Messages

1071

General Mach Discussion / Re: Bridgeport Discovery 308 retrofit

« on: June 07, 2007, 02:37:18 PM »

After talking with Brian the other day it seems that the best way to go on this retrofit is the Galil route.  Everything we need to do with the machien can currenty be done with the Galil and 64 I/O extesnsion board.  The cost diffrence between the two options is only in the $600 range with the Galil provideing the least complicated finished system.

I've downloaded all the Galil docs I can find and have been reading like crazy.  I was specing out the computer parts wich will be mounted in the same large enclosure as the original 80286 MB' this cabinet also contains the drives and other bits.  It occured to me that I'll need a way of securing the Galil PCI card and video card.  I've seen other have stripped an old PC case and used that.  I have an old case that I could use in the same way.  Does anyone knwo of anyother options?  Something like a mounting panel for the MB that has a riser to hold the cards?

Thanks,

1072

General Mach Discussion / Re: Bridgeport Discovery 308 retrofit

« on: June 05, 2007, 11:16:29 AM »

The type of parts, that's a tough one....the machine is going into a university machine shop setting.  It will be used by a limited number of students to make parts for student design competitions.  So, stuff like hubs for the solar car, parts for robots, etc.  They have no CNC machines presently so we can live without features that may not be working yet like, rigid tapping or CV mode.  Clear as mud?

What I'm most concerned about is system complexity.  Although the G100/Pixies may work fine the route of Mach III -> G100 -> Pixies -> Drives is more convoluted than Mach III -> Galil -> Drives.  Simpler = Better

1073

General Mach Discussion / Re: Initial Setup

« on: June 05, 2007, 09:14:24 AM »

There is also a weath of information available in the documentation and videos.  Look in the 'tutorials' and 'downloads' sections at the top of the page.  I've read over some of this stuff 2-3 times and still learn somethign each time...

1074

General Mach Discussion / Re: Digitizing

« on: June 05, 2007, 09:10:46 AM »

Why not have them accept a standard styli?  I've bought some from here before http://www.itpstyli.com for my old CMM.

1075

General Mach Discussion / Re: Bridgeport Discovery 308 retrofit

« on: June 04, 2007, 04:58:21 PM »

after a bit more research I find that the Discovery 308 requires the following I/O:

19 GP inputs (18, digital 1 analog)
15 axis specific inputs (encoders and limits)
13 GP outputs
4 Axis specific analog outputs (drive command signals, or could be generated with S/D converter)

So it looks like I could get by with a G100, I am still unclear on how/if it works with S/D converters but am attempting to find out.

I still like the idea of the Galil PCI card, but will have to do a bit more reading on it.  Which ever route I go I'm sure that that the Mach III crew will be there to help out.

1076

General Mach Discussion / Re: Bridgeport Discovery 308 retrofit

« on: May 31, 2007, 12:38:15 AM »

I'm just rying to consider all the options.  Mach works great with a single LPT on my Dyana 2400.  The Bridgeport has MANY more requiments such as, tool changer, more limits, enclosure safety switches, spindle control, probing, MPG and etc.  Now if I went the LPT route I would need at least two LPT's, two breakout boards, 4 Pixies, and likely a PLC to handle the tool changer or other auxillery functions.  Add up the cost and complexity of such a system and your in the same ballpark as a Galil, the G-Rex however seems to have 90% of the lower cost Galil board functions, for 1/3 the price.  I would only slightly disagree with you on the necessity of closed loop operation, I would not say it is 'rarely needed', but rather 'it is not always needed', it all depends on what the system is designed to do.  (But then I could be picking nits  )

So, if anyone is really using a Galil board how is it working for you?  Are you closing the loop?  Are the encoder inputs really used on the G-Rex? I have emailed Gecko but not heard back yet, guess I'll try calling tomorrow.

Thanks again to everyone for all the help,

1077

General Mach Discussion / Re: Bridgeport Discovery 308 retrofit

« on: May 30, 2007, 09:21:34 AM »

The grex doesn't care about the encoder inputs. I doubt it ever will. The Pixe's and a grex should work fine. ( I haven't tried it yet.)

Hmm...that's curious as the G-Rex description PDF says...(the inputs are also described in teh programming manual)

2) 6 quadrature encoder inputs including index channel. Maximum encoder count rate is 1 MHz. Encoder inputs are filtered and have indicator LEDs on each input.

So, am I to understand that this functionality is not available/utilized with Mach III at this time (or ever)?  You still set accel/decel and velocity withing the G-Rex, correct?  And, I guess if the G-Rex does not handle the encoder inputs it is runnign in open loop mode making the Galil boards the only current choice for closed loop operation?  I would also like to hear from anyone who is succesfully running a Galil board.

Thanks for all teh help guys, just trying to get this all striaght in my head.

1078

General Mach Discussion / Bridgeport Discovery 308 retrofit

« on: May 29, 2007, 08:42:50 PM »

I tired to respond to a old thread (http://www.artsoftcontrols.com/forum/index.php?topic=2570.0) on this same subject but it does not seem to show up properly so I thought I would start a new thread.  The subject is retrofitting a Bridgeport Discovery 308.  While it's basically in good shape the control is shot and no parts are available, etc.  I would like to keep the drives etc, but the drives have analog inputs.

I have the same mill in my lab that we are giving to another department and I am going to retrofit it for Mach III for them.  From reading the above mentioned post and other posts about the Galil 18x2 boards and Grex, it looks like the Galil might be the way to go. The Grex analog outputs are only 8 bit resolution so I would have to us it's SD outputs and something like Pixie's to control the analog drives.  Considering that fact that both the Pixie's and Grex would want acccess to the encoder signals, I can't see how that would work; please correct me if I'm wrong. (I did email Gecko to see what they say  ).

Here is the cost breakdown of both options as I see it:

Gecko:        $400                                  Galil: DMC-1842         $1200
Pixe's: (4)      320                                  64 bit I/O expansion     200     
                   ------                                                               ---------
                   720                                                                  1400

So from a initail price the Galil is about twice as much but the Grex might not be able to do the job, any input?

Thanks,

1079

Show"N"Tell ( Your Machines) / Re: First Post, First Machine, LOTS of questions

« on: May 29, 2007, 03:52:04 PM »

I was kind of wondering if this ever whent anywhere?  I have the same will in my lab that we are giving to another department and I am going to retrofit it for Mach III.  From reading this and other posts about the Galil 18x2 boards and Grex, it looks like the Galil might be the way to go. The Grex analog outputs are only 8 bit resolution so I would have to us it's SD outputs and something like Pixe's to control the analog drives.  Considering that fact that both the Pixe's and Grex would want acccess to the encoder signals (I think Grex does) I can't see how that would work; please correct me if I'm wrong. (I think I'll contact Gecko and ask  ).

Here is the cost breakdown of both options as I see it:

Gecko:        $400                                  Galil: DMC-1842         $1200
Pixe's: (4)      320                                  64 bit I/O expansion     200     
                    ------                                                               ---------
                    720                                                                  1400

So from a initail price the Galil is about twice as much but the Grex might not be able to do the job, any input?

1080

General Mach Discussion / Re: limitations?

« on: May 29, 2007, 02:18:31 PM »

And honestly, $160 is a heck-uv-a deal.  I downlaoded the trial was able to get my mill modified and confirm that Mach II was going to work for me/my machine and then bought the license, you can't ask for a better trial offer than that, IMHO.  I'm as tight (as in cheap, thrifty) as the next guy but will gladly pay for Mach.  They way I look at it the more we support Art and Brian and the guys the better Mach gets for us.  Just food for thought.....