RV-8 HS-404 & HS-405 Drilling Mistakes

plbarrett2004 · Post by **plbarrett2004** » Thu Feb 14, 2013 7:16 pm

Hi all,

So I have two problems.

1. The previous owner of the empennage kit marked on the empennage that the right HS-404 rib needed to be replaced. I wanted to assemble it to see exactly where the problem was and determine if it is fixable. I think I COULD fix it, but its probably better if I simply replace the part. There is a space of about 1/8 inch between the flange of the HS-404 and the front spar. My thought is, that it could probably be reshaped to work since this is not a part that should undergo large structural load... but probably better and easier to just replace the part.

2.

Last night I made a completely stupid mistake, but I'm sure its not the last. I measured and drilled the holes that will connect the HS-405 to the HS-404 upside down. End result is that the holes will meet the HS-404, but not where they should be (in the picture the holes are shifted down on the HS-405 from their proper location). One will be way too close to the edge of the 404. My thought again is to replace, but another option may be to press on and/or maybe add a third rivet. The spar and the forward rib have not been drilled, so replacement will be an easy fix. Thoughts?

captain_john · Post by **captain_john** » Thu Feb 14, 2013 8:57 pm

Peter, with respect to question 1, I am thinking you could shim it with a thin piece of aluminum. I wonder why you ended up so far away from the spar to begin with though. Mine was spot on.

Question 2, if you want to drill another PAIR of hole there you can. Observe your edge distance and you should be fine. The plans call for 2 rivets at that location and I really doubt that they need to be exactly where they are prepunched. Again, so long as you have edge distance, you will be fine.

I always say, It isn't about your mistakes. It is how you fix them that counts!

CJ

Post by **bullojm1** » Fri Feb 15, 2013 9:53 am

Hey Peter,

For your first issue, I think it is completely OK to shim the distance between the rib flange and the front spar. However, I do recall when I visited you earlier in the week, some of the hole spacing on one side of your rib was near the edge. This spacing here probably explains why the hole alignment existed. It might be best to order a new rib. This shouldn't slow your progress down at all, because you can still move on with everything else (including priming) and just drill this rib last.

The second issue is near and dear to me because I drilled my flange too close to the edge:

My solution was to add another rivet in the middle. After 100 hours, I haven't fallen out of the sky yet!

And here's a tip for ordering replacement parts - call Van's up (i.e. don't do the web ordering) because they will process and ship your order the same day. Web orders seemed to be delayed by a day or two. Also, request USPS priority shipping. Typically it is cheaper than UPS or FedEx, and it only takes 2-3 days for the parts to arrive. UPS and FexEx can take up to a week to ship across the country.

plbarrett2004 · Post by **plbarrett2004** » Fri Feb 15, 2013 10:22 am

Mike & CJ... thanks for the input. Van's technical support echoed the ideas you presented here. Right now I'm thinking I will shim the first part, and most likely order a new HS-405 because I have not drilled the 404 or the spar on that side. One replacement part, and I can install as intended.

The HS-404 with the odd space can probably be shimmed, but there is another issue; the 404's flange holes do not line up perfectly with the holes drilled in the spar. If I replace the part I can ensure that all the holes line up AND avoid the shim. The other option is to shim, match drill, and if needed increase the rivet size... I'm going to have to think about this a little more.

My next question would then be... is there anything more to shimming it than shoving an appropriately sized piece of aluminum between the two and continuing on?

plbarrett2004 · Post by **plbarrett2004** » Fri Feb 15, 2013 11:04 am

Hoping this shim will do the trick for the HS-404:

Post by **bullojm1** » Fri Feb 15, 2013 4:19 pm

Peter,

That will definitely do the trick. Nice fix!

plbarrett2004 · Post by **plbarrett2004** » Sat Feb 16, 2013 9:16 am

Thanks Mike. I ordered replacement parts, despite some good solutions. I'm ok with one error, but I don't like having multiple errors in the same area... If for no other reason than how I'll feel about it. I'd definitely do the shim... But the holes are off too.

Anyways, thanks for the help. I'll post photos when it's done. Btw, took your advice on the USPS shipping. Thanks.

plbarrett2004 · Post by **plbarrett2004** » Wed Feb 20, 2013 5:34 am

Wow, you were right about the shipping... I decided to order new parts for my own peace of mind. Put the order in by phone late friday afternoon via USPS priority. The parts arrived Tuesday... with a federal holiday on Monday!