Dany, from what I gathered, the 3040 models are practically same stepper motors, with the same precision.  The difference is that the 3040's all seem to have higher powered spindle (800w in the one your linked)  The one Iinked above the 3020 has only a 180w spindle.

Has anyone built the FLA-100 from Fine Line Automation?

https://www.finelineautomation.com/store/s/CNC%20Router%20Kits/FLA1...

Seems to have a good size working area, and can handle aluminum if you go easy on it.  I'm looking at putting one of these together sometime this summer.

That FLA-100 looks like it has a pretty large x-y-z travel, but it looks like the spindle gantry is using only one rod, which from what I learned today, is not going to be very solid.  At least the 3020, I linked above has two rods holding the spindle on the gantry.

I would recommend these cnc machines...

http://steering-inc.com/

They are hand-made in the USA. I have a very similar one that I use to cut foam cores and it works great!

have a look at www.diylilcnc.org.

I have bought one, but not assambled it yet...

The price to have this delivered in Norway was a pain in the ... ;-)

Just a little shout out to anyone cutting CF. CF dust is nasty stuff, and VERY dangerous to get into the lungs. Make sure you have a good suction/ventilation system and that the dust is blown outside.

John, what is the deal with CF dust?  I've cut a bit using a dremel tool.

I guess you can get black lung, like coal miners got, if exposed on a long term basis.  One tip I saw on this done by some on this forum, was to do the milling in a water bath.  Then there's no air borne carbon dust, and way less mess.

Also, Bjorn, the kit you linked to seems to be just some CNC'd wooden frame parts.  None of the hardware or electronics seems to be included, and it's already $225.  Am I right in that?

Yes, that's sort of what I figure.  I see this warning all the time from hobby people, but I've never seen anything official such as an MSDS sheet stating the fact that it's carcinogenic or anything like that.  Best I can figure, as long as you aren't doing it on an industrial scale, day-in day-out, it's not going to be a problem.

I've done a fair bit of heavy fabrication in my shop, built a large HD offroad camping trailer, and that project meant a LOT of grinding with angle grinders which generates tons of black dust from the grinding wheels.  I'm sure that's not good for me either but it was only over a few months timeframe, I don't fabricate for a living.

I can't imagine carbon fiber is worse than that?  It's not asbestos.