Re: [CAD_CAM_EDM_DRO] Re: replacing feed screw with a hydraulic cylinder

----- Original Message -----
From: Vajk Fekete <vajk.fekete@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Thursday, November 07, 2002 10:37 AM
Subject: Re: [CAD_CAM_EDM_DRO] Re: replacing feed screw with a hydraulic
cylinder


> i am thinking on this approach, and like it. what you meen, i could "help"
my stepper with a hidraulic/pneumatic cilinder/pair of cilinders.
>
> but what ideas you have for changing the direction of this "help". it is
easy to build a thrust in the cilinder in one direction, but you have to
change the direction when the movement changes
> direction.
>
> vajk
>
> alex wrote:
>
> > There are numerous pneumatic cylinders available, some consisting of
> > an outside beam/inside slide with the stoke as long as 10 feet, which
can
> > become part of the structure of a router, quite naturally, in this case
> > small stepper will only serve as an
> > interface to the PC.
> > Do you think this is workable?
> > Regards, Alex Likhterman
> > ----- Original Message -----
> > From: Van Der Sandt Coert <vandersandtc@...>
> > To: <CAD_CAM_EDM_DRO@yahoogroups.com>
> > Sent: Thursday, November 07, 2002 7:47 AM
> > Subject: RE: [CAD_CAM_EDM_DRO] Re: replacing feed screw with a hydraulic
> > cylinder
> >
> > > If you are going to 'lock' the axis with the worm gear anyway - then
you
> > > could also use pneumatic cylinders, no?
> > >
> > > -----Original Message-----
> > > From: alex [mailto:telecomt@...]
> > > Sent: Thursday, November 07, 2002 1:44 AM
> > > To: CAD_CAM_EDM_DRO@yahoogroups.com
> > > Subject: Re: [CAD_CAM_EDM_DRO] Re: replacing feed screw with a
hydraulic
> > > cylinder
> > >
> > >
> > > Sorry made a mistake - not coaxial but parallel to the drive screw.
> > > Force of the cylinder should be applied towards the carriage parallel
to
> > the
> > > screw.
> > > Alex
> > >
> > > ----- Original Message -----
> > > From: Jon Elson <elson@...>
> > > To: <CAD_CAM_EDM_DRO@yahoogroups.com>
> > > Sent: Wednesday, November 06, 2002 12:21 PM
> > > Subject: Re: [CAD_CAM_EDM_DRO] Re: replacing feed screw with a
hydraulic
> > > cylinder
> > >
> > >
> > > >
> > > >
> > > > Van Der Sandt Coert wrote:
> > > >
> > > > >What if you had one big pump to keep up the pressure and some kind
of a
> > > > >rotary valve on each axis that just lets a metered amount of fluid
> > > through
> > > > >every time its activated.
> > > > >
> > > > >Alternatively you could have a pump on every axis and calculate the
> > pump
> > > > >speed so that every axis reaches its goal at the same time.
> > > > >
> > > > >
> > > > And, what is going to drive those pumps? Electric motors?
Clutches?
> > > > How can this be better
> > > > than just driving the machine directly with the motor? If you are
going
> > > > to hook a servo motor
> > > > to a reversible hydraulic pump, then drive the table with a
cylinder,
> > > > that has to be the
> > > > Rube Goldberg method of replacing a leadscrew!
> > > >
> > > > Just as a reference point, hydraulic systems, especially hydraulic
> > > > motors driving a leadscrew,
> > > > was a VERY common system on larger CNC machines, in the 1970s. I
> > > > believe it was the
> > > > most common axis drive system on the larger ones, in fact. Direct
> > > > electric drive cam in
> > > > VERY quickly after larger power transistors became available. The
> > > > makers of big machines
> > > > never looked back, and you'll be VERY hard pressed to find any
larger
> > > > CNC machine with
> > > > hydraulic drive today. The only machines still using hydraulic
drive
> > > > that I can think of are
> > > > surface grinders, where they just have a steady back and forth feed
> > > > between limit switches.
> > > >
> > > > The buyers of these machines must have a REAL good reason for making
> > > > this choice.
> > > > The reason, of course, is they had HORRIBLE experiences with the
high
> > > > maintenance
> > > > costs of hydraulic systems! Another side light, the commercial
aircraft
> > > > industry is trying
> > > > to desing their way away from hydraulics, for the same reason -
high,
> > > > VERY high, maintenace
> > > > costs.
> > > >
> > > > Jon
> > > >
> > > >
> > > > 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@...
> > > > Moderator: jmelson@... timg@...
[Moderator]
> > > > 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
> > > >
> > > >
> > > >
> > > > Your use of Yahoo! Groups is subject to
> > http://docs.yahoo.com/info/terms/
> > > >
> > >
> > >
> > > 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@...
> > > Moderator: jmelson@... timg@... [Moderator]
> > > 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
> > >
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
> > >
> > >
> > >
> > > Confidentiality Warning
> > > =======================
> > > The contents of this e-mail and any accompanying documentation
> > > are confidential and any use thereof, in what ever form, by anyone
> > > other than the addressee is strictly prohibited.
> > >
> > >
> > > 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@...
> > > Moderator: jmelson@... timg@... [Moderator]
> > > 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
> > >
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
> > >
> >
> > 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@...
> > Moderator: jmelson@... timg@... [Moderator]
> > 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
> >
> >
> >
> > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
>
>
> [Non-text portions of this message have been removed]
>
>
> 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@...
> Moderator: jmelson@... timg@... [Moderator]
> 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
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>