section 24

Everything has gone together so beautifully I dont even worry about it. When I got the Roll bar assembly ready to slide on to the F1231D roll bar base, it was about 5/16" too narrow. I drilled out some rivets, spread it, and now its only about 3/16" too narrow. I can force it on to the mounts with 90 lbs force spreading it apart (edited).

Should I drill out more rivets and tweak it untill it does not put a load on the fuse?

Should future builders clamp it onto a table and hold the dimension between the F-1231D roll bar bases before riveting it? It seems like that would also eliminate possible warping, which I have a bit of.

John- Are you sure you didn't miss something when you did the rollbar match drilling? My roll bar was a lot of work with all the holes, but everything fit pretty well on the bases when it was done. By the way, the fore and aft halves do have a gap between them. Steve

Roll bar

My roll bar fit pretty good too. I did find it easier to leave the bolts in the bases lose about 2 turns until all of the rivets were in place, then tightened the bolts up with a swivel-head wrench like this: http://www.grainger.com/Grainger/items/1Q284 John, maybe the fuselage is too wide. I measured mine at 43" on the aft side of the roll bar. The roll bar is 42 7/8" wide at the base. All measurements plus or minus a 1/32".
Joe

Thanks guys!

I think the F1205 Mid fuse brace keeps the width the same for all our fuses, so I didn't worry about that.

I did it right, used #40 clecos followed by gradual match drilling and replacing with #30 clecos.

I fixed it by drilled out some rivets and adjusting the bottom strap.

I wish I had originally bolted the bases down and measured the width. Then I could have match drilled it flat clamped down on a table with the legs the correct distance apart.

Roll Bar page 24-02 Step 1

John,
When I built the roll bar, not only did I cleco the top center plate F-1231E in step 1, but I also temporarily put a rivet in every empty hole to make sure that all of the holes lined up and that the roll bar halves were aligned properly. Clecos are slightly smaller than rivets and allow some play that gets amplified at the ends of the roll bar. Putting rivets in the holes eliminates that play.
Joe

John,

I just finished trial fitting the roll bar to the bases which I had bolted to the fuselage. With every other hole cleco'd on both flanges (inner and outer surfaces), and a bunch of clecos in the roll bar plates, I slid the roll bar onto the left and right base. Took a width measurement. Removed the roll bar and with it sitting on the table, that same width was 3/16" shorter.

This might be similar to what you experienced. Thanks for the heads up, I'll maintain the original width dimension as I rivet.

Roll Bar match drilling

Does anyone see a problem with clecoeing the roll bar together, fitting it to the roll bar base plates and match drilling it in place, to the extent that you can. then removing and finishing match drilling on the bench. Would this not give better assurance that the end result would fit the base?
Scott

Yes Clamp it to table correct width

okiejohn said:

<SNIP>

Should future builders clamp it onto a table and hold the dimension between the F-1231D roll bar bases before riveting it? It seems like that would also eliminate possible warping, which I have a bit of.

Click to expand...

Yes it is a good tip, and if I remember correctly my RV7 instructions had it like that.

By clamping it down correct width, you can also see if you have any roll bar warp as well. Sort it out before match drilling #30 and riveting. I did it just like this over the weekend and my roll bar fits perfectly.

Regards
Rudi

Slane said:

Does anyone see a problem with clecoeing the roll bar together, fitting it to the roll bar base plates and match drilling it in place, to the extent that you can. then removing and finishing match drilling on the bench. Would this not give better assurance that the end result would fit the base?
Scott

Click to expand...

Scott, that is what I did. I had no problems at all with the roll bar afte the heads up by Marty. (Thanks man!) I had to straighten the pieces a little (prior to assembly) but it fit perfect the 1st time. It may have been twisted 1/8 of an inch when I trial fitted the rear window, but I was able to work around that latter. You'll see the "problem" (if you have one) when you match drill the windo to the roll bar. It won't be exactly in the middle of the aft 1/2 of the roll bar.