Re: Digest Number 12

I tried using maxnc on a Shoptask with a servo system. Since the shoptask
had .015 backlash and the servo system has 24000 counts to the inch the
maximum number that could be put into the backlash comp field was 255
counts.I needed to put 285 as I recall.
When did they fix the file size problem. As of January it was still there on
the 4 axis delux version that I got.
Dan
-----Original Message-----
From: Andrew Werby <drewid@...>
To: CAD_CAM_EDM_DRO@onelist.com <CAD_CAM_EDM_DRO@onelist.com>
Date: Monday, May 17, 1999 11:03 AM
Subject: Re: [CAD_CAM_EDM_DRO] Digest Number 12

>From: Andrew Werby <drewid@...>
>
> "Dan Mauch" <dmauch@...> wrote:
>
>The big problem with maxnc is the max size of the tool path file is limited
>to ~250K bytes and the limitations in the config file for backlash.
>
>[The filesize limitation hasn't been true of MaxNC's software for over a
>year. Their newer software (MaxL) supports unlimited file sizes, as well
>as 4 axes. If you have an older version, you should get the upgrade. Newer
>versions of the mill (the MaxNC 15, for instance) include "zero-backlash"
>screws as standard hardware; they are available as options for the less
>expensive models. Are you saying there's no backlash compensation in the
>software? ]
>
>Andrew Werby
>
> Tom Kulaga <tkulaga@...> wrote:
>>Subject: Re: Digitizing arm - CMM
>>
>>James P Crombie wrote:
>
>>>I am a machinist with lots of available machines to work with and
>>>own a copy of Rhinocad. Aside from the mechanical part of the
>>>arm you are going to need an interface box that can convert the
>>>signals of the 4-6 encoders and either store the points for
>>>export to rhino or have a little program that will introduce the
>>>points to rhino as they are taken. There are several little
>>>programs that people have designed for Rhino like the calculator
>>>add-on Rhinolator. It can generate a group of random points and
>>>then send them to Rhino and make a surface from them. With the I/O
>>>toolkit available for Rhino I guess that a knowledgeable person
>>>could make up the interface program( but that not me :-)
>>
>>The interface is covered, don't worry about that. I was interested
>>in something else you said though. Is it possible in import a series
>>of points into Rhino and have them assembled into a solid?
>
>[I've never had any luck with that myself, although I hesitate to say
>anything's not possible with a program as versatile as Rhino. But I haven't
>tried the "Rhinolater" approach outlined above either. (I do have a link to
>it from my page at www.computersculpture.com , under Rhino Links- it is
>freely downloadable.) There is a program called Geomagic Wrap which
>specializes in this function- fitting surfaces to pointclouds- but even the
>"lite" version costs around $1500. ]
>
>If so,
>>could you pass along the file format info? Gathering the points is
>>easy enough, but I was concerned about what to do with them when I
>>was done. If I can just store them into a text file, we're in
>>business. Well, after I slap together an arm to experiment with, and
>>write the software, and buy the parts for a 6-axis encoder board,
>>and... and... :)
>>
>>-Tom Kulaga
>
>[If you have a digitizing arm, it's no problem to enter points into Rhino
>directly, one by one. But you'd need to do something tricky (like maybe
>write a macro) in order to feed it a whole bunch at once. Also, Rhino is
>oriented towards building surfaces from splines, not points, so connecting
>the points in parallel rows would be a necessary first step.]
>
>Andrew Werby
>
> From: john@... (John Stevenson) wrote:
>Subject: Re: What does everybody use...
>
>
>
>Mines easy its called checkbook CNC not as interesting as a project but I
>needed
>to get up and running quick as I work with mine.
>
>I have a Beaver CNC, like a manual Bridgeport only bigger that had an old
>Posidata controller on when I bought it from a college, worked but tape

reader

>broken, limited to 999 lines of code and MDI input.
>
>[I just got a big old CNC mill that sounds a lot like this one, with the
>same file-size limitation, although it can currently be programmed in
>G-code, and I'm looking at converting it to a modern controller setup that
>will run unlimited file-sizes. Mine is a "RAMCO", purpose-built for CNC,
>with servos on 3 axes and ball-screws. (After pricing out the conversion
>of my old Bridgeport, I realized that starting with something closer to
>what I wanted was going to save a lot of time and money.)]
>
>We bought the Ahha card plus an opto isolator card that's available here in

the

>UK and fitted it into a PC.
>
>[What's an "opto isolator card"? Do I need one too, if I'm powering servos
>instead of steppers?]
>
>The isolator card then plugs direct into the stepper controller on the

posidata

>controller.
>This meant that we kept the bottom half of the cabinet and scrapped the top
>half
>with screen and keyboard etc.
>We then made a sheet metal housing to accept a 12" monitor and keyboard on

the

>side of the beaver.
>
>[I'm planning to keep the existing servo amplifiers, but gut out the rest
>of the control hardware like John mentions. I'll probably hook it to an old
>486 running DOS. (I'm not sure I'm ready for Linux). Is the Aha system
>going to work for me, or should I be prepared for major problems and
>expense? I've also been checking out Flashcut as an alternative. Has
>anybody used this one for a mill retrofit? ]
>
>As I say all cheque book engineering and possibly not in the theme of this
>group
>but the conversion took a weekend and paid for itself with a month.
>
>
>Regards,
>John Stevenson
>Nottingham, England
>
>[That sounds good to me, much as I like to tinker around...]
>
>Andrew Werby
>
>Andrew Werby - United Artworks
>Sculpture, Jewelry, and Other Art Stuff
>http://unitedartworks.com
>
>
>
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