Well, you have lots more homework to do... For the gecko drives you only need a breakout board like a C11 (I think) from CNC4PC. I prefer automationdirect steppers as they are cost effective. Keep in mind the larger the steppers the slower they go. Looks like you have got a firm bite on the start... Took me a while to figure out my plasma cutter but the homework was worth the effort. The cable tracks can be purchased from McMaster Carr among other places... They ain't cheap no matter where you buy them...
John On 20 Jul 2008 at 14:35, Rafael Skodlar wrote: > Hi guys, > > I'm following this mailing list for a while but still have a few > questions about designing (ideal :-) CNC machine for use with woodwork > mainly. > > Here are the preliminary specs: > > tool motion: 120 x 90 x 20 cm (X-Y-Z) > frame material: T-slotted aluminum > motors: 3 stepper > drivers: 3 geckorive (1 opt.) > controller: Mesa 5120 (?) > power supply: linear 35-55V 600-800W (?) > X-Y motion: moving arm (X-Y axis) (with ball bearings and steel rod) Z > axis: optional: 4th axis for rotating parts table: fixed Software: EMC > of course > > Questions: what size of the stepper motors should I pickup for X-Y? I > was thinking in a range of 500 - 800Nm for X-Y and 200 Nm for Z but am > not sure about it. Brand names are also a question. Are > http://www.anaheimautomation.com/hightorquesteppermotors.aspx good > enough? Is brake mandatory for Z-axis? > > What kind of a moving mechanism would be the most cost effective for > each axis? Lead screw, pinion gear and rack, belt, or something else? > I haven't seen anybody using steel cable to move the arms around in > CNC machine for example. > > What comes to mind here is an old HP plotter model 7221 which uses a > rather complicated but efficient and precise mechanism with steel > cable, pulleys, and two motors in fixed position to move the pen. > While the cable will wear out faster than a lead screw for example, > it's way less expensive and easier to setup with no backlash IMO. > Steel cable doesn't collect much dust either making it suitable for > the job IMO. > > I tried to find a source for plastic cable track to protect and guide > the cable but Google did not respond kindly. What kind of flexible > cables are used for connecting power/data to stepper motors and > encoders? > > All suggestions are welcome but note that there is a budget limit :-) > which should be significantly or reasonably lower than a commercial > product of the same size and capabilities. > > Thanks, > > -- > Rafael > > > ---------------------------------------------------------------------- > --- This SF.Net email is sponsored by the Moblin Your Move Developer's > challenge Build the coolest Linux based applications with Moblin SDK & > win great prizes Grand prize is a trip for two to an Open Source event > anywhere in the world > http://moblin-contest.org/redirect.php?banner_id=100&url=/ > _______________________________________________ Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
