Here's You Sign #98 - Pennsylvania USA

[Tom Ayres]

I'm not a machinist guy and it amazes me that anyone can center drill a tiny ball bearing, I'm not even familiar with the equipment, how do you find center and what do you drill it with? wow

[darren salyer]

I thought the exact same thing, Tom.
it's impressive to me.

[pblackburn]

Stainless steel ball bearings only have a hardness of 45 RC which is still in the machining range. Regular steel ball bearings are in the 55 - 60 RC. It is all in the material that you are using and by stroke of luck that I decided to go with stainless bearings and not steel. Seeing how the smallest quantity of bearings I could buy was 100, I figured I had nothing to lose. The rest of the material was 4140 steel.

[pblackburn]

Still trying to drum up information on a modbus board for IO. Not much out there and what information I do find is minimal. Just spent 8 hours researching and I am still no further ahead than I was when I started. This is the part of DIY that causes most to pay an absorbent amount of money for something. My hardheadedness stops me from doing that though

[racedirector]

Have you looked at Homanndesigns in Aus? Peter H is a bit of a guru when it comes to modbus and is a damn helpful guy to boot. Address is:

http://www.homanndesigns.com/store/

[KenC]

Modbus info are fairly limited especially when one has no idea where to look for them.
If you would elaborate what you intend to do, what you want & what you need. maybe we can chip in some help.

[danilom]

I made one from Arduino, but never used it since the smoothstepper has 3 ports of IO.

[pblackburn]

Bruce,
I have an email to his webstore since yesterday.

Ken,
I would like to have more inputs. I don't need outputs. I have an abundance of outputs. Would be nice to add a pendant later that could be plugged into a port on the gantry. But what I really need is more inputs and about 10 would do for now. I do not like series connections on any circuit and want individual indication and feedback.

Danilo,
Which smoothstepper do you have? This was not an avenue I was looking toward but if it gets me more IO I may have to venture down that path.

[danilom]

Mine is usb , got it cheap 2 years ago. Ethernet one has 51 IO I think, that first port is set as "standard LPT" so only 5 inputs but the other two can all be in or out.
Its a win win, you get smoother operation, higher rapids (very steady pulse stream compared to LPT - confirmed by me) abundance of IO and you can use any computer or a laptop or x64 x86 OS. And no need for any brains or stuff like that.

I wire my inputs (buttons, etc) trough 24V DC relays

[KenC]

MCP230S13 io expander chip can give you 16 ports, choice of input or output , SPI through 2 wires (the serial pins), & you can connect with up to 16 chips with the same serial pins. I have no idea how to get them tie to the HAL though.
but since you only need 10 input, an arduino should do it with its 20 i/o pins. You can disguise your Arduino as a Modbus slave. here

[pblackburn]

Thanks Ken, it is appreciated.

[pblackburn]

Danilo, from your idea I found this and thought I should post it on here for others looking at PMDX-126 and a smoothstepper and how to tie it together.

[dbinokc]

Another option might be to use a raspberry pi, which is my personal controller of choice. There is a linux modbus driver available.

Below is a pic of some experimentation I have been doing that makes use of some of the extra DIN terminal blocks I have. This is intended for a homebrew home security system. However now that I know about modbus, I will probably make another for interfacing with mach3.

[pblackburn]

Apparently I still can't spell or post something correctly.

Was supposed to be on post 642

http://www.cncrouterparts.com/ethern...-34-p-274.html

[pblackburn]

The more I dig into Arduino, the less I think it will be applicable. It seems it has to be connected through USB. This would make the RS485 option of multiple devices more complex. This may be just my thick-headed skull getting in the way but since I already use RS485, I would like to stay within that wiring structure.

[pblackburn]

So I called PMDX and was able to talk to Steve Stallings. I will be for the time being be going with the option card PMDX-108. It has a descent response time at 20us. Modbus has a 20ms response. I will definitely be looking into the ESS for next year. Looks like I may need it anyway with Mach4 if and when I upgrade. As far as my conversation with Steve....great guy, extremely helpful and just an overall good experience.

[pblackburn]

PMDX-108 Input installed.

That would be a very general statement. I have just learned more about parallel ports. Where to begin. I received the part yesterday with a cable. Unfortunately I was sent the wrong cable, first I modified the received cable but then I used some old computer ribbon cables and connectors, modified them, tested it and connected the board successfully. That is a story in itself. Well I set Mach parallel port 2 to have pins 2-9 as inputs, assigned them as OEM triggers and created Brain to manage the inputs. Decided to use Config 4 for 'merged touch probe' for both my digital probes (one as Z zero and the other for probing). First I set the power jumpers on the 108 and tested the cable between the 108 and 126. No power on 108....hmmm....So I tested the touch probe. It works flawlessly, both probe activate the touch probe input so back to the 108. I used the header to header cable from the 126 to the 134 and now I had power. However I was not receiving confirmation in Mach when the circuit for the pin was closed. Back to the internet. Found before bed on MachSupport forum that sometimes the add on pci parallel port cards do not work with pins 2-9 and to try swapping the cables.

In the morning, I powered up the machine for another test and noticed the 126 LEDs were all lit up before power was applied and only the computer was on. When I turned the main power on, they went out. Suspect it is a parallel port problem. So I unhooked the 108 and tried again. No lights...good. Put the 108 back in and lights again. So I shut down, swapped the cables on the parallel ports and tried again. No flickering lights on the 126. So that much is solved, now onto the input status. Tried the inputs again and Mach was not picking them up. So I went into the BIOS and changed the LPT setting from ECP to EPP only. Fired it up and now the inputs registered. Ok, now why does not the ribbon cable work because it should receive power from pin 26. The cable they sent me was a 26 header to 25 DB25 so I looked and it was a 25 wire cable. So I went back up and found another extra long floppy ribbon and disassembled it and made a new cable. Tried it and it worked. Now I hooked back up the 134 to the 126.

Did some more reading and I found this ' Here is one point that I am not sure was mentioned very clearly. For a device to be in the EPP mode the device must have pins 1,14,16 and 17 pulled high otherwise the pc would default to the ECP mode.'. This was copied from and located here. Not so sure this applies but I do know that when the pci parallel port was connected to the 108 and 126 that neither one functioned correctly but they do now on the integrate parallel port.

So now I have to do some testing to find if the card swap will cause any unintended hiccups. The ECP setting that the integrated port was set to before did not work. Only when I set it to EPP did it work. This may have made some trouble before but I am not sure. I am using port 2 pin 1 and 14 for my 4th axis but apparently that is not enough to change the card to EPP mode. I would prefer to let the integrated parallel port be the main runners for the step and direction. However I believe I will follow Danilo's advice and upgrade to a smooth stepper in the foreseeable future. The 108 is setup to work with it so there would not be any losing ground.

[pblackburn]

Running tests to make sure all is well. Just cut out another set of circuit boards for another touch probe. Since I have enough ball bearings to make at least 10, enough copper clad for 6 and enough components for 2, I figured spares are good. Going to use my test wood piece for making sure all is still well, it will be the Winter Wonderland plaque I shared on here a while back.

[Tom Ayres]

Put it through its paces Pete. Why were you needing the additional inputs? what types of things are you loading on this new board?

[Fox]

If you'll be offering the probes/or parts of them to fellow MM-s let me know I'm interested.

[pblackburn]

Tom, I did not get to far. Norovirus struck the household and laid everyone out. This is the first I even cared to look at the computer. The reason I wanted more inputs is from working in industry there are certain things that will drive a maintenance person insane. One of these things is series or parallel circuits. It takes longer to troubleshoot. It comes down to engineers not having to troubleshoot their own work and with uptime at a premium it is wasted time. I will have all the home switches and limit switches separate now so I can see each individual input and not a shared input. Plus it allows more push button actions at the machine, such as setting z zero after changing the tool. That is the end result I am working toward.

Fox, if I decide to do that I will let you know.

[pblackburn]

Sorry I would post the picture on here but Flickr geniuses have created a bug in their bccode generator. Hopefully they get it fixed soon. Here is the link to the cutout of the Christmas file I posted that I used for my test piece.

[sailfl]

Pete,

I like the pictures of the snow. It is always nice to look at snow when it is beach weather.

[darren salyer]

That's just mean Nils.....
Some of us are SICK of winter....

[sailfl]

Yea, I am sick of it too. I will have to put away my sweaters till the next cold season. You noticed I did not say WINTER!

[pblackburn]

You are all nuts, you can always put layers on but there is only so much you can (and should in most cases) take off. I will take snow any day.

[racedirector]

Originally Posted by pblackburn

You are all nuts, you can always put layers on but there is only so much you can (and should in most cases) take off. I will take snow any day.

My sentiments exactly. Living is Australia with horrid heat and humidity I long for winter every year. Loving today as it is raining

[Tom Ayres]

We got 6 inches of snow yesterday morning. It was gone by 7pm, temps reached mid 40's (f) and rain washed it away. But today in the 20's, crazy weather. I too am sick of it.

[darren salyer]

We were close to 80 last week for one day, then high 20s with 25 mph wind gusts yesterday, and mid 50s today.... crazy.

[ger21]

7° this morning. Coldest winter ever and we're about 1-1/2" short of the all time snowfall record.