RE: [CAD_CAM_EDM_DRO] LARGE Gantry table: Geckos on large servos.

I don't know if a Gecko will run a really large servo motor.

We've got a 3HP servo motor, depowered by running at 80V, on a large
table of a special machine. We recently tested it with a Gecko 320 and
blew it up. It would operate fine at lower speeds, but the drive ran
warm. At higher speeds, the drive failed. It seemed to have problems
getting the damping/gain correct for such a large motor.

We sent the drive back to Gecko. They looked at it but have not
commented on what exactly caused it to fail.

I suspect that the motor would draw more than the rated max drive
current (ie 20Amps) during acceleration.

Kim

On Tue, 2004-03-09 at 17:03, Leslie M. Watts wrote:
> Heh. Confused Chris? My friend Bob Campbell said a Gecko would
> handle it. I said it would need something bigger.
>
> To put things in perspective my 1000 lb gantry IS run by a Copley
> 412 which is about the same as a Gecko in power. So Bob is absolutely
> correct for the weight you asked about.
>
> I just think that a 20 ft gantry will be much more massive than my
> system. Things tend to go up in mass as the cube of length for equivalent
> stiffness. Sometimes even more. A finite element structure analysis
> can define this in the design stage.
>
> Les
>
> Leslie M.Watts
> L M Watts Furniture
> Tiger Georgia USA
> (706) 212-0242
> http://www.lmwatts.com
> Engineering page:
> http://www.lmwatts.com/shop.html
> CNC surplus for sale:
> http://www.lmwatts.com/forsale.html
> CNC carved signs:
> http://www.lmwatts.com/signwp.html
>
>
>
>
> -----Original Message-----
> From: Robert Campbell [mailto:bob@...]
> Sent: Tuesday, March 09, 2004 6:09 PM
> To: CAD_CAM_EDM_DRO@yahoogroups.com
> Subject: Re: [CAD_CAM_EDM_DRO] LARGE Gantry table
>
>
> Chris,
>
> You will defiantly need a servo system. I would think that a Gecko drive
> would do it.
>
> You may want to post on the Gecko drive list.
>
>
> Bob Campbell
> Bob@...
> www.campbelldesigns.com
> Breakout board
> THC board sets
> CNC router plans
> Stepper Motors
> ----- Original Message -----
> From: "cutthroatplasmaco" <cutthroatplasmaco@...>
> To: <CAD_CAM_EDM_DRO@yahoogroups.com>
> Sent: Tuesday, March 09, 2004 3:52 PM
> Subject: [CAD_CAM_EDM_DRO] LARGE Gantry table
>
>
> > Can someone point me in the direction of suppliers for motors/drives
> > for LARGE gantry machines... I'm talking 20'x40' cutting area. Off
> > the top of my head, I'm guessing the gantry might way a half ton or
> > more. I'm very familiar with smaller steppers/servos, I just don't
> > quite understand where/what route you take when talking about large
> > machines that need significant torque to make a 1000lb gantry change
> > directions on a dime. It seems you need an ac servo that would run
> > off of signicantly more power than a gecko or similar can provide.
> > Any help/links would be appreciated.
> > Thanks,
> > Chris
> >
> >
> >
> > Addresses:
> > FAQ: http://www.ktmarketing.com/faq.html
> > FILES: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/
> > Post Messages: CAD_CAM_EDM_DRO@yahoogroups.com
> >
> > Subscribe: CAD_CAM_EDM_DRO-subscribe@yahoogroups.com
> > Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@yahoogroups.com
> > List owner: CAD_CAM_EDM_DRO-owner@yahoogroups.com, wanliker@...,
> timg@...
> > Moderator: pentam@... indigo_red@... davemucha@...
> [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: CAD_CAM_EDM_DRO@yahoogroups.com
>
> Subscribe: CAD_CAM_EDM_DRO-subscribe@yahoogroups.com
> Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@yahoogroups.com
> List owner: CAD_CAM_EDM_DRO-owner@yahoogroups.com, wanliker@...,
> timg@...
> Moderator: pentam@... indigo_red@... davemucha@...
> [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: CAD_CAM_EDM_DRO@yahoogroups.com
>
> Subscribe: CAD_CAM_EDM_DRO-subscribe@yahoogroups.com
> Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@yahoogroups.com
> List owner: CAD_CAM_EDM_DRO-owner@yahoogroups.com, wanliker@..., timg@...
> Moderator: pentam@... indigo_red@... davemucha@... [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
>
>
>
>
--
Kim Lux <lux@...>