main gear fairing fitting question

[trib]

I've put the two halves together for the main gear fairings and sanded the edges a bit working on the fit. At this point the halves on both pair have a nice fit on about 75% of the mating edges. Both halves have about 3" at the bottom on each side where there is a tapering gap, starting flush to about 3/16" inch at the edge where the opening starts for the tire. Is this typical to what others are experiencing? To correct two options come to mind:

1) Mix up some micro and fill the gap
2) Continue sanding the edge until the gap is eliminiated, meaning take the 3/16" off the 75% which has a nice fit.

Looking to see what others have done before me. Is the typical process to sand until there is a nice fit all the way 'round or do you stop at this point and fill? Would appreciate a few opinions!

[lrfrey]

I had he same problem Tim, especially on the nose pant. I put slick packing tape on the inside and edge of the forward pant and filled the gap with micro.

Larry

[trib]

Thanks for the reply, Larry.

Filling would take care of the situation without any risk, but I am very curious if this is how people are typically getting a good fit, or do they go ahead and take the extra material off of the front half of the fairings and not affect the overall shape. It appears that it is doable, but I was hoping to get some success stories before removing that much material, as it would be very difficult to go back if it does not fit well after that. Are builders out there who can say it's no problem removing a quarter of an inch from the perimeter of the front half- or the opposite- don't do that because I did it and was very sorry!?

[Brantel]

One of mine was fine and the other terrible. If I had taken it all off the front, it would have made a big mess!

Here is my recent post...

Originally Posted by Brantel

Waiting on my engine so I can get started fitting the cowl.

In the meantime, I decided to work on the wheel pants and fairings.....
One of my pants fit together really well after about 30 minutes of filing of the front half to the back parts. Not too much work on one of them. I designated it the co-pilot side and completely installed it before getting started on the pilot side.

The biggest problem with these is that there is no way reference for centerline in any direction on these. The starter hole for the wheel is totally off and should not be used for any reference!

What I did was take the aft part of the pant and lay it down open end down on some poster board. I then marked all the way around the pant and then cut out the oval. I then folded the oval perfectly in half in both directions to get a centerline. I used this to mark center marks both vertical and horizontal. You can measure the aft end so then all you do is connect the dots. I used tape to laydown a straight line.

To find the exact center point of the front half, I held the front part nose up with a blunt pointed object. I shook it around till it found the center point and marked the point on the nose. Then I connected the dots to the rear half.

This gives you some reference lines to go by...

One note: Automotive hose clamps are only stainless on the band. Lowes and Home Depot sell all stainless hose clamps. I used these per the plans to hold up the gear leg fairings.

Here is the co-pilot side ready to go. There is no way the 8-5/8" dim they give me on the plans would work. I ended up with 8-1/4" when the pant was sitting on the 1" spacer block.

You can see that the fairing is in perfect alignment with the parallel line on the floor. I pulled this shorter line off of the centerline of the tire.



Now for the pilot side!!!!

This thing was a total piece of poo! The front half would not match the rear half due to wavyness of the edge around the front half.
So I took it and sat it on a flat board and scribbed a line all the way around it and filed to the line.

Next problem was that the "flange" width on the rear half started out at 1-1/8" on one side and came up to 1-3/8"+ on the other side. There was no way to make the front fit the back without some major grinding and misshaping of the front half.

One side looks ok.. The grid is to help with the intersection fairings later.



This side had a 1/4"+ gap....



So I said the heck with that and after sanding the gloss off and cleaning the parts with MEK and taping off the joint, I mixed up a batch of 50/50 flox and microballoons with epoxy to the concistency of toothpaste. I painted the joints with pure epoxy and then I applied a liberal coating of this stuff and let it sit.



After sanding, the parts fit together perfectly.



Here is a pic that will let you do a rough cutout for the axle hole. These gridlines are made with 3/4" wide tape so you can tell approximately how to make these cutouts to get them on there. They may need modifying a little to get the brake line thru.



The centerlines mentioned above will be critical for you to layout the wheel cutout to ensure it is symetrical. The starter hole Van's puts in there is not close! Don't trust it!

Now I can go fast during the test flight! Oh wait, still have the intersection fairings to do