Drilling arm rests to F-704 ?

[JurgenRoeland]

Hi,

I'm in the process of rivetting my forward fuselage and side skins to the tailcone and all excited to get to the point of rolling over the canoe.

During rivetting I noticed that I didn't drill the forward tab of the armrest F-720 into the F704 main spar bulkhead. The F704 is not predrilled at this location. I didn't do this yet because I realised the F-704K upright cap strips still needs to be put in place later. This tab in the armrest goes in with a LP4-3 pop rivet because of the impossible access on the inside later.

When did you guys actually drill this hole in the F-704 and install the pop rivet ?

[tgmillso]

You've got plenty of time yet. You just want to have it drilled preferably prior to painting the interior, which given that you are building a slider, should be about the last thing you do before you rivet on the F-7106 forward top skin (for access reasons). Before you get to this point make sure you have pre fitted your fuel lines, rudder bar (then removed it because you will need to get in there to buck rivets), drilled all the required holes in your firewall and mounted any doublers, put the belly insulation on (if you are doing it) and prepped the materials for the firewall insulation (but not yet installed). The arm rest should Not be riveted on until you have installed the canopy roll bar, as there is a nut holding the roll bar down on both sides that you will need to access. Once the F-704k is riveted on, you will lose access to this nut. Basically, prep/paint your arm rests and F-704K, but don't rivet them on until right at the end.
As our American cousins like to say, your mileage may vary (the metric version of that saying just doesn't seem to work).
Tom.

[BillL]

Agree - during final routing of static lines & wiring, you may want to route lines/wired under that rail, having the caps off until that is completed is a good idea. Mine were installed too early and caused extra work.

[JurgenRoeland]

so the K's stay of as long as possible which I was also planning.

Did you already rivet the arm rest horizontal line on the side skin and just leave the tab unattached from F704K or did you leave the whole arm rest unrivetted until last?

[Raymo]

Originally Posted by JurgenRoeland

Did you already rivet the arm rest horizontal line on the side skin and just leave the tab unattached from F704K or did you leave the whole arm rest unrivetted until last?

Yes. Many also install a piece of aluminum angle under the arm rest to give it extra support.

[JurgenRoeland]

thx for the response guys. building on

[bret]

As mentioned above I would recommend the angle reinforcement for the arm rest also. I used a router to radius the outside corner of a length of 3/4 X 3/4 .125 angle and riveted to the arm rest.

[Tucson_Mike]

Originally Posted by bret

As mentioned above I would recommend the angle reinforcement for the arm rest also. I used a router to radius the outside corner of a length of 3/4 X 3/4 .125 angle and riveted to the arm rest.

Bret,

How did you attach the angle to the armrest with the fluting that was done on the armrest flange? That seems like a really good idea with how flimsy this potentially is. I haven't riveted it on yet.

[bret]

The angle goes under the bend, not the area near the fuse skin. worked out nice.

[wirejock]

I used a piece of J-sfiffener. Fit perfect. Probably not as strong as angle.