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Reversing Y Axis
« on: May 07, 2010, 07:22:57 AM »
 :)
Many part are small enough to fit in the mill's Kurt vise.
The back jaw is stationary and has a stop affixed near the left end.
All of the parts / blanks then register to this point which would make X0,Y0 the upper left of the part/dwg.

With this in mind, just wondering what is the convention of using lower left as typical origin ?
Tried a dwg with origin at top left, tried changing mach to jog and display in this reversed direction with no luck.

How can I configure mach to work from this reversed Y config ?  And jog / display correctly ?

In sim for the moment.

Thanks,
Russ
 

Offline Hood

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Re: Reversing Y Axis
« Reply #1 on: May 07, 2010, 09:10:36 AM »
If using CAM to produce the code you can normally tell it where the origin is and which directions X, Y and Z positive are. Dont see why you would need to alter anything in Mach as the code produced would be correct, ie Y would be negative values but X still positive.
Maybe I am not understanding what you are meaning though?

Hood
Re: Reversing Y Axis
« Reply #2 on: May 07, 2010, 09:38:56 AM »
Hood,
 If the part is in the machine like the pic, and drawn/selected in your CAM as 0,0 as shown, does the crosshairs on the Mach toolpath jog Y+ towards the front of the machine with the DOWN arrow on the keyboard ?
Can see where to set the zero point up in SheetCam but not the directions.....still looking though.
Will try Vectric next.
Thanks
Re: Reversing Y Axis
« Reply #3 on: May 07, 2010, 10:16:56 AM »
Should have used a better example for the part in the vise, one not symmetrical.

I took the code for a normal part, replaced all  Y with Y- .It doesn't only reproduce the part in the opposite Y direction, it flips, or mirrors it as well.

My 2 Cam's don't seem to have the function you mention Hood.

Offline stirling

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Re: Reversing Y Axis
« Reply #4 on: May 07, 2010, 10:45:29 AM »
All of the parts / blanks then register to this point which would make X0,Y0 the upper left of the part/dwg.
Is this correct Russ? Sure, that's where the registration point is - top left, but does that neccessarilly make that point 0,0? Can that point not be anything you like? i.e. lets say your part is 1.5 inches "high" then is that registration point not 0,1.5? and everything else is just normal. So if for example you somehow home to the registration point, can't you just set home to be 0,1.5 instead of the "normal" 0,0? Or am I missing the point?

Cheers

Ian
Re: Reversing Y Axis
« Reply #5 on: May 07, 2010, 11:13:17 AM »
Hi Ian,
 Lets say you have several different parts to make all of which will fit in the vise.
There is only one point on each piece that is common....and that's the back left corner at the back jaw stop.
Just seems that this would be 0,0 ....  not the lower left, which moves with the moving vise jaw.

This would be a permanent reference point for all parts that fit in the vise.
When sketching/ working manually, this is the way I do it. (rite or rong)
My head is still stuck in manual mode.

See now how the CAM addresses this now too.
Thanks

Offline stirling

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Re: Reversing Y Axis
« Reply #6 on: May 07, 2010, 11:27:49 AM »
Hi Russ - I see where you're going but it's making my brain hurt trying to figure it out  ;D TGIF - certainly you can get Mach to jog y-ve when you hit the up arrow etc. just by changing the keymapping but that's where I come to a stop - sorry.

Cheers

Ian

Offline Hood

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Re: Reversing Y Axis
« Reply #7 on: May 07, 2010, 11:29:26 AM »
Hood,
 If the part is in the machine like the pic, and drawn/selected in your CAM as 0,0 as shown, does the crosshairs on the Mach toolpath jog Y+ towards the front of the machine with the DOWN arrow on the keyboard ?
Can see where to set the zero point up in SheetCam but not the directions.....still looking though.
Will try Vectric next.
Thanks

No, the Y+ should still be from the back of the vice up the way in your drawing, the way you have Y+ would be Y-
If you can set an origin in your CAM I would imagine it should also be possible to tell it which way X and Y are although I have never used SheetCAM so cant say for sure.

If you can do that  then all the Y moves in that part would be negative and all X positive.


Just wondering what would happen if you scaled the Y axis as -1, I do that at present on the lathe when I am using the front post as Turn doesnt support both Front and Rear toolposts yet, Rev4 should :)


Hood

Offline Hood

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Re: Reversing Y Axis
« Reply #8 on: May 07, 2010, 11:34:36 AM »
Nope, Y-1 scaling wont work for that I dont think, looks like you will have to find out how to set the origin and axis direction in your CAM
Of course you could always turn your vice round and have the stop at the other end ;D
Hood
Re: Reversing Y Axis
« Reply #9 on: May 07, 2010, 11:41:36 AM »
Hood, I remember you mentioning the -scale some time back. I tried that first, it just mirrors the part.

Just curious...
Can you make the UP arrow key, move the crosshair Up the screen with the Y axis DRO going NEGATIVE as it is moving ?
Or is that locked internally ?

I'll come round to convention shortly. Have a cool one on me.
Russ

Yes, I'd thought of turning the vise 90 deg which would put the stop LL but I prefer it in the typ installation.