The problem gets even more elaborate and potentially more constrained. First, when most people carve a pumpkin they don't worry about the depth. Unfortunately, I don't usually carve like most people *grin*. I actually vary the depth of the cut. Sometimes I use a Dremel, sometimes chisels, the result is fairly cool - the light shows through and the results are quite pretty. I've enclosed a picture or a hand carved pumpkin done without varying the depth.
Second, the correct solution may be to create a subtractive depth map of the pumpkin but there is a cost constraint imposed by the target audience. I would like to submit the mechanism to my friends at MAKE magazine. Their projects are generally very low cost. While my personal preference would be to use high-tolerance motion stages, simple surplus helical screws will be used with drawer-slides instead! Except for the motor drivers and PC, I'm pretty sure an entire (albeit low-tolerance) machine could be created for less than $200. I view this as one more "fun" dimension to the project. Third, someone pointed out that the more information you give the better the answers you get. There is much truth to the comment. But there is also something to boiling down the problem. Sorry for not explaining all of the constraints up front. -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Kenneth Lerman Sent: Monday, January 29, 2007 5:17 PM To: Enhanced Machine Controller (EMC) Subject: Re: [Emc-users] Is there an easy way to work withanirregularsurface? When I carve a pumpkin by hand, I don't worry about the depth. I jab my knife all the way to the center. Then I remove the piece I've outlined the perimeter of. Ken [EMAIL PROTECTED] Mark Kenny Products Company, LLC 55 Main Street Voice: (203)426-7166 Newtown, CT 06470 Fax: (203)426-9138 http://www.MarkKenny.com -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Chris Radek Sent: Monday, January 29, 2007 12:31 PM To: Enhanced Machine Controller (EMC) Subject: Re: [Emc-users] Is there an easy way to work with anirregularsurface? On Mon, Jan 29, 2007 at 11:38:13AM -0500, Michael Dubno wrote: > To be honest, I am trying to make an automated pumpkin carving machine. > The mechanism would be a custom built rotary stage and a horizontal arm > mounted on a vertical post. (Custom built because I don't want pumpkin > goo all over my metal mills). Obviously all pumpkins come in different > shapes and sizes and they also have ridges. I would like to use existing > software to convert images and patterns into g-code. A small program to > post process the g-code before it is run would be easy for me to write. > The idea of a cutting tool who's depth is controllable being held in > place by a spring loaded "follower" or "leader" might work out as well. > I suppose the resolution of the pattern might make a difference. > I think the way to look at the problem is 2 1/2 axis or 3 axis. Treat > rotation as x, the vertical axis as y and the cutter as z. > Thanks for all of the suggestions, they are quite helpful. > - Mike Thanks for being brave and telling us what you are doing, it sounds really fun. This reminds me of the torch height controller Dallur made. The basic problem is to have a height sensor, and make your requested Z relative to that height. I'm picturing that you could sense height with a spring loaded arm with a roller on the end. You'd have the roller "close" to the tool, and the arm pivots on an encoder. If the arm is relatively long, the movement of the end will be fairly linear. You would derive height from the encoder counts. At the HAL layer, you would add this to EMC's requested Z. (You may have to subtract it back out for feedback to the motion controller.) That way Z becomes relative to the pumpkin surface. Now your gcode is very simple... Chris ------------------------------------------------------------------------ - Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDE V _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------ - Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDE V _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-usersTitle: Photo Gallery
Fish tank jack-o-lantern Copyright 2001 - Michael Dubno - New York |
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