Edward R. Ford made some notes on spindle options in the thread Re: Treating spindles as a consumable:
- The knockoff dremel - great starter tool and will take you further than you might expect. These are prone to working great and then dying all of the sudden.
- The official dremel - IMO, gives you no advantage over the knockoff.
- The DW660 - great upgrade from the dremel knockoff, allows you to use a router speed controller with some success, also gets you into the 1/4" shank game!
- The DWP611 - better choice thant he DW660, I think it's a tad bit quieter, but seems to be more robust, with less plastic and more metal.
- The Chinese foredom knockoff - This is a pretty good little spindle. For the most part you can only get to 3/16" shank, which isn't really an advantage over 1/8" because the bits are so hard to find, but what it does get you is "off-site" power. It uses a flexible want connected to an AC motor. The motor turns between 15-20k RPM. I used one of these for about 6 months before it died. You can see it in my phone dock video: [youtube]http://www.youtube.com/watch?v=yUaGZh4WK0Y[/youtube]
- The 180w DC spindle (48v) - This is ninja quiet! And IMO does a nice job with simple engraving features, but is SERIOUSLY lacking in the power category. Don't plan to cut much (or anything) with this. I don't do PCB engraving, but imagine this thing would be great.
- The 300w DC spindle (48v) - This is the second quietest spindle on the list. It's still lacking in power compared to even the knockoff dremel, but can manage to cut through most woods & plastics if treated nicely (1/32" depth pass). It also has a 1/4" ER-11 collett option, but IMO is worthless because of the lack of power.
- The Bosch Colt - This thing is a MONSTER! It's loud as hell, and weighs more than any of the others, and is pretty big, but it can really tear some stuff up. Cat saw it run first hand on one of my prototype machines when he was in Chicago last month and could attest to it's sheer power. I used a 1/4" 2 flute Onsrud bit and tore through a piece of maple at 1/4" depth pass without the Colt even flinching.
The foredom knockoff is to-date my favorite choice *IF* I could get it with a 1/4" collett. It's good enough that I've contemplating buying a non-knockoff foredom handpiece just to see if it's any better, but at $355 I'm not sure that's ever going to happen. Because of what EJ was talking about (mounting the majority of the weight) off the machine, gives some great advantages. One that wasn't mentioned is the fact that the tool itself is closer to the z-axis, creating less of a lever arm.
The next one on my list is the 800w water cooled VFD from ali-express: http://www.aliexpress.com/item/0-8KW-WA ... 11446.html. At $271, it's pricey, but this one runs off 110v, so the need for a 220v drop isn't required. The 220v versions are about the same price, but most people don't have 220v available and would have to pay and electrician to get it installed.