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Deckel Mach Retrofit
« on: August 13, 2007, 07:17:08 PM »
Hi Everyone,
My name is Sean and I am the moderator of the Deckel forum over at Practical Machinist.

After many years of talking about it, it looks like the "Deckelites" may finally be willing to attempt a PC conversion of a Deckel CNC milling machine as a group.

While I am a pre-Mach user/owner of Art's software, it has been years since I have been in this forum as at the time, Art's software was quite "young".  I did manage a Bridgeport Boss retrofit using the beta of Mach 1, but the Deckel was out of reach at that time.

Today, as Mach has evolved, and more interest in converting a Deckel NC has been introduced, we are now very interested in moving on with a retrofit.

The Deckel NC is a very special machine, of the highest quality, and a very friendly conversational called a "Dialog", which can still hold it's own 20 years later.  This control excels at shop floor programming and the logical subsitution of buttons/modes for what would otherwise be a "manual" milling operation using handwheels.

In any case, if you could offer and help, or would just like to follow along, that thread can be found here:

http://www.practicalmachinist.com/cgi-bin/ubbcgi/ultimatebb.cgi/topic/6/2104.html?

We'll probably be directing most tech' questions to this topic here on the Mach forum, but will have more machine specific issues at the Deckel forum.

It's good to be here again, and thanks for having a look!

Sean

Re: Deckel Mach Retrofit
« Reply #1 on: August 13, 2007, 09:19:03 PM »
Here is an example of the machine we are hoping to retrofit.

It has glass scales for feedback, AC servo's, a gearbox for speeds...etc.

Offline ART

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Re: Deckel Mach Retrofit
« Reply #2 on: August 13, 2007, 09:56:20 PM »
Very nice machine. Looks like quite a challenge, but will be one cool tool when done..

Art
Re: Deckel Mach Retrofit
« Reply #3 on: August 13, 2007, 10:37:20 PM »
After reading your forum I can see that you have been a little slow at finding that there are ways to make Mach3 a closed loop control :)  There are a few ways that this can be done and I would be happy to tell you more about the pro's and con's of each system... There is the Galil card (I am not telling you to get one by the way) that is a good system to run a +-10V amp... I have done a conversion with this and it works well ONLY if the accel of each axis is about the same. Why is this??? Well it all has to do with how galil chains the moves... I would like to change the galil to use an other mode but I don't think we can move data to the buffer as fast as we need to in that mode. The other way is to do what Hood told you and use a Pixi... This is one way that it can be done and is the lowest cost solution... There is an encoder board from Ron Rogers that works well... I made the code for the plugin and I can tell you that it works :) The Pluging is watching the encoders and tracking the following error of the axis. You could say "IT is not right because it is not telling the axis to correct the error"... To that I say WRONG! The servo is driven by the Pixe that has a PID loop.. THIS is where the error is taken out NOT in the computer! the computer will track the error and IF you get over on following error it will fault out. Yes this is how a Fanuc or any other works... I could add code that could look at the following error and slow the feed to try to limit the error that it is getting... This is not a big deal and can all be done with 2 P ports...  So why would you use P Ports if you could have something so grand as a Galil! For 1400.00 I got a 6 axis one here for testing! The P port is going to be far less and there is going to be a NEW USB board that can run your machine at up to 4MHz pulse rate! Now you may be saying .. I want the standard!!!! +/-10V uuummmm... Not any more :( The new way is digital drives and I have also worked on bus systems that only send data!  So for me I would take the new USB board and a few Pixies to get the best closed loop that I can for the money... For the people that are hard core and need to have it all one one board because it makes them feel better there is the Galil BUT you need to know that there is a limitation of the accel needing to be the same AND that I have not coded in the probing :( One thing that it will do VERY well is homing to an index pulse :) If there are people out there that think they can do better... I have the plugin code and if you think you can handle the code I would be willing to work with you... You need to have VS2003..

I hope that helps, I just wanted you to know what we can do now and that there are ways that don't have to cost you :)

ALso there is this board that I just got in the mail:
http://www.kelinginc.net/CNCSoftware.html

I have not started the code for this board but it looks like it is going to be good. It is less money then the Galil and looks like it will not have the accel problem


Well I have to get back to work :)
Brian

 
Fixing problems one post at a time ;)

www.newfangledsolutions.com
www.machsupport.com
Re: Deckel Mach Retrofit
« Reply #4 on: August 13, 2007, 11:45:38 PM »
Is there a way to get rid of the annoying underlining of posts?  Every word you folks have written in your threads is underlined for some reason???  Wierd.

OK, Brian, I have a quick question for you.  Can you point me to this board by Ron Rogers.  I'd like to read more about this and to better understand how this integrates in with the control.  Specifically, you mentioned that a plugin you wrote for the card provides positional information back to the control.  What is the control doing with this.  My understanding is that because Mach is open-loop, it has no capacity to use this type of information.

The next question I have is related to your comment about how Fanuc and other machines work.  I am baffled because you have stated that they work in an identical fashion as the open-loop Mach.  But those systems do not have pixie interfaces in them.  The encoder feedback is fed directly into the control and the PID is performed within the control.  If your contention is that the internals of the control are doing the same thing as the Pixie, then I would agree with that.  One way or the other a PID has to be performed on a servo based system.  So long as the following error can be accurately monitored and error trapped, I personally don't care too much about where this is performed.  Of course, having it inside the control does give one a bit more flexibility in configuration. 

Finally, I am confused about the comment regarding the digital drives.  I have heard a myriad of different comments regarding this.  Some state that steppers are coming back into vogue.  Others claim that the manner in which the control indicates the desired position is changing, specifically to a digital format.  I guess that I really don't care one way or the other. I would agree that the digital invocation of position is probably becoming much more popular, but servos still seem to rule the roost over steppers... I'm curious about your thoughts on that though.

I'd love to hear your comments on these... I am one of the (more vocal) members in the thread that Sean was describing before.  For the record, I think Mach is a great product.  I am less thrilled about making anything on a Windoze platform though.  I just don't trust that.  For that reason, I am actually more of an advocate for doing this project in EMC than Mach.  However, I have also readily acknowledged that doing the project in Mach would be faster and hence that is attractive.  In the long run, however, I think I would ultimately move it to EMC for the previously described reasons.  The (ultimate) donation to Mach would be easily given as I think the application should be supported. :)

I guess that is about it.... If you can provide links to any useful tools/accessories/interface boards/etc, that would be great....

Oh, one last thing.... I spend my days in VS2005... I am assuming that this is OK too?  Sometimes the upgrade path between 2003 and 2005 is a little "murky", so I thought I should ask.... 

Alan

P.S.  Just for kicks, I am currently looking into Mono to see if I could use .Net for EMC.... That should be "interesting"  :)
Re: Deckel Mach Retrofit
« Reply #5 on: August 13, 2007, 11:48:22 PM »
<chuckle>  Sean has taken a picture of my machine.... He has been storing it a year and I'm getting a good laugh because he now voluteering it as a guniea pig <LOL>.  I say this, of course, with a good dose of humor because it doesn't bother me in the least (and I suppose there is tacit approval anyhow).

Alan
Re: Deckel Mach Retrofit
« Reply #6 on: August 14, 2007, 12:05:28 AM »
Found the Roger board and I'm happy with that.... I do have a concern about the fact that it is a parallel device though.  To devote one of the two printer ports (hmmm, can't remember the I/O map on the PC... is it 2 ports or 4...) to the Rogers seems risky. 

What type of implicit support is there in Mach for eithernet or USB based devices?  Do you need to write all of that yourself?

I am liking what I am seeing but I am still very uncomfortable with the Windows platform...  I would love some compelling arguments for why I should *not* be worried about it.

Alan

Hood

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Re: Deckel Mach Retrofit
« Reply #7 on: August 14, 2007, 02:35:24 AM »
Alan
 My servo drives (Giddings and Lewis DSA) are digital drives and take various inputs such as analogue, step direction, follower input etc. from your  staement above,  if I read right,  it seem you think just because you use digital signals you must use steppers, I can tell you that is NOT the case.
 The underlining I found very annoying at first and to be honest I still find it mildly irritating. It is there because all the text is being used as a hyperlink to the videos page,  and that is the reason I find it most annoying, I have a tendancy to occasionally click my mouse when not meaning to and every time I do that I get transported to U Tube :D

Hood
« Last Edit: August 14, 2007, 02:54:18 AM by Hood »

Hood

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Re: Deckel Mach Retrofit
« Reply #8 on: August 14, 2007, 02:59:43 AM »
Alan, also with regards to Rons board, you can still used the unused I/O on it as normal if I remember correctly, been a while since I had one. As far as the parallel port is concerned then its 2 max. This issue however will be getting addressed with the USB board brian mentioned. From what I have seen written so far it will be capable of taking the paralell port cables from your existing system, also it will have much more I/O than the parallel ports have. Heres the post on that board http://www.artsoftcontrols.com/forum/index.php?topic=3862.msg28602#msg28602

Hood
Re: Deckel Mach Retrofit
« Reply #9 on: August 14, 2007, 03:00:18 AM »
Hood,
Not at all... I think you misunderstood my meaning... Digital interfaces for servos are not unusual, although I do not profess to be an expert in that area (my CNC machines are either pure stepper or 1 to +/-10VDC servo amp based.  I do know that there are digital servo systems out there...  They have historically just outside my price range and/or need.

The comment I was making was that digital amps for servos need not be limited to step/direction.

Alan

P.S.  Am I the only one that has underlining of all the poster's thread text in this forum?  It is *really* annoying!  Argh!  I've got to see if there is a setting on my profile.  Separating the lines is tough on my computer.
« Last Edit: August 14, 2007, 03:08:21 AM by wrench »