Removable walls / inserts?

[Krugerrand]

What's the best way to attach the hardware cloth to the panels? Raccoons are my main concern. We don't have foxes, bears, loose dogs, etc. to worry about.

I used plastic zip ties. They've only been in place for 2 months ... so not the best resource.

I've seen people reference metal zip ties, hog rings, bailing wire, and concrete rebar ties.

I started with some concrete rebar ties but they started to rust pretty quickly, so I went all plastic zip ties.

 

[NatJ]

What's the best way to attach the hardware cloth to the panels? Raccoons are my main concern. We don't have foxes, bears, loose dogs, etc. to worry about.

Some people attach it with zip ties. (The plastic tends to wear out over time, especially in the presence of sunlight.)
Some people use metal rings of one sort or another.
Some people "sew" them together with a length of wire.

I think I've tried all of those, and they can all work fairly well. I would choose zip ties for fast & easy, metal rings are probably my favorite, but sewing with wire works when that's what I have on hand.

For any attachment method, I would put the panel on the outside and the hardware cloth on the inside, to make it harder for any predator to pull the hardware cloth completely off. (You will still have to fasten them together, so the hardware cloth doesn't get pushed inward, but at least the whole thing won't get ripped off.)

 

[Ebony Rose]

They make outdoor, uv resistant zip ties too, usually black in color. These should last two or three times as long as the plain-jane zips.
For the price difference (at least here), I use the plain-jane zips and check & replace any that have snapped periodically. Once you have the hardware cloth secured, reparations are a snap...er... zip.
Buy a high quality hardware cloth for the job as you truly get what you pay for; the save-a-nickel brands often find you redoing the work FAR SOONER than you thought possible.