Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: Robhi on February 25, 2009, 04:07:45 PM
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Hi ,
I am building my machine CNC, for milling, specially for wood. I would like to add another axes for turning the workpiece.
when I red the manual for configuring the Mach3 turn, I found that I need something called a Spindle that i ignore what it is.
This is spindle must be controlled by mach3 , etc..
question is, Should I have to buy a spindle? or a simple motor can do what spindle does? or could I use a stepper motor to replace the spindle which would be controlled by mach3? its speed, step an direction etc..?
thanks in advance, hoping that I am clear.. hope so.
Robhi
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Afraid I am not clear what you are meaning, if it is a mill you have and you are just wanting to rotate the work slowly so that you can mill as the work revolves then you are wanting a 4th axis, you will need a servo or stepper motor to rotate it and you will set it up as the A axis.
Hood
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Hello every body
Thanks Hood and of you, :)
Exactly as you mentioned, it is a mill, but I would like to rotate the work .
But this kind of machine will do the same work as a machine for turning (lathe)?
In other words, could I use the same G code in both mach3Mill and Mach3turn?
Hoping am a little bit more clear than before.. :)
Robhi
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No, the programs don't interchange because the of axis change between the two. Z axis on a vertical mill (what you are configuring) is vertical and it is horizontal on the lathe. You would rotate a part in either X (the most usual) or Y and call it 'A' on a mill. (of course you can call it anything you like but the post processor would need to be configured to make that designation). Yes you can do lathe work on a mill but the program must be processed for the mill and rotate the part in A - as Hood explained.
Bill C.
More...working as you wish to on the milling machine is configured two ways: The Post processor will rotate the part in X or Y axis (A) and feed in Z into the part. So the program is either Y,Z and A or X, Z and A. The other axis is not needed in a basic rotating part - X or Y as stated.
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Hi, thanks BClemens :),
I will take all what you and Hood said in consideration. I will try to do so and of course let you know. ;)
Thanks a lot
Robhi
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Again, you can configure your machine any way that you wish, but a nonstandard set-up is very unfriendly to standard programming. If you do all your own programming you will do OK but when you wish to transpose a program to run on a non standard machine, you'll see the good reason for a standard set-up. (a man named Ray L. explained that well on this forum the other day)
Bill C.
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Hello,
As I understood, when someone likes to build his own machine lathe, he need one stepper motor for the X axis, another for
the Z axis. The other motor, or stepper motor (the rotary one) is called Spindle to rotate the work. could I use a stepper motor for this (Spindle) or could I use a 3 phased motor with a converter? I have already one that I control its speed. in the mean time, I would like that Mach3 control its speed, specially its step and direction..is it possible or am writing, thinking nonsense..
thanks a lot
Robhi
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If you want to control the Step/Dir as a precise axis then you will need either a servo or a stepper.
Hood
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Hello,
Thank you Hood and all of you,
So all what I need (for the spindle) is one stepper motor and one G201 for example? and of course a head for connecting all together....LOL That's all what i need? am I right? or Need I something else?
Thanks
Robhi
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Yep thats it, as long as a stepper will provide the speed and torque you require. Problem with steppers is the torque falls off quickly at higher speeds, a better option would be a servo but its more expensive so if you dont need to constant torque and speed of a servo the stepper may be the best bet.
Hood
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Hello,
I have a machine lathe, with two axes, X one and Z one.
Spindle is à stepper motor that works with step and direction. It works well for turning, about 470 RPM. wood turning.
Could use my spindle (stepper motor) for engraving on wood?
Thanks Robhi
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Hello,
Thank you Hood and all of you,
So all what I need (for the spindle) is one stepper motor and one G201 for example? and of course a head for connecting all together....LOL That's all what i need? am I right? or Need I something else?
Thanks
Robhi
A stepper motor would be about my *last* choice to drive a spindle. It won't be very smooth, it won't go very fast, and even a momentary overload will cause it to stop dead in its tracks. If you try to run within the resonance range, you'll find greatly reduced usable torque. A regular DC motor or servo would be a FAR better choice.
Regards,
Ray L.
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Hello, thanks so much,
I guess you and Hood are right , but how to configure it to to run normally, slow, fast, and change the direction etc.. and if I can engrave ( write) on à piece of wood ? lathe.
Hoping am clear
Best regards
Robhi
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Hello, thanks so much,
I guess you and Hood are right , but how to configure it to to run normally, slow, fast, and change the direction etc.. and if I can engrave ( write) on à piece of wood ? lathe.
Hoping am clear
Best regards
Robhi
You can pickup a nice DC motor and speed controller from surpluscenter.com for next to nothing. Treadmill motors and controllers are quite commonly used for spindles. Pickup a DigiSpeed from www.homanndesigns.com to interface the speed control to Mach, and you're in business. Or, get a small 3-Phase motor and VFD. That's the best solution, but more expensive.
Regards,
Ray L.
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Seems to me if you want to 'write' on a piece of wood that is held by your spindle, you are going to need a few extra goodies.
For starters, what exactly is going to be the 'pen' that you write with? Do you have a high speed spindle rigged up to your cross slide or something like that?
You are going to need to control the direction and azimuth (radial position) of the workpiece in order to 'write' on it, so a motor and speed controller is not going to be adequate at all.
If you want to use the same spindle for turning and 'writing' you are going to need a servo motor with a timing belt drive on the spindle . . . -or- . . a 4th axis on your mill table.
Look here for some ideas:
http://www.machsupport.com/forum/index.php/topic,11422.0.html (http://www.machsupport.com/forum/index.php/topic,11422.0.html)
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Hello,
thanks for replying,
I guess that all what I need. it is the forth axis that rotate the workpiece, (only for wood). I do not want the spindle any more LOL. So, could I use a stepper motor in order to rotate the workpiece as the one that I see in this video? http://www.youtube.com/watch?v=2KNit__LJE4
hoping it is possible.
Best regards
Robhi
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Dang, I think I recognize that video!
The indexer in that video is driven with a servo, but initially it had a NEMA34 stepper of 640oz-in which was adequate for holding the workpiece with a 3.6 to 1 reduction.
Yes, if you only need to rotate the workpiece for the purpose of engraving, then a stepper would be fine. I would suggest a microsteeping drive and gear it down a lot via a wide timing belt with an idler or other method for tensioning the belt, which has to be very tight.
Keep in mind that in this situation, the belt stiffness and the motor holding power alone is going to provide the rigidity.
What is it you are making?
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Hi,
Thanks again.
I would like to turn wood, as well as engraving. I love wood too much. I would like to do so.
How could I know that my forth axes works well?
trying to read your answer next week.
best regards..
Robhi
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I am not a woodworker but I think it would need high speeds when turning, if so then servo is the only way to go if you are also needing indexing.
Hood
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Hello, thank you Hood,
even if I use a (spindle ) to cut (mill) the workpiece?
thanks
Robhi
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Might be OK, as said not a wood worker so cant say for sure, only thoughts are if moving too slow on the rotation you may burn the wood.
Hood
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Robhi,
Can't speak for the others, but I am confused about exactly what your configuration is, especially what 'spindle' you refer to from one post to the next.
My impression is that you have one high speed spindle which will be the 'pen' and do the actual engraving and the second spindle is holding the workpiece and does not need to do anything other than slowly rotate the workpiece in the manner of an 'A' axis for a mill.
If the above description fits your machine, then the remaining question is how fast you need to turn the 'A' axis. If you need to go fast for wood TURNING, you need a servo. If you only need to go slow for wood ENGRAVING then a stepper would be adequate.
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Hello,
thanks again for all you.
that is really what I need.
I have my forth axis. it (i guess) works well. at any rate it turns as the other axes. I have no Programme (GCode) to test it.
But I guess it must work. question is:-
how could I configure it , in order to work in degree? I mean, if I would like to turn my workpiece into 90° or 45° , or the cam will do it itself?
Hoping I am a little bit clear.
Robhi
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Hello,
I can not convert the step per revolution into degrees.. how could I do that?
My motor is coupled directly to the chuck..I have a normal stepper motor, as well as G201.
Forth axis works well, but it turns three or four times, more than 360°.....
thank you for your help
Robhi
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2000/360 will give you the step per degree.
Hood