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Author Topic: Help spindle speed  (Read 4283 times)

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Re: Help spindle speed
« Reply #10 on: August 30, 2022, 08:57:36 AM »
Ok, I already made some of the changes you recommended, but I have doubts about the frequency of kernel speed and on PWMBase freq. I also have doubts with my motor as I have 6 threads, 2 are from the power supply, 2 are from the encoder supply and 2 are encoder outputs, one of these outputs is connected as a index signal, but the second signal to where I connect it , I ask why a signal is to record the rpm, but how to count the fractions back to be able to make a string. Annex the pdf with the changes and the engine.

Will this encoder work for a 120V AC motor?
Re: Help spindle speed
« Reply #11 on: August 30, 2022, 03:55:12 PM »
Hi,
what encoder? You have provided no technical details.....the two outpts you mention are probably A & B outputs, not an index signal at all.

Craig
'I enjoy sex at 73.....I live at 71 so its not too far to walk.'
Re: Help spindle speed
« Reply #12 on: August 30, 2022, 03:59:45 PM »
Sorry, this one.
the one pictured at the beginning of topic.
« Last Edit: August 30, 2022, 04:01:58 PM by byteman59 »
Re: Help spindle speed
« Reply #13 on: August 30, 2022, 04:48:58 PM »
Hi,
none of what is pictured is an encoder???
All that you have pictured is an adjustable power supply for a DC motor. There is no encoder or any other means for Mach to measure the speed.

Craig
'I enjoy sex at 73.....I live at 71 so its not too far to walk.'
Re: Help spindle speed
« Reply #14 on: August 30, 2022, 04:52:42 PM »
I think i found what i was looking for.

https://www.cnc4pc.com/c47-a-c-speed-controller-relay-board.html
along with this.

https://www.aliexpress.com/item/2251832705665188.html?spm=a2g0o.best.old-user.4.23a12c25PufyFW&scm=1007.28303.271905.0&scm_id=1007.28303.271905.0&scm-url=1007.28303.271905.0&pvid=21628fda-b3ac-45ce-af10-81280c410ff7

I have a MF70 which i am upgrading. I wanted to have speed control. Do you have any concerns about what i have selected to accomplish it?
Re: Help spindle speed
« Reply #15 on: August 30, 2022, 05:02:47 PM »
Hi,
that is just another speed controller board....its not an encoder. Mach will have no idea how fast the spindle is going unless you have an
encoder or an index pulse.

A speed controller board will drive the spindle just fine but if Mach sends out a 50% duty cycle PWM you'd expect and want the spindle to do 50%
speed, and it may be close, but likely not better than 10%. Once the spindle comes under load it will slow down, and Mach has no way to know that
nor have any means to correct it.

Craig
'I enjoy sex at 73.....I live at 71 so its not too far to walk.'
Re: Help spindle speed
« Reply #16 on: August 30, 2022, 05:16:36 PM »
Good point. Is there a way to monitor spindle speed?

I have built a laser and now working on a CNC. Just started the journey.
Here is my laser. Also been working on a A10 SimPit, have completed several panels.

Thanks for the input.


Re: Help spindle speed
« Reply #17 on: August 30, 2022, 05:21:41 PM »
Hi,
Quote
Good point. Is there a way to monitor spindle speed?

Yes there is, but it requires an encoder or an index pulse fitted to the spindle. Mach can count the pulses and can calculate how fast the spindle is going.
Depending on your controller mach may be able to adjust the PWM duty cycle to compensate for the load induced slowing for example.

Craig
'I enjoy sex at 73.....I live at 71 so its not too far to walk.'
Re: Help spindle speed
« Reply #18 on: August 30, 2022, 05:25:00 PM »
I'm pretty sure i know what you are refering to.

Thanks!