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Messages - hanglide

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1
Disclaimer:  I know only what I've read about the DSPMC motion controller on their website so I'll reply in general terms only. 

Full disclosure: While I represent a company that sells another control, I'm simply trying to help answer your original question and I'm not trying to convince you to buy anything.


That said, there are several reasons why you may need an analog input and many reasons why you may not.


Reasons you may need an analog input:

1. Some BOSS machines return a 0-10VDC value that can be used to determine a rough spindle speed.  (from a pot on the vari-speed)
    You could use this, combined with the speed/up down solenoids to control spindle speed, in a rudimentary way.

2. An analog input can be used to display spindle load on the screen -either via an output from a VFD or directly through the use of a shunt.

3. Feedrate/Spindle Override knobs

4. For specific applications-thousands of reasons: Torch height control, flow rate monitoring etc.. etc..

Reasons you may not need an analog input:

1.  Spindle speed is probably better controlled through the use of an Inverter/VFD.  Also, do you really need spindle speed control on a knee mill?  You have to manually change the tools anyway -How hard is it to adjust the spindle speed when doing the tool change?

2.  Feedrate/Spindle Override - Mach allows you to control both through onscreen controls.  Unless you really want to use knobs (and it's understandable if you do) you can just use the onscreen controls. 

3.  Specific applications -that's up to you to decide if you need (or may need) something out of the ordinary for you knee mill.

Regards

Scott



2
I'll try to put it into simpler terms:

I want to re-label the X axis as Z.  It quite common on other controls and is used for a variety of reasons some of which
are:

When used in conjuction with a scaling factor, it can be used to wrap an X,Y Z program around a rotary axis by swapping the X with a rotary axis label.

On big 4 axis horiz it is often used to perform pecking and other light duty operations with the quill axis rather than humping 10,000lbs of saddle back and forth with a .25" drill. 

You may also want to use it  for probing operations in the same situation.

In my case I have a right angle head attachment on a vertical and want to do lathe operations hence Z<->X (and Y<->X)

Hope that clears it up for you.


Regards

Scott

PS Of course I could do a bunch of search and replace with an editor or code my utility but that wouldn't be what I want or nearly as flexible

3
General Mach Discussion / Possible to re-label axes in Mach Mill?
« on: May 18, 2010, 11:58:48 AM »
I need to re-label the first axis to Z so that Mach outputs vectors to the first axis instead of the 3rd axis when processing G code programs.  Is this possible in Mach Mill?

4
Hi,

1.  Yes, this kit supports up to 4 axes.  No addiitional software options are required.

2.  Yes, Mach should still run any and all plug-ins and features.  The only problem I can think of is if some other third party plug-in stepped on the motion commands Mach generates or if it stepped on I/O.  I don't have any reason to think there would be any problems though.   

3.  Yes, you can use differntial encoders with an index pulse - in fact, they are the only type supported.

4.  Any mpg or input device that interfaces with Mach through the PC should work fine.  As long as Mach sends us motion commands, our hardware will follow.

5.  I beliieve the file size is limited by Mach to 10,000,000 lines of G code.  No limitation is imposed y our hardware.

6.  We have several layers of optical isolation.  All of the encoders and inputs come in through opto's.  On top of that, all communications between the I/O/Drive board and the motion control board are over fiber optic cables.  We were probably the first CNC control manufacturer on the planet (literally) to utilize fiber optics for communication and have been using fiber optics for almost 20 years.

Regards

Scott Pratt 

5
Terry,

Thanks for the input. 

FWIW The mustang is not "micro segmented" as you would define it.  As I pointed out previously, the mustang is made up ENTIRELY of .01" moves -it is pure point cloud data (XYZ pts) from a digitize run we made on a .01" grid.  We're now trying to figure out why Mach is artificially capping the velocities it outputs for vectors...  even on a straight line, single axis move of 8" made up of .01 increments...

Any thoughts Brian?
 

6
 <a href="http://www.youtube.com/v/vgs7efyjV10" target="_blank" class="new_win">http://www.youtube.com/v/vgs7efyjV10</a>

Probably could hit ~750 or so but the machine is on a skid so it rocks a little :-)

7
Mea Culpa...

It turns out you're right Terry.  I didn't run the Mustang myself (that what I get for letting the pubs guys do it) and I didn't question it because we routinely achieve these published rates running that program.

It turns out that Mach doesn't increase the velocities when they cranked up the overrrides (how they -the operators- didn't notice it wasn't changing the speed is beyond me).  We looked into it and it appears that Mach won't increase the velocities of the vectors even when we change the program feedrates?  It will increase rates for longer vectors but that particular program is ENTIRELY made up of .01" moves and Mach just won't put out anything higher than about 100"/min with vectors that short.

Thanks for pointing out the feedrate display as well -we will take control of that shortly- it never occured to me that it wasn't reporting the actual feedrate. I assumed it the feedrate was being calculated based on the vectors that were being removed from the buffer... We already are displaying the actual encoder positions so it should be trivial to derive the combined axes velocites from that to display the feedrate.

FWIW  I will post another video shortly of the same machine ACTUALLY running at 450-500"/min -straight line but pretty good for a 5tpi pitch.  I will also get another Mustang video posted when we can figure out why Mach is limiting the velocities.. I'd understand if it was lookahead related but it seems odd that the commanded velocity curve flattens out well below the max velocity of the axes

FYI All our vectors are brought down as .001 sec (1 milli sec) vectors

8
Thanks Brett

Any ideas on how to get the video to embed properly? Never mind- GOT IT!

Thanks

Scott

9
                            <a href="http://www.youtube.com/v/rr0DC3R_iNk" target="_blank" class="new_win">http://www.youtube.com/v/rr0DC3R_iNk</a>




10
Hi Hood,

Thanks for the interest.  I apologize for the lack of specs - we are in the process of publishing everything for the Mach interface as we speak.  These are the same drives we have been using for several years except that we've now added a plugin and protocol for Mach to bring down the vectors via ehternet in addition to our propriatary method using fiber optic communications.

Electrical specs on the Drive/Motion control:

Configurable from 6-15 amp continuous (will run up to 40-50"lb motors)
12 - 130VDC
125Khz Switching frequency
6 - 5Mhz Encoder inputs (32768 ppr @6000rpm)  

Best regards

Scott Pratt
scott@ajaxcnc.com


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