On 05/21/2012 09:15 AM, Jon Elson wrote: > Rafael Skodlar wrote: >> On 05/20/2012 12:12 PM, Dave wrote: >> >>> On 5/20/2012 12:40 PM, Rafael Skodlar wrote: >>> >>>> I wonder what kind of power and data cables would you recommend for use >>>> in X-Y-Z CNC about 1.2mx1m size? Besides power, it's not clear to me how >>>> many data lines for sensors, encoders, motor control, etc. are needed in >>>> general. >>>> >> I'm well familiar with flexing and shielding issues in general since >> early HP plotter days. I was hoping to get a simple answer based on real >> life experience, get this or that cable with x number of shielded and >> stranded or twisted wires ;-) That's why I mentioned size as that would >> give one an idea of motor sizes and other requirements. >> >> Is it better to have one cable with x number of wires to take care of >> all needs or a number of smaller cables (y) with x/y wires? >> > With non-filtered motor drives, it is pretty important to NOT put > encoder or other signal-level > wires in the same cable as the motor wires. I usually separate encoder, > home/limit sensors > and motors on 3 cables per axis, even though my motor drives ARE filtered. > A plain quadrature encoder needs 4 wires, if it has index then 5. If > differential, > then 6 or 8 wires. If brushless motors are used, those usually need > Hall sensors, > add 4 more wires. Stepper motors need a minimum of 4 wires, brush servos > need 2 plus maybe a safety ground, brushless would need 3 plus ground. > > You can check the catalogs for the number and size of the wire strands. > The more fine > wires there are, the better the cable will handle flexing. The good > stuff has #36 AWG > or finer strands, thinner than hair. > > Jon
Thank you very much for detailed advice to all of you that responded to my question. I received enough material to spend a few evenings doing my homework. It's much easier to start knowing what others have tried and what works in different circumstances. Using Cat-5 was a surprise to me as it's a bit stiff unless each wire is made of even smaller wires, not common in general use. -- Rafael ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
