Machsupport Forum
Mach Discussion => Mach4 General Discussion => Topic started by: j2mariashop on February 17, 2018, 03:25:38 PM
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I'm migrating from Mach 3 to Mach4 on my lathe and I want to enter the 2:1 pulley ratio I have on my spindle drive. Mach3 had a Configure Pulley Ratio screen where I could enter the ratio to fine tune the rpm. However, the only place I see in the Mach4 Lathe screen set where I can enter a ratio is under Spindle Range. When I enter 2 in the Ratio box it does not stay at 2.000; instead it reverts to the original 1.000. My feedback is correctly set to 1:00. When I issue M3 S1500, the spindle maxes out at around 850 rpm which I have confirmed with a tach. Any ideas?
Joe
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Hi,
try a ratio of 0.5 instead. Only a guess.
Craig
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Hi Craig
That didn't work either. Actually, entering any number in the ratio box in the wxLathe screen doesn't seem to take. It reverts to 1.00
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Hi,
it works with the mill profile.
Spindle ratios are saved/stored as part of your profile. When you change a parameter that new value will have to be written to the profile, the .ini file.
Then the profile has to be read in order for the new value to be recognized.
Try changing the ratio, hit <apply>, which should cause the value to be written to the .ini file. Then restart Mach, the restart will ensure that the updated .ini
file is read.
Not saying this is the problem but I've encountered this behavior before and until I understood how the .ini file is updated and when it is read I would have sworn
Mach was faulty.
Craig
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Hi Craig,
It looks like <apply> is not an option in this screen. It is an option on the Spindle configure screen but there it only allows you to change the Feedback ratio and not the pulley ratio. It's not an option also in my PMDX411 Config either.
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Hi,
it rather suggest that this screen is not the correct place to alter the ratio parameter, otherwise it would require some button/mechanism to flush the data
to the .ini file.
May I suggest trying the feedback ratio on the spindle screen. Can't hurt.
Craig
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I did that. What happens is that it multiplies the actual rpm x feedback ratio and reports that new rpm to Mach4. The actual rpm as measured by a tach doesn't change. I'm stumped. There seems to be no way to enter the pulley ratio without editing the .ini file.
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Hi,
broadly speaking that's what the feedback ratio does. I think the idea is that spindle will be close loop stabilized by the feedback and if the feedback ratio is chosen correctly
the actual spindle rpm can be chosen correctly as well.
I'm not familiar with a gear ratio in Mach4.
Craig
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There is no place to enter a ratio. Only the max RPM of motor and max RPM of spindle for different ranges in the spindle configuration dialog. Mach4 is smart enough to determine ration based on those 2 inputs.
So, if your motor has a max RPM of 4500 and Range 0 has a max RPM of 4500, then its 1:1.
If the motor has a max RPM of 4500 And Range 1 has a max RPM of 9000, then Range 1 is 2:1, etc.
It might pay you to temporarily forget some of what you know about 3 and study up on how 4 works. I only say this because they are different. 4 is better IMO but lots of things are different but usually in a better kind of way. If your moving to 4 and assuming you know how to do things because you know how to do them in 3 you will likely pull some hairs out. Maybe all of them.
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Feedback ratio is for confirmation. Maybe you have an encoder for this with 1200 pulses per rev. Well, Mach can't determine the feedback ratio because it doesn't know what the feedback is reading, drive or driven or how many times it reads per rev., etc. ...... so you have to tell it.
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Okay. Good to know I don't need to enter the pulley ratio. I did follow the Mach4 manual but the confusion arises when something doesn't work and your trying to figure out why and you revert to see how you did it in Mach 4.
I still haven't got a variable speed from my Spindle. It just turns at one rpm no matter what S# I issue.
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I did follow the Mach4 manual but the confusion arises when something doesn't work and your trying to figure out why and you revert to see how you did it in Mach 4.
I think you meant "how you did it in Mach3" didn't you?
But yes, looking at how Mach3 did something to try to figure out how Mach4 does something often only leads to more confusion. Working with Mach4 is much easier when not comparing it to Mach3. They are different so they work different and do things differently. And the same would be true if using any other controller. Your time is far better spent learning how your hardware works. Once you understand how the hardware works setting up any controller is much easier.
What hardware are you using to vary the speed of the spindle?
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Yes, it's probably not a good idea to revert back to Mach3 once you've committed to Mach4.
I'm using a NOWFOREVER 100ES VFD, a Gecko540 and a PMDX411 SmartBob running on a 2012 Shopmaster Patriot.
Joe
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Have you ever been able to change the spindle speed by changing the S rate in Mach (3 or 4)?
If so how is Mach communicating with the VFD so it can control the speed?
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Yes, both under Mach 3 and under manual control I've been able to change Spindle speed with various S commands. I confirmed that a S value issued matched the rpm shown by a handheld tach under both Mach3 and manual control of the VFD (NOWFOREVER ES100). It's just in Mach4 that the Spindle runs at a constant 850 rpm.
My index is on Pin 10 any my Gecko 540 assigns the Spindle to Pin 14.
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Have you configured the modbus plugin in Mach4 to communicate with your VFD?
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Eh?
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Sorry, meant to type no Modbus ports on my PC
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Hi Joe,
how did you control the VFD when using Mach3?
To my knowledge there is two possible ways
1) An analogue (0-10V) voltage OR
2) Modbus (a serial communication protocol)
Craig
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Seems they got it fixed. Sounds like they were using the analog out from the G540 to the VFD to control the spindle speed.
His PMDX-411's spindle speed signal was configured for Pulse Frequency mode
whereas the G540 requires PWM mode.
http://www.machsupport.com/forum/index.php/topic,36605.msg251426.html#msg251426