Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: KTM on August 02, 2008, 02:13:55 AM
-
Hello
I have a plate that is already punched with holes with 2 reference holes on the edge of the plate, now I want to plasma cut the plate.
Is it possible to use a laser probe to set the angular offset and zero position of the X and Y axes to align the plasma cutting and punching?
Regards
KTM
-
Quite clearly, the thing you need to do is set the 0.0 position of your plasma program and align the plate with the X or Y axis. I do not see the purpose of the two reference holes on the plate unless you are going to do multiples of the cutting. In that case you need to make some sort of jig on your table to hold the plate, with some sort of indent (or outdent) for the holes, so that subsequent plates locate in the same place.
If you know the relationship between the holes and the rest of your program, the laser probe is irrelevant. In this case a drill bit, or rod of the same sixe as the hole will suffice. Zero your table if you have lhome switches, put the drill or rod in the chuck and move the table , until the the drill bit or rod slides smoothly into the hole. If the holes are semi-circular, move the table to the correct position and put the plate in place against the rod.
The alternative is with a drill and two short pieces of rod, drill your table in the correct place for the holes, and the two pieces of rod will tap into the holes. All you plates will then fit in exactly the same position on your table.
-
Every punching job is different. The cad drawing is made in 2 layers - 1 for punching and 1 for cutting.
To get the overlay exact it is more accurate to set a reference point on a punched mark and set the angular offset on the other mark. I cannot drill the table, as it consists of a supporting grid.
There are plasma machines that do this - some with video probes and others with laser probes.
I just have to figure out how it is done.
Regards
KTM
-
Tried using the Set Rotataion wizard?
Hood
-
Where do I find this mysterious wizard? ;D
Regards
KTM
-
Presume you are using Plasma, if so then big button under the SoftLimits button, it says Load Wizard. Click on that then go down to set rotation wizard.
If you are using another screenset it may be different.
Hood
-
It is not in the list of wizards - see attachment
-
What version you running? Its definitely in mine. No problem however, I will attach it in a few mns.
Hood
-
OK shut down Mach, download the zip file and unzip to C:\Mach3\Addons then restart Mach and it should now be in the list.
Hood
-
Thanks a lot Hood. ;D ;D ;D
-
is it what you are looking for?
Just so you know how to set it back to normal, clcik the Get Pos button, then without moving the axis clcik it again and it should set the rotation back to zero degrees.
Hood
-
Just to confirm the usage here....
I have to 'known' coordinates on my pcb (actually crosshairs etched onto a pcb)...to save fiddling about aligning manually to cut the pcb outline, I wanted to mount the board roughly & align these know points with a webcam.....
Can the rotation wizard be brought into play here - if so, is this how it works...
Jog to my first etched pcb cross hair position & align - I know these exact coordinates - so do I now enter them in to the wizard's DROs then click 'get position'
Now do I jog to the second ectched pcb crosshair & align - again I know these coordinates ...this is where I'm a little unclear of the workings of this wizard...do I again enter these second cordinates into the wizard's DRO then click get position?
Or should I be approaching some other way?
-
You could jog to the point you want to start and enter the values in the DRO then press Get Pos and then jog the X and Y to align a point further along the edge then press Get Pos again and that will set the rotation. All the wizard is doing is setting the angle of rotation so you can zero ( or enter a value) the DROs before or after you do this setup.
Hood
-
Thanks...at the risk appearing a little slow, will this wizard even do what I wish to do, that is
1. Mount a pcb board with known markings (mount it any old way as the aligment is going to be done optically with a webcam)
2. Jog to each of the markings and tell Mach3 the marking coords
3 . Press run to start the cutting!
Wizards are great but where they fall down a little is the supporting info as to when/how to use them.
-
The wizards are there to provide you 1 way of doing a function. You woul deither work that function into how youdo things or change the wizard to do what you need or just develope a new way of doing what you want.
What you are wanting is very simple to do IF you understand the process. SO now would be a GOOD time to learn the processes involved. Then you can do what you need on the fly.
Mount the PCB. Move to the point of rotation. Then run the macro to do the actual rotation(G68) then move to the next point of refererence. The macro will then calculate the rotation angle and apply it to the G68 and the part is then rotated based on the 2 points. It could then even set the Point of origin based on the rotation point position.
It can be done many ways. You just have to develope 1 to work as you need it.
Hope that helps, (;-) TP
-
I'm not sure a wizard exists to do exactly what I want.
I want to use a webcam to jog/align my cutter over a known pcb coordinate/mark then let mach 3 know the coordinate - obviously the camera is going to be offset from the cutter tip...so there's one offset that I need to cater for!
Next, I want to jog to another known cordinate - align the webcam over it, then enter these known coordinates ....and then Mach3 magically updates itself to reflect the fact that the pcb is not squarely mounted.
Now if I had a clue about how to approach this then I would...where's a good starter for learning how to do this? (would it be a macro - language?, a wizard...what would be the best approach here?)
I seek to do exactly via Mach3 what this guy is doing here....
http://www.youtube.com/watch?v=JJnenOsbCzU&feature=player_embedded (alas, the functionality is embedded in code within is own CNC application software)
I'm surpriseed there's not more call for this type of thing - lots of folks etch their pcbs, but still need a way of cutting them out - presently it's a major time sump registering/aligning the pcb with the CNC software (not a problem of course if the whole board is isolation milled, but I'm talking for boards with track widths beyond the capabilities of my modest machine hence chemically etching)
-
OK first do you have your camera mounted???
You first need to LEARN to deal with offsets.THey are several ways to do it. Thesimple way is to use fixture offsets.
You can read up on them in the manual.
The other ways to do it would be to use a G52 or a G92 or use the G10 offsetting to account for the offset of the camera . These also can be found in the manual.
Once you have offsetting down pat the Wizard can be used to auto rotate the part program in Mach.
Move to the rotaion point as veiwed with teh camera, press the button then move to the second reference point and align it in the camera and press the button again. The wizard will take the points and then rotate the part program based on the reference points.
Simple as that.
NOW NOTE: that once you rotate the part(G68mode) then MACH not longer JOGs in relation to the rotated part it still jogs in normal mode. BUT it will cut in rotated mode.
(;-) TP
-
No my webcam isn't mounted yet, I did plug in the family webcam, just to make sure I could get mach3 working ok on my workshop PC - it was fine, so I ordered a cheap & cheerful (manual focus) webcam off ebay that I can butcher! I'll make a mount for it when it arrives in a day or two & then I'll be ready...that's why I'm trying to do some spadework in the meantime...thanks for your help (off to read about offsets!)
(just one thing, does the rotation have to happen around my first point...in other words do I have to arrange it that my first index mark on the pcb is X0,Y0?)
-
NO it does not have to be the rotation point. THe 2 points are just require to be able to calculate the rotation angle. Then you go back to the part Point of origin(X0Y0) and set it to X0Y0. THen you are ready to machine.
I would start with teh LH point frist then move to the RH point. Look at the picture in the Wizard it says a lot(;-)
(;-) TP
-
NO it does not have to be the rotation point. THe 2 points are just require to be able to calculate the rotation angle. Then you go back to the part Point of origin(X0Y0) and set it to X0Y0. THen you are ready to machine.
I would start with teh LH point frist then move to the RH point. Look at the picture in the Wizard it says a lot(;-)
(;-) TP
Damn just when I thought had it mapped out loosely in my head....so the rotation wizard only sets the angle of rotation?!!
Ok, so the steps would be...
1. Jog to/Align point 1 - tell Mach3's rotation wizard the coordinates
2. Jog to/Align point 2 - tell Mach3's rotation wizard the coordinates
3. exit the wizard (the rotation angle is set).
4. Now jog to any known point on my main pcb (doesn't have to be 0,0) & tell Mach3 the specific coordinates (again using my webcam to align over the mark)
Now I'm ready to cut?
The end goal here must be a wizard that not only works out the angle of rotation but remembers the coordinates that you entered while in the rotation wizard
-
You CAN set the point of rotation with a G68 call. I will Check the wizard to see what it is doing.
With the Wizard you don't tell Mach anything it records the point you are currently located at. then when you move to the second point it does the same thing.
After the rotation is set then you would move to a known point and set that as the reference point.
NOW NOTE: The 2 reference marks on the part must be on the same plane as each other OR you would have to add in that offset angle. But normally lineup marks are created on the same plane to make things easy.
(;-) TP
-
OK I just checked the Code for the SetRotation Wizard. It does NOT set the poijnt of rotation ONLY the rotion angle.
So you would have to go back and set a referrence point.
Now it is possible to modify the wizard to include the Reference point(first set point) as the point of rotation. AND 2 more Dros to input the correct values. That would allow it to set the reference point in MACH and rotate on that point.
(;-) TP
-
Many thanks...all useful for when my webcam arrives!