Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: Overloaded on May 07, 2010, 07:22:57 AM

Title: Reversing Y Axis
Post by: Overloaded 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
 
Title: Re: Reversing Y Axis
Post by: Hood 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
Title: Re: Reversing Y Axis
Post by: Overloaded 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
Title: Re: Reversing Y Axis
Post by: Overloaded 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.
Title: Re: Reversing Y Axis
Post by: stirling 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
Title: Re: Reversing Y Axis
Post by: Overloaded 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
Title: Re: Reversing Y Axis
Post by: stirling 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
Title: Re: Reversing Y Axis
Post by: Hood 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
Title: Re: Reversing Y Axis
Post by: Hood 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
Title: Re: Reversing Y Axis
Post by: Overloaded 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.
Title: Re: Reversing Y Axis
Post by: Hood on May 07, 2010, 12:02:56 PM

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 ?

Nope, Y+ is always up the screen.

Hood
Title: Re: Reversing Y Axis
Post by: Overloaded on May 07, 2010, 12:05:08 PM
Ha...just turn the keyboard up-side down....right ? ::) ::) ;D :D
Title: Re: Reversing Y Axis
Post by: Hood on May 07, 2010, 01:46:45 PM
Nope, you can have any key you wish for the Y+ or Y- ,  but Y+ will always move up the screen so you will need to make an upside down screenset and turn the monitor upside down, problem then would be X goes the wrong way ;D

Hood
Title: Re: Reversing Y Axis
Post by: BR549 on May 07, 2010, 02:32:21 PM
IF in CAM you set the 0,0 to the top left then everything will work fine. When the program posts it will set the 0,0 to be top left. That is exactly where you need it to be when you set 0,0 to the left of the stationary side(back jaw ) of the vise.


Hope that helps
Title: Re: Reversing Y Axis
Post by: Hood on May 07, 2010, 02:46:43 PM
IF in CAM you set the 0,0 to the top left then everything will work fine. When the program posts it will set the 0,0 to be top left. That is exactly where you need it to be when you set 0,0 to the left of the stationary side(back jaw ) of the vise.


Hope that helps


Not necessarily, in some CAM packages if you select the top left corner as the origin it will then rotate the part to suit normal convention, thus the need to define the X, Y and Z directions.
Hood
Title: Re: Reversing Y Axis
Post by: Overloaded on May 07, 2010, 11:35:26 PM
 It does work as you guys say in SheetCam, don't see exactly how to differentiate the part origin from the machine origin though. Need to work on that with a bit of study.
Will try with another CAM when I get a chance.
Thanks.

Title: Re: Reversing Y Axis
Post by: BR549 on May 08, 2010, 01:22:52 AM
Hood, I have Never seen that.  In all the Cams I have used IF I define the 0,0 as top left the Cam will Draw and Post it that way. Now IF you do not define it it will ASSUME the 0,0 as bottum left and Draw/Post it as such.

Title: Re: Reversing Y Axis
Post by: BR549 on May 08, 2010, 01:29:25 AM
;-)
Title: Re: Reversing Y Axis
Post by: edvaness on May 13, 2010, 08:03:48 PM
Russ ,

All you need is a decent cam program . I can set you up.  ;D ;D

Ed
Title: Re: Reversing Y Axis
Post by: Overloaded on May 14, 2010, 12:55:44 AM
Sounds great Ed.
Next time I'm up your way, I'll need to quit foolin' with the airplanes so much and come see you folks and your shop...maybe get a tutorial or two. I'll by the refreshmemnts !
Thanks,
Russ
Title: Re: Reversing Y Axis
Post by: edvaness on May 14, 2010, 01:01:45 AM
Russ ,

 Welcome anytime. Plan on spending a whole day. You won't be sorry.  ;D
I'll set you up.  ;D

Ed