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Author Topic: reversing "A" axis rotation on toolpath display?  (Read 44446 times)

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reversing "A" axis rotation on toolpath display?
« on: March 18, 2013, 08:37:36 AM »
allo! its about my screen, so im gunna put it here with "screens".

i made a little turbine impeller the other day, ripped out the gcode on deskproto still under trial rights.

so, the image i used is a left handed turbine. it spins clockwise to "suck".

wasnt really an issue, its more just fiddling, but!

it wasnt until id finished that i realised that it was now right handed!

the image is still left handed. but the toolpath display is right handed when i load the code onto mach3.

i obviously have axis rotation enabled in configurations.

now, obviously theres no Y offsets or i would have made a mess, not a mirror image.

so, if the hand of the turbines an issue, i can either rewrite the code by flipping the image, or by flipping the direction control in the settings(saves writing new code,huh?). im wary of doing this as then my table rotates in reverse to the toolpath display!

i currently have it set up so it rotates with the display, thankyou very much! :p but this appears to be incorrect :(

now, flipping images and rotation directions also affects whether im climb milling or not. new gcode for a flipped image is different, obviously(strategies...), though now i know i can mirror things with the click of one setting if i dont mind what way it cuts! i vaguely recall when i first ran the code thinking "so much for choosing climb..." but if the tables rotating the wrong way of course it wouldnt climb anymore!

what i want to know is...

how do i change the direction the display rotates in mach 3? without affecting parts produced or by perpetually living with it being round backwards? is it even possible?

changing stepper direction doesnt affect the toolpath displayed.

not that ive noticed, at least. didnt try the old close and reopen trick...

OOOOOOORRRRR

maybe its just deskproto being in trial mode thats doing it?


anyways. its not critical, i could live with it being backwards if i have no choice, but id rather have a choice, yes? and its going to bug me until i know for sure! :-[
« Last Edit: March 18, 2013, 08:42:13 AM by HeadSmess »

Offline Chaoticone

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Re: reversing "A" axis rotation on toolpath display?
« Reply #1 on: March 18, 2013, 10:17:33 AM »
No way for me to test here but are you sure your axis are following standard convention?  If your code is correct the display will be correct no matter if the machine is moveing the right direction or not.  At least in XYZ I know this to be true.  Direction is all in perspective.  Looking form one end a CW movement would be CCW viewed from the other end which I know you know, just wondering if it is following standard convention.  Also, if the center of the diameter is 0 in Z a negetive move would of course be going deeper than the center as would a negative Y or X (depending on orentation) if their 0 is center of the diameter.

Brett
;D If you could see the things I have in my head, you would be laughing too. ;D

My guard dog is not what you need to worry about!
Re: reversing "A" axis rotation on toolpath display?
« Reply #2 on: March 19, 2013, 12:43:18 AM »
my axes are all conventional(i think!), "follow jog" does exactly that. follows the jogs. positive (tool)moves are RIGHT, AWAY, UP and CW, whilst negatives are LEFT, TOWARDS, DOWN, AND CCW. the display and my table/tool correspond with each other. :D and what comes off the machine resembles the display exactly. if i swap the rotary to go opposite to the display, ill get what i wanted, but not whats displayed.

perspective? looking at the table with it on my left so im looking down at the slots/chuck/front face/ rotating part... inclining my display so it is also being viewed from the same direction.

all other codes ive tried in 3 axis setups have worked with no flipping of dimensions.

only other 4 axis ive run is gear/spline wizard, and for straight splines or spur gears, direction is irrelevant. but i can go have a peek and see if it flips too... ::)

file attached is LH but mach3 displays and produces RH... or, both my copies do at least. (do the old curled fingers and poking thumb like for testing threads). both RH and LH copies of g-code rotate the table the same way, positive moves to 360 then a backtrack to 0.  


it could be a setting on deskproto, it could just be the trial version, it could just be im going crazy and should give up...iunno!

Offline Chaoticone

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Re: reversing "A" axis rotation on toolpath display?
« Reply #3 on: March 19, 2013, 01:23:46 AM »
Did I show you this link already?

http://www.machsupport.com/forum/index.php/topic,10308.0.html

The toolpath will display what the code tells it to.  However if you have an axis reversed it can flip, mirror, or make opposite hand parts.  Draw out a word parallel to the x axis to cut and then reverse your x and cut the part.  It will be perfect............ if your viewing it through a mirror.  Now reverse Y and cut another.  It will now be mirrored and up side down. The toolpath with the exact same code will display no different if you have your axis reversed or not.  Mach isnt smart enough to figure out which way is + and which is -, we have to do that.  Its just smart enough to go where we tell it to.  If we tell it turn right when it should turn left........... you know what that does.

Brett
;D If you could see the things I have in my head, you would be laughing too. ;D

My guard dog is not what you need to worry about!

Offline BR549

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Re: reversing "A" axis rotation on toolpath display?
« Reply #4 on: March 19, 2013, 06:40:09 PM »
Mach displays in conventional  axis configuration . IF your toolpath display is correct then your  G code is correct.

IF any of your axis's machines in reverse/mirror  then "it" is reversed to conventional setup. 

Just a thought. (;-)TP
Re: reversing "A" axis rotation on toolpath display?
« Reply #5 on: March 20, 2013, 01:35:07 AM »
talking to the machinist at my new (old) job, he says tables are usually on the right hand end of the table. mines on the left.

so if i mount it that end, keep axis settings the same...it will spin opposite to the display. switch direction and it will rotate with the display again. this could be it?


no. it cant be, because it will still produce the part to correspond with the display... and i dont want it on the right anyway as then i have to remount it on the left to cut any gears!

im just going to say its a bug in deskproto.

display corresponds to part produced, display is a mirror image of gcode generated, therefore it cant be mach3 thats playing silly buggers as it will only display what gcode tells it to...

guess i have a go of meshcam and see what happens?

i shall be back with a response...

 

and no, i didnt see that right hand rule link before.

definitely how my xyz is set.

but...it says positive A axis is counter clockwise looking from X+.

this would mean that it should rotate with the top towards the front? ie, by following curled pinky and ring finger from knuckle to nail?

if it does, then my display WILL rotate in reverse to the real rotation. as i have positive rotating from nail to knuckle...

that PDF needs a neat lil circular arrow for A!
« Last Edit: March 20, 2013, 01:45:04 AM by HeadSmess »
Re: reversing "A" axis rotation on toolpath display?
« Reply #6 on: March 20, 2013, 03:32:55 AM »
hard freaking logic. i think i have it.

i think of my table in the 3 axes.

for the tool to move positive, as is convention, the table moves negative, basically. as the tool is fixed on a spindle that doesnt move, yes?  if i had a gantry router, the tool would move... whatever. i think of the tool moving... zero being bottom left corner, a box of
xoyo
x10yo
x10y10
x0y10
x0y0
would be the tool moves right?
then away from me, left, and back to me and zero.

incremental?
x10
y10
x-10
y-10

the table will do the opposite.

the table will do the opposite.

i run a tool around the circumfrence of a circle.

to move it positively, the TOOL, the table goes backwards.

the table goes backwards.

the table goes backwards.

so i SHOULD HAVE THE DAMN DISPLAY SET UP IN REVERSE TO THE WAY THE ROTARY TABLE SPINS!!!!!!

i have to look at the table as if im a camera.

a TOOL!

its not rotating at all.

I AM.


sorry i even started this thread guys.... jeeeeeeesus wept... but i get it now. oh boy do i get it :)

how many dimensions did einstein come up with?
« Last Edit: March 20, 2013, 03:43:23 AM by HeadSmess »

Offline Greolt

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Re: reversing "A" axis rotation on toolpath display?
« Reply #7 on: March 20, 2013, 06:26:45 AM »
Conventional direction is best described via the Right Hand Rule.

Doesn't matter from where you look or which end is the chuck.

Offline BR549

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Re: reversing "A" axis rotation on toolpath display?
« Reply #8 on: March 20, 2013, 01:04:33 PM »
BUT you do have to remember what type of machine it is, the rules is for tool tip movement not always table or rotary movement.

For example knee mills are backwards to gantry mills and on rotarys you have to consider which way the tool tip moves NOT the chuck.

Just a thought, (;-) TP

Offline Greolt

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Re: reversing "A" axis rotation on toolpath display?
« Reply #9 on: March 20, 2013, 07:39:42 PM »
................ on rotarys you have to consider which way the tool tip moves NOT the chuck.

Not going to argue about.......but I disagree.

Rotary axis direction IS the way the chuck moves.