Messages

4631

Galil / Re: galil and backlash compensation

« on: May 10, 2010, 02:08:26 PM »

Backlash can be set in CONFIG>BACKLASH. As Nosmo reponded it is implemented on change of axis direction.
The backlash settings determine how fast it will be implemented. Works quite well.
RICH

4632

General Mach Discussion / Re: Radius Compensation

« on: May 10, 2010, 08:20:52 AM »

The active plane for a lathe is X-Z.  G18 defines the plane to be used.

RICH

4633

General Mach Discussion / Re: Spindle

« on: May 09, 2010, 12:08:12 PM »

Not sure what you want to do. The amp measurement can be manipulated give you torque, but pressure is due to force and for that you would  want to measure strain which can be manipulated to force, which will vary in a non linear fashion above a certain point. But non of this is absolute due to the electronics. IE; measure pressure via strain gaging, null a bridge to zero, but that's only good to 1% of total. Accelerometers can be indicative of movement and related to pressure. Again not sure what you want to actualy measure and do with the info you aquire and i am not an instrument guy.....
RICH

4634

Show"N"Tell ( What you have made with your CNC machine.) / Re: COLLIMATOR MODIFICATIONS, BASE , AND TRIVET STAND

« on: May 09, 2010, 11:50:58 AM »

The collimator provides you a target at close range. So I can focus a theodolite / surveying instrument at say 100 feet or infinity and check calibration even though the distance between them is only a few inches.
There are actualy three targets in the collimator, one is just a cross hair , the other two have different cross hair scales.
So i can calibrate the micrometer head on the level, or check the adjustments say to bubble movement. That level pictured is extremely accurate.
Resolving to 3 arc seconds, and the level / bubble is maginified and split imaged / coincidence and can be repeatably to 1/20 of an arc second and set to 1 arc sec.
To put it into perspective, say you have a machinst level with a sensitivity of .0005" per foot or roughly 10 arc sec's, well at 100 feet you could be
+- .060" in accuracy ( of course you would need a true reference ) , were as the level will be 10 times more accurate and is it's owne reference.

I leveled out a guys 60 foot long mill bed as he was having difficulty trying to do it. Actualy i spent 12 hours doing it as  data was taken along the bed over  a time peroid. The concrete was found to be expanding and contracting due to temp changes ( from day to night time).  The bed  was profiled
and compared to the varient over hours used, and changes as the 10 ton head moved over the bed was noted. Then all the data was resoved to how the leveling should be done and set to the best tolerance that could be had. So he was able to then face a 6' x 6' x 4" thick Al plates to within .003" before grinding was done. But your intruments need to be spot on and known to be accurate.
Just one of the devices used in quickly checking  them.

There are more accurate ways ( autoreflection ) but i made the collimator for kicks.
RICH

 

4635

General Mach Discussion / Re: Mach3 Turn and CNC setup

« on: May 09, 2010, 08:30:04 AM »

Not still clear the problem with the coordinates system. No answer to my questions, but the upgrade?

- Never used v1.84, and there have been a number of upgrades sine then.

- In Mill there is no radius / diameter selection as in Turn, so when you use the calibration it makes no difference. The Mill should be in metric  units also and make sure that your axes are not scaled.
So just do a move of say 10 mm and when the moved distance is correct as compared to the commanded distance accept the steps per unit and they will be
saved to current profile. So if your digital the readout is diameter then it should agree with Mach.

When you go back to using the lathe set you will see that the steps per unit were changed. Your configuration  in ports and pins >lathe options should be diameter.
Make sure you have selected Program or Part coordinates in the manual screen of Turn. If you have selected Machine coordinated the dipslayed DRO value will be
1/2 the commanded as machine coord displays in terms of absolute and radius.

I am thinking that is where you are getting confused, but, like i said i never used that old version and can't say what is does.

RICH

4636

General Mach Discussion / Re: Turning wizard problem - "FilletRadius is too big"

« on: May 08, 2010, 06:02:31 PM »

I can greate the the error message, but i can also change the fillet radius and thus make the error go away.

Remember that output from the wizard is influenced by your configuration, if you are in diameter mode don't use radius values, and
BTW some of the wizards only work when in radius mode if memmory serves me.

Can you post a screen shot of your current inputs for that wizard?

RICH

4637

General Mach Discussion / Re: Adding DRO to MachTurn

« on: May 08, 2010, 05:43:34 PM »

I am just curious

Timing was in a sense a way of trying to mimich an encoder and was limited depending on the number of slots and spindle rpm. Additionaly the info recieved was manipulated for the DRO display and was influenced by the particular pc being used. I would need to look through all my testing notes to
give you more specifics. ( frankly i would rather just forget the issues  )

The single index was proven to be very accurate.
But....if you want electronic gearing then more resolution  / an encoder will need to be used, but before that could happen there are program changes and testing required, and that may come about in the future .... future defined as whenever ......

RICH

4638

General Mach Discussion / Re: Mach3 Turn and CNC setup

« on: May 08, 2010, 05:04:31 PM »

I would suggest you update to a later version of Mach.

Is there anything like this for the Lathe version?

Not available in the lathe screen , but you can use the mill screen and then use those numbers in the lathe screen motor tuning.
( while in Mach 3 Turn , just change the screen set to the mill set and then go back to the lathe set. )

What is the correct procedure to calibrate each axis?

I use an indicator to compare commanded movement to actual movement. You should also check for backlash.
Have a look at the manual.

Remember, when in Mach3 Turn and machine coordinates, the DRO will show the absolute X distance in terms of radius, even though you are in diameter mode.

RICH

4639

General Mach Discussion / Re: Spindle speed readout

« on: May 08, 2010, 09:03:11 AM »

The sensor needs to provide an on - off signal which represents a rev of the spindle. The signal must be able to change the pin state at the computer.
Then you can tell Mach where the signal can be found ( pin # or input )  and configure Mach appropriately.
In general the sensor output signal must eventualy go to a pin on the PP. The sensor output can be modified / conditioned / or connected indirectly via a BB or whatever. I am thinking your may be looking at the gear teeth and then in that case the output is like an encoder and there are limits
on the number pulses that can be read.

FWIW,
RICH

4640

General Mach Discussion / Re: Mach3 Turn and CNC setup

« on: May 07, 2010, 04:36:19 PM »

Alberto,
I change between radius and diameter a lot on the lathe and have never seen what your saying happened.
Did you save the configuration?
What version of Mach are you using?
Are you using a custom screen set for your lathe?
What units are you working in?

RICH