Messages

5481

General Mach Discussion / Re: Problems threading on the lathe

« on: October 30, 2009, 09:50:32 PM »

Thanks for the compliments ART,
Hopefully some practical threading by many users of the version over time will hold true. The testing basicaly implies that if you can't do threads on your lathe, it's not the software part but rather your "Lathe system" along with experience using it.
While you  were tweaking the program i was  compiling a whole bunch of "stuff" which will be put into the members docs as a tutorial or whatever. The write up attempts to capture the big picture on threading so it covers
a lot of territory. If anything it will be a good first stop for  getting a handle on threading on a CNC lathe using MACH3 Turn.

I am just glad that you put the effort into upgrading the threading. The threadings problems are very difficult to put into perspective because they are so interrelated and hard to isolate in a meaningfull way.

BTW, My profession is a process engineering designer and background includes code design of equipment, piping, and whatever. This is fun and the profession is work!

I'll look for your write -up.
RICH
 

5482

General Mach Discussion / Re: Problems threading on the lathe

« on: October 30, 2009, 07:24:13 PM »

ART,
Just some scirbing test info as it's easy to post.
402RPM / 20 PASSES / 0.1, .050, & .025 PITCH
115RPM / 20 PASSES / 0.1, 0.50

The pitch error is for those tests were for practical purposes "0". ie; at 1.5" there may be a slight lead error
of -0.0004 or +0.0002 total.

Will do a few more at different rpm's and pitches to see if any scaling happens,multiple pitch ( should be interesting ), and something for alternate flank ( need to think about that one ). Maybe some real high passes just for kicks.

So don't go breaking it in the meam time! 

RICH

5483

General Mach Discussion / Re: Problems threading on the lathe

« on: October 30, 2009, 03:22:48 PM »

ART,
Take a look at the attached files. Any comments?
RICH

5484

General Mach Discussion / Re: Problems threading on the lathe

« on: October 30, 2009, 10:26:36 AM »

ART,
I figured you are curious on how latest threading post will do.
I cut a few short threads and they looked very, very good, the cutting was smooth, didn't notice any goofy passes,
no lead error problem, so this is looking DAM  good at the moment.

Need to cut some CS and see how it goes. I'll post some data later, want to break it first.
So keep the fingers crossed!
RICH

5485

G-Code, CAD, and CAM discussions / Re: G83 peck drilling - rapid plunge height parameters

« on: October 30, 2009, 07:04:00 AM »

Thanks Graham,
That's one of those settings that was  buried away in Mach. Now I remember Brian commenting on it at the Cabin Fever Show when someone asked a similar question about peck drilling.
Not sure you will even find it in the manuals.
RICH

5486

General Mach Discussion / Re: Problems threading on the lathe

« on: October 30, 2009, 12:56:17 AM »

ART,
No rpm shows in the DRO. The index is sensed in diagnostics. The threading diagnostics will give rotation realtime speed but the spindle rotation is not sensed.    Thus can't do any threading. 
Axis will jog, step , and MPG's work.
RICH

5487

General Mach Discussion / Re: Problems threading on the lathe

« on: October 29, 2009, 11:17:29 PM »

ART,
Will check it out tomorrow and post.
RICH

5488

Show"N"Tell ( What you have made with your CNC machine.) / Re: 2 picture Lithopane merged using Aspire

« on: October 29, 2009, 07:59:21 PM »

Good work Kent. Logan ( the Husky ) you did for me still has a place on the end table in the family room.
He dosen't look at it anymore!   
RICH 

5489

Show"N"Tell ( Your Machines) / Re: more stupid questions bits and end mills.

« on: October 29, 2009, 07:55:18 PM »

I used to use 4 flute end mills on woods, like walnut, bambinga, ebony ( watch out for stone  in the ebony ), and other harwoods in the mill. I would recomend cobalt over HHS as you will be running at high speeds. You can use the same end mills for Al and brass. Frankly, the carbide router cutters would be better for wood.
I am am sure the gantry / router table guys will chime in with better advice.
RICH

5490

General Mach Discussion / Re: How many pulses for a lathe spindle encoder is really needed?

« on: October 29, 2009, 04:55:01 PM »

TJ,
The limitations will be due to  the "Lathe System" you have.
Threading is actively being reviewed and tested for modification. Hopefully it will be all sorted out
in the very near future ( like a week or so/ never know ). 

Don't get hung up on the single pulse per rev. Threading is way more complex than just the single index pulse.
RICH