I don't consider most of what you have listed as a specification; I consider it to be mostly a list of parts.
Specifications are things like: speed: 100 cm/minute acceleration: zero to full speed in 100 msec cutter diameter: 10 mm spindle speed: variable in a single range to 20,000 rpm x, y, z accuracy: .1 mm x, y, z repeatability: .05 mm ----- It makes no sense at all to specify the power supply and drives and then ask the question what motors should you use. The specifications should determine the motor sizing. Then the motor sizing should let you pick the drives and the power supply Ken 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, > -- Kenneth Lerman Mark Kenny Products Company, LLC 55 Main Street Newtown, CT 06470 888-ISO-SEVO 203-426-7166 ------------------------------------------------------------------------- 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
