost slipped int a very bad dream. Thank goodness I am awake, I love my nutplates!

For more info http://www.gen-aircraft-hardware.com.../nutplates.pdf

RVG8tor · #10 01-07-2008, 10:24 PM

Quote:

Originally Posted by GAHco

As far as I know Van's only supplies the Steel nutplates that are Black Moly coated and they are magnetic. Although the steel ones can be made with a yellow cad finish also they are just not as popular.

Tom,

So are you saying the nut plates we get from Van's need to have primer applied, from previous posts to my question it seems the consensus is that they are protected but primer would add more layer of protection. Your post seems to allude to priming as requirement.

The first nut plates for me to install are the one that hold the rudder (**** can't remember what it is called) but it is the threaded bearing that hooks to the VS hinges. These will not be easy to get out after they are installed, I would want something that will hold up for a very long time. Van's sends the K1000's I think, I don't have my plans in front of me to confirm. If there is a better option for these and the elevator nut plates I would be interested to hear about it.

Cheers