Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: Transformer on March 24, 2016, 09:02:44 PM
-
Nothing has worked so far so a fresh start.
1. To get threading to work I need to get a stable readout of actual spindle speed into Mach3. Is this correct? Or does the input signal have to be of a certain form? (Absolutly no luck getting a stable readout using two different proximity sensors.)
2. If I figure out how to do the slotted disk, optical readout approach to get spindle speed into Mach3 do I have to worry about noise from the VFD or other source corrupting the signal? Special wiring needed etc?
3. Once I can get a stable spindle readout into Mach3 then the hardware part is finished and from there on it is pounding away at Mach3, OR do I need more index input signals? I am operating under the assumption that if I can get a stable read out of spindle speed all my hardware issues are behind me, agreed?
Thanks.
-
Yes you need a table stable input for the index signal and the more stable the better, but at least within in the 1 rpm range.. Noise can be a problem and would suggest shielded wire as it is easier to keep noise out then to try and remove it. Will just have to try and see if there is a noise problem.
Slotted disc works fine but I use a Hall affect sensor as it is easier to mount ( just be aware that some are reed sensors and have response limits).
Currently only index input is used in ports and pin's.
Hardware can be a problem if your axis is not repeatable, has backlash, or is not accurate.
RICH
-
So, carrying on. The proximity sensor will give me wildly varying RPM numbers varying in a random pattern from actual RPM to 1/2, 1/3, 1/4 etc of actual RPM, but never a readout greater than actual RPM.
Then I tried a Hall sensor. Again wildly varying RPM but of no discernible pattern. Running at 300 RPM I get readings varying from 1 to 30,000. This time a shielded cable.
I have played around with debounce levels, varying spacing for the sensor, etc but as far as I can tell nothing has made any difference in the readout pattern.
Does this sound like a hardware problem or a problem in my Mach3 settings? And if the problem might be in the settings, where should I start to look?
Thanks.
-
It could be your hardware but you haven't given details of what it is so everyone is guessing ;-)
-
Start by giving full details of your system, the less guessing the better!
-
The proximity sensor I am using is from Automation Direct http://www.automationdirect.com/adc/Shopping/Catalog/Sensors_-z-_Encoders/Inductive_Proximity_Sensors_-z-_Proximity_Switches/8mm_Round_Industrial_Automation/Standard_Sensing_Distance_(8mm)/AE1-AN-1A
and is one that was recommended by one of the knowledgeable people on Hobby Machinist (Dawson).
The Hall sensor is one that came with a MachTach kit I ordered and all his other bits and pieces have worked flawlessly, but that kit only gives RPM readout, it does not feed it into Mach3. With the MachTach I used an optical sensor and since a Hall sensor came with the kit I put it to use to get spindle speed readout into Mach3. This setup allows me to compare the accurate MachTach readout with what I am getting in Mach3.
Spindle speed is controlled by hand directly at the VFD, and spindle speed is not controlled through Mach3. I am just trying to get an RPM readout into Mach3, not to control spindle speed.
Hope this helps.
Mach3 is version R3.043.066
-
Are you using a parallel port, or an external motion controller?
-
My system is a parallel port from my computer to a Camtronics controller which is based on a Gecko board. The spindle sensor signal goes into the Camtronics unit.
http://camtronics-cnc.com/stepper-components.asp
-
- I can't speak / have not used Ver.066 but it is known to be problematic.
V 062 is in use here.
- For threading one would use the index, but if you have a VFD then you set the rpm manualy
but MAch will need to read the rpm based on the index input. It needs that input to know when to start the next threadng pass. Just thought to mention this.
- Are you using an otpical sensor along with a slotted disc? A cd rom painted black with a
slot work fine. Can just put black tape on it to adjust the slot width if so desired.
no harm on the slaot being wider than calculated.
- I use a small ( 1/8" diamater ) rare earth magnet along with my Hall sensor. Works like a charm!. Radio Shack used to carry them.
RICH
-
Where does the wire from the spindle sensor go to inside the Camtronics box. I would think that it would then go to an input pin of the PP cable connector.
RICH
-
FWIW,
You may want to consider adding a dual PP card to your computer as that will give you additional inputs. I use a Rosewell card ( 403? not sure on the card number....only a few bucks). You can then just independently wire the sensor and have the input go to the second port. Later on you may want an input for probing or whatever and you'll have them available.
RICH
-
Wire from spindle sensor goes to pin 13 on parallel port. In Pins & Ports, index is enabled, set to port 1, pin 13, active low X, emulated X
-
- Use spindle feedback in sync mode should be checked in Spindle setup
- Ok to also check spindle speed averaging
- make sure the index is enabled and uncheck emulated, may want to and try active low for the index for the input signal. Pin 10-13 and 15 are inputs to Mach thus 13 should be ok.
- Timing should not be enabled
- No Turn Diagnostics should be enabled in plug in control
- OH, BTW, need to turn on the spindle in lathe to have RPM show......
RICH
-
Rich: Thanks for the suggestions.
1. Yes, spindle feedback was checked.
2. Checked spindle speed averaging. This made no difference. Spindle speed readout was as erratic as before.
3. Ports & Pins, Index. Checked Active Low. This made no difference. Spindle speed readout was as erratic as before.
4. Plug in control. Nothing is checked but I did get a picture of myself.
5. Yes, I have M3 in my setup lines.
I am amazed that nothing changed, especially when putting on spindle speed averaging.
I take it from your suggestions that you feel this is a Mach3 issue and not a hardware issue?
Thanks.
-
I take it from your suggestions that you feel this is a Mach3 issue and not a hardware issue?
Not really, just need to be sure the configuration is correct for using the index and as said, don't know about V 066.
If you turn the spindle by hand does the index light come on, stay on, turn on and off as you slowly rotate the spindle?
RICH
-
Yes light on the sensor goes on as spindle rotates and seems to be regular and not fluctuate like the numbers in Mach3. I have tried changing every setting I can think of. None make any difference. Makes me wonder why there are so many settings when most of them seem to do nothing.
So now I will take a break from this most annoying problem. When I figure out how to do it I will try version .62
Thanks for your efforts.
-
I am amazed that nothing changed, especially when putting on spindle speed averaging.
Spindle speed average has to do with what is considered am average rpm during a thread pass and is used to refine the next pass, thus nothing as you thought.
Personally I think it's your sensor, and try 062 as suggested. If it was a slotted disc I would recommend you widen the slot.
My thoughts for they are worth,
RICH