Need help w/ setting up a newly acquired Mirac PC

Post by **Denford Admin** » Thu 10 Jan , 2008 12:39 pm

Have you double checked the serial port is working at all ?
Try a google search on RS232 loopback plug

Martin · Post by **Martin** » Thu 10 Jan , 2008 18:48 pm

You may need to boot the computer directly into Dos.

What version of windows are you running from??[/b]

yantra3d · Post by **yantra3d** » Fri 11 Jan , 2008 1:58 am

I am currently booting directly into DOS, although I have seperate installs of both win2k and winXP that I can boot into. I did do a quick test with dosbox on xp but received the same error. However, I didn't attempt to configure the port settings like the baud rate, etc...

I will try to test the port to make sure it's functioning correctly. I also have a pc w/ xp that I can test dosbox with in case it has something to do with the serial port/laptop configuration.

Thanks for the help guys!

yantra3d · Post by **yantra3d** » Mon 14 Jan , 2008 22:08 pm

Well, I was able to confirm that the serial port is functioning and tried launching from a winxp box through dosbox and that was unsuccessful as well.

I have a feeling that it's the cable configuration that's causing it to fail. I had mixed replies in this thread about what the configuration is for this machine cable; one mentioned a straight-thru connection, another sounded like a common null-modem type crossover cable and then of course the IBM-to-Machine wiring diagram that uses a custom crossover connection.

According to the manual it requires it's own custom wiring config but the manual refers to a different control board than the LCB3 that my mirac is using so I wonder if the diagram is applicable in my case. It mentions two different controller/driver setups but not the LCB3 so is it possible that my particular machine requires another wiring config than those Miracs that were supplied with the other two board types mentioned in the manual?

Also, I have tried pretty much every possible combination with the mirac.go file but it always aborts with the same error. However, after removing all the lines except for the final "mirac.app" line I get an error saying that it can't locate the keyboard.

The only other thing I can think of that is not in order is the broken axis limit override switch, but that wouldn't cause the software to not connect to the machine would it?

Post by **Denford Admin** » Tue 15 Jan , 2008 9:48 am

Sorry - I'm not sure at all which cable to use - crossover or straight, and really don't know what else to suggest

I suppose I would be looking at Mach by now anyway - it just depends on:
1. How quickly you need to get it working
2. How much you want to get involved with the electronics upgrade
3. How much time and money you want to put into it

Post by **Denford Admin** » Tue 15 Jan , 2008 11:00 am

Drawings here now:

viewtopic.php?p=4636#4636

yantra3d · Post by **yantra3d** » Thu 17 Jan , 2008 22:27 pm

Thank you admin... those drawings are helping me figure out how to convert it over to mach control as you intuited.

I have an existing mach 3 setup with a Grex g100 driving servos for a benchtop mill and am currently only using 3 of the 6 available axis on the controller. I am considering purchasing some g201's to drive the 2 steppers and loading up a separate config for machturn and that way I won't need another pc, etc... to control the lathe.

Right now I am trying to figure out if it's possible to configure mach3/grex to utilize the homing switches (datum sensors) that are equipped with the mirac, and also if I can use the spindle encoder equipped with the mirac.

I'm planning on using a digispeed xl for the pwm conversion but am not sure how (if possible) to configure mach to take advantage of the encoder for the spindle control. Would save me the hassle of putting together a pulse-type indexing setup.

Thanks again for everything... you guys are a great help!

Here's the encoder:

Post by **Denford Admin** » Fri 18 Jan , 2008 10:06 am

I'm sure there will be a way to condition the signals for the Gecko or Mach - CNCzone would be the place to get those kinds of answers though.
There seem to be plenty of people willing to build interface boards for Mach !

While we're on the subject - how does the G100 perform ?
Have you had any issues with reliabilty or bugs ?
Have you any opinions on the NCPod compared to G101 ?

yantra3d · Post by **yantra3d** » Sat 19 Jan , 2008 23:33 pm

Well, I can't speak w/ much experience regarding the g100 as I'm still pretty much in the initial stage of retrofitting the mill. I have successfully set it up and tuned the servos on the machine, but have only been able to cut some motor mounting brackets out of delrin so far because I still need to mount the 3:1 gearheads on the servos before I can cut any metal. Also, I have only ran it under win2k w/ 128mb of ram so an upgrade is in order before I can make an honest report but so far it's working well for me. Once I am setup and cutting metal then I'd be happy to report on my experience.

I have no experience with the ncpod but have been hearing more about the usb-based "smoothstepper" which sounds pretty promising for a usb friendly board.

yantra3d · Post by **yantra3d** » Mon 21 Jan , 2008 23:28 pm

I'm looking into using the z channel on the spindle encoder to signal the one ppr that mach 3 requires for spindle control. Apparently mach 3 doesn't support more than 1 pulse so I won't be to make use of the 60 ppr signals generated by the A/B channels.

So, I'm curious... does anyone know what the LCB3 controller was doing with the A, B and Z channels from the encoder? Or rather, what was the purpose of the indexing (z) channel in this application? How did the LCB3 specifically make use of the encoder's indexing feature?

Mr Magoo · Post by **Mr Magoo** » Tue 22 Jan , 2008 10:02 am

The index pulse is only used during threading. The controller needs to know the orientation of the spindle so that the position of the spindle is the same for each threading pass.

And it uses the 60ppr to measure spindle speed.

Hope this helps!

yantra3d · Post by **yantra3d** » Tue 22 Jan , 2008 19:14 pm

Thank you Magoo... that's great! I mostly just wanted to know what I was giving up by possibly letting go of the 60ppr channel with the upgrade. My most obvious concern was losing any threading capabilities so this is good news. So the 60ppr must also be used to indicate direction as well then I would assume.

Mr Magoo · Post by **Mr Magoo** » Tue 22 Jan , 2008 21:18 pm

In this case it is only used for speed (the B phase of the encoder isn't used)

Post by **Denford Admin** » Fri 25 Jan , 2008 11:23 am

I presume that Mach will still be able to calculate spindle speed from the index pulse - it will just be less accurate.
I'm also guessing that you won't be able to do threading in Mach if you ditched the single pulse and retained the 60ppr signal ?
- unless Mach can keep counting up to 60 and therefore knows when to start the next threading pass ?

yantra3d · Post by **yantra3d** » Sun 27 Jan , 2008 2:29 am

I found out that the spindle encoder functions at 5v (input/output) so theoretically it could work w/ mach using the 1 ppr indexing channel. I am told that mach is unable to read more than 1 ppr and so it seems like an ideal match to me. If the 1 ppr indexing channel was originally setup to control threading and mach is designed to utilize 1 ppr for threading control then why shouldn't it work?

Someone at the mach forums mentioned that the 1 ppr signal may be too short for mach to register it through a parallel port. But, I was planning on using the Grex's ethernet port to send the signals back to mach so I wonder if this could make the difference?

yantra3d · Post by **yantra3d** » Mon 31 Mar , 2008 3:38 am

Thought I'd post an update on my upgrade progress. I switched over to a new USB-based controller board by http://www.dynomotion.com called "kflop" and I'll be working with the developer on solving the indexing issue for the existing spindle encoder. The kflop is mach compatible and has a built-in processor so it doesn't require the pc to generate the pulses using the mach kernal.

I am using a pair of used IMS drivers that I picked up on the cheap along with a new CNC4PC C6 speed control board for the VFD spindle control. I'm actually at a complete standstill right now because I can't seem to figure out how to wire the spindle relays into the C6 board. It would seem simple enough considering that the VFD uses the standard ENABLE, BRAKE, CW, CCW signals.

I have tried to be careful to not make any permanent changes to the original configuration so that I could easily revert back to the original setup if I should ever wish to.

I started with the bottom plate of sheet aluminum and added a heat sink for the drivers. At the top right you can see the kflop breakout board with the ribbon cable tied up above it. I will shorten this cable soon but it connects to a parallel port that replaces the original port and connects to the kflop controller board outside of the enclosure.

Directly below the BOB on the bottom right side is an opto-isolated input board that converts all the 24V input signals from the x & z datum sensors, door/guard and estop switch circuit into 5V ttl signals so I can feed them into mach via the kflop controller board.

On the far bottom left of the cabinet are some relay boards that I planned to use in place of the old LCB3 onboard relays but am still unclear on what they actually do for sure as that whole 24V circuit gets a little confusing when I study it and I have no clue what the software was doing with those input signals in the first place.

Anyway, I'll try to post some updates as I make more progress. Cheers!

yantra3d · Post by **yantra3d** » Mon 07 Apr , 2008 2:24 am

Hey, I have a question for you guys.

Do any of you happen to know if the x and z datum sensors are used for limit switches as well as for homing?

The reason I ask is that one of the LCB3's relays (labeled AUX in the wiring diagram) appears to be connected to the circuit for the datum sensors so I wondered what might be the purpose for this.

My guess is that they doubled for limit switches which would be handy since they are located at the extreme end of travel on each axis.

Can anyone validate this?

Post by **Denford Admin** » Tue 08 Apr , 2008 10:24 am

I switched over to a new USB-based controller board by www.dynomotion.com called "kflop"

This control looks really powerful for the money (is it about $250USD ?)
almost overkill for a 2 axis stepping m/c ?

The kflop is mach compatible

I guess their KMotion software is not suitable for lathes ?

PS Sorry I can't help with the AUX relay

Magoo or Martin will possibly know what it was for.

yantra3d · Post by **yantra3d** » Wed 09 Apr , 2008 2:44 am

Well in my particular case I am using the kflop w/ the snapamp (driver board) for my mill conversion which is using servos. I was able to close the loop in the kmotion software and tune it really quickly within the software... which was nice.

Because the snapamp has plenty of I/O's to handle the mill I am able to break off the unused kflop IO's to control the lathe components. So I will have one controller board and pc for both the mill and the lathe. I do not intend to run them both simultaneously so I don't perceive any problems with this setup (fingers crossed). Will have two mach config's - one for lathe and one for mill.

I think the kflop will work well for the lathe once we get the spindle encoder working with the vfd. Tom from Dynomotion is working on the program to make this happen and I am going to work with him on it by supplying my time and lathe, etc...

I got the spindle motor rotating this morning in fwd rev direction and responding to step/dir jog cmd's. Once I get the enable relay sorted out on the cnc4pc C6 board then I will be connecting the spindle encoder channels and then we will push ahead with developing that. We will be using all 3 channels of the encoder as a differential input (A, A-, B, B-, Z, Z-) where the Z channel is used to track the rotation of the spindle.

Will post more once I have some progress to report...

Denford Software & Machines

Denford Software & Machines

Need help w/ setting up a newly acquired Mirac PC

spindle encoder - indexing

mirac conversion update

datum sensors used for home AND limit switches??