You actually want Micro-SD card. Get a Class 10 card. I am not sure if the Acer can handle 128gb cards, but they are still expensive. Amazon has a bunch of 64gb cards on sale now though.
64gb microSD cards at Amazon

I can confirm that 64g works as I am using one in my ACER W3 without issue...

As am I (however as stated earlier I haven't actually needed to use it yet since I haven't come close to filling the space left on the tablet).

I would imagine that if all that is on it's hard drive is windows and ARC (after the bloteware is removed) the only other thing that you would need room for is sound files and the ARC robot project. If you can use mp3 files instead of wav (mp3 is much smaller) you may not need extra storage space.

Thanks for the great comments and tips on the Acer W3. Has any one utilized a Bluetooth mouse on this unit? Rich mentioned A bluetooth mouse and keyboard would always be a good option to have. Thanks, Steve S

Both bluetooth keyboard and mouse are on my wishlist (and after having to use mine tonight to do some excel spreadsheet stuff I really could have done with it).

While I haven't used one on this I do use a bluetooth mouse on my desktop PC without any issues. It should, at least in theory, work in exactly the same way.

I'll test out my BT mouse tonight or this weekend and report back. After taking the tablet bike riding with me because I was on-call a few weekes afo, and struggling to actually do some work when one of my systems crashed, a small BT keyboard with touchpad are also on my upcoming purchase list

Alan

Just paired my Microsoft Presenter Mouse 8000 and it works perfectly, and makes selections much easier in the traditional desktop (which is not touch optimized to begin with, made more difficult by the screen only being 8.5").

Wish I had thought of doing this earlier.

Alan