Rebuild partial VS

[haydnc]

I have been searching for almost an hour now, and have not been able to find any posts:

I have to replace the VS spar as i ruined my first attempt. I now have a new spar and doubler.

The VS skin is already dimpled (from the last effort).

When I match drill the new VS spar, should I match drill through the already dimpled VS skin or just drill the VS spar only?

If I match drill through the skin dimple will i weaken the dimple as the drill runs through it?

Thanks for your idea!

 

[apkp777]

Hi,


Maybe someone else with more experience will chime in, but I had to
replace one spar on the tail. No big deal with the matched hole technology.

This is my experience:

Don?t touch the skin. After dimpling, the holes have expanded a little.


Just take the new spar, drill holes to size, deburr and dimple. Cleco the
spar and skin and you will see that it fits perfectly.

Tell us how it went, we are here to help each other.

Yep, that's how I'd do it. Don't try to match drill through the skin, that'll create some issues for sure.

 

[rbibb]

Not sure how you could drill the spar rivet holes and assure alignment without drilling through the already dimpled skin. As pointed out the dimpled holes will have expanded a few thousanths and if you are careful you can drill the underlying spar without further enlarging the dimpled skin.

If you had access to a CMC mill you could set up the spar and drill the hole pattern required with enough accuracy but that is probably not a practical approach.

Drilling through the existing skin is the technique used in repair of damaged aircraft the world over. Just go slow and perhaps centerpunch the holes first lest the drill wander off center.

 

[haydnc]

Not sure how you could drill the spar rivet holes and assure alignment without drilling through the already dimpled skin. As pointed out the dimpled holes will have expanded a few thousanths and if you are careful you can drill the underlying spar without further enlarging the dimpled skin.

If you had access to a CMC mill you could set up the spar and drill the hole pattern required with enough accuracy but that is probably not a practical approach.

Drilling through the existing skin is the technique used in repair of damaged aircraft the world over. Just go slow and perhaps centerpunch the holes first lest the drill wander off center.

Rbibb: The holes are pre punched so its just 'final' drilling the spar

 

[apkp777]

Not sure how you could drill the spar rivet holes and assure alignment without drilling through the already dimpled skin. As pointed out the dimpled holes will have expanded a few thousanths and if you are careful you can drill the underlying spar without further enlarging the dimpled skin.

If you had access to a CMC mill you could set up the spar and drill the hole pattern required with enough accuracy but that is probably not a practical approach.

Drilling through the existing skin is the technique used in repair of damaged aircraft the world over. Just go slow and perhaps centerpunch the holes first lest the drill wander off center.

The spar is pre-punched. He just needs to final drill (#40), debur, dimple. As the other poster indicated, the skin will fit perfectly like that.

 

[apkp777]

Sorry Hayden, we posted a reply to Ribb at the same instant and said the same thing.

 

[rbibb]

If its prepunched then by all means just ream to final size, debur, dimple, and thank God you are building a newer model than the -4 or -3 where every single hole was laid out and drilled by hand....

Even though I'm building a -10 I still revert to thinking like I am building my -4 again.

BTW - by "ream" above I just mean run a drill through the hole not use an actual "reamer"....

 

[haydnc]

Sorry Hayden, we posted a reply to Ribb at the same instant and said the same thing.

We're onto it!

If its prepunched then by all means just ream to final size, debur, dimple, and thank God you are building a newer model than the -4 or -3 where every single hole was laid out and drilled by hand....

Maybe a 4 next, but for the moment this one is causing me enough problems!