Messages

6951

General Mach Discussion / Re: I'm lost

« on: November 01, 2008, 09:35:20 AM »

Dan,
Curoius on how your mill quill  or mill head is mechanicaly driven up or down.
RICH

6952

General Mach Discussion / Re: True Spindle Speed

« on: November 01, 2008, 09:10:29 AM »

Gerard,
Take a look in Mach III Turn manual page 4-12. It gives info about the spin index pulse.
Threading has come a long way / been fixed in the latest development version and spindle readout
works better than ever ( for me anyway using a single slot ).
Backlash in your lathe axis's dosn't provide for good threading. Just thought i would mention that.
RICH
 

6953

General Mach Discussion / Re: general newbie questions

« on: November 01, 2008, 07:46:35 AM »

Bob,
What you want to do requires some manipulation / time / work and some accurate drafting.
I will just give some concept here then you can play around with it.
If you use a camera, the better the resolution, the more accurate will be the CAD overdrawing
on the image. You will be drawing over pixels probably. I have done this with microscope pictures and dims can match to
one or two ten thou's. Accuracy varies as distance increases but still can be quite good. Of course the optics come into play.
In general, with camera at center point and focus perpendicular to plane then a=a, b=b and any distance about center
line both in height and width can be drawn, measured or even calculated anyware along the sighting of the plane.
Of course knowing where the camera is relative to the plane is required ( especially if not on center of the plane ). ......call this poor man's laser photogrametry. Attached picture should help understanding.
Have fun and lol,
RICH

6954

General Mach Discussion / Re: crazy circles from an ARC PP on one machine, OK on another!

« on: October 31, 2008, 05:38:36 PM »

JIM,
Looks like the spindle is creeping up or the cutter ( doubt it ) . When doing engraving work you need good  Z
axis repeatability. Also indicate out the surface and make sure it's flat. Styrafoam surfaces .......look for a flat spot
to try out the machining.
RICH

6955

General Mach Discussion / Re: general newbie questions

« on: October 31, 2008, 05:19:44 PM »

RABPHXAZ,
You can do a search for raster to vector file software and will fiind some posts. My experience is that raster to vector software "sucks" and i don't care who makes it and how much you spend. Should you find something that truely works
please post as I would be interested along with a lot of companies.

You can take your picture or scan and draw over it CAD. Place know accurate markings on it which are visual in the picture.
Import to CAD, scale it to size, draw over the figure, export as a DXF file. You will need a CAM program to generate the code for the profile / whatever from the dxf file. You can try LAZYCAM ( its beta ) which may or may not be for you, or purchase some other program. You should try a number of programs to see what satisfies yourself in a price range that suites you wallet.

Recommended pc for Mach should be adequate for most software. Windows XP 1 GHZ W/ 1 TO 2 GHZ ram are about norm
today.  Avoid on-board graphics if you can. If the pc turns out to be a problem the Super Stepper which uses the USB should be considered ( consider one right from the start).

You'll need controll software , of course MACH since it's the best in town, and a contoller composed of the power supply/ motor drives/ cables.
Hopes this helps and just my opinions,
RICH

6956

General Mach Discussion / Re: Jogging distance varies. Set to .001, jogs .0005 then .001, then .0015, etc

« on: October 30, 2008, 07:47:45 PM »

simpson36,
I would quess that the rack and pinion on your mill is not adjustable such that you can adjust the mesh of the gear to
the rack. And if you could and did you would probably end up with a tight spot because the rack and pinion is not precision. You have the equivilent of screw backlash in the rack and pinion. You can take out some of it when change in direction occurs using backlash compensation, it will help minimiize it, but not eliminate it.  I have the same problem with my quilled mill directly driven via the fine movement gearing. I jog it down to take the play out, but on retract, even with backlash compensation, the Z accuracy is not repeatable.
Yes, a few sweet spots, but in general not in the one to 3 thou range. So for general milliing I can work around it,but,
 for engraving requiring very precise movement, forget it.

Positioning the head via ball screw should eliminate your problem. Make sure that part of the system has adequate torque
to hold position and microstep.
Now just as an option to consider and if you can live with the tolerance of the belt driven rack......you can add another
removable compact / short ball screw movement driven spindle for fine work. Just a thought.
RICH
 

 

6957

Show"N"Tell ( What you have made with your CNC machine.) / Re: Lithopane

« on: October 29, 2008, 10:38:52 PM »

They are all great and it's nice having experienced resources should i ever want to try it out.
RICH

6958

General Mach Discussion / Re: Mach Workshop at Cabin Fever Expo

« on: October 29, 2008, 10:32:00 PM »

Dave,
We plan on attending all three days and definitely spending Friday night in York.
So maybe I'll bring a cushion for the chair. 
Of course any consumptiion on Friday night will be purely for medicinal purposes. 
RICH

6959

General Mach Discussion / Re: Smooth Stepper

« on: October 28, 2008, 06:42:11 PM »

I'll second what just Ray just posted.
RICH

6960

General Mach Discussion / Re: Smooth Stepper

« on: October 28, 2008, 06:38:53 PM »

Flipz01,
Emailed me  an invoice and i used PayPal. You can probably call them and arrange differently, but i can't speak for Warp9. You may also want to order the ribbon cables as they are very reasonably priced.
RICH