Hey all,
I recently decided to take the plunge and get myself a small-ish CNC router. I was particularly inspired by this excellent resource: Guerrilla guide to CNC machining, mold making, and resin casting But a lot of the decision to go for the generic Chinese model off of eBay came as a result of reading these forums-- I was much more prepared for what I could expect, both good and bad. So far everything seems reasonably accurate. Below is my beginning experience in case it helps someone else make a decision about whether to get a similar machien or not.

I wound up buying the CNC 6040 from eBay seller industry-village. I bought it for $1769 (a steal! It's listed at $2099 now), with free shipping-- I chose them specifically because they shipped from California. I live in San Diego and received the machine in about 3 days! That right away made buying from "China" all the more appealing. It came in two boxes that were at least 50% bubble wrap. Everything appeared undamaged as a result. I put it together the next day-- there were no instructions, but everything seemed to fit only in one place so it wasn't too hard.

When I opened it all up, I was impressed by the heft and apparent quality of the aluminum frame. It looks like the YOOCNC and all the others available from various places, though mine is completely unbranded. I was also pleasantly surprised that everything came as 120V electronics-- I purchased a large 1500W step up transformer that I hope I can return.

At first I thought I got lucky with the stock electronics, as everything seemed to work fine when I plugged it in, fired up Mach3, and used the pin/motor settings from their manual. I even fired up the VFD spindle and didn't have any immediately apparent noise issues (electronically or acoustically-- this thing is super quiet) in spite of all the cables being unshielded. But working fine isn't the same as working reliably-- first, the steppers would lock up if I left their speed at the default 2000mm/min, so I turned that down to 1000mm/min. Then I zip-tied a pen on the spindle and tried drawing some circles. This worked OK at first, but in maybe 30 minutes of operating it spontaneously lost its place and shifted a few cm to the side, then continued on as normal. At $20/endmill I figured this was going to get expensive fast.

Fortunately, I had also purchased a Gecko G540 based on the advice of many people here. I wired it up using the stock 24V power supply (though what I read says I could go higher?) and put it in the stock case. I banged my head against the wall for a while trying to get it to respond to the charge pump signal until I realized I could just disable this. I am using a [ame="http://www.amazon.com/gp/product/B000SR2H4W/ref=oh_details_o03_s00_i01"]PCMCIA parallel port card[/ame] in a circa 2006 laptop, so that may be part of the problem, but all the stepper signals work great, so I'm not worried about it too much. I hooked it up to my oscilloscope and found that the nice 3.3V square wave charge pump signal turned into a bunch of noise when connected to the G540. (Surprisingly, the 3.3V signal seemed to drive the stock electronics just fine for the most part, in spite of what others have said.) Also, the G540's provided xml file didn't work (no motor response, another couple of wasted hours), so I just used a modified version of the stock setup with the correct pins for the G540.

I'm running the VFD with manual speed control though I would like to get it hooked up via the G540 for automatic control. Haven't looked in to this yet, hope it's possible. Did I mention how quiet the spindle is? I've only seen these machines with standard air cooled rotary tools/routers for the spindles and this is a world of difference. The water pump, as others have noted, however is the loudest part of the setup and needs to be replaced.

I built a dust/sound enclosure out of one 4'x8' sheet of MDF. I also built a table/shelf system with 1" aluminum square tubing. Pictures of the whole thing attached. If anyone wants details on my enclosure, I'd be happy to make some drawings or at least provide more detailed pictures (you can probably figure it out by looking at it). I put some LED strip lighting on the top cover (which is removable, separate from the whole enclosure box which just lifts off if needed). They are four 12V strips wired in pairs in serial, so I can power them from the stock 24V supply meaning they turn on whenever the G540 has power.

I've milled a couple of tests in MDF but I'm just getting going. I have a set of small endmills (Niagra Cutter tools from Amazon Supply-- seems like reasonable prices with free 2-day shipping. I like stuff to come fast so I can replace things quickly when they inevitably break). I have a CNC drag knife from Rockcliff on the way as I want to try cutting some stencils. I probably need to mill a flat spoil board for that first (will report back with some measurements on TIR and the squareness of the spindle when I do that).

So, in other words, :wee:!

Pictures (higher res on Flickr):