On 4 Dec 2007 at 16:51, [EMAIL PROTECTED] wrote: This is a very interesting and quite challenging project... The cost to drive each joint of the pivot mill would far exceed the cost of Dremil size slides. While the concept is sound the mechanics of the gears would be the killer. You are designing a robot. The gears would need to be planetary perhaps double reduction to get enough torque to drive the arms. Of course you can't buy them off the shelf they would have to be custom made or purchased from an OEM $$$$.
I would make the first joint also be the Z axis drop the links to the Z that way your tool position is constant as the Z axis moves. If you do pursue this path please keep us posted as to your progress it is very interesting... and a challenging project... I would look at the options like using 80/20 with their slides and acme threaded rods and nuts if your not needing super tight precision. I'm building a plasma cutter with that as we speed and it is super simple to work with. For a load capacity of 315 lbs each from McMaster Carr you can get slides for $34 each and the rail is $0.09/mm and come in 500mm and 1000mm lengths So for $226 you would have 4 slides and 2 rails with about 16" of travel... Part# 9867K1 and 9867K11 for the rail if you want to look it up. 3/8" acme precision threaded rods are only $28 for 36" and the nuts $22 Part# 95072A124 and 99030A326 So for less than $600 you could have the the mechanics for a 16" x 16" table... And then there is always FleaBay that sometimes has bargains for rails and such... http://cgi.ebay.com/Wafer-Handler-Automation-Robot-21-arm-10- range_W0QQitemZ180186126744QQihZ008QQcategoryZ45044QQssPageNameZ WDVWQQrdZ1QQcmdZViewItem John > I believe that the greatest hurdle in constructing a small CNC machine > is the cost of the linear slides, ------------------------------------------------------------------------- SF.Net email is sponsored by: The Future of Linux Business White Paper from Novell. From the desktop to the data center, Linux is going mainstream. Let it simplify your IT future. http://altfarm.mediaplex.com/ad/ck/8857-50307-18918-4 _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
