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Correct Mach 3 motor tuning settings (1 viewing) (1) Guest
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TOPIC: Correct Mach 3 motor tuning settings
#367
David Da Costa (Registered)
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Correct Mach 3 motor tuning settings 5 Years, 4 Months ago  
The Mach3 motor tuning settings are wrong on my KX1.

Mach 3 is set to inches, but the movement shown on the DRO is way to large for the actual movement of the table.

Could you please tell me what the correct settings are for the Mach 3 motor tuning are.

Thanks

David
 
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#368
John Stevenson (Admin)
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Re:Correct Mach 3 motor tuning settings 5 Years, 4 Months ago  
Have you run the setup files from off the CD ?

It will install Mach in metric mode as all the screws etc are all metric.

This makes no difference to uses who want to work in inches as the G20 code at the start of a program will tell it to use imperial.

For anyone want to work in all imperial by default go into config > general config and in the initialisation line type in G20 and change the F125.0 to 6.0

This makes Mach start up in imperial mode with a feed of 6" per minute for jogging etc.

Any feed rates in a program will over ride these startup setting but the default settings, G20 F6.0 etc will be there next time by default.

John S.
 
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#369
Adam Stevenson (Admin)
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Re:Correct Mach 3 motor tuning settings 5 Years, 4 Months ago  
you need to set the F to a metric rate as the machine will use metric when setting the feed rate before applying the G20 command so for 6IPM you would need to put F152.4 and not F6.0
 
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#370
David Da Costa (Registered)
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Re:Correct Mach 3 motor tuning settings 5 Years, 4 Months ago  
Hi John,

Yes I loaded Mach3 and the kx1.xml file that came with the mill.

In the "set default Units" menu option it is set to inches.

But under "motor tuning" I have 500 steps per, 1999.8 velocity and 300 acceleration for x and y and velocity 1000.2 for Z.

I changed the default units to mm and entered the initialisation line you suggested and now if I enter a 1" move it moves 1" - Thanks

One further question are the velocity and acceleration for the axis the maximum for the KX1?



Thanks

David
 
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#371
Adam Stevenson (Admin)
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Re:Correct Mach 3 motor tuning settings 5 Years, 4 Months ago  
QUOTE:
One further question are the velocity and acceleration for the axis the maximum for the KX1?


They are set at a value that will work with most computers, some computers can handle the faster pulses need to run faster but the motors on the machines are very close to the maximum that they would be able to do.
Remember just cus it can jog fine doesn't mean that it will not stall a motor under cutting load. You can change these values and see if your computer and machine can handle it but for the sake of standardising the install we went with the slightly slower but more reliable settings.
 
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#845
Ron Ginger (Trader)
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Re:Correct Mach 3 motor tuning settings 4 Years, 1 Month ago  
I just set up my new machine. I choose to setup in inches. The calculated value for steps per inch is 12700. However when I check with an indicator that does not move correctly, I have to set it to 12744 to get accurate inch moves.

Any idea why? The spec says the screw is 4mm pitch, I use 25.4 mm/inch
 
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#847
Pete (Owner)
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Re:Correct Mach 3 motor tuning settings 4 Years, 1 Month ago  
Ron -

I did the same thing and found that I needed to go a bit longer like that. I have been getting good repeatable results so I know that it works. i compared it to an indicator. You might want to machine a square and see just how small/large it comes out.

More comments on the Mach3 Forum under Seig Machines.

Pete
 
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#850
Adam Stevenson (Admin)
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Re:Correct Mach 3 motor tuning settings 4 Years, 1 Month ago  
Ron Ginger wrote:
QUOTE:
I just set up my new machine. I choose to setup in inches. The calculated value for steps per inch is 12700. However when I check with an indicator that does not move correctly, I have to set it to 12744 to get accurate inch moves.


The machines are metric. Native units should be metric.
Mach3 don't care what your machine is set too when running a program. Type G21 or G20 in the MDI box and it will change the units displayed.
If you want your machine to always be in metric or imperial mode then add the G21 (metric) or G20 (imp) to the init string in the general config. It will switch to the correct mode after you press the reset button but as you can't move till you do that anyway that's a minor issue.
I spent about a week playing with the settings when we made the setup file for US machines and in the end we was told by Art Fenerty that you setup in the native units of the machine not the user as that's what the G20 and G21 are for. The error is due to rounding in the mach3 software and is more apparent in large step per unit values.
 
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#852
Ron Ginger (Trader)
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Re:Correct Mach 3 motor tuning settings 4 Years, 1 Month ago  
The machine may have been designed in metric units, but a 4mm screw can just as well be described as a 0.16" pitch screw.

The machine units in Mach should be set to the users native units, not some design unit.

Just as a test I setup my machine as metric and carefully measured the movement. It requires 502 steps per mm to get accurate movements. So the real problem is a pitch error in the lead screw, it is not accurately 4mm, or 0.16" but very slightly less. It may well be iwithin design tolerance.

So the bottom line answer is one must measure his machine movements carefully and set the steps per unit as measured, not to some calculated value.
 
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#853
John Stevenson (Admin)
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Re:Correct Mach 3 motor tuning settings 4 Years, 1 Month ago  
Ron,
We have been thru all this before, all we can do is advise.
We have outlined why and how the errors occur, check with Art if you don't believe us and we have laid out how to get by this by letting the software sort it out using G21 / G20.

If you go out and buy a brand new Hass machining centre how do you know if it's been setup for inches or metric? you don't and there is no way you can change it anyway as it's proprietary.

Perhaps it's the difference between paying $3,000 for something you can alter and $45,000 for something you can't ?

We have many English uses with metric setups using Imperial with no problem.
We have many American users with metric setups using Imperial with no problem.

At the end of the day a CNC uses units as measurement and it's the G21 G20 codes that define what these units are.

John S.
 
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