Re: [CAD_CAM_EDM_DRO] EMC, ISA and other Questions...

Art,

That is a VERY nice way of dealing with this problem. I currently do not
have a computer in my shop that will allow the use of Mach1, but I may have
to just give it a try.

I simply post process all of my G-Code files in Microsoft Excel
spreadsheets. I have created a set of macros that will take a G-Code Text
file and dissect it into columns of X,Y,Z,and A data. I then calculate a
feedrate for each G01 move based on the linear and angular step changes. I
have some 20,000-50,000 line g-code programs with a new feedrate calculated
for each G01 call. It only takes me about 30 seconds to post-process a
file.

How does Mach1 handle the situation when you make a step change in the X
direction that is smaller than a single step size (but not zero) and no step
pulse is given, but the A axis needs to move 3 degrees (example only). I
have run into situations where the calculated feedrate will then apply only
to the rotation change and will be agonizingly slow. I have some logical
IF-THEN statements in my calculations to prevent this scenario.

Does the demo version of Mach1 allow a rotary axis to be implemented?

Thanks,

Daniel J. Statman, Statman Designs
www.statmandesigns.com
dan.statman@...

----- Original Message -----
From: "Art" <fenerty@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Wednesday, January 22, 2003 4:45 PM
Subject: Re: [CAD_CAM_EDM_DRO] EMC, ISA and other Questions...


> Hi:
>
> I just noticed some questions on the rotary capabilities of EMC and
Mach1.
> In EMC, the rotary axis is designed to follow the X,Y Z axis in their time
> frame. That is to say a move like G1X1A360 will try to "fit" the A move
into
> the time necessary to move the X 1 unit at the present Feedrate. This
causes
> a runaway rotary axis and usually lost pulses. If you try a G1X.1A360
you'll
> find it races away in the A axis.
>
> I have redesigned that section to recalculate the feedrates for the
> rotary move by applying a ratio of feedrate necessary to maintain the feed
> at the proper speed. This is done by setting the diameter of the rotary
> stock. The feedrate is then calculated as a function of the circumference
of
> the item beingn machined taking into account the movement in the Z axis
for
> the move.
> It can be used 2 ways. Either tell the machine the diameter is zero( or
> close to zero) .0001 or so in diamter in which case the Z must be set to
the
> distance from the center, or tell the system the actual diamter of the
stock
> and set the Z to zero as it touches the stock. The circumference is
adjusted
> on each move to be an average of the Z position during that move. The
> feedrate is then recalculated onh each move to take these varibales into
> account. Internally, the feedrate of an F60 move may be changed to F.034
for
> example to allow the X to complete its move in the time frame of the
rotary
> axis instead of the other way around. The recalculations are not very
> complicated but do necessitate adding new information inputs such as
> diameter of stock to the input screens.
>
> The rotary axis center is assumed to be from the Z axis in both the A
and
> B and no correction is yet applied to the C, but in the end it will be
> corrected as a function of the X,Y offset from center. The A and B are
> designed to be XZ and YZ axis while the C is rotational in the XY plane.
> Ideally, a selection will be aded to allow for reconfiguration of the axis
> planes in a per session basis.
>
> Hope this information helps,
> Art
> www.artofcnc.ca
>
>
>
> 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@... [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
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>