Re: [CAD_CAM_EDM_DRO] Re: servo vs stepper

Hi Keith

So you are using a motion board. I didn't realize that. What kind?
Here's a suggestion--pull the motion board out, hook the parallel port up
to the Geckos--actually you would just need to hook up three connections to
try it on one axis. Step and direction and common. One person suggested
using turbo-cnc probably a very good suggestion. Install that software,
probably they have free demo, I haven't used it yet but I just bought a
license for it for $20. Make sure you wire the parallel port per the
turbocnc requirements. This will let you experiment with the
motor/driver/axis setup and see what it will do. It should do way better
than 20ipm.
Bob

----- Original Message -----
From: "Keith Clark" <mail@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Thursday, September 02, 2004 1:05 PM
Subject: [CAD_CAM_EDM_DRO] Re: servo vs stepper


> Bob,
>
> Mine is a Series I. I will check out the compumotor drives. Maybe I
> will never get to 100 ipm but 20 sure is pittiful. I have set the
> Geckos to maximum power and have a healthy power supply. It looks
> like from the power speed graphs that the motor just needs more
> juice. I am trying to investigate the pulse generator question. I
> have not found a software to test. My motion board connects to the
> serial port. I am not sure what software to look at. The one I have
> is quite expensive meant for professional shops so it ought to work.
>
> Keith
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "Bob Muse" <mtebob1@s...>
> wrote:
> > Hi Keith
> >
> > Sounds like you have a series II BP. I think the belts give it a
> little
> > flex like the couplings do, which helps.I used the original BP
> motors-I
> > think they were Sigma. I had CMD drives which worked OK-I think I
> got about
> > 60 IPM, it's been a few years. I had a chance to try compumotor S-
> 6 or
> > maybe it was S-8 drives on it one time--wow did they make it
> scream! I
> > don't have direct experience with Geckos but from what I've heard
> they
> > should be doing much better. Why don't you have the current set to
> motor
> > max? Also the software has a great deal to do with it. I use
> CNCPro now
> > but back then I was using Dancam. When I switched, it made a big
> > difference. The other thing I used to test with was just a function
> > generator, controlling accel by how fast you manually turn the
> freq up. I
> > don't know how much configuration your software allows. With some
> besides
> > accel and such you can set the step signal width etc and all this
> stuff is
> > important. Good luck with it.
> > Bob
> > ----- Original Message -----
> > From: "Keith Clark" <mail@t...>
> > To: <CAD_CAM_EDM_DRO@yahoogroups.com>
> > Sent: Thursday, September 02, 2004 10:29 AM
> > Subject: [CAD_CAM_EDM_DRO] Re: servo vs stepper
> >
> >
> > >
> > > Thanks Bob, I have a belt drive with a 2:1 reduction to a 5 pitch
> > > ball screw using a timing belt. This machine was CNC so all the
> ball
> > > screws and pulleys were already installed.
> > >
> > > What is strange to me is that the geckos are not working even
> though
> > > the motors are rated at 7 amps. The motors stall at 5 rev/sec on
> the
> > > bench. I know there is very little mechanical load on at least
> the z
> > > axis. All three axes stall at about 20 ipm and it is not location
> > > dependent. The original Bridgeport Sigma motors stalled at
> exactly
> > > the same speed. Do you have any suggestions at to what motors you
> > > have had success with and the oz/in ratings? I am using a Nema 42
> > > motor that should be able to go 20 rev/sec at 7 amps before
> stalling.
> > >
> > > Thanks
> > > Keith Clark
> > >
> > > --- In CAD_CAM_EDM_DRO@yahoogroups.com, "Bob Muse" <mtebob1@s...>
> > > wrote:
> > > > Hi Keith
> > > >
> > > > I have not been following this thread that closely but having
> done
> > > a fair
> > > > number of retros including series I and series II BP's I would
> > > encourage
> > > > you to hang in there a little longer before giving up or
> scrapping
> > > what you
> > > > have and going with servos. I spent a lot of time (being as
> how I
> > > had time
> > > > but no $$) playing with steppers before I got a good handle on
> them.
> > > >
> > > > I think the geckos should work very well. Just a couple of
> other
> > > > thoughts/questions that may have already been mentioned but here
> > > goes-are
> > > > you using ball screws? How much friction in your ways, are you
> > > getting good
> > > > lube flow? I see you mention that your motors are high-
> inductance,
> > > > generally that's not that desirable it probably would be better
> to
> > > rewire.
> > > > How is the motor coupled to the leadscrew? My series I used
> lovejoy
> > > > couplings with rubber inserts and I think it helped quite a bit.
> > > Had to
> > > > change the rubber twice a year or so.
> > > >
> > > > The learning curve can be frustrating but having the CNC is
> worth
> > > the
> > > > effort.
> > > >
> > > > Bob
> > > > ----- Original Message -----
> > > > From: "Keith Clark" <mail@t...>
> > > > To: <CAD_CAM_EDM_DRO@yahoogroups.com>
> > > > Sent: Thursday, September 02, 2004 6:47 AM
> > > > Subject: [CAD_CAM_EDM_DRO] servo vs stepper
> > > >
> > > >
> > > > > As many have read, I have been having a bad time making
> stepper
> > > > > motors work using Gecko drives. Several have recommended
> > > switching
> > > > > to servos but I have been fearful of tuning the motors etc.
> Is it
> > > > > really that difficult and that much more expensive? At this
> > > point I
> > > > > have spent $550 on each motor. I am also concerned about the
> > > > > difficulty of selecting the correct servo motors since I have
> had
> > > so
> > > > > much trouble with the stepper motors. I guess I would
> appreciate
> > > > > some encouragement or discouragement at this point especially
> from
> > > > > those of you that have done it with a Bridgeport. My machine
> is a
> > > > > Boss 6 Bridgeport.
> > > > >
> > > > > Thanks
> > > > > Keith Clark
> > > > >
> > > > >
> > > > >
> > > > > 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@a...,
> > > > timg@k...
> > > > > Moderator: pentam@c... indigo_red@q... davemucha@j...
> > > > [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@a...,
> > timg@k...
> > > Moderator: pentam@c... indigo_red@q... davemucha@j...
> > [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
>
>
>
>
>