A quick but not perfect way to check for aluminum vs. copper windings in smaller electric motors is to see if the motor housing around the windings is "open" or more of a sealed/closed housing. In other words, can you see the nice shiny copper-coloured windings just sitting there in the daylight, or do you have to look through a small cooling vent or maybe remove a cover? If they're exposed, like on the majority of appliances, they're usually aluminum windings. If it's more of a sealed motor where all the windings are inside of a tin can, so to speak, it's usually copper. Like I say not perfect, but it's sometimes handy like in a case at one of the local scrapyards, where lots of appliances are dropped off out front of the yard while the yard is closed for the weekend. Lots of scrappers come cruising by to strip wire/motors and such, so the good stuff goes pretty quick usually.