Seat pan and seatbelt mounting

[FoxTrotter]

The instructions for mounting the seat pan say to redrill the tabs using a #40 drill. That works for the pop rivets; what about the center hole? I’m thinking #21 drill-right?

The tabs that seem to be for the shoulder straps are solid; no bolt holes. The airframe serial number is embossed on the starboard tab. The instructions show the correct tabs as being predrilled. Am I missing something, or I just need to drill them? 0.25”?

Thanks - Michael

[FoxTrotter]

Further --
It appears that the rivet holes are mis-positioned as well; either that, or I've got the wrong nutplates (but the numbers match); see photo. The existing rivet holes make it challenging to position correctly spaced holes without encroaching on the old holes, but if I offset I think I can make it work.

The online build instructions are identical to the printed manual I'm working from; did the hole spacing change to match the nutplates on fuselage weldments built after mine or is everyone dealing with this? Am I missing something?

Thanks - Michael21994

[jmodguy]

Looks like the tab is drilled for a K-1000 series nutplate and the nutplate that you have is an MK-1000 series. The M is for miniature and that means the rivet spacing is closer and the tabs are shorter.
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[jiott]

I just redrilled the tab rivet holes to match the nutplate. There is no strength issue here-the rivets just keep the nutplate from rotating or falling out.

[FoxTrotter]

Good thought, Jeff, but that's not it; my rivet holes are .750 on center and the K1000's are 0.688.

Yup, I've redrilled, but it's good to have confirmation - thanks, Jim. As an aside -- I had to tap the nutplates to 10-32; the screws wouldn't turn without tearing up their threads. You have that issue too?

- Michael

[jrevens]

Those tabs are drilled for Camloc receptacles. Kitfox evidently has a bunch of those (for the turtleback, etc.), and they’re using them there too. In my opinion it wouldn’t be bad to use Camlocs there if you wanted to. They’re more expensive, & there would be a small weight penalty, but removing & installing the seat pan would be very quick & easy.

[FoxTrotter]

Seems reasonable, but then why supply the (non-fitting) nutplates with the kit instead of the camlocks?
- Michael

[N213RV]

I installed camlocks to hold my seat in. The holes do match the camlocks footprint.

[colospace]

Way back when I was doing these "nutplates", I researched so many mil-specs for nutplates that my eyes began to cross. :rolleyes: I finally noticed that the spacing was identical to Cam-Loc spacing, and as you have noticed, precludes putting in properly spaced holes for a standard nutplate of any sort. I decided to use Click-Bond nutplates as they do not require rivets for mounting. Click-Bonds are a bit pricey compared to standard nutplates, but they sure are nice to install.

[FoxTrotter]

Yes, after fighting to do the nutplates on the pan-back tabs, I ordered Click-Bonds for the front 4 based on your earlier thread.
Thanks! - Michael

[Mesteve]

My seat tabs only had the single center pilot hole. The problem I ran into is that the tabs are smaller and I have had to get creative to get the top nutplate to sit flat on the backside of the tab.