Aluminium Heatsink Case extra thermal pads?

The instructions for the case say to just use a pad on the CPU and keep “the other” as a spare but I received three different sized pads obviously intended for three different chips. Should I fit them all or just the CPU pad? Seems like the instructions may be out of date.

Yeah, it sounds like those instructions are for an earlier model case that only used the one pad. If you can match the pads up by the size I’d go for it and apply all three. Post a picture of the pads if your still unsure what to do.

I have shown them placed on the chips in the picture above. The small one is too small and slightly in the wrong place I think but probably better than nothing.

I am replacing a 3D printed case with a fan shim with this because it is an always on NextCloud server which I don’t have physical access to for about 5 months of the year, so I thought no moving parts would be a better idea.

The fan shim works fine but will probably wear out eventually. Thinking about it it the fan will cool the whole board but this will only cool the chips with pads, so it seems a good idea to use them all.

Ah, totally missed that they were applied, ops. Yeah, no moving parts may be a better option for something like that. I just wonder how a metal case like that will affect WIFI?
The Pi will also get a bit dusty / dirty with the Fan Shim. Well any fan cooling setup really. I have a fan shim and like it, Pibow Coupe case that is nice and open.

They are not applied yet, just laid on.

I have a wired Ethernet connection, so I don’t need WiFi. It is never great on RPIs, even with a plastic case. It would probably work in this case though because it only about 0.5m from the router!

I agree about the Pi WIFI quality. It’s just not desirable, for me anyway, to run Ethernet to my Pi’s. I have a lot of Zero’s and 3A+'s running headless, they don’t have an Ethernet jack. For something like what your doing I would likely make an exception though. I’d likely be running a 3B of 4B anyway.

Not only is the signal quality bad but also I find WiFi lags for many seconds. So if I am streaming video from my 3D printers using OctoPrint I use cables to prevent a massive lag in the video. Also I find WiFi dongles use a lot of CPU time, which is not good for 3D printing.

I do have a couple of RP0s with EnviroPlus boards but they are close to routers as well.

As mentioned in another thread the paper backing on the pads pulls off the adhesive. Even though I was wise to this I failed to separate it correctly on two out of the three pads. Odd because I have fitted lots of heatsink pads in the past without problem.

It occurs to me that it doesn’t really need adhesive on both sides because the case clamps together. In fact, it is probably better stuck on one side only so that the case can be opened, for example, to insert a camera lead.

I bought a sheet of the 3M thermal pad a while back from Adafruit. It’s come in handy when repurposing heatsinks from other bits of tech to use on a Pi. And backup in case I mangle a pad trying to pull the backing off. I haven’t done that yet, but I’ve come close a few times.

I think the antenna is at the edge of the board so it may not be affected.

It’s right on the edge next to the WIFI chip and beside the DSI connector. On a 4B, and 3B+ its a cavity built right into the circuit board. On a 3B its about in the same spot but its a little white brick of ceramic or something.
The RF radiation pattern is what I wonder about? Does it radiate perpendicular to the board or parallel to it, or both? Or maybe just out away from that edge?