Gear Weldment Installation QB 9A

[avi8tor50]

Happy Holidays (in advance) to all!

Getting ready to drill the holes in floor skins for the gear weldments in my 9A QB. Any hints to make my life easier drilling the holes?

[jlfernan]

I just did mine. Use tracing paper to copy the template off the plans. Cut out the hole and then tape it to the BOTTOM of the fuse making sure the location of the rivets and the hole for the brake line fitting, line up. Mark the hole. I used my Dremel with a side cutting bit from Rotozip to make a rough hole. Take your time, these can get away from you. I then used a drum sander in my Dremel to finish the hole. You do have to cut/smooth through part of the spar, so it will probably eat up a few sanding drums. I was totally stressed about these, but is was actually easy.

[ge9a]

I did mine EXACTLY as Jorge describes, with the SAME tools, and it worked fine. I, too, was nervous about cutting the holes, but if you take your time, and fit, refit the weldments, it won't be a big deal. It just takes a little time to get it right, and don't be in a hurry. I find that is advice I tell myself on everything I do on this plane!

Good luck.

[Jamie]

The gear leg weldments for the -7A are indistinguishable from the -9A.

Here's a link to my site with all the pages that mention the weldments.

Have fun....it was a frustrating part of the project for me. Be especially mindful of the rivets that may interfere. There are two that interfered for me. They're both mentioned on my site.

Hope that helps,
Jamie

[RV_7A]

Pictures speak a thousand words...

[tx_jayhawk]

Be adivsed that you will likely need to make the cutout notably bigger than the oval you trace from the plans....you won't be able to get the weldment in place otherwise.

Scott

7A Finishing

[cytoxin]

Originally Posted by tx_jayhawk

Be adivsed that you will likely need to make the cutout notably bigger than the oval you trace from the plans....you won't be able to get the weldment in place otherwise.

Scott

7A Finishing

and you will likely get into that rivet closest to the edge of the circle on the spar.

[sportpilot]

Here is our take on installing the gear mounts on the 9a. We cut out the hole pattern including the rivet pattern and reference marks. Place this cutout over the rivet row and line up the rivets and tape it down. This orients the cutout. Mark around the cutout area with the blue line pen. Use your dremel tool with a cutoff disk to rough cut. We borrowed a nibbler and nebbled down to the line. Thne changed over to the air drill and a rotary file to do the finish work.

We had to carve off a bit of the spar flange almost up to the edge of a rivet. The final deal is to get a loose enough fit so the weldment will slide in place. Using the rotary file Cleve ground off a bit, then we tried a fit, and marked the area of conflict, then ground off a bit more, etc.
It wasnt easy its good to go slow and mark your cuts before you grind away.

Pictures on the gear weldmet install. 9a

Good luck!

[brian]

several good replies already - here's one more set of descriptions and pics to check out:

http://brian76.mystarband.net/April03fuse2.htm#apr14

This was one of the very first jobs I did on my QB. Back then, I did nothing unless I was told to in the plans or manual. I didn't see anything in the manual about enlarging the weldment holes for the wing attach bolts, so I didn't do it.

HUGE TIP - make sure you drill out the holes in the weldments that the wing bolts will be going through. They'er probably a bit undersize from the powder coating, and they may not align perfectly with the holes in the spar, so it is VERY important to open them up a bit. If you don't do it now, you will be very sorry later. It's trivial to do now, and it cost me over $300 in reamers to do it after everything was mounted.

http://brian76.mystarband.net/fuselage.htm#may-06

http://brian76.mystarband.net/FuselageNov06.htm#nov12