[jscottpilot]

On page 42 of the prepunch fuselage instructions, last sentence it says "File a small radius on the corners of the U-801-L-R Gear Legs so they nest flush in the U-804 Inboard Main Gear Attach Brackets."

The U-804 is a perfect 90 degrees the gear is has a slight radius already. They seem to fit now. Am I missing something? Hopefully someone has puzzled at this and figured it out.

 

[vansrv8]

Mine were the same....no filing needed

 

[dbuds2]

What does "nest" mean?

My u-803 fits the U-801 leg perfectly with no filed radius required to eliminate interference in the radius.

Does "nest" mean to slide the 803 out board to have interference fit on all three sides? In that position, the leg tip extenda about 1/8" inboard of the 803, and the picture on the plans show the same, but, no mention of a dimension.

 

[scsmith]

file the outside corners where the U-bracket fits under the skin

In order to get the U-bracket as far outboard as it is supposed to be, you have to radius the outside edges of the bracket, just for a 1/4 length or so at the front and back, because the corners fit inside the curved fuselage skin fore and aft of the gear mounting opening. You need to have the U-bracket 3/16 inch inboard of the outside edge of the longeron so you get good edge clearance on the bolt holes, AND note that the longeron is rotated (twisted) at an angle compared to the floor. IF the U-bracket is too far inboard, part of it will bear on the flat floor angle rather than the angle of the longeron....NOT GOOD.

To see easily whats happening, don't put the gear on yet, just set the U-bracket in place and try to position it correctly ( the 3/16 inch dimension) and you will see where the edges hit the inside of the skin.
Hope that all makes sense,

 

[scsmith]

But, I guess I answered a different question

I know that's not quite what you asked. I was thinking ahead. I also had no trouble with the U-brackets fitting the gear legs themselves.

 

[dbuds2]

Spoke without looking at the B/P's

My question was really about the U-804 inboard bracket and the plans instructions to nest on the 801 leg.

My outboard U-803 bracket fits the 801 leg very nicely, I can slide the bracket to any location in the non-powder coated area.

New question? What have others done to protect these uncoated areas on the legs, brackets and wear plates?

 

[Geoff]

Or remove the skin

In order to get the U-bracket as far outboard as it is supposed to be, you have to radius the outside edges of the bracket, just for a 1/4 length or so at the front and back, because the corners fit inside the curved fuselage skin fore and aft of the gear mounting opening. You need to have the U-bracket 3/16 inch inboard of the outside edge of the longeron so you get good edge clearance on the bolt holes, AND note that the longeron is rotated (twisted) at an angle compared to the floor. IF the U-bracket is too far inboard, part of it will bear on the flat floor angle rather than the angle of the longeron....NOT GOOD.

To see easily whats happening, don't put the gear on yet, just set the U-bracket in place and try to position it correctly ( the 3/16 inch dimension) and you will see where the edges hit the inside of the skin.
Hope that all makes sense,

Alternatively, you could remove a little bit of the skin here, leaving the steel part intact. It's a lot easier to cut aluminum than steel. This whole area gets covered up by the fairing anyway.

Incidentally, for anyone who is reading this and hasn't drilled the holes yet, you might want to read this post that references Randy's site: http://www.vansairforce.com/community/showthread.php?p=160634. That 3/16" on the drawing may not be correct.

 

[dbuds2]

3/16" or 3/8", what did you do?

I've read the postings about whether this should be 3/8" or 3/16".

While building the gear towers and before attaching the forward skins, I did some inspections and determined if you moved the U-803 an additional 1/32" (0.031) inboard the bolt and nuts would be on the centerline of the WD-822 channel. That would position the U-803, 3/16"+1/32" = 7/32" from the edge of the F-843 longeron.

So has anyone really used 3/8" instead of 3/16"? I will do more evaluations with dimensions facts and understanding of how the gear are intended to function.

 

[Geoff]

I've read the postings about whether this should be 3/8" or 3/16".

While building the gear towers and before attaching the forward skins, I did some inspections and determined if you moved the U-803 an additional 1/32" (0.031) inboard the bolt and nuts would be on the centerline of the WD-822 channel. That would position the U-803, 3/16"+1/32" = 7/32" from the edge of the F-843 longeron.

So has anyone really used 3/8" instead of 3/16"? I will do more evaluations with dimensions facts and understanding of how the gear are intended to function.

I did 3/16", but it's totally impossible for me to get a socket or wrench on the nuts on the inside. I couldn't determine any reliable way to make the measurements for a possible adjustment on my quickbuild since the gear towers were already assembled into the fuselage, so I just followed the plans.

I also suspect that, despite the best of intentions, it's very hard for people (myself included) to drill those holes exactly straight. You don't have an option to start small and get progressively bigger because you're using the steel piece with a big hole in it as a drill guide. So there you are, on top of the upside-down fuselage with a big 1/2" drill motor turning a large bit. Not exactly the best recipe to prevent wobble and get a perfectly straight/perpendicular hole.

Even though there "shouldn't" be, perhaps there is some variation between different fuselages as well. Maybe the "correct" dimension isn't the same for everyone, which could explain the varying levels of difficulty reported when torquing those @#$^&* bolts.