Messages

1361

General Mach Discussion / Re: Absolute Machine Coordinates Shifting??

« on: March 09, 2015, 03:56:59 PM »

Suggest you post your xml file.

How does Mach3 come up with the Machine's Absolute Coordinate's upon boot up?
Go to Diagnostics after Mach opens. The table at the top of the screen shows how the current position is calculated.
Mach defaults to G54 offset on startup. Also note the current Mill> items in affect.

Depending on some settings and  configuration, what you did after start up, the state of things on exit can all affect what
happens when Mach is opened. I will add that Machine Coordinate 0,0,0 is used at start up from a controlling software viewpoint as it dosen't know a practical machine reference point 0,0,0 (ie; home position / referenced) until it is defined by you in sme manner to the controller.

May want to start reading the manual,

RICH

1362

General Mach Discussion / Re: Threading on lathe issues

« on: March 08, 2015, 11:53:30 AM »

rpm is read by Mach (when threading) via the rpm DRO or directly off the index pulse

Directly off the timing of an index pulse, before, during , and at the end of the threading the DRO just shows results of the COMPLEX cycle.
Spindle speed averaging is the average of the upper and lower timing ( if i recall...) so helps but is not a cure all for a varing or way off
pc kernal / pulse frequency, spindle speed variation, etc. Not sure, but, the rpm used in the cycle is to 4 decimal places ( there were at least 20 different versions
of thread testing routines and just don't recall specifics.)



FWIW,
RICH

1363

General Mach Discussion / Re: lathe motor conversion?

« on: March 07, 2015, 07:40:27 PM »

I have a wee Sherline and the motor is punny, but if you don't tax the machine it can do nice work using small cuts.
Also you may wnat to try alternate flank threading as that helps with the cutting of the thread.
I have done threading on it sucessfuly. From 0-80's to maybe 1/4-20.  The 150 in oz on mine were replaced with 350's I think.
The speed control on the Sherline is not all that great.....once set it would vary some +- 2 rpm and slowdown is expected on threading.
Get too much slowdown and the thread may be trashed!
Also have the anti backlash kits installed and that works well but need to check and adjust them. Used a blalk painted CD rom for the index disc with
a slot  bigger than recomended.

FWIW,
RICH

1364

General Mach Discussion / Re: Abnormal condition alarm

« on: March 07, 2015, 07:21:40 PM »

Do you have an answer to my actual query?

Based on you saying that you added software, which may be running in the background, that could create problems.
Why address specific problems when the source may be the problem?

Only people that do not know how to change/understand the power management on laptops say not to use them

Not really true, totaly false. We have have tried probably 10 different laptops and would say 7 of them did not work well. I have an old one with a PP
that works fine, but extremely slow, so gave up on that one.

BTW,
Did you ever read ArtSofts recomendations on PC's?

That's where I was coming from.

RICH

1365

General Mach Discussion / Re: Threading on lathe issues

« on: March 07, 2015, 07:07:49 PM »

DICKEYBIRD,
Still using the PP.

RICH

1366

General Mach Discussion / Re: new hardware same problem

« on: March 06, 2015, 09:06:53 PM »

Use the axis calibration feature of Mach which can be found via the ALt6 page. No need to to convert to metric system.

RICH

1367

General Mach Discussion / Re: new hardware same problem

« on: March 06, 2015, 08:49:37 PM »

Chinese routers, the famous 3040, 6040 drives..........

Once I made a dumb comment to a psychitrist that I was introduced to. Told him that I heard that they are the first to jump off the bridge.
He corrected me and said that was not true and said it was dentist's that jumped first.

Everytime this dude see's a post with Chinese or 3040, 6040............I feel like a dentist! 

RICH

1368

General Mach Discussion / Re: Abnormal condition alarm

« on: March 06, 2015, 08:30:53 PM »

Laptop's  are not recomended unless using an external motion device. Software shoud never be running in the background for a computer in use
for CNC purposes.

RICH

1369

General Mach Discussion / Re: Threading on lathe issues

« on: March 06, 2015, 08:21:30 PM »

A fluctuation in rpm of say 1 ie; flickers between say 99 to 100 should be ok. Idealy the rpm should be constant since the movement during threading is a
cut at a constant feedrate. If the feedrate is not constant the thread will vary in pitch. If it varies too much then the following pass is modified to adjust for the varying feed rate. That's why you set vfd  manualy to an rpm so the VFD is not fighting with the correction the program provides.

If you were to scribe a line, allowing for some time for accelration, say 0.5" ( 5 pitch diameters) and then contact with the material using a G01 Z 1.5 F... the scribed line should be constant. You would need to use a microscope to measuse the variance over a few inches. Scribe line is only as accurate as 
the ball screw / screw moving the axis.

If as you say, the rpm goes out of whack, say  it goes to zero or drops say from 100 to 20, the threading cycle will try to fix the the threading by adjusting the next cycle. I have tested it for extreme drops in rpm, almost a complete stop, and the threading recovered but the thread pitch was not in spec.

In general the more stable the rpm the better the cut screw thread pitch will be. Should you consistanty get something , say less you can always change the pitch in the wizard and it will be used, and the thread will be good. But that is just tricking the program  pathing and is self defeating.
This is all in the write-up.

I think you have an index problem, or it can be the vfd's ability to maintain rpm.

I can't speak for version 57....I use 38 and never had a problem.

If you are measuring the rpm, check to see what the +- specs are on your measuring instrument.
-------------------------
 A test that can be done to check the acceleration / indexing is to mount a thin disc, the bigger the better, say 2" diameter, and do a thread.
You should see just one tick /scribe mark in the exact same location on the disc outside diameter. Under maginification the variance of the tick marks shold be almost zero / no distance between the marks. In fact if you try to do multiple start threading you will quickly find out just what your lathe can do.

RICH

1370

General Mach Discussion / Re: Threading - Recommended Version of Mach3?.

« on: March 06, 2015, 04:29:41 PM »

ED,
Use at least version R3.043.034,  R3.043038 would be better. Have a look at the Mach3 change log
to see what changes have been done for the lathe.

RICH