Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: jezx on October 08, 2012, 07:59:15 PM
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syilx6 mill , under mach3
my 3 axis mill is losing some distance somewhere in y . but only when running programs .
when i move the table in and out on y axis rapid a bunch of times it will go to 0 with in .001'' ( dial indicator set up ) . but if i run a program , even a short one it can get off up to -.020'', i think this is a new thing to happen since its been working well til last week .
i manually can turn the skrew when the machine is off and it seems dead on or very lil back lash .
would reinstalling do anything ?
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Sounds like you might be skipping steps. Has anything gotten worn or dirty that would make the axis bind? Dull tooling, or maybe just trying to be more agressive than the machine can handle? You could try to make lighter passes and/or detune the motor a little and see if that helps but I would check the mechanical bits first.
Brett
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it's really clean , it's only ever used for small aluminum milling , big cuts would be .05'' deep /1/2'' at 4 to 10''/min .... i oil it often with a light oil on the skrews
ive ran a few different short programs in different ''0'' areas with no cutting at all (just air:) and got the same results ,
i even worried the g0 rapid travel was throwing it off so i turned my rapid x,y to 50ipm with slower excel . ( was at 120ipm)
there is a backlash setting , at .0003 at 90%of max speed . dont think that matters ?
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I dont think the backlash will be causing you any trouble but you could disable it and test to find out.
Brett
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going to try just about everything today . hopefully i'll find the problem .
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the backlash settings seemed to change a lil , but the machine still is having a problem with y axis beyond what ever changes that can be done with backlash. the x is staying with in .001'' .003 ''after full programs are run . tried turning it off and reseting for more of less . but no great difference .
next test ..the motor is hard to get at but im imagining it not being tight and turning it self a bit . or the bearing blocks at the end of the ball skrew needing tighting . more likely that then the actual ball assembly ... i hope
cnc machines ... so great yet such a pita:)
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Yes, check all mechanical bits first. Loose pulleys on shafts, worn keys, etc. Software will rarely be intermittent, it usually does the same thing over and over no matter if it is good or bad. A loose set screw, pulley, bolt, keyway can seem to have a mind of its on.
Brett
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think im skrewed . looks like the motor is directly driving the ball skrew , and there is a brearing and mount infront of that . everything seems tight .
the problem may be dirt some where in the balls . could take for ever to come out im guessing , or its messed up to bad .
amazing how much dirt grit and crap Syil allows on there machines before they get sent to the distrubuter .. who's suposed to clean and check them , but realy does nothing .
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after spending alot of time cleaning everything , cleaned the skrews and i then kept loading the ball skrew with a thin oil and running the table back and forth while cleaning and adding new oil , new CLEAN rags ever time
and ....... it worked . , id cleaned it about 40 times trying to get the full length on both side finally figured it must be clean .
now after setting up 2 dials x /y and running a busy program with extra stops and rapids g2 g3 it goes to about .0005'' from the orignal .0000'' .
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:)
Brett