Hello Guest it is May 06, 2021, 05:30:46 PM

Author Topic: Concept Validation: Dual Belt Spindle Setup  (Read 405 times)

0 Members and 1 Guest are viewing this topic.

Concept Validation: Dual Belt Spindle Setup
« on: February 09, 2021, 09:29:20 PM »
Hello all, I'm seeking some advice from the mach 4 gurus who know more than me in the software department.
I'm a mechanical engineer who is eager to learn more about the ins and outs of Mach 4 LUA, etc, but, my current knowledge is quite limited. I have a concept for a dual belt spindle setup that I know is mechanically feasible, and I'm willing to learn how to implement it into Mach 4 through trial/error and research once the time comes, however, I'd like to confirm that it is do-able before investing the time and effort.

I have a 2.2kW BLDC motor controlled via 0-10V analog through a VFD with a pokeys57cnc board. I'd like to build a dual belt setup for 2 speed ranges (approx. 0-4000rpm and 4000-10,000rpm). Each belt would be separately engaged by its own pneumatic air cylinder. For example, when commanded M3 S2000, air cylinder one would be engaged and thus belt number one is engaged; when commanded M3 S8000, air cylinder two would be engaged. This type of dual belt system can be seen on older Fadal machines.

My plan is to alter the M3/M4 scripts to read the commanded/desired spindle speed and output a signal to the appropriate solenoid in order to engage the belt. I know you can set up multiple speed ranges within Mach 4 but never done so. How well does mach deal with separate speed ranges, and how does my bob know what voltage to send to the VFD? As a very crude example, sending 5V to the VFD would achieve 2000rpm or 7000rpm depending on which belt I have engaged. I'm assuming mach just knows that when S8000 is commanded it is in the 2nd speed range?

I guess my overarching question to the mach veterans out there is: do you see any catastrophic problems with my plan that may arise? Any input is greatly appreciated!

--
Adam.
Re: Concept Validation: Dual Belt Spindle Setup
« Reply #1 on: February 10, 2021, 07:01:18 AM »
I can show you how to do this with the PMC and you tweak it :)
Fixing problems one post at a time ;)

www.newfangledsolutions.com
www.machsupport.com
Re: Concept Validation: Dual Belt Spindle Setup
« Reply #2 on: February 10, 2021, 10:51:24 AM »
Thanks for the reply Brian, that would be very helpful!
I never thought about using PMC to achieve this but seems like the easiest way to go about it. Using PMC would mean I don't have to rely on executing M3/M4 commands in order to engage the appropriate belt. The PMC script would continuously run and change output signal to the appropriate air solenoid based on the spindle speed - am I correct? Time to start reading up on the PMC editor...
Re: Concept Validation: Dual Belt Spindle Setup
« Reply #3 on: February 10, 2021, 11:46:59 AM »
You are correct sir! it's like magic ;)
Fixing problems one post at a time ;)

www.newfangledsolutions.com
www.machsupport.com
Re: Concept Validation: Dual Belt Spindle Setup
« Reply #4 on: February 11, 2021, 02:29:33 AM »
Brian i give up ,you so press so i want learn on PMC
is there manual pdf ?
only one question ,until now i use only M function and i have many many that do many thing,is there problem of Mfunction that can conflict with
PMC ? and in that case how system will do?
Re: Concept Validation: Dual Belt Spindle Setup
« Reply #5 on: February 11, 2021, 04:00:11 AM »
It just so happens we do have a manual for the PMC. Have a look in the docs directory.
Fixing problems one post at a time ;)

www.newfangledsolutions.com
www.machsupport.com
Re: Concept Validation: Dual Belt Spindle Setup
« Reply #6 on: February 16, 2021, 06:15:25 PM »
So I've been playing around with m3/m4 scripts as well as PMC.

I think a PMC script for actuating the individual belt drives is easiest and should be done based on the active spindle range. ex: if spindle range 1 is active, coil for pneumatic cylinder 1 is active and vice versa.

I'm having difficulties with m3 and m4 scripts to read the commanded spindle rpm and then set the appropriate spindle range. The issue arises when a spindle range is already active (for example range 1 which is 0-3000rpm) and a higher rpm is commanded. Because range 1 is already active and has a max rpm of 3000, any commanded spindle rpm that is above 3000 rpm automatically defaults to the ranges' maximum rpm. I've tried setting up a "dummy" range (spindle range 0 which is 0-8000rpm) and having the m3 and m4 scripts reset the range to 0 before the remainder of the script runs but there has to be a better way to do this. Is there a better way to read commanded rpm? Currently I'm using mcSpindleGetCommandRPM
Re: Concept Validation: Dual Belt Spindle Setup
« Reply #7 on: February 17, 2021, 11:37:20 AM »
So we need to make an auto shifter .... Well, I need to think about that.

We can do it a few ways. In the mori we have here we shift with M41 and M42 with neutral  being M40. Now we can make it so it would allow you to shift on the fly . The other way would be to make it all one spindle range with some code in the background to change how we calculate  the RPM / analog out. You tell me and we will make it happen :) I like this project!

Fixing problems one post at a time ;)

www.newfangledsolutions.com
www.machsupport.com
Re: Concept Validation: Dual Belt Spindle Setup
« Reply #8 on: February 17, 2021, 12:29:47 PM »
Yup, auto shifter is exactly what I was thinking and is the route I want to take. I don't really want to change how RPM/analog out is calculated.

My low gear is 0-2999 rpm and high gear is 3000-8000 rpm. Like you explained on the mori, I tried incorporating a neutral gear (spindle range 0). Range 0 was set at the beginning of each m3/m4/m5 function. Then, for m3/m4, the commanded rpm was read and the appropriate spindle range was then set again based on commanded RPM (low gear spindle range 1, high gear spindle range 2). I couldn't get mach to like this approach...

The PMC script that activates the appropriate air cylinder based on current spindle range works great though :)
Re: Concept Validation: Dual Belt Spindle Setup
« Reply #9 on: February 17, 2021, 01:53:37 PM »
If you want to do an auto shifter we will simply make it so the shifting is done in the PMC... When we get to some RPM we will swap the shifter. we will need to tweak the analog out but that is not a big deal. I am the one that made all the calculations in the core for it so I have an idea how it is done ;) .

Fixing problems one post at a time ;)

www.newfangledsolutions.com
www.machsupport.com