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Author Topic: Entering Pulley Ratio in Mach4  (Read 2153 times)

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Entering Pulley Ratio in Mach4
« on: February 17, 2018, 03:25:38 PM »
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
Re: Entering Pulley Ratio in Mach4
« Reply #1 on: February 17, 2018, 03:42:47 PM »
Hi,
try a ratio of 0.5 instead. Only a guess.

Craig
My wife left with my best friend...
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Re: Entering Pulley Ratio in Mach4
« Reply #2 on: February 17, 2018, 03:51:14 PM »
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
Re: Entering Pulley Ratio in Mach4
« Reply #3 on: February 17, 2018, 04:21:14 PM »
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
My wife left with my best friend...
     and I miss him!
Re: Entering Pulley Ratio in Mach4
« Reply #4 on: February 17, 2018, 04:44:31 PM »
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.
Re: Entering Pulley Ratio in Mach4
« Reply #5 on: February 17, 2018, 04:59:32 PM »
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
My wife left with my best friend...
     and I miss him!
Re: Entering Pulley Ratio in Mach4
« Reply #6 on: February 17, 2018, 05:07:46 PM »
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.
Re: Entering Pulley Ratio in Mach4
« Reply #7 on: February 17, 2018, 05:36:35 PM »
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
My wife left with my best friend...
     and I miss him!

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Re: Entering Pulley Ratio in Mach4
« Reply #8 on: February 17, 2018, 07:55:48 PM »
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.
« Last Edit: February 17, 2018, 08:04:05 PM by Chaoticone »
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Offline Chaoticone

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Re: Entering Pulley Ratio in Mach4
« Reply #9 on: February 17, 2018, 08:11:24 PM »
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.
;D If you could see the things I have in my head, you would be laughing too. ;D

My guard dog is not what you need to worry about!