Hi,
Rolled ballscrews C7 grade are good to 50um per 300mm and economically priced. A 20mm diameter screw about 600 long with support1-What i need ?Simple ballscrews or preload precision ballscrews ?
bearings would cost about $100, the same thing in C5 ground ballscrew will cost over $1000. To achieve 0.1mm accuracy C7's are fine.
To get to 0.01mm then you need C5's (or better).
You will use microstepping no matter what the size of your machine. It is tempting to believe that microstepping vastly increases the resolution of a plain old2-For what step motors i should be looking for ? I read the term microsteping. Is this something i need to consider for my working area 40x40cm?
stepper, and to a small degree its true, but the real value of microstepping is smoother motion without midband resonance which plague steppers.
You will see a lot of hype about closed loop steppers....and most of it is just that....hype. Don't be taken in. There are some advantages in closed loop
stepper design but insufficient to justify the premium paid.
What you should look for instead is LOW INDUCTANCE steppers. You will see that I have posted extensively on the absolute requirement of low inductance in
steppers. I imagine you will want 23 size steppers, they should be 1mH-2mH, 1mH preferred and reject anything over 2mH. Low inductance means that the stepper will
turn fast without losing steps whereas a high inductance motor will not only lose steps but stall over a few hundred rpm. LOW INDUCTANCE is a MUST, it is as important
as torque.
The next thing you can do is get the best high voltage drivers you can. 80V Gecko's would be nice, but pricey. Leadshine AM822's are reasonably priced ($75)
and 80V capable. Next you want, ideally a transformer type power supply of 72 or 80V. Switchmode supplies are cheaper but transformer types are so much more forgiving
and have vastly superior overload characteristics.
The alternative to steppers is AC servos. Chinese manufacturers are producing some very credible servos and drives. They still attract a preminum over steppers
but the difference is much less than it used to be. If you really want speed servos are the go.
I have always used Mach, first Mach3, but for the last five years Mach4.
To use Mach4, my own recommendation, you will need an external motion controller, like an Ethernet SmoothStepper by Warp9. It is not the only choice but it is a popular
choice among Mach users. Avoid cheap Chinese controllers, they don't work as advertised and once they've got your money they won't help. In fact you'd swear that China
is in another galaxy!
The other choices, approximately similarly priced and intended to run on PC hardware are UCCNC, Centroid and LinuxCNC. Each have their own fan base.
I would guess that most of the motion parts like ballscrews, linear bearings/rails, steppers and stepper drivers will come from China. The prices are just too compelling to5-Where can i order the above parts in Europe (/ebay maybe?) ?
ignore. Software and motion control electronics are likely to be US or European made. It is my observation that many UK and European buyers shy away from US made because
of import tax only to end up with over-priced under-performing European made stuff. Don't be a dickhead....if US is the best...get it, who cares about a little tax, if you buy the
right product you will have it for years and years and a extra $50 in tax is nothing over that time frame.
I have bought servos and drives from this Ebay supplier:
fasttobuy2012 | eBay Stores
I have also bought high quality new old stock and second hand motion components from:
https://www.ebay.com/str/industrialpartsshop
Craig