VS-702 cut-off

Airhead · #1 05-15-2010, 08:20 AM

I am getting ready to mount the vertical stabilizer. The first step is to "trim" the front spar (VS-702) by 5/8". Before I trim something that was a manufactured part, (and had no other reason to be 5/8" longer than necessary) I thought I would get confirmation from someone past this step. I read the plans (sht 27A) which say "trim flange and web". In my vernacular the text and plans could have said "cut-off front spar 5/8", and it would be clear. I am surely being overly cautious, but this is not a part easily remade.

Thanks,
Bob

UnPossible · #2 05-15-2010, 09:18 AM

Bob - I would hold off on trimming until you test fit the VS. On my QB, I went ahead and trimmed off the 5/8" indicated by the plans. When it was time to mount it to the VS-781, I did not have the edge distance I needed.

My solution was to fabricate a taller VS-781...not a big deal, but it would have worked fine with the stock part if I had left it untrimmed (or trimmed it a bit less)

Hope this helps,
Jason

Bob Ellis · #3 05-15-2010, 09:43 AM

Same happened on my 8. Advice from another builder was to trim 2/3 of what is said on the drawing and I just had the edge distance required. I would follow Jason's advice and trim very gradually.

Bob
www.rv-8.co.uk

Airhead · #4 05-15-2010, 12:02 PM

I can tell already that I'm glad I asked. I actually had the 5/8" cutoff line drawn and the hacksaw in hand, layed it down and said to self...well, no harm in asking, except sounding foolish.

I did position the VS approx. and I can see that some amount needs to be trimmed, but difficult to tell exactly. Guess, I better do as suggested and trim a little at a time. I still don't understand why the plans don't call for the usual cut to fit, drill to match, but seem specific. If they were sure, why not supply the spar 5/8" shorter.