In my last email I said brass when I should have said bronze. Here is a webbsite for you to visit:
http://www.keystonethreaded.com/prec.htm John ----- Original Message ----- From: "john labutski" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Sunday, November 07, 2004 10:16 AM Subject: Re: [CAD_CAM_EDM_DRO] Gantry Drive Topology > > John > > You might look at acme 12 foot long screws. One piece would handle the x and > y. I assume plasma cutting is only plus or minus about .020 and brass nuts > are easily available to make halfnuts. I don't think you need ball screws > and they don't get along well with the metal spray and dust. Brass half > nuts can be tweaked periodically for back lash of about .005 to .007. Or you > can spring load them to minimize this. > > If you attach to the halfnuts with a hook type bracket the screws can be > protected from the splatter with U channel. Your prime concern is > protecting what ever drive system you end up with from splatter. Also, this > would allow the x axis motor to be attached to one end of the frame. Less > dangling control wires that way. Just use a bigger motor on the x axis. > There is a lot of stored mass in an 8 foot long screw when you add that to > the weight of the rest of the moving part of the gantry. > > This is just my opinion. I have not built one any near this big. There are > a lot of guys in the different cnc groups that have built this big stuff. I > suggest you just look at the pictures in each cnc group on Yahoo. Most guys > will be happy to return an email with their experiences. > > John Ocala Florida > > > ----- Original Message ----- > From: "John" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Sunday, November 07, 2004 7:05 AM > Subject: [CAD_CAM_EDM_DRO] Gantry Drive Topology > > > > > > > > Hi! > > > > I am thinking of making a gantry for plasma cutting. I will > > probably use something like Bosch Rexroth modular aluminium frame > > for the travelling sections. > > > > I understand the difference between steppers and servos, and will > > most likely be using servos to achieve a more dynamic movement on > > thinner materials. However, I would like to ask for your advice on > > choosing a motion system however. > > > > The table will be designed to take standard sheet metal sizes, > > which means that a travel of approximately 1.5m by 2.5m is required. > > > > With the gantry being made from inherently light materials and only > > spanning 1.5m, it shouldn't weigh very much at all. > > > > As I see it, I have a few options available. Lead screws, timing > > belts or rack and pinion. > > > > I imagine lead screws are the first to go, but what would you > > recommend I look at for the drive topology? > > > > Best wishes, > > John > > > > > > > > > > > > Addresses: > > FAQ: http://www.ktmarketing.com/faq.html > > FILES: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/ > > Post Messages: [EMAIL PROTECTED] > > > > Subscribe: [EMAIL PROTECTED] > > Unsubscribe: [EMAIL PROTECTED] > > List owner: [EMAIL PROTECTED], [EMAIL PROTECTED], > [EMAIL PROTECTED] > > Moderator: [EMAIL PROTECTED] [EMAIL PROTECTED] [EMAIL PROTECTED] > [Moderators] > > URL to this group: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO > > > > OFF Topic POSTS: General Machining > > If you wish to post on unlimited OT subjects goto: > aol://5863:126/rec.crafts.metalworking or go thru Google.com to reach it if > you have trouble. > > http://www.metalworking.com/news_servers.html > > > > http://groups.yahoo.com/group/jobshophomeshop I consider this to be a > sister site to the CCED group, as many of the same members are there, for OT > subjects, that are not allowed on the CCED list. > > > > NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY POSTING THEM. > DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........ > > bill > > List Mom > > List Owner > > > > > > Yahoo! Groups Links > > > > > > > > > > > > > > > > > > > > > Addresses: > FAQ: http://www.ktmarketing.com/faq.html > FILES: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/ > Post Messages: [EMAIL PROTECTED] > > Subscribe: [EMAIL PROTECTED] > Unsubscribe: [EMAIL PROTECTED] > List owner: [EMAIL PROTECTED], [EMAIL PROTECTED], [EMAIL PROTECTED] > Moderator: [EMAIL PROTECTED] [EMAIL PROTECTED] [EMAIL PROTECTED] [Moderators] > URL to this group: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO > > OFF Topic POSTS: General Machining > If you wish to post on unlimited OT subjects goto: aol://5863:126/rec.crafts.metalworking or go thru Google.com to reach it if you have trouble. > http://www.metalworking.com/news_servers.html > > http://groups.yahoo.com/group/jobshophomeshop I consider this to be a sister site to the CCED group, as many of the same members are there, for OT subjects, that are not allowed on the CCED list. > > NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY POSTING THEM. DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........ > bill > List Mom > List Owner > > > Yahoo! Groups Links > > > > > > > > Addresses: FAQ: http://www.ktmarketing.com/faq.html FILES: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/ Post Messages: [EMAIL PROTECTED] Subscribe: [EMAIL PROTECTED] Unsubscribe: [EMAIL PROTECTED] List owner: [EMAIL PROTECTED], [EMAIL PROTECTED], [EMAIL PROTECTED] Moderator: [EMAIL PROTECTED] [EMAIL PROTECTED] [EMAIL PROTECTED] [Moderators] URL to this group: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO OFF Topic POSTS: General Machining If you wish to post on unlimited OT subjects goto: aol://5863:126/rec.crafts.metalworking or go thru Google.com to reach it if you have trouble. http://www.metalworking.com/news_servers.html http://groups.yahoo.com/group/jobshophomeshop I consider this to be a sister site to the CCED group, as many of the same members are there, for OT subjects, that are not allowed on the CCED list. NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY POSTING THEM. DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........ bill List Mom List Owner Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
