Re: [CAD_CAM_EDM_DRO] Digest Number 2240

Well, let me know.

Thanks.

Michael


At 04:23 PM 4/16/2002 -0000, you wrote:

>Addresses:
>FAQ: http://www.ktmarketing.com/faq.html
>FILES: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/
>
>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 as 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.

>
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>
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>bill,
>List Mom
>List Owner
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>
>------------------------------------------------------------------------
>
>There are 4 messages in this issue.
>
>Topics in this digest:
>
> 1. Re: oz*in NOT oz/in
> From: "stvdnb" <dsa3@...>
> 2. Re: Re: CNC Pulse jitter?
> From: Jon Elson <elson@...>
> 3. Re: Re: CNC Pulse jitter?
> From: Jon Elson <elson@...>
> 4. RE: Re: CNC Pulse jitter?
> From: "John Guenther" <j.guenther@...>
>
>
>________________________________________________________________________
>________________________________________________________________________
>
>Message: 1
> Date: Tue, 16 Apr 2002 04:39:51 -0000
> From: "stvdnb" <dsa3@...>
>Subject: Re: oz*in NOT oz/in
>
>--- In CAD_CAM_EDM_DRO@y..., Doug Fortune <pentam@c...> wrote:
>...
>> torque is measured in 'force*lever arm'
>> in other words, oz*in lb*feet N*m
>>
>> etc, NOT oz/in , lb/ft etc.
>>
>> (Yes I know oz & lb are not exactly units
>> of force, we should be using Slugs but I'm
>> afraid that will lead to even More Confusion!)
>
>If I remember correctly, the slug is a unit of mass, not force.
>Pounds and ounces _are_ units of force.
>
>- Steve
>
>
>
>________________________________________________________________________
>________________________________________________________________________
>
>Message: 2
> Date: Tue, 16 Apr 2002 05:18:53 +0000
> From: Jon Elson <elson@...>
>Subject: Re: Re: CNC Pulse jitter?
>
>Patrick Mendiuk wrote:
>
>> Jon,
>> Has you or anyone else measured jitter with EMC?
>
>Well, mostly I have been looking at servo update cycle jitter,
>and step timing jitter with my stepper rate generator chips.
>EMC's jitter on the servo update cycle is about 10 uS on a
>100 MHz Pentium classic, and under 5 uS on a 333 MHz
>Pentium II. With a 1 KHz servo update cycle, that is under
>1%, which sounds pretty good.
>
>My step rate generators have excellent timing, with the pulse
>ALWAYS within 100 nS of where it should be. I don't have
>equipment to measure jitter down in this range, it is basically the
>jitter of the 10 MHz crystal oscillator. The logic can cause up
>to 25.5 uS (user programmable) delay on one step pulse, when
>a change in direction occurs too close to a step pulse. This doesn't
>throw off the whole pulse train, it just delays ONE step pulse.
>Anyway, direction changes should only occur near zero speed,
>so it is mostly a non-issue.
>
>HP (now Agilent) has a really nice "time and frequency domain
>analyzer" that runs $25,000 that would be real nice for checking out
>stuff like this, but I don't have that kind of money!
>
>I will have to check out steppermod.o and freqmod.o and compare.
>
>Jon
>
>
>
>________________________________________________________________________
>________________________________________________________________________
>
>Message: 3
> Date: Tue, 16 Apr 2002 05:21:37 +0000
> From: Jon Elson <elson@...>
>Subject: Re: Re: CNC Pulse jitter?
>
>Patrick Mendiuk wrote:
>
>> Rich,
>> I had similar problems with DOS and Windows with different software. Linux
>> and EMC seem to be better, but those glitches I saw/felt prompted me to go
>> for a DSP motion controller card. I have another project in mind and I
>> think I will try EMC again with servos.
>
>Well, I can tell you, you can get VERY smooth motion with EMC, even with a
>very moderate speed CPU.
>
>Jon
>
>
>
>________________________________________________________________________
>________________________________________________________________________
>
>Message: 4
> Date: Tue, 16 Apr 2002 07:40:49 -0400
> From: "John Guenther" <j.guenther@...>
>Subject: RE: Re: CNC Pulse jitter?
>
>I'll second that one, I have very smooth motion with EMC, using either
>steppermod.o or freqmod.o on my stepper system.
>
>John Guenther
>Sterling, Virginia
>
>> -----Original Message-----
>> From: elson [mailto:elson]On Behalf Of Jon Elson
>> Sent: Tuesday, April 16, 2002 1:22 AM
>> To: CAD_CAM_EDM_DRO@yahoogroups.com
>> Subject: Re: [CAD_CAM_EDM_DRO] Re: CNC Pulse jitter?
>>
>>
>> Patrick Mendiuk wrote:
>>
>> > Rich,
>> > I had similar problems with DOS and Windows with different
>> software. Linux
>> > and EMC seem to be better, but those glitches I saw/felt
>> prompted me to go
>> > for a DSP motion controller card. I have another project in mind and I
>> > think I will try EMC again with servos.
>>
>> Well, I can tell you, you can get VERY smooth motion with EMC, even with a
>> very moderate speed CPU.
>>
>> Jon
>>
>>
>> Addresses:
>> FAQ: http://www.ktmarketing.com/faq.html
>> FILES: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/
>>
>> 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
>> as 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.
>>
>>
>>
>> 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
>> bill,
>> List Mom
>> List Owner
>>
>>
>>
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>>
>>
>
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Michael Leonard Tilse | draemr@...