Tip: Wheel pants, alignment and mounting

Here is how I did the wheel pants on my RV 10.

Some of this is my ideas, most is borrowed from master RV builder Steve Barnard. The fixture is something he did, and passed on to me.

This fixture is used to hold the wheel pant in correct alignment, after the aircraft is jacked up, and in level flight attitude. You can see the #30 drills used to pin the fiberglass to the wooden fixture. What is not visible is the fuse center line on the floor, and the offset lines that are used to locate the wheel pant center lines.

A single #30 hole is drilled in the front, and rear center of the pant.



The green masking tape is holding the spacer block to the top of the tire, to give clearance. The fixture is holding the wheel pant level, and also giving the correct spacing for the mount that will be drilled soon.



One more shot, front half of the pant now in place on fixture. Notice leveling feet on the fixture-----all needs to be level. Seeing as it requires putting things in place a few times to get it all correct, we marked the floor so the fixture could be relocated correctly.





Now that the wheel pant is correctly located, you need to drill the hole for the mounting screw in the pant. The hole is already drilled in the mounting tab, and a nut plate is installed. To make locating the hole easier, I rigged up a light to go inside the pant.



Here is the light located at 90* to the nutplate, a long drill is used as a pointer to position the light.



Pretty easy to find the hole



After getting all of the mounting holes correctly located and drilled, I added a pattern of holes around the mounting hole, these additional holes are used to insert the "liquid shim" to lock in the correct spacing for the pant. The black boxes give an idea where the shim needs to be.

Wheel pants part 2.

Next step is to mix up epoxy with some flox, and cabosil. The flox gives it strength, and the cabosil keeps it thrixopoctic ---fancy word I cant spell, means the goo will not drip off while it is curing.



The mixture is sucked up into a syringe, and then is shot into the gap between the wheel pant, and the mounting tab. I used packing tape to protect the alum, and sanded the inside of the pant for better adhesion.



After things set up, this is what you have when you remove the wheel pant.





Next, grind/sand down the excess epoxy/flox/cabosil shim, and then counter sink for a screw.



Hope this helps someone.

Wow, super helpful since I took my new wheel pants out of the box today and stared at them. Are those pants James or Vans? Also, are those the stainless steel wheel pant brackets from Fairings-etc?

All stock Vans parts.

Good information Mike...

getting ready to pull cabin top off to deburr, add top antenna, rg-400, f/g junction boxes, prime/topcoat inside, then final install next week with led strip lights for baggage/cabin/panel.

Thank you for the excellent diagram.

This information will come in handy in a few weeks!

Thank you, Mike...

for taking the time to put this out here. I'll be using your tips in the next few months on my -6.

Thanks. I'll be doing this in a couple three weeks.

Great post Mike.

Pat

One of the best posts...

....on this subject, Mike....thanks and I know you'll be helping a bunch of guys with their installations on any Van's model.

Best,

Mike,

WOuld you mind posting the dimensions of your jig, so that others can more quickly duplicate it?

thanks,

bob

Here's how I did the wheelpants on my Rocket:

https://picasaweb.google.com/rocketbob/WheelpantPics?authkey=Gv1sRgCLil3-T8krfg2AE&feat=directlink

I can have a wheelpant off in under 15 seconds, and just as easy to put back on. I also replaced the felt seals with amphibious seals and modified the axles for a grease zerk, so I never have to take the wheels off to repack them. There's a machined pvc tube that goes in-between the inner bearings to contain the grease.

The attractive detail about Mike's "flox block" method is the thick, tough base under the head of the screw. No countersink depth issue in the thin fiberglass shell, nor any real need for a Tinnerman washer to spread the screw head bearing load. If you want countersunk screws it's a nice way to go.

rleffler said:

Mike,

Would you mind posting the dimensions of your jig, so that others can more quickly duplicate it?

thanks,

bob

Click to expand...

They are really not critical, just make to fit the pant with an inch or so clearance in length, and tall enough to allow the pins to engage the pant.

This technique should work for planes other than a 10, so make up a jig as needed.

DanH said:

The attractive detail about Mike's "flox block" method is the thick, tough base under the head of the screw. No countersink depth issue in the thin fiberglass shell, nor any real need for a Tinnerman washer to spread the screw head bearing load. If you want countersunk screws it's a nice way to go.

Click to expand...

Also, it allows the fiberglass to stay in its original shape----it prevents the stress that would result in pulling the fiberglass to the mount.

I did basically the same thing on the outboard side of the pant, where the single large screw mounts in, but I do not have any photos of that.

The outboard side is done with a large area washer attached to the hex extension with double stick tape, the pant side of the washer is roughed up for the flox to adhere better, and then the flox is put in without first doing the screw hole, the pant is held in place by the other brackets, to allow proper alignment.

One thing, it is critical that the washer is aligned with the hex extension!!

When the flox has hardened, remove pant and back drill using the washer hole as a guide, and counter sink from the outside.

Hope this makes sense

Hi Mike, any chance you still have those jig dimensions?

Mike,
How does your jig ensures for lateral alignment?

As a side note, I had built a similar jig (only from angle aluminum) for front/back vertical alignment but I had to run strings/lines to make sure it is parallel to the fuselage, hence in the air stream.

Bavafa said:

Mike,
How does your jig ensures for lateral alignment?

Click to expand...

I dropped a plumb line from the center of the tail, and from the center of the firewall, snapped a line from front to rear, which gave me a line on the floor that was fuse centerline.

I then measured out and made lines parallel to the center at the wheel pant locations.

Lines on the jig line up with the ofset parallel lines. First post, fourth photo shows the marks.

fore to aft centerline

How do you find the forward to aft centerline on both sides?
How do you find the top centerline on the pant? Mine doesn't seem to be on top.

A tip for those considering the nightlight technique. Instead, go buy a string of LED white Christmas lights. They work great, provide a more even light, can be stuffed into any tight spot, won't burn out, and don't get hot.

We have some for $10. Call Blake and ask him. They aren't listed on the store.

LED rope lights also work very well.

Both are great for working in the tailcone or under the panel too.

Wheel Pant Lateral Alignment

How accurate does the lateral alignment need to be. I thought I had them right on, but after getting holes drilled it appears the front of the pant is 1/4 to 3/8 inch closer to the centerline than the aft point of the pant. I suppose I can try moving the inboard holes to get it to move slightly.

new color pant from Van's

I used Mike S's method a couple of years ago to put on my pants. I live on an occasionally fairly rough strip and they held up very well. No cracks. Due to a recent "incident" shall we say, I now have to rebuild the left side from new pieces I just got from Van's. They apparently now come with grey gel coat on the outside. I guess this will make finishing easier, but I'm not sure the transillumination will work to see the mounting brackets from the outside. If any one has encountered this, what did you do? I guess I could sand off the gel coat, but it looks so smooth and nice. I will again use the flox backfill method. It really strengthens the screwholes nicely.

Wiley said:

I used Mike S's method a couple of years ago to put on my pants. I live on an occasionally fairly rough strip and they held up very well. No cracks. Due to a recent "incident" shall we say, I now have to rebuild the left side from new pieces I just got from Van's. They apparently now come with grey gel coat on the outside. I guess this will make finishing easier, but I'm not sure the transillumination will work to see the mounting brackets from the outside. If any one has encountered this, what did you do? I guess I could sand off the gel coat, but it looks so smooth and nice. I will again use the flox backfill method. It really strengthens the screwholes nicely.

Click to expand...

The latest Rev. level of Section 5 (Page 5-18) of the construction manual describes a means of locating blind holes in gel coated parts.

I set up a laser pointer - beam on a bracket mounting hole. Then set up the wheel pants, re lit the laser with the pant in place, drilled a small hole to make sure it hit right, filed the hole a little if needed to correct any misalignment & drilled to size. I forget but I think I may simply measured to get the location of the adjacent hole on the fore & aft attach points. Easy - just don't bump the laser out of position when fitting the pant.