Milspec Camloc Install
Like many others in the RV community, I took advantage of the group buy for the Milspec Camloc Fasteners for my FWF. I burned my hand enough on my 8A pulling the top hinge pins out to gain access to my top cowl. I decided on this plane I would take another path.
I'm dedicating this section to my good friend Jeff Bordelon. If it wasn't for his experience, things might have turned out much differently in this section of my site.
I decided to just use 0.063 tabs to support the camlocs. It was a no brainer to circle the firewall with this stuff and just bend the tabs in with some slip joint pliers to the right approximate height. Not super accurate, but it's not really necessary. As long as your tabs are located a bit below the under surface of the cowl, there will be enough tension on the fastener to keep it in place.
Milspec is nice enough to provide you with a nifty little drill template for locating the position of the fasteners with relation to the firewall to ensure that there is enough clearance. I used this tool to drill centered holes in all my tabs the with the correct spacing. Then I match drilled the cowl to the tabs.
Next I took that same drill jig and very carefully used my unibit and a circle template to cut a 1/2 in hole exactly centered between the holes. One of the big problems you have with the installation of the camlocs is that you have to drill a hole through the cowl and the mounting tab below that at the same time. Keeping this centered can be a real challenge. My plan was to just use the jig to find a good place for the hole, drill it through both the glass and the tab, and then use it to center the camloc on the rivet holes that hold it on
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Funny thing happened when I bent all my tabs down... the registration on my holes changed. Not so much across the top, but the sides slid down by about 3/32. The nice thing about this technique is that you can move your attach holes around a bit in the process of drilling the camloc 1/2 inch attach hole. So... I put the hinge pins in the length of the cowl, put a few clecos on the top to hold the cowl on and lest the rest float. My idea was to do the top camlocs first, and then just reposition the side holes as I worked my way down the sides.
Next I used my reworked template to draw a 1/2 hole centered on the original pilot hole. You can use the template to double check at this point that you have the necessary spacing away from the firewall. The issue with using unibits to cut holes in aluminum is that they will walk. The good news is that you can usually pull the drill in the right direction ( if you have a target circle to aim for ) and center the hole on the fly.
If you do this right, you can no longer see any of the circle outline when your done cutting the hole.
Another one of the tools you get with your camlocs is this snap ring centering tool. As it turns out, it has a mandrel that is exactly 1/2 inch in diameter. This comes in very handy.
Now that you have removed the cowl. Take the reworked drill jig and that 1/2 inch mandrel from above, and use it to center the jig.
Use two cleco clamps to keep the jig in place while you drill the two mounting holes.
Me, doing that drill thing.
The finished product. A perfectly aligned hole left to right and front to aft. This is important. While these camlocs can slide from side to side, they do not slide fore and aft. So it's VERY important that you get that part of the registration correct.
I then opened up the hole to 9/16 to make it large enough to accommodate the snap ring that holds the locking collar in place. The instructions that come with the receptacle suggest that the hole be opened up large enough ( 11/16 ) to get to the locking pin from the front of the receptacle. This is not necessary for the RV installation as all of the receptacles can be accessed from the back. By minimizing the size of the hole, you minimize the amount of travel that the cowl will move forward.
I used a small C clamp to pull the camloc receptacle up tight against the tab for riveting. You will find that when you put a cleco in one side that the other springs out pretty good. I used a piece of scrap to hold the top of the C clamp off of the receptacle to provide room for the squeezer.
The finished product is a perfectly centered receptacle. Room to move left and right but solid fore and aft
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This is a shot of the adjusted fastener with the locking pin removed. Using the -1 stud, there are several threads still inside the barrel of the receptacle
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To install the snap ring around the locking collar you use the snap ring centering tool above.
Slide the locking ring around the mandrel.
Slide the collar through the cowl and insert the mandrel into the underside of the locking collar.
Put the other part of the tool over the mandrel and push.
The snap ring pops in place and locks the collar in place.
Here is the final product. Interesting to note that this is the only fastener attached to the top cowl. With the weight of the entire top cowl on the joint, there is still no gap between the cowl and the firewall. Perfect alignment. :-)