Installing tailspring mount in finished fuselage

[meloosifah]

Greetings all - has anyone added the tailwheel weldment to an -A fuselage? I know that some of the metal must be removed where the stinger protrudes but trying to do it with as little rework as possible. What is the easiest way to get the weldment in and how much metal must be removed? Anyone willing to talk me through this or send pictures of theirs?

Is it easier to pull the entire last bulkhead or can you sort of peel back the side skin or bottom skin and fit it in?

 

[D-Dubya]

Well, just about anything can be done. Someone can correct me if I'm wrong, but I believe that Van's original RV-7 was converted to an RV-7A after it was flying. Theirs was already painted, so I would guess they didn't have to remove any bulkheads. The conversion should be able to go the other way as well, but there will be some challenges along the way.

You may want to find a completed RV-7 (or two) and take a lot of pics and measurements of that area so you know what material to remove. Maybe even make some paper templates with the shape of the "mouse hole" where the spring protrudes. It's been so long since I did that work that I don't recall what Van's does and what they recommend in the drawings and manual.

You didn't mention the complexities of changing the engine mount and main gear arrangement, so maybe you've got that all figured out already.

 

[vfrazier]

Yes, you will need to remove the aft bulkhead to install the Wd-409 tailspring weldment.

Before doing anything else, drill the hole for the tapered spring (through the spring and the WD-409) if it's not already there.

 

[meloosifah]

I was able to get a tailspring and mount that were already match drilled and I have already made all of the modifications (except the cowl adjustments) to the front end. That part of the project was actually quite easy. I was just hoping there was a hitherto unknown method for installing the weldment without taking out that last bulkhead. It’s a double bulkhead, so there are quite a few rivets there. The plans call for it to be installed prior to installing the last bulkhead but I was just hoping for some trick that I was unaware of. In the grand scheme of things, however, I guess it’s not that big of a deal.

 

[vfrazier]

Just do it. You could be done by now!

 

[sahrens]

I have done this work

I have modified a 7A to a 7. I had to remove the last bulkhead to install the spring mount.

There is an additional consideration. if you compare drawings 27 and 27A you can see the vertical is mounted in a slightly different manner. I discovered the holes were not exactly the same. I decided it was easier to remove F-712 and replace it with a new part. With the pre-punched holes the new bulkhead will fit without any issues.