ml>> i know the files are something.dxf... and i used to look
 ml>> thru them when i'd export them from autocad... in a way, its
 ml>> almost like reading postscript...

 RJT> Hmm.

yeah... you should have seen me the first time i got postscript source from
a printer rather than the results of that source... postscript really is
another language...

 RJT>>  There are also a couple of fairly standardized plotter
 RJT>> "languages" and some of the software that's out there will
 RJT>> no doubt provide those as output.  Or a plotter driver
 RJT>> will.

 ml>> yup... the thing is that it would be part of the DIY aspect,
 ml>> wouldn't it? somehow, you'd have to code something that told
 ml>> the system that x=+1 might be to move the x access in the
 ml>> positive 1 step... its been a while since i dabbled in
 ml>> engineering areas... i forget, at times, about computers
 ml>> talking to computers for some of this stuff... it could be
 ml>> as simple as that x=+1 causing a pulse on one pin of the
 ml>> parallel port and that pin being cabled to the positive side
 ml>> of the x axis motor...

 RJT> Nah,  I'd think you would want a bit more intelligence in
 RJT> the thing than that,  but that's not hard to do with even an
 RJT> 8-bit processor.  Or throw an old MB at it,  with a
 RJT> custom-burned eprom in there.  But that's probably even more
 RJT> than you'd need.

well, i didn't say how far +1 would go, either >  working
with the scopes and doing a lot of reading, i see that there are motors
available where one pulse only moves them some .00002 inches or so...
something also about halfstepping, too... there's one guy, mel bartels, who
has written software to talk to a two axis setup for telescope movement
that uses stepper motors... its freely available, IIRC... a small group is
also working on adding a third motor... many telescope mounts are AltAz
(altitude and azimuth)... in other words, they rotate about a compass and
raise and lower in altitude pointing... these are required to be set up
with the azimuth base to be tilted at an angle proportional to your
latitude so that when you point the scope at polaris, polaris doesn't move
in the visual field... the design with the third motor is what they are
calling a AltAltAz setup and basically, IIUC, works like this... you are
basically raising and lowering the X (left/right) and Y(front/back) axis'
in Z(altitude) and rotating all that around the azimuth... part of the
whole thing is what's called (slightly modified) visual field derotation (i
added the visual part for better understanding)... basically, as your scope
tracks an object or objects in a group, its movement has to be such that an
object that is at the bottom midpoint of the visual field will stay in that
position all the way across the sky while you are tracking it... without
this field derotation, if you start tracking an object on the east horizon
and go to the west horizon, the image will be "upside down" when
you get to the west horizon...

i started a discussion about multiple mirror scopes similar to the keck
10meter scope... they have many small mirrors that all work together to
form one primary rather than having one huge chunk of glass that weighs
several tons... in a multi-primary mirror setup, they have to have three
adjustments for each mirror to maintain proper focus of all the images as
the scope tracks... this also allows them to use visual feedback into a/the
computer to adjust the focus to battle atmospherical abberation to get
views as good or better than what hubble can offer of some objects...

 ml>> i'm getting into some of this type stuff with telescopes and
 ml>> computer controlled tracking and positioning and such...

 RJT> Seems to me I remember reading that this was why the Forth
 RJT> language was first written.  I have an implementation of it
 RJT> here but never did anything with it.

i've heard several folk say that in the past few weeks... both parts
>

 ml>> seems to be very similar... two motors for guidance and
 ml>> there's also some new stuff working for a third motor in the
 ml>> mix to eliminate having to align the scope in the
 ml>> traditional ways...

 RJT> I never got into any of that.  I expect that there would be
 RJT> some stuff in common,  though.

yes, all it is is simple motor control... the differences are only in the
orientation of the motor axis and what is being moved by the motor...

 ml>>> in any case, the CAM platform was fixed in place and you
 ml>>> anchored the flat material to be engraved... the engraving
 ml>>> stuff was basically little more than the (old style?)
 ml>>> "moving cross" flatbed plotter movement with a dremel type
 ml>>> tool attached to a z-axis for automatic height adjustment
 ml>>> and precision control instead of the pen-up and pen-down
 ml>>> type stuff...

 RJT>> Y'know,  I have a dremel tool and the thought never occurred to
 RJT>> me that it might be a thing to use for this.  

 ml>> it might... though i've burnt up a few simply by using them
 ml>> for too long in a session...

 RJT> Mine does get pretty hot.  Maybe applying somewhat less
 RJT> power to it would help.

i dunno how to do that with the units i've burnt out... they were simply
plugged into the 110VAC outlet and used...

 RJT>> Mine is an older model for which the common accessories are
 RJT>> no
 RJT>> longer available,  and i was lucky to be able to find collets for
 RJT>> it,  all four of them.  But somebody pointed me to a source where
 RJT>> I could buy a "drill press" setup for it that was made by a
 RJT>> third
 RJT>> party.  Perhaps something like that would be useful,  adaptable
 RJT>> to this sort of thing.

 ml>> cool...

 RJT> The unit was available at Lowe's,  if you have one of them
 RJT> around you somewhere.  I never did look at it too closely,
 RJT> just went in and asked the guy if I could bring my dremel in
 RJT> and see if that'd work with it and he said yeah...

yeah, we have a lowe's superstore here... i know several of the guys
there... most times you can/will find friendly assistance like that...

 RJT>> I hadn't envisoned much z-axis motion being necessary,  do you
 RJT>> think I'd need much?  And precision in it at that?

 ml>> sure... think about etching "relief" art (i think that's
 ml>> right)... basically, you don't want to just drop the cutter
 ml>> head right into the material... you'd want to ease it in to
 ml>> the proper depth... depending on the material, you may need
 ml>> to make several passes with each being deeper than the
 ml>> last... and what i was thinking about "relief" art was along
 ml>> the lines of small sculptures or even being able to work
 ml>> with material that's not flat...

 RJT> Ok,  so I guess some vertical control and motion are going
 RJT> to be necessary.  But not all that much.

that only depends on the depth control you need and what it is that you are
working on... yes, for plaques and nameplates, not much... for 3D objects,
a bit more :wink:

 ml>>> the stuff came with its own CAD package but these guys
 ml>>> already had autocad and just stayed with it...

 RJT>> Probably a lot more to it than the one that came with the
 RJT>> machine.

 ml>> autocad is/was the bee knees when it came to cad software...
 ml>> i don't know what the current leading package is, these
 ml>> days... i got a copy of v2.1.1 some 15+ years ago and it was
 ml>> $3600+ at that time... even then, it did wireframe 3d
 ml>> stuff...

 RJT> Yeah,  it's pricey.  Does it still require a "key" to
 RJT> operate?  I have some other programs of that sort around,
 RJT> but never really dove into them that much.

the last one i saw a few years ago did have to have a key device attached
to the machine...

 ml>>> this is why i believe the the talk between the CAD and the
 ml>>> CAM was dxf...

 RJT>> Yeah.  You mentioned something about engraving?  Was that
 RJT>> what they were doing with it?  My thinking was along the
 RJT>> lines of
 RJT>> circuit boards,  machining rather than etching, and perhaps the
 RJT>> drilling,  and maybe some other things.

 ml>> the ones that i was working with were doing plaques and
 ml>> trophys... name plates and such...

 RJT> I've seen those setups,  somewhere.  They don't look all
 RJT> that complicated or expensive,  either.

they don't look it but $$$wise, they can be and really shouldn't or needn't
be... what i see is that the makers of them are getting their $$$ while
they can...

 ml>> hey could etch many materials but metal and wood were the
 ml>> most common... though i did see them working on getting the
 ml>> movement speed right for working with solid blocks of
 ml>> plastic some company wanted something done with...

 RJT> Plastics of one sort or another would seem to be a logical
 RJT> choice for this too.

mold making? yep...

 ml>> AIR, something about "reverse etching" such that everything
 ml>> was mirror imaged and what would normally be etched out was
 ml>> left as raised material...

 RJT> Sounds time-consuming.  Unless you had software that could
 RJT> cope with a number of different-sized cutters.

oh yeah... one of the settings was what diameter the cutting bit was...
this so that you could use it to remove "large" areas of material
without leaving any "lines" or "ridges"... oh! and
speaking of that, i just remembered that some of these setups also have two
axis tiling of the Z axis... like a gearshift in a car.. tilt forward,
back, left and right... thinking of how an airplane moves in 3
dimensions...

so, there's X,Y positioning over material, z positioning for depth, and
then tilting forward/backward on another axis and tilting left/right on a
fifth axis... mmmmmmm...

 ml>> basically like making a stamp or mold or something... once
 ml>> they got the prototype samples done, they were looking at
 ml>> processing orders of 10000 lots or more...

 RJT> Yow!

oh yeah, they were talking about moving into a much larger shop area and
highering quite a few more folk... never heard if they did it or not...

 ml>>> i'd love to DIY one of these... if nothing else, it'd give
 ml>>> me something easy enough to do and market and keep me
 ml>>> busy... i've run out of ideas and the job market isn't
 ml>>> giving me any hits, either ;-(

 RJT>> You in the market too?  I got "terminated" last
 RJT>> wednesday... :-(

 ml>> kinda pretty much... been doing a lot of stuff just nothing
 ml>> steady
 ml>> ;-(  getting tired of hunting down my paycheck from week to week...

 RJT> I hate that aspect of it.

yeah, no doubt!

 ml>> the economy is so bad in this area that if you hear about
 ml>> any type of job opening, you'd best be there waiting in line
 ml>> like folk do for concert tickets...

 RJT> Where are you,  anyway?

central carolina... middle of no where and about an hour from everywhere...
hate the traffic in the city, hate the long drive both ways, definitely
don't want the stress, and surely don't want to go postal on anyone due to
any combination of those factors...

[trim]

 ml>> place... couldn't even walk thru the house without running
 ml>> into something or having to turn sideways to get thru...

 RJT> That accurately describes both the hallway and this office,
 RJT> though the office isn't as bad as the hallway.  At the very
 RJT> least I've gotta shift some of this stuff over to storage.

 ml>> i can see most of the ceiling, now...

 RJT> Well,  that's certainly worse than *I* ever got!  :-)

hehehe, when i've closed each of my companies/offices, i had to put the
stuff somewhere... and with needing all the income for living, there was no
way i was going to pay to store it anywhere...

 ml>> and several boxes of stuff to take to the recycler's
 ml>> place... geez, i could have a pretty decent handyman's
 ml>> yardsale if there were a real call for old electronics parts
 ml>> and such...

 RJT> It finally hit me a while back that I've probably got more
 RJT> parts than I'll ever use.  Really.  Lots and lots of Rs and
 RJT> Cs and transistors and diodes and chips and all sorts of
 RJT> other stuff.  And way too much equipment that I either might
 RJT> get around to fixing at some point (3 monitors in the room
 RJT> here!) or might end up scrapping out at some point
 RJT> (storage).

 ml>> too bad its against the neighborhood charter to have a
 ml>> yardsale

 RJT> I wouldn't pick a neighborhood like that.

we did because of the privacy and such... lots are 5 acres or larger...
plenty of trees, peace and quiet... no cars racing up and down the road and
no kids yelling and such all the time...

 ml>> and i'm not toting it all to the truck to move to some place
 ml>> where i have to rent a booth and such...

 RJT> A hamefest might work.

what i was thinking... my problem is finding out about them and then getting there...

 ml>> i do know that i've carried over 1500 pounds of stuff out...
 ml>> the recycler has to weight the truck going in and coming
 ml>> out...

 RJT> Heh.  If I were getting into that much weight I'd load my
 RJT> truck up and go down to the place that buys scrap metal.
 RJT> Which might just barely pay for the gas it takes to get
 RJT> there and back.    If my truck were showing a current
 RJT> inspection sticker...

yah, that too >

)\/(ark