CAD CAM EDM DRO - Yahoo Group Archive

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

Posted by alex
on 2002-11-06 10:22:52 UTC
I really don't think that low reliability which requires high
maintenance is an issue with the hydraulics. Some others - may be
high costs, weight, ?
We found it to be extremely reliable in machinery applications.
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
>
>
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Discussion Thread

al5502 2002-11-05 06:30:34 UTC replacing feed screw with a hydraulic cylinder Jon Elson 2002-11-05 09:52:32 UTC Re: [CAD_CAM_EDM_DRO] replacing feed screw with a hydraulic cylinder Bill Vance 2002-11-05 11:54:45 UTC Re: [CAD_CAM_EDM_DRO] replacing feed screw with a hydraulic cylinder alex 2002-11-05 12:10:05 UTC Re: [CAD_CAM_EDM_DRO] replacing feed screw with a hydraulic cylinder b564htf 2002-11-05 17:04:39 UTC Re: replacing feed screw with a hydraulic cylinder JanRwl@A... 2002-11-05 20:29:36 UTC Re: [CAD_CAM_EDM_DRO] Re: replacing feed screw with a hydraulic cylinder Bill Vance 2002-11-05 21:18:25 UTC Re: [CAD_CAM_EDM_DRO] Re: replacing feed screw with a hydraulic cylinder Jon Elson 2002-11-05 21:56:12 UTC Re: [CAD_CAM_EDM_DRO] replacing feed screw with a hydraulic cylinder Jon Elson 2002-11-05 22:35:01 UTC Re: [CAD_CAM_EDM_DRO] Re: replacing feed screw with a hydraulic cylinder wanliker@a... 2002-11-06 00:52:53 UTC Re: [CAD_CAM_EDM_DRO] Re: replacing feed screw with a hydraulic cylinder Rose, Gary 2002-11-06 05:28:09 UTC Re: replacing feed screw with a hydraulic cylinder bjammin@i... 2002-11-06 05:53:31 UTC Re: [CAD_CAM_EDM_DRO] Re: replacing feed screw with a hydraulic cylinder dakota8833 2002-11-06 06:18:43 UTC Re: replacing feed screw with a hydraulic cylinder alex 2002-11-06 10:22:52 UTC Re: [CAD_CAM_EDM_DRO] Re: replacing feed screw with a hydraulic cylinder Brian 2002-11-06 14:11:08 UTC Re: [CAD_CAM_EDM_DRO] Re: replacing feed screw with a hydraulic cylinder alex 2002-11-06 14:28:57 UTC Re: [CAD_CAM_EDM_DRO] Re: replacing feed screw with a hydraulic cylinder alex 2002-11-06 15:32:08 UTC Re: [CAD_CAM_EDM_DRO] Re: replacing feed screw with a hydraulic cylinder alex 2002-11-06 16:03:00 UTC Re: [CAD_CAM_EDM_DRO] Re: replacing feed screw with a hydraulic cylinder alex 2002-11-07 07:01:35 UTC Re: [CAD_CAM_EDM_DRO] Re: replacing feed screw with a hydraulic cylinder alex 2002-11-07 07:12:24 UTC Re: [CAD_CAM_EDM_DRO] Re: replacing feed screw with a hydraulic cylinder Vajk Fekete 2002-11-07 07:32:34 UTC Re: [CAD_CAM_EDM_DRO] Re: replacing feed screw with a hydraulic cylinder alex 2002-11-07 09:45:28 UTC Re: [CAD_CAM_EDM_DRO] Re: replacing feed screw with a hydraulic cylinder bjammin@i... 2002-11-07 18:19:30 UTC Re: [CAD_CAM_EDM_DRO] Re: replacing feed screw with a hydraulic cylinder alex 2002-11-08 07:11:32 UTC Re: [CAD_CAM_EDM_DRO] Re: replacing feed screw with a hydraulic cylinder jim davies 2002-11-11 16:10:02 UTC Re: [CAD_CAM_EDM_DRO] Re: replacing feed screw with a hydraulic cylinder alex 2002-11-12 06:52:57 UTC Re: [CAD_CAM_EDM_DRO] Re: replacing feed screw with a hydraulic cylinder blown_mgb_v8 2002-11-29 17:43:03 UTC Re: replacing feed screw with a hydraulic cylinder Ray Henry 2002-11-30 10:35:05 UTC Re: Re: replacing feed screw with a hydraulic cylinder Marv Frankel 2002-11-30 15:05:49 UTC Re: [CAD_CAM_EDM_DRO] Re: Re: replacing feed screw with a hydraulic cylinder Jon Elson 2002-11-30 16:27:58 UTC Re: [CAD_CAM_EDM_DRO] Re: Re: replacing feed screw with a hydraulic cylinder Ray Henry 2002-12-01 07:25:29 UTC Re: Re: Re: Re: replacing feed screw with a hydraulic cylinder Sven Peter 2002-12-01 11:03:39 UTC Re: replacing feed screw with a hydraulic cylinder blown_mgb_v8 2002-12-01 13:56:49 UTC Re: replacing feed screw with a hydraulic cylinder blown_mgb_v8 2002-12-01 14:06:07 UTC Re: replacing feed screw with a hydraulic cylinder Bill Vance 2002-12-01 17:14:21 UTC Re: [CAD_CAM_EDM_DRO] Re: replacing feed screw with a hydraulic cylinder Sven Peter 2002-12-02 04:58:34 UTC Re: replacing feed screw with a hydraulic cylinder Ray Henry 2002-12-02 11:05:11 UTC Re: Re: replacing feed screw with a hydraulic cylinder Jon Elson 2002-12-02 21:37:13 UTC Re: [CAD_CAM_EDM_DRO] Re: Re: replacing feed screw with a hydraulic cylinder Ray Henry 2002-12-03 06:22:09 UTC Re: Re: Re: Re: replacing feed screw with a hydraulic cylinder blown_mgb_v8 2002-12-03 20:30:12 UTC Re: Re: replacing feed screw with a hydraulic cylinder Jon Elson 2002-12-04 10:01:30 UTC Re: [CAD_CAM_EDM_DRO] Re: Re: replacing feed screw with a hydraulic cylinder blown_mgb_v8 2002-12-05 18:15:35 UTC Re: replacing feed screw with a hydraulic cylinder Ray Henry 2002-12-06 07:32:46 UTC Re: Re: replacing feed screw with a hydraulic cylinder blown_mgb_v8 <jblackwood5@i... 2002-12-14 21:05:01 UTC Re: replacing feed screw with a hydraulic cylinder blown_mgb_v8 <jblackwood5@i... 2002-12-15 02:47:22 UTC Re: Re: replacing feed screw with a hydraulic cylinder Mike Gann 2002-12-15 12:05:15 UTC Re: [CAD_CAM_EDM_DRO] Re: replacing feed screw with a hydraulic cylinder cisco_bits <iaing@n... 2002-12-15 12:55:08 UTC Re: replacing feed screw with a hydraulic cylinder Ray Henry 2002-12-15 14:40:57 UTC Re: Re: Re: replacing feed screw with a hydraulic cylinder Jon Elson 2002-12-16 01:29:43 UTC Re: [CAD_CAM_EDM_DRO] Re: Re: replacing feed screw with a hydraulic cylinder blown_mgb_v8 <jblackwood5@i... 2002-12-16 20:17:33 UTC Re: replacing feed screw with a hydraulic cylinder Scott A. Stephens 2003-01-06 13:48:03 UTC CNC Retrofit for the Taig Mill