first mistake

[datsclark]

I have about 12 hours into the HS thus far. I've spent at least twice that time on the learning-what-i'm-about-to-do steps. Fluting is one of those seems easy processes, but I just can't get my head around it, and I spent 20 mins on each part. I've had a few ah-ha moments though, so hopefully that'll get better.

I did make a mistake in drilling the main rib (HS405) to to front spar (HS702) to angle reinforcements (HS710 & HS714) to leading rib (HS404) section. I used the nifty angle-drill from Avery tools, which seems to work great. However I managed to let it walk around a little bit while drilling, and got the following few bad holes, including one that went through to the spar.

Is this salvageable? I will call Vans and ask, i'm just trying to get a feel for how bad mistakes like this really are. Can i drill out and bolt?

 

[Webb]

Inhale first

If this is the worst mistake you make, you're way ahead of the curve.

Everything will be fine and can be salvaged. Here is what I would do.

Ditch the angle drill unless absolutely necessary. Drill each side one side at a time so you can use a straight drill and use the spar's holes as a template.

Drill 2 new holes equally spaced between the 2 bad holes. Plenty of metal for the rivets.

Mark the spar where you want to drill through. Place it flat on a work surface so it won't bend when you use a punch. This gives your drill bit a starting spot so the drill won't walk. Drill it using a #40 so you have a good starting hole. Cleco one rib and match drill with a #30. Remove rib and put the other rib on and drill out with a #30 from the other side.

Then drill out the 2 bad holes with a larger bit such as a 12 and debur. Consider them lightening holes and forget about them. I would wait to do this until after you drill new holes since you can still use clecos in the bad hole to steady the ribs and cleocs in the new holes to keep the ribs steady for drilling out the bad holes.

As far as fluting, search the threads for the fluting lesson in which you place the rib on a flat surface to judge straightness and speed fluting along.

Also, in the picture of the spar, I see what appears to be a sharp wire edge on the inside of the curve near the spar attachment area. Be sure to take a bit of sandpaper and smooth that out.

Now, inhale....go get a beer...fix it....and move on......

Good luck with the build. Oh - its not a mistake, it's just one of those darn moments that makes the build time a bit longer.

 

[mototopo]

I made the same mistake on my HS, but I misdrilled the HS-710 too (the hole was not perfectly perpendicular). I contacted Gus at Van's and his answer was as follow:

1. Don't care about the elongated hole on HS-702 spar because it is sandwiched between two other components;

2. Not a big problem on the HS-405 rib (well, my hole was a little less elongated). Just put a doubler plate on the flange to reinforce it.

3. Make a new HS-710 because it is a very important structural part.

I decided to buy a nes HS-405 and rebuild it (maybe not necessary, but I preferred to do this way).

Using the angle attachment in that location was the cause of my mistake.
My next attemp to drill throug those components was a little different. I clecoed all the components and using a #40 drill bit I marked the location of the hole on HS-710 using the rib as drill guide. I then drilled HS-710 on the bench drill to have it perfectly perpendicular. I re-clecoed the components toghether and drilled the HS-405/HS-702 from the front of the HS with a 12" long #30 drill bit using HS-710 as drill guide. Perfect result.
Hope this help.

 

[danielhv]

yup, easy fix. Good job and keep pounding!

 

[Charles in SC]

Try using split point drill bits. They are not as likely to walk around when starting them.I usually turn the drill by hand slowly a time or two before pulling the drill trigger.

 

[datsclark]

Thank guys for your help--good to know I'm not alone in bugger things up from time to time.

I also spoke with Vans, just to get the official recommendation. They said HS405 must be replaced (already on order now) and that the rest looks ok. I believe I will heed the advice here and look for a better way to drill this than the angle drill. I sorta like the idea of a 12" drill bit with all the pieces together, but i'll have to go out and look at the geometry of it all.

Hopefully the next post will be with a better picture.

 

[dhall_polo]

no big whoop.

did you use a center punch?

drill tips:
I think pressing down too hard with the drill leads to walking. Try altering downward forces, let the drill do the work.
Point with your pointer, squeeze with your birdie finger.