On 01/27/2013 03:24 AM, Marshland Engineering wrote: > I'm running Colpey servo drives but I cannot get them tuned in with > LinuxCNC. > > The servo is a current drive with a +- 10 volt input. > As there is not much load on the drive so a +-0.4 volt will swing the motor > at full speed. > > The manual for the drive says to supply a stepped input to it and tune the > feedback pot till the motor steps nicely without overshoot. Done this with a > 1 HZ signal generator. > > Now when I'm runing it with LinucCNC, I get a lot of overshoot and > eventually, if the step is big enougth, a following error. > > I've tried P, I and D values varying from .05 to 5 and output voltages from > 1-10 and none seem to make any real improvement. > > I'm stuck. > > Thanks Wallace > > > ------------------------------------------------------------------------------ > Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, > MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current > with LearnDevNow - 3,200 step-by-step video tutorials by Microsoft > MVPs and experts. ON SALE this month only -- learn more at: > http://p.sf.net/sfu/learnnow-d2d > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users I use Copley 423's a lot. Tune the copley with expected load and no linuxcnc 1st. Use maximum command voltages of 8 to 9 Volts ( allows headroom for correction needed when at max cmd Vltg.) The Copley manuals tell how. Basicly use a 'battery box' like 2 pcs 9V batteries with a pot and a switch. Use that as the command voltage source (+/- 0 to 9V). Test with expected load. After it gets stable, inject the maximum ( 8 to 9V) cmd using the preset pot and the switch. This is the 'step test' ( immediate reaction to max cmd. Measure how long it takes your system, under load, to get to max velocity). Have the scope on the tachometer. How long it takes to get to the max tacho value is the accleration potential of your system. The sharpness of the corners of the ramp are how well you have it under control ( 'stiffness'). Go for a bit of undershoot on those corners rather than overshoot, or at most oscillation. The Copley manual really do tell how to do this step by step. AFTER you get the amp ready, THEN let linuxcnc send the command voltages. You will not get the acceleration you achieved in your 'open loop' tests, expect at most 80%. This testing is neccesary and has to be done under expected loads. So clamp stuff onto moving joints (clamp well too, cuz this is the time when runaways occur at first. hth tomp
------------------------------------------------------------------------------ Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current with LearnDevNow - 3,200 step-by-step video tutorials by Microsoft MVPs and experts. ON SALE this month only -- learn more at: http://p.sf.net/sfu/learnnow-d2d _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
