Replies to This Discussion

Permalink Reply by Walt Snyder on March 22, 2015 at 10:30pm

Gary, you may have already looked at this but have you considered a fly cutter? I've used that to cut dozens of instrument and access holes in aircraft, on a panel flat on a workbench to cutting a hole in an assembled aircraft. Just use a quality cordless variable speed drill and be patient, and it will turn out great.

Walt Snyder

• ▶ Reply

Permalink Reply by Gary Welch on March 22, 2015 at 10:48pm

I haven't tried a flycutter. I've watched the videos but they haven't given me a warm fuzzy feeling with it. In fact, watching the EAA video by Sebastian really left me uncertain about it. They seem to struggle cutting a single hole with the cutter jumping all over the place. I understand they were cutting a tank that could not be properly braced like a flat panel, but still...
If it came down to it I would pay the $150 to ensure the panel got done right the first time. I just can't deal with the thought that I would get nine of the holes cut perfectly and then slip up the fly cutter on the last hole. My tolerance for these kind of setbacks is quite low after recently screwing up my canopy %^)...

• ▶ Reply

Permalink Reply by Walt Snyder on March 23, 2015 at 8:22am

Gotcha, I haven't seen the video, and the first time it was a little spooky, but now it seems to be no big deal, even kinda enjoy it. You might want to purchase one and cut a bunch of practice holes on scrap first to see how comfortable you are with it. I think you'll be fine with it.

Walt Snyder

• ▶ Reply

Permalink Reply by Bob Jones on March 23, 2015 at 8:39am

Gary , even the two piece hole punch distorts the dash metal , look at all the holes I made in my dash and you will see another way , I made a dash blank that fits in the back of the panel out of 3/4" plywood , then hole saw your pattern thru the plywood down onto a second piece of plywood , this makes a perfect hole with no walk of the hole saw ..BOB

• ▶ Reply

Permalink Reply by John Austin on March 27, 2015 at 6:49am

 I just can't deal with the thought that I would get nine of the holes cut perfectly and then slip up the fly cutter on the last hole.

Gary,

I second the fly cutter, but even if you use a punch, give some serious consideration to using sub-panels! You can make 2 or 3 sub-panels and each will only have a few instrument/avionic holes in it ... if you screw one up, just make another sub-panel and not the whole panel! The sub-panels, held in place with just a few screws, will also allow generous access to behind the panel. Finally, I guarantee that after a short time, you'll want to change or move something on that panel! Again, it's so easy to make a new sub-panel rather than a new entire instrument panel!

John

N750A

• ▶ Reply

Permalink Reply by Gary Welch on March 23, 2015 at 2:27pm

Thanks for the link. I'm going to go ahead and buy one and try it out.

• ▶ Reply

Permalink Reply by Walt Snyder on March 23, 2015 at 10:44am

Another thing I did to get plenty of practice  with fly cutters was cut a rough duplicate panel out of thicker aluminum that would stand upright on my bench with a bent aluminum leg, and then did my layout on that, cutting and fitting, prior to final layout on the final panel. Gave me plenty of practice in hole cutting, as it seems throughout your build you find reasons to change the panel every month or so, especially with the newest and latest products coming out.

It sure made it easy to sit at your bench rather than inside the plane and fit and mount everything, knowing you can easily change what you did not like.

Another advantage is you can use them for any size, as I did, and I made some access holes bigger than normal for my big hands, and I wanted to reach something specific, to little small ones for mounts. 

The key is slow with patience, and making sure the item is secured. But it is easy once you get the hang of it.

Walt Snyder

• ▶ Reply

Permalink Reply by Tim Juhl on March 23, 2015 at 10:05pm

All the circular holes I cut in my aircraft were done with a fly cutter.  I turn it by hand and score the aluminum thru about half it's thickness.  Then I enlarge the hole with a step drill to the point where I can get the snips in or a nibbler tool.  I cut carefully to the scored mark and then using needle nose pliers simply work the edge until it comes free and peel it around.  Works like a charm.

I cut inspection holes by scoring two circular holes and then connecting the top edges with lines scored using a Olfa knife.  A few step drill holes and peel the pieces off as before.

Tim

Attachments:

• 107d.jpg, 108 KB

• ▶ Reply

Permalink Reply by Gary Welch on March 24, 2015 at 9:44am

When you say "turning it by hand" do you mean using a hand drill?

• ▶ Reply

Permalink Reply by Tim Juhl on March 24, 2015 at 8:30pm

Nope, I mean by hand - no mechanical assistance.  The object is to score the metal, not to cut it all the way thru.  Things will go better if you can get a piece of wood behind the area you want to cut as the hole in the wood helps keep the cutter straight and the wood itself allows you to apply more pressure with the cutter.

The wood is not absolutely necessary but it will take longer without it.

Tim

• ▶ Reply