Messages

6861

General Mach Discussion / Re: making parts to size on customer prints

« on: November 24, 2008, 07:10:02 AM »

I have done many pieces to size using cutter compensation. Let me make a few points without getting specific on programing  or the tool tables and such. A lot of my mills are regrinds done by me on a Darex end mill sharpener.
I measure the end mills using 3 or 5 flute anvil micrometers to determine the endmill diameter. I think one should do some testing of their machine to see just how well it can hold dims. Try milling an outside circle as a test and maybe at
 a few different diameters or an inside circle. That will quickly tell you what to expect as it takes into account
the "whole system" ie; tool, depth of cut, feeds /speed, table movement, material, cutting fluid  etc..  If the system doesn't have the ability in movement or cutting to begin with you can't expect software to make up for what is lacking. With some testing done and knowledge of what can be expected, you can appropriately try to make up for those shortcomings to some tolerance.
In summary do some testing and apply to your machining.
RICH

6862

General Mach Discussion / Re: Spindle Speed measurement question

« on: November 23, 2008, 07:08:31 PM »

Dave,
Mine came out of the junk box. I use a single index and with the latest Mach update threading seems to work
well. Pic attached for one on a lathe for what it's worth.
RICH

6863

Show"N"Tell ( What you have made with your CNC machine.) / Re: Some things I've made and did.

« on: November 23, 2008, 06:52:15 PM »

Ed,
Glad you posted the links. You should send Jay a copy of the picture with a comment like " remember when you only had one" as it may get a laugh on the show (assume it's his). Suggest you add to your site. Liked the bikes.
Is the little puppy friendly?
RICH 

6864

Show"N"Tell ( Your Machines) / Re: Arnie's CNC router build (just getting started)

« on: November 21, 2008, 06:48:55 PM »

ZARZUL,
Must be nice to have space. So what's the first project?
RICH

6865

Show"N"Tell ( Your Machines) / Re: New CNC Machine

« on: November 21, 2008, 06:18:17 PM »

Rick,
Looks good and i am sure your having fun.
Make sure you post pic's of things you make with it.
RICH

6866

General Mach Discussion / Re: Motor tuning

« on: November 20, 2008, 10:44:19 PM »

JOHN,
Since he recommended them why not start off with them? You could also just start off at a much less velocity and increment up and see what happens ie; 20,40,80,100,120, 140 and should you start skipping steps at any point back off by say 20 to 30% leaving that as a margin of safety. Not having a motor curve which would delineate
the torque to rpm based on how they are wired at some voltage / current leaves with you with trial and error. Even if you had that you would probably still do the incremental increase trials before actualy trying to cut something. Then try cutting some of whatever your going to do and see if your margin you left for cutting is adequate.
RICH

PS: You don't go from 0 to 60 instantly in your car so give it a ramp and you can refine that also thru some trials.
Also you can use jog the motors to try them at different settings ini motor tuning. Make sure you save your settings and go out and come back into MACH. There is a MACH 3 tutoriial " setting up a basic three axis machine" in the downloads section and also  a fresh of the press MACH 3
software installation and configuration manual available for download.

6867

SmoothStepper USB / Re: Backlash issues.

« on: November 20, 2008, 10:28:49 PM »

Anton,
If the nut has no backlash and is rigidly mounted to the table, the coupling has no play,.......... then that leaves the bearing or bearings on either side of the table as the source of backlash. Can you add a little more preload to them?
RICH 

6868

General Mach Discussion / Re: Having a small problem with mach3

« on: November 20, 2008, 07:14:36 PM »

Understand you want to go fast, but I'm a slow poker who prefers accuracy, repeatability and reliability over speed.
So find a speed that gives you that then fool with the settings until cutting is achieved. Now bump the speed gradually
up until you find the max speed for what you are cutting and back off say 20% for that particular material. What you are cutting may require a slower speed. Again, if you were cutting using circular interpolation ( G2 / G3 ) instead of cutting small straight line segments it would not be jerky. Your motors would be singing to you.
RICH

6869

General Mach Discussion / Re: centering cross hairs on video camera

« on: November 20, 2008, 07:17:20 AM »

Hi Jimpinder,
I don't know if you can electronicaly adjust the crosshair (been a while since i fooled with it ).
I would have added adjusting screws ,three of them, so you could adjust the crosshair to the viewed target.
Adjust using the screws till on target,rotate and repeat until croshair dosn't move off target. If the cosshair dosn't
stay on target then your seeing the spindle runout.  But that would only be good for that particular distance.Could be all wet here.

A mirror may make a better target, as the reflection from the mirror back to the camera could be infinity and adjustment then would be more accurately centered. I have to think more about that one as an image is not
being projected from the camera. hey it's early in my neck of the woods.
RICH

6870

LazyTurn / Re: LazyTurn

« on: November 19, 2008, 09:57:46 PM »

Hi ART,
-Seems like the smallest value for the "iniscribed circle" in the tools is .1, will go larger but not smaller.
-It would be nice if you could stop the back and forth motion of the tool in the future

-The depth per pass is initialy set by the tool radius when the rough profile window opens. If you change the
depth per pass to a different value, it is not saved and reverts back to what the tool radius defined it.
Is this intentional....a reminder of what the tool radius is?

-Some of the rough profiles which were generated based on "small depth passes" can take a fair amount of time.
Long enough in time that you start thinking there is a problem / the pc locked up. The progress line becomes void of movement.Don't know if it's a worth fix, like "ok my friend still working on it" or an audio sound after a minute.
Note that this is not the norm.
RICH