I'm having trouble with my Seat Bases?  I followed the Zenith Manual and drilled the pilot holes in the edges, but now when I am ready to install, the holes don't line up properly with the holes in the Cabin Side?  They are @ 1/16 to 1/8 high and forward of where they should be on the pilot side.


I can either do a lot of "forcing" or add a strip behind the edge and redrill?  Is anyone else having this issue?

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I drilled and clecoed all my cabin parts together before fitting to the rear fuselage and when it came to removing the seat base, I found that it wanted to shift after the clecos were remove probably due to the cabin sides pulling in once the fuses were joined. I have had to put in and take out the seat base several times and each time I use a pin punch(or ice pick) to line up one or two holes and they get back into line. Since all of the holes were drilled from factory pilot holes, I am not concerned. Try a punch or pick and you may find not a lot of force is actually needed to line up the holes.


Thanks, I've used that trick before, but I thought this was much harder.  I'll give it another try, using your idea.


There was a change to the rear seat channel ch7511-3 angle changed to 81* from 90*.  The new seat angle made the fit improved. That is if I interpreted you correctly.


Thanks for the reply, but no, my problem is with the seat base, the edges that contact the cabin sides.  Those holes don't line up.  I have the 81 degree rear channel.  I think the problem is in how they tell us to drill the holes.  The procedure leaves a lot to be desired.


Ed Have you followed the the seat base thread on the 750 forum. It looks to me that the angle attachment to the seat base sides is a good thing .



What do you mean by the angle attachment being a good thing?  I've looked at the thread, but that seems to be discussing how to rivet the sides to the tunnel?


You can use the same technique (except it takes 3 separate angles instead of one long one) on the outboard side, too. Looks like it would be especially helpful if you have alignment issues - you could match-drill the angles to your present holes and not have to force the fit. Then, match-drill the seat base to the angles (cut off the three flanges on the outboard side of the seat base, of course).

I only did the inboard/tunnel side because I had already done the outboard side and didn't have any problems. BUT, if I had known about this prior to drilling the outboard side, I would have definitely gone with this method!



That is about what I have decided to do on this one.  I'll call Caleb to check, but I see no other way.  If the original directions are followed, it seems to screw things up down the line.



Well said, very good description of the process.


So, the general consensus is that you have to install l angles?


It FINALLY dawned on me that the reason I wasn't getting your total message was that you used the method for the inside edges, along the console.  That would be easy, but the problem I had was that I used the Zenith construction manual and the Jon Croke tapes and neither did a very good job of guiding me through the drilling of the OUTSIDE seat base flanges to the cabin sides.  I think I'm just going to have to redesign how I accomplish the task.  


I think you missed the point of my post yesterday. On the OUTSIDE flanges, you can use a similar technique to the INSIDE flange. You'll have to make at least 3 individual lengths of L angle for the outside flanges, since the cabin sidewall is divided up by vertical stiffeners. Just match-drill each individual L to the outside cabin sidewall holes you have already drilled and cleco them in place. Then, cut off the three flanges on the outboard side of the seat base, lay the seat base in place on top of the L's, and match-drill the base along the outboard side to the L's. That way, there will be NO alignment problems!

I did the inboard/tunnel side with an L mainly because it is just a PITA to rivet with the torque tube and all the fuel and brake lines I have in the tunnel. It's up to you as to method, but looks like this would work well for the outboard side, especially if there are alignment issues.



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