Using Sherline Mill as CNC with Head Turned 90 Deg
27 Jan 2015 03:31 #55362
by johnl2
Using Sherline Mill as CNC with Head Turned 90 Deg was created by johnl2
Hello, I was recently posting in a Moschip thread I started but need help on a new topic. Thanks to all who helped me with the Moschip, I am very grateful for all of your input.
Now I am trying to Mill using CNC with the head turned 90 degrees due to not enough movement on the z. Keep in mind that on the Sherline Mill, (not sure about all others), the x and y axis move independently of the z axis. What this means is that only the z axis moves true positive and negative, where x and y move negative but it is actually positive and vise versa. This is known as the "Cartesian Coordinate System". Now if anybody has any ideas on how to turn that head 90 degrees and still use my CAM software and have the program go in all the right directions, please let me know.
What I have tried so far, (which I kinda knew it wouldn't work), is change the driver box wires on the x and z axis. I switched them. But of course fake x and fake z went in the wrong direction due to the "Cartesian" on x and y. I also had a thought. I was thinking maybe tricking the CAM software and telling it I am starting on the far left when I'm really starting on close left. And doing the same for the other axis. I have not tried it yet, but I'd like something more concrete, like changing the parallel port pins or something to that nature.
Thanks in advance,
John
Now I am trying to Mill using CNC with the head turned 90 degrees due to not enough movement on the z. Keep in mind that on the Sherline Mill, (not sure about all others), the x and y axis move independently of the z axis. What this means is that only the z axis moves true positive and negative, where x and y move negative but it is actually positive and vise versa. This is known as the "Cartesian Coordinate System". Now if anybody has any ideas on how to turn that head 90 degrees and still use my CAM software and have the program go in all the right directions, please let me know.
What I have tried so far, (which I kinda knew it wouldn't work), is change the driver box wires on the x and z axis. I switched them. But of course fake x and fake z went in the wrong direction due to the "Cartesian" on x and y. I also had a thought. I was thinking maybe tricking the CAM software and telling it I am starting on the far left when I'm really starting on close left. And doing the same for the other axis. I have not tried it yet, but I'd like something more concrete, like changing the parallel port pins or something to that nature.
Thanks in advance,
John
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27 Jan 2015 03:56 #55363
by alan_3301
Replied by alan_3301 on topic Using Sherline Mill as CNC with Head Turned 90 Deg
The best way would be to change the coordinate system in the cam program, so that you don't have to mess with anything.
If that isn't an option,you could swap x and z wiring.
If that isn't an option,you could swap x and z wiring.
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27 Jan 2015 03:57 #55364
by alan_3301
Replied by alan_3301 on topic Using Sherline Mill as CNC with Head Turned 90 Deg
If it moves in the wrong direction, could you not just rotate the head the other direction?
or swap the direction of both axes?
or swap the direction of both axes?
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27 Jan 2015 04:22 #55366
by andypugh
Replied by andypugh on topic Using Sherline Mill as CNC with Head Turned 90 Deg
Changing the wiring is slightly dangerous, as it risks damaging the drives as they do not like having the motors disconnect when powered up. If the connections are good it is better not to disturb them.
You can make a copy of the configuration and then edit the HAL file so that the "X-motor" responds to axis.2.motor-position-cmd and the "Z-motor" responds to axis.0.motor-position-cmd. (Or you could swap at the parallel port pin connection point in the HAL).
The INI file will need to also be changed to swap the axis limits around and possible also the velocity and accel.
As you have spotted, a simple swap does not give you a "left hand" coordinate system, as you also need to change the direction of the new X and Z axes. You can either do this by changing the stepgen scale to be negative, or just set the direction pins to "inverted" in the HAL file.
You can make a copy of the configuration and then edit the HAL file so that the "X-motor" responds to axis.2.motor-position-cmd and the "Z-motor" responds to axis.0.motor-position-cmd. (Or you could swap at the parallel port pin connection point in the HAL).
The INI file will need to also be changed to swap the axis limits around and possible also the velocity and accel.
As you have spotted, a simple swap does not give you a "left hand" coordinate system, as you also need to change the direction of the new X and Z axes. You can either do this by changing the stepgen scale to be negative, or just set the direction pins to "inverted" in the HAL file.
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27 Jan 2015 04:44 #55368
by johnl2
Replied by johnl2 on topic Using Sherline Mill as CNC with Head Turned 90 Deg
The problem is that if I turn the head, then the other axis will be wrong. It is b/c I am trying to change two opposing axis. Example: If I wanted to change x and y, switch the wires, it would work. But doing a "Cartesian axis" and a normal one just won't work b/c they are opposing eachother with direction.
John
John
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27 Jan 2015 04:47 #55369
by andypugh
I don't understand the problem. You have three physical axes at right angles. Therefore it can be configured to work. It is just a matter of getting the directions right, and connecting the right motor to the right G-code letter.
Replied by andypugh on topic Using Sherline Mill as CNC with Head Turned 90 Deg
The problem is that if I turn the head, then the other axis will be wrong. It is b/c I am trying to change two opposing axis.
I don't understand the problem. You have three physical axes at right angles. Therefore it can be configured to work. It is just a matter of getting the directions right, and connecting the right motor to the right G-code letter.
The following user(s) said Thank You: johnl2
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27 Jan 2015 04:47 #55370
by johnl2
Replied by johnl2 on topic Using Sherline Mill as CNC with Head Turned 90 Deg
Okay, so I need to make a whole new config file, I know how to do that, but I'm just confused on changing everything around for the swap I plan to do. I guess I just need it spelled out for me. I don't have much experience with this. I will give it a go and as the questions come, I'll post them.. Thank you Andy.
John
John
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27 Jan 2015 04:51 #55371
by andypugh
If you want to share tool table files etc then you can just make copies of the INI and HAL files to a different name in the same folder.
You then also need to make the new INI file reference the new HAL file instead of the old one. You can probably use a common postgui file etc.
Then start messing about with stuff in the copies.
The config-picker sees any INI as a "config" to be picked.
Replied by andypugh on topic Using Sherline Mill as CNC with Head Turned 90 Deg
Okay, so I need to make a whole new config file,
If you want to share tool table files etc then you can just make copies of the INI and HAL files to a different name in the same folder.
You then also need to make the new INI file reference the new HAL file instead of the old one. You can probably use a common postgui file etc.
Then start messing about with stuff in the copies.
The config-picker sees any INI as a "config" to be picked.
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27 Jan 2015 05:39 #55373
by alan_3301
Replied by alan_3301 on topic Using Sherline Mill as CNC with Head Turned 90 Deg
does your sherline look like this?
If the Z axis ways rotate also, and not just the head, I think you will end up with 2 duplicate axes, and one missing.
If the head rotates and the ways stay the same orientation, I think it will work.
If the Z axis ways rotate also, and not just the head, I think you will end up with 2 duplicate axes, and one missing.
If the head rotates and the ways stay the same orientation, I think it will work.
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27 Jan 2015 07:28 #55375
by johnl2
Replied by johnl2 on topic Using Sherline Mill as CNC with Head Turned 90 Deg
Yes, that is the mill I have. I know that if I turn the whole z axis I will get 2 duplicates. I am only turning the head, not the whole axis, otherwise I will have two x axis.
John
John
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