Mach3 RPM sensor?

[sparkness]

Schmitt trigger may be required and some index debounce in general config for mach. I will try to test that in parallel port and smooth stepper as that is what I use now. I am going to order a AS5047P dev board as that is a perfect fit for many motors

[CL_MotoTech]

I like the Vista CNC USB spindle tachometer. It's optical as many suggested before, and being USB it doesn't require a BOB input. It is perhaps a little pricey at $65, but was well worth it in my opinion because after I had a bracket to mount the sensor it took all of 1 minute for RPM to be displayed in Mach. Time is money.

Edit: the Vista CNC documentation as I recall claims the sensors will work up to something like 30k RPM, but it is confirmed working up to 6k RPM on my machine.

[sparkness]

Nice a simple turnkey solution. I have a pendant from them, works well, $65 is very fair price for for this

[CL_MotoTech]

The plugin is rather feature rich (for a tachometer) as well. All in all, it can't be beat IMO.

[ballistic42]

Wow Thanks for all the input as lots to think about. I have this magnetic sensor more so to just see if I can make it work. If it works, it should send the signal from the C3 board back to my c32 board and show up on the Mach3 screen. The magnet I just imbeded into my spindle pully, that thing is very small put it works. I have the sensor which takes 24vdc but the Circuit board only can handle 5vdc @ 24Ma. I am trying to figure out how to go from 24VDC @ 5amps(Power to the sensor) to 5vdc @ 24Ma (Power to the C3 board). I know its not a must but a want and just to say to myself I did it. Tyring new things is what is fun even more so when it works!

Thanks for the help!

Jeff

[jalessi]

Jeff,

There are several eBay sellers that have decent 5 volt 2 amp switching power supply's for less than $3.50 USD

Model S-10-5

See attached link:Switching Power Supply Adapter AC 110V-220V TO DC 5V 12V 24V 2A~20A LED Strip | eBay

Jeff...

[ballistic42]

Ok got the sensor wired to the 24vdc power supply for the feed. The sensor is PNP. The sensor is wired to the Pos. neg. to the 24 vdc power supply. The signal wire from the sensor goes to a C3 (CNC4PC) board. The C3 board has an RJ45 to carry the signal to a C52 (CNC4PC) board. The C52 board is connected to a ESS (Ethernet Smooth Stepper). The signal on the C52 board is going to Pin 15. Its set up right but it is not working. The magnetic sensor is powered but the signal is not reaching the C52 board. I think the C3 board is not allowing the signal to go through as it was really made for a Hall effect sensor. My solution is this product, a RJ45 breakout board to carry the signal directly to the C52 board. Listed below is the RJ45 BOB. This will replace the C3 board. I hope it works and if I can't make it work I will try something different!!!!

https://www.amazon.com/RJ-45-Screw-T...board+din+rail

[sparkness]

that will work, can you sacrifice an rj45 cable for testing? make sure resistor is in place when connecting to the c52 board

[ballistic42]

Well funny you should ask I did and for some reason its not getting the signal. I know the ports work. Looking togo directly into another board to check that M23 board that has input on it, I just have to look at the settings in mach to make sure I have a pin left.

[ballistic42]

OK AWESOME works GREAT I mean it is reading right on the money could not be better!!!! My hand held RPM tach and the sensor through Mach3 are reading exactly the same. To make it work I went straight into the C52 board with the signal on port 3 pin 15. I bypassed the C3 board. Now, the only issue I have is I tell the spindle to run at 500RPM but it really goes to 793RPM. I am using the tread mill motor through the KBMM 225D controller. All that is hooked up using my C32 board PWM. I did what I was told in the directions ran the spindle to the max rpm for my setup (4000RPM) and set the trim pot to give out 10VDC at max RPM. I did that still off on RPM's. In the ethernet smooth stepper config I have Base Hz set to 300, PWM box checked, pulse width set to 5.0, and last spindle index prescale set to 1.

Spindle motor tuning and setup are as follows.
steps per...........1000
Velocity.............1500
Acceleration.....250
step pulse......3
Dir Pulse......3

Ports and Pins Config Spindle Setup
Motor Control
Use Spindle Motor Output box........ CHECKED
PWM control....................................CHECKED
Step/Dir Motor................................UnChecked
PWMBase Freq............................301
Minimum PWM.............................5%

Can anyone give me some insight how to bring the RPM that I ask for, to match what is really what it is showing. When I ask for 500 it's going 790 so 290rpm Off.

Thanks for reading and helping. I have seen a lot of people asking about this, but I have not seen a solution.

[ballistic42]

Brain storming. I wonder if there is a way to go into the M3 code and have Mach3 look at the pin 3 port 15 and the selected RPM and make them match. May be a way to write a little VB script to make this work. Going to experiment and see what I come up with.

[sparkness]

search "closed loop spindle mach3" you will see why it will not work

[jalessi]

RPM = RPM * 0.8

RPM = RPM * 100 / 270
or
RPM = RPM * 0.37

[sparkness]

goto config/Spindle pulleys and adjust max speed above your actual for default pulley number 4. you should get close

[sparkness]

here is an explanation on how to adjust the linearity so actual speed will closely match what you set in mach
Canlnot synchronize spindle RPM in Mach3 to actual

[ballistic42]

Well from reading it appears there is no way to make it right on or even just 50 rpm off. PWM just wont do what I want. I have looked at the ESS (smooth stepper) docs. and nothing in there really addresses the issue. Sure if I was running a VFD would not be a problem, but I am running a KBMM 225D board through Mach3 PWM. Like I said I wonder if I can get Mach3 to look at the real RPM and from the new Tach sensor and feed the info. to mach3 to tell it that it is not on RPM and to adjust voltage accordingly.

[sparkness]

mach cannot read tach signal and then adjust the output. try adjusting the spindle pulley max speed it worked for me. My spindle is 24k so in pulley setting I have it set to 28k and this causes my actual speed to be close to what mach is set for. you can also make a voltage divider therefore adjusting the voltage going back into your speed control. editing the linearity.dat file works as well just takes a bit of time.

[sparkness]

1. run your spindle at full speed what is the actual speed?
2. this is the speed that config/Spindle pulleys should be set to. enter that value in config/Spindle pulleys and save
3. now tell mach to run at half of your actual speed . it is off by a a percentage value .
4 now set the max pulley speed * that percentage value . this should get them to match up

[ballistic42]

Ok tried that and everything else under the sun and nothing seems to make it match. The good news though my RPM tach show on the Mach3 screen exactly what it is turning. If I tell it to run at 1000rpm why does it not! I see the RPM's fluctuate at different speeds, at 1000rpm the spindle is really turning 1250 + or - 3 RPM.

[sparkness]

what is config/Spindle pulleys Pulley Number 4 set to?
what is the maximum speed of your spindle?