Hello Guest it is July 20, 2019, 04:08:19 AM

Author Topic: radius or diameter circle  (Read 3306 times)

0 Members and 1 Guest are viewing this topic.

Re: radius or diameter circle
« Reply #10 on: December 29, 2016, 09:21:57 AM »
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
Newbie needs some help! Stepper Motor Tuning and Setup.
« Reply #11 on: December 29, 2016, 09:33:49 AM »
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

Offline Davek0974

*
  •  2,556 2,556
    • View Profile
    • DD Metal Products Ltd
Re: radius or diameter circle
« Reply #12 on: December 29, 2016, 09:35:51 AM »
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.
Bridgeport Mill, Mach3 V062, CSMIO-IP/A controller, AC Servo Drives

Offline RICH

*
  • *
  •  7,342 7,342
    • View Profile
Re: radius or diameter circle
« Reply #13 on: December 29, 2016, 02:59:46 PM »
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
« Last Edit: December 29, 2016, 03:07:33 PM by RICH »
Re: radius or diameter circle
« Reply #14 on: December 31, 2016, 03:39:49 PM »
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
« Last Edit: December 31, 2016, 03:44:30 PM by usajet »

Offline RICH

*
  • *
  •  7,342 7,342
    • View Profile
Re: radius or diameter circle
« Reply #15 on: January 02, 2017, 06:55:47 AM »
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
Re: radius or diameter circle
« Reply #16 on: January 02, 2017, 06:36:28 PM »
Thank You very much RICH!! I will take a look.


Nathan
Re: radius or diameter circle
« Reply #17 on: January 04, 2017, 02:27:32 PM »
Well RICH that worked out very well. Thank You!!!



Nathan