Tank attach angle platenuts

Michael Burbidge · #1 12-12-2008, 10:00 PM

I'm just finishing the attach angles on my first tank. I went to rivet the platenuts to the attach angle and found that for almost all of them the holes for the rivets in the attach angles are two close together, by about 1/32.

I don't know how this happened. The way that I drilled the holes for the platenuts is I took a platenut and one of the bolts that go into the platenut and screwed the platenut to the attach angle. I then clamped one side of the platenut and drilled then other. I then put a cleco in the drilled side and drilled the other one.

I assume that the platenuts are consistent in size. I guess I'll be ordering new attach angles.

Is there a better way to drill the rivet holes for these attach angles?

sglynn · #2 12-12-2008, 10:56 PM

Mike, I'm building a 7A in Anacortes, WA. I drill platenuts the same way with the bolt and a clecoe. And sometimes they are a little off. I think there is some variation in the platenuts. But I just run the drill thru again and rivet. Van's once reminded me, the rivets on the platenuts are merely to hold the platenut from turning. They are not part of the structural integrity of what the platenut holds. So I advise: drill em and keep building. I'm just closing my tanks now. If you'd like to come see over Christmas break let me know.

rvbuilder2002 · #3 12-12-2008, 10:58 PM

Quote:

Originally Posted by mburbidg@adobe.com

I'm just finishing the attach angles on my first tank. I went to rivet the platenuts to the attach angle and found that for almost all of them the holes for the rivets in the attach angles are two close together, by about 1/32.

I don't know how this happened. The way that I drilled the holes for the platenuts is I took a platenut and one of the bolts that go into the platenut and screwed the platenut to the attach angle. I then clamped one side of the platenut and drilled then other. I then put a cleco in the drilled side and drilled the other one.

I assume that the platenuts are consistent in size. I guess I'll be ordering new attach angles.

Is there a better way to drill the rivet holes for these attach angles?

While drilling, did you possible have the nutplates located on the opposite side of the attach angles from what they eventually get installed on. If so, if you don't drill exactly perpendicular through the .063 thick material the hole location is displaced on the opposite surface where it exits. Then when you flip the nutplate to the opposite side, the holes are to far displaced to insert rivets

Rick6a · #4 12-13-2008, 06:55 AM

Mike,

You are right to accept that consistently accurate hole patterns do exist from one nut plate to the next. If all three holes in the nutplate do not line up perfectly after you drill the pattern through the work, it is a virtual certainty the problem is with builder technique. This is not meant as an indictment, merely a dry statement of fact. I have installed countless tens of hundreds of nutplates over the years and not often have been able to produce a precise hole pattern by free handing the pattern which is what you are essentially describing. Sure, you can make the nutplate fit by wallowing out a hole or two but at the price of diminished quality. The thicker the material, the more difficult true accuracy becomes. Some builders are perfectly happy to settle for "good enough," but the question is...will you?

Scott's post clearly indicates he knows a thing or three about nutplate "gotchas." Whether his scenario is correct or not in this particular case, the common misalignment you describe is even easier to achieve with floating type nutplates because the element can easily shift a wee bit as you move hardware, clamps or clecos around.

The only sure way to quickly produce high quality nutplate hole patterns also happens to be a dirt simple alternative to eyeballing it and free handing. By using the proper nutplate jig you will save yourself a ton of time, tedium and aggravation while quickly producing better, more accurate work. You don't have to invest in expensive new jigs either. Check out eBay for used nutplate jigs as various sizes of the tool are almost always offered for sale there.

Michael Burbidge · #5 12-13-2008, 09:51 AM

I also see them for sale on Cleveland and Avery, but I don't see the right size. All I see is for screws #10, #8, etc. What is the right size for the tank attach angles? The bolts are AN3-4A. Is there an equivalency to one of the numbered screw sizes?

I see a few for sale on ebay. I also certainly buy a new one if someone could point me at the right jig.

Thanks.

az_gila · #6 12-13-2008, 10:00 AM

Quote:

Originally Posted by mburbidg@adobe.com

I also see them for sale on Cleveland and Avery, but I don't see the right size. All I see is for screws #10, #8, etc. What is the right size for the tank attach angles? The bolts are AN3-4A. Is there an equivalency to one of the numbered screw sizes?

I see a few for sale on ebay. I also certainly buy a new one if someone could point me at the right jig.

Thanks.

...an AN3 ( 3 times 1/16 diameter) is actually a #10 screw size - a 10-32 thread.

So a #10 is the size you need for AN3 bolts.

Rick6a · #7 12-13-2008, 10:34 AM

Quote:

Originally Posted by mburbidg@adobe.com

I also see them for sale on Cleveland and Avery, but I don't see the right size. All I see is for screws #10, #8, etc. What is the right size for the tank attach angles? The bolts are AN3-4A. Is there an equivalency to one of the numbered screw sizes?

I see a few for sale on ebay. I also certainly buy a new one if someone could point me at the right jig.

Thanks.

As far as RV construction is concerned, the rivet hole pattern is the same on the majority of most #4, #6, or #8 single leg and double leg nut plate sizes normally used with the kits. For instance, provided you FIRST drill the center hole to accept the pin in the center of the nut plate jig, you can use a #4, #6 or #8 nutplate jig to drill the #40 rivet attach holes, and only THEN bring up the center hole to its full size. In this particular case though with the fastener hole already brought up to 3/16" nominal size, using a #10 jig is best. By referring to a drill index chart, you will see that a #10 hole is .1935 so you may or may not have to slightly ream the existing hole to accept the pin in the #10 jig. Other than that, it is very easy to check and see if a jig will work with a given nutplate. Simply center a nut plate over the jig and if the rivet attach holes line up, you are good to go.