Messages

7241

General Mach Discussion / Re: I could use a GCode file for Lathe

« on: July 13, 2008, 07:55:37 PM »

jimpinder,
Sounds like your lset and macros would be handy to use. Can you post them?
 
RICH

7242

General Mach Discussion / Re: I could use a GCode file for Lathe

« on: July 12, 2008, 08:51:17 PM »

Dear Dave,
After reading your post, I just must say this, you will think you died and went to heaven when you get a lathe working in MACH.
It takes some learning but it's worth the effort. I am sure you can drive a car but i would bet money you couldn't just place yourself into my 66 mustang and drive it 20 feet! As a convert weening myself off another program, there are some things, manny things, that in the big picture MACH gives you. But then it's your decision.

RICH

7243

General Mach Discussion / Re: I could use a GCode file for Lathe

« on: July 12, 2008, 08:29:58 PM »

Dave,
I started with MACH Turn. Using a little barebones Sherline with no limit swithes etc and have the gcode for a number of parts for a model kit I'm making. So if you want some tested files that worked I can post. The stuff is on the small side of things, like 1/8" to 1" stock will be required but at least you can play around for pennies. I would also recomend starting with the wizards, just take a few seconds to look at how the cutting is done as it may define what kind of tool you need to use.
Do you use a CAD program?
I made a post some time ago about using Lazycam for the lathe. For that I can give you a pesky little file that works
but some reason was a challenge when I first started using Lazycam. So it may help in the learning curve.
Your nickle,
RICH

7244

General Mach Discussion / Re: Perfect circle--I wish

« on: July 12, 2008, 09:39:26 AM »

Cutting a circle is a good test of what the machine can do.  Play around by milling a circle a number of different ways to see what you get. This is done done after MACH is set up. Having a flavor of what your machine will do saves you from not wasting time on something that may never happen. Use a piece of round stock as this is easier to measure. if you can't achieve some tolerance on the outside you probably won't get it on an inside cut.
Start from the center of the stock and make a single circular light cut. Measure diameter in 90 degree increments  noting the plus or minus away from what was wanted.
Now try milling a circle using same cut, multiple cuts or finish cuts, start the actual cut from different quadrants, etc. and see what you get out of them all.
You can mimic rotating the piece, offset the center starting point, change the axis backlash deliberately wrong or the steps wrong, etc.. 
Long story short, your just trying to set up and compensate for what your machine couldn't do in the first place such that a circle comes witin some tolerance.  Please note, that what I am posting, is after MACH is set up, and again are
just machining "tricks" which you can fool around with later on.
RICH

7245

General Mach Discussion / Re: Perfect circle--I wish

« on: July 11, 2008, 10:34:17 PM »

inivator,
A CNC mill can do some very accurate work but they are not as accurate as a lathe. A CNC mill with good components can approach a lathe. Now if you have backlash, you will cut an egged shaped / ovaled circle. If you use backlash compensation you can minimize the oval within the tolerances of your machines capability. With experience and knowing your machine you can get a bearing to just drop into or press into a hole done on a CNC mill even on an old converted mill. I say the above so you have a practical perspective of a perfect hole or circle. That said, you need to get some of the settings right as already noted.

Quoting my music teacher " PERFECT IS SOMETHING TO BE PURSUED BUT NEVER ACHIEVED".
Prettyclose just doesn't cut it, but then, a lot of the things made in my shop certainly fall into that category.
 :)RICH

7246

General Mach Discussion / Re: power supply

« on: July 10, 2008, 07:14:56 AM »

"I do not know whether it is dangers or not.."

When it comes to personal safety nobody can speak for someone elses use of devices, machine, or human actions.
That burden falls on you and the manufacturer and it's totaly your responsibility to pursue until satisfied.
In fact "SAFETY FIRST" should just be a way of life.

If you have safety concerns in regards  to the use and integrity of a kit you should contact the manufacturer.

As a packaged kit the product sold should preform within manufacturers recomendations for use.

PS: No experience with that particular kit.

RICH

7247

General Mach Discussion / Re: Progressive Move Error with X and Y

« on: July 09, 2008, 10:32:48 PM »

CARL,
I agree with Brett and others.

You can get bombarded with so many questions and suggestions. So sometimes it's easier to find and eliminate a problem by eliminating major pieces of the system. And then homing in on that piece.
 
- Check out the mechanics of the machine and if things look right then move on.
  I don't know what you have there.
 
- Try a different PC - maybe also a newer version of the software ( that's two major related pieces )

- Eliminate BOB

- That leaves the controller

And try doing only one thing at a time.

RICH


 





 

7248

General Mach Discussion / Re: Progressive Move Error with X and Y

« on: July 08, 2008, 11:43:26 PM »

Hi Carl,
You got me stumped. Printed and read this post numerous times looking for a missing clue. What bugs me is the amount you are out and how it's varying. If the board elimination works you can forget these as I'm streching a little. I assume your motor is direct coupled to the screw.

MECHANICAL - Can you confirm that your motor to screw coupling is tight / not slipping?

SOFTWARE - Did you ever consider trying a later version of MACH?
                   Maybe somebody else can answer this question. Is there something in MACH like a home setting, etc
                   not apparent that could contribute to this? Maybe a dumb question but just thinking.
TUNING - Drop your velocity to say 10 IPM, adjust ramp for say 1/3 ramp up, 1/3 vel, 1/3 ramp down relative to time.
              Don't use the Z axis during any of your  x-y testing moves ( and just for kicks, set it just like the X & Y axis ).
              Maybe you want to try upping the current setting on your drives up one amp.

PS: Didn't see anthing wrong with the file you posted, the quadrants are symetrical about the CL's, ran it. PLayed around with my mill and couldn't duplicate what's happening to you.

Just some thoughts and back to the sidelines.
RICH

             
 

7249

General Mach Discussion / Re: Setting up a 4th axis?

« on: July 06, 2008, 05:07:35 PM »

Dave,
I posted some pictures in show and tell. The "save good junk" is a picture of an extra mounting. Should you decide on a Sherline and want some good junk, for the price of postage you can have it.
 :)RICH

7250

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

« on: July 06, 2008, 04:50:40 PM »

Nice piece Sam,
What is beaver puke?
RICH