Final drilling vertical stabilizer skin

Jarrett · #1 05-20-2020, 06:36 PM

I've recently been working through the Vertical Stabilizer and Rudder and I have to say that as a first-time builder it is an amazing kit! I'm about to start final-drilling the holes on the vertical stabilizer skin to the skeleton and was wondering if I should be using a reamer or drill bit? Also in general when final drilling, which should be used? So far I've done all of the drilling (match and final) with drill bits and I've been getting decent results. I've seen that some builders use reamers all the time and some hardly ever use them. Is there a right or wrong way of doing it? Thanks!

mturnerb · #2 05-20-2020, 06:47 PM

Reamer will give you rounder holes and less burr in general. Here's the fun part of building an RV-14: the VS has many parts shared with other Van's models. Most other sections/parts are unique to RV-14 and are final punched at the factory to full rivet size, so "final drilling" is not a frequent need. Deburr, dimple, (prime), rivet.... I spoke with Scott early on in my project on this topic. He pointed out that the plans will tell you specifically when/where "final drilling" is needed. I got into the habit of testing parts for drill sizing by sticking a rivet into the holes - if they fit, generally speaking that part is already punched to size. Of course there are places in the build where you drill up from smaller sizes etc, but the instructions usually make that very clear.

Taltruda · #3 05-20-2020, 06:56 PM

I was going to use a #40 reamer in my holes, but then I heard that maybe the slightly imperfect holes may hold the rivets better. Drills make a slightly triangle shaped hole, and when the rivet expands to fill the hole, it?ll expand into that shape. I liked the idea of that, don?t know if it really matters though.

Jarrett · #4 05-20-2020, 11:18 PM

Thanks for the input, looking forward to those parts!

Nova RV · #5 05-21-2020, 05:05 AM

The skin holes are final sized, no need to make them bigger as they come final sized from the factory. Many things on the 14 kits are different from previous kits so be careful what advise you heed as you can make things worse in some cases.

mturnerb · #6 05-21-2020, 05:54 AM

Quote:

Originally Posted by Nova RV

The skin holes are final sized, no need to make them bigger as they come final sized from the factory. Many things on the 14 kits are different from previous kits so be careful what advise you heed as you can make things worse in some cases.

True but not on all parts (some are legacy parts shared with other Van's models) - as I mentioned, the instructions are specific where you need to do "final drilling" to get skin holes or other part holes up to size.

Nova RV · #7 05-21-2020, 06:06 AM

Quote:

Originally Posted by mturnerb

True but not on all parts (some are legacy parts shared with other Van's models) - as I mentioned, the instructions are specific where you need to do "final drilling" to get skin holes or other part holes up to size.

Yes, that's right and your test of seeing if the rivet would fit is exactly what I did too.

HAL Pilot · #8 05-22-2020, 06:05 PM

Also all the dimpled holes end up being a bit larger. They start around .093" and end up .102" This can result in the ability for the rivet to wobble a bit when being driven with corresponding bent shop heads.

One fix is to take the next longest rivet and pre squeeze it to fatten it up for the rivet hole. I use modeling tweezers (pointy end to them) to hold them so the factory head is away from the pneumatic squeezer piston (tends to not get bent as much when pre squeezing) They can get cocked of when pre squeezing so check visually for a straight squeeze.

The other option is there is someone out there that came out with a slightly fatter shank on no. 40 rivets that sound like they would work for this. Unfortunately I lost the add/article about it. So hoping the collective can remember for me. :-)