Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: usajet on December 27, 2016, 03:09:09 PM
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Radius or diameter for a panel connector? Thank You Nathan
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Radius or diameter for a panel connector? Thank You Nathan
I think you need to give us a few more details.
Tweakie.
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I need to make a hole that will fit a 18 mm diameter round panel connector. I tried to mill it and it was twice it was supposed to be. I set it up for 18mm but it was more like double the size.
Thank you Nathan
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The Gcode created by the Cut Circle wizard works just fine. Have you checked that your Steps Per Unit are set correctly ?
Tweakie.
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No. How do I do that?
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If twice the size, are you sure your units were correct - inch / mm ?
Or were you entering the diameter when it needed the radius?
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Yes I am using mm and I did use Diameter. So Radius is what I needed to use? Can you give me an example of when I should be using the diameter?
Thank You Nathan
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No. How do I do that?
Section 5 of the Mach3 manual explains it better than I can; http://www.machsupport.com/help-learning/product-manuals/
Tweakie.
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Follow Twekies advice, he knows far more than i ever will ;)
You have said you were cutting a hole and it came out twice as big - you have not said how you coded the path - manually, CAM, wizard???
No help can be given in such vague circumstances.
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Can you give me an example of when I should be using the diameter?
The Cut Circle Wizard specifically asks for the circle and tool diameter, but as Dave replied, we don't know what or how you are generating the gcode for your work. Your machine must be configured correctly and one of the steps is Motor Tuning and Setup.
CNC is not plug and play and one MUST learn some things before using their machine. So I highly recommend you have a read of the Mach manual and also watch the videos.
RICH
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I am using Cut2d for my Gcode. I setup the tool diameter with the circle size. My issue is motor tuning and setup. I need high torque for the stepper motors because I am cutting aluminum and I have a vise that is heavy. If I tune it for faster speeds I can't even move the x and y axis with the vise on it.
Thanks Nathan
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I need some help with my tuning of stepper motors. I have the excel file I seen on here to do the calculations but not very clear on what I need to put into Mach 3.
Here is the link of what I have as a kit, http://www.omc-stepperonline.com/3-axis-31nm439-ozin-nema-24-stepper-motor-m542t-driverr-kit-for-cnc-router-p-305.html
I also have 2 SFU1605 Ball Screw and 1 SFU1204 Ball Screw.
I need high torque for the stepper motors because I am cutting aluminum and I have a vise that is heavy. If I tune it for faster speeds I can't even move the x and y axis with the vise on it.
I need some help with the calculations. Should I run half current or full current? I am at a loss.
Thank You Nathan
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If you cannot move at faster speeds with the vise mounted etc then you have exceeded your machine's capability it seems.
The only option would then be to fit bigger motors, drives, power supply and so on.
The best thing to do is to tune your setup by increasing speed until it skips steps/loses position, then decrease speed by 30% and increase acceleration until it fails again then drop 30% - this should be close to your machine limits based on motor power/ weight/ drive system etc. Tune with the vise loaded of course.
It may be possible to tune in such a way that you can do the job needed but at a lower pace than wanted or required by tool specs etc.
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The motors are rated at 439 ozin at 3.5 amps. Power supply is 36V & 9.7amps.
The drives are good for 24-50V 1.5-4.5A.
So to get the most overall preformance I would suggest you set the drives for say 2.8 amps. Can't get more than 36 volts out of the power supply but you will need 8.4 amps total from the power supply if all three motors are being used and that is under the max rating.
Set your drives for 0.1126 step angle / 3200 pulses per rev as that would be
micro stepping at 8X and FWIW over 10x is a waste of time and you have no setting for 10x)
There is no motor curve so the max torque based on the above suggestion will be below 439 oz in. Just tune as replied by Dave and see what you can get.
I'll guess axis travel will be around 40 to 60 IPM.
You will be leaving some headroom for cutting forces when you reduce the max velocity found.
It's not how fast you can go but rather the system power, accuracy, and reliability when machining that counts. That said, set feed rates in CAM appropiately for
your "system" and would suggest you experiment some to gain some experience.
Now as far as the motor tuning.......
Haven't the foggiest idea of the specs for those ball screws,if any gear reduction is used, the size of anything you will be moving with your setup.
That's why you need to RTFM. Look at the index and you will see what pages to read. Also you will find in the manual how to have MACH set the
steps/ per unit so you don't need to even calculate. Once you read that you will know how to use the spread sheet in members doc's.
RICH
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Thank You Rich. I am doing everything in MM's. Also I just bought a 48v power supply to run with the drivers. I have 2 SFU1605 Ball Screws. The x axis at 600mm and the y axis at 350mm and 1 400mm SFU1204 Ball Screw for the z axis. Of coarse that is the size of the ball screws but the travel is smaller.
x axis
http://www.banggood.com/600mm-SFU1605-Ball-Screw-with-Ballnut-for-CNC-p-1016639.html?rmmds=search
y axis (Which was turned downed to 350mm).
http://www.banggood.com/400mm-SFU1605-Ball-Screw-with-BK12-BF12-Supports-and-6_35x10mm-Coupler-for-CNC-p-1054582.html?rmmds=search
z axis
http://www.ebay.com/itm/Zyltech-Antibacklash-Ball-Screw-12mm-1204-w-Ballnut-BF-BK10-End-Support-L-400-/322144605017?hash=item4b01509359:g:xhAAAOSwvg9XWhSm
Thank You Nathan
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Look up the lead for the ball screws you purchased and do the math.
SEE:
Using Mach3 Mill Manual
See section 5.5 .1 Calculating the steps per unit.
OR:
In Members doc's you will find the "topic Steps per unit math example".
here is the link:
http://www.machsupport.com/forum/index.php/topic,12512.msg81001.html#msg81001
RICH
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Thank You very much RICH!! I will take a look.
Nathan
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Well RICH that worked out very well. Thank You!!!
Nathan