Question for 7/9 taildragger builders

I can?t find anything in the plans about trimming the firewall and/or belly skin where the main gear exits the fuselage. What did you do here and what tool did you use. Thanks.

Don Broussard
RV9 Rebuild in Progress
57 Pacer

There doesn't need to be a lot. There's not a whole lot of movement in this location. It's hard to tell from the photograph, but I'd say there's somewhere around 3/16". Enough to not rub the powdercoat or paint off the mount when you are trying to install it, but not so much that's it ridiculous. That said, I still had heaps of painters tape on the engine mount to stop scratching during the install, so it didn't matter if it butted up by accident. I've actually got my cowling and gear leg fairings off for a 50 hr oil change/service, so I can take an actual measurement tomorrow if that makes you more comfortable. I just rough cut with a dremel reinforced cutting disc, and finished with a file then sanding drum.

Tom.
RV7

Measured tonight and it's closer to 3/32". The issue will really be that you may need to trim almost all the way back to the firewall, at least that was the case with my setup, and there's really not a lot of clearance between the gear legs and the firewall. At the end of the day all of this will be covered by the upper intersection fairings.

Tom.

Hi Don,

As to how: IIRC, I just hung/removed the bare mount by the top bolts and progressively trimmed until it cleared at the bottom. Check, remove, cut, repeat.

Again, if memory serves, I used a 1/2" dia *aluminum cutting* carbide burr in a small (Harbor Freight, ~$10) die grinder. The burr costs almost as much as the grinder. It does take some practice if you've never used one. Make sure you have something to brace your hands against, and always feed the cutting side into the work. If you're well braced and take very light 'bites', it takes very little pressure. Keep the burr perpendicular to the work.

Charlie

I just took the gear leg, wrapped a strip of sand paper around it (the rolled kind) and gently rotated against the opening and checked often until it fit evenly. The mount frame was in place.

Edit: Post #6 is downright clever.

Easy and Accurate

Here's how you can do it without any of the guess and check work. See the last pic of this post.

Mark it as shown then use a sanding drum on a die grinder to cut back just past the mark.

http://www.vansairforce.com/community/showpost.php?p=1322049&postcount=30

Gear leg cut outs

Thanks Guys. Post 6 it is.


Don B