HOW IS A ZERO POSITION ESTABLISHED.

[Anonymous]

GOOD MORNING,

I HAVE A COMPONENT UP IN MY FOURTH AXIS WHICH I NEED TO ORIENTATE OR 'TIME' TO MY A AXIS ZERO POSITION. I PRODUCED THE CODE ON FUSION 360 AND HAVE IT SET UP AND RUNNING CORRECTLY ON THE PART, BUT NOW I HAVE REMOVED IT AND NEED TO RELOAD THE PART FOR MORE MACHINING I CANT FIND HOW TO IDENTIFY MY A ZERO POSITION RELATIVE TO MY MODEL? 

IS IT SAFE TO ASSUME A ZERO IS THE STANDARD 3 O'CLOCK POSITION WHEN LOOKING DOWN THE X AXIS FROM BEHIND THE FOURTH AXIS AT THE MODEL?

[Anonymous]

well its definitely not in the three o clock position the search goes on...

[Anonymous]

sorry i didnt mean to make this post have a big alarm bell on it.

i have attached a picture showing where the program is machining when it is at A zero, does anyone know how i could load the model in so that it uses the big hole at the top in the twelve o clock position as the A zero?

[Anonymous]

i have now attached the entire file if anyone could please tell me how i make the centreline between the main shaft and the large hole in the top of the middle lever to be A zero i will love you for ever this is really frustrating. it doesnt seem to work even if i clock the top hole true to centreline (ie upright) and then set that as the angular difference between the face being machined at zero in my previous post. this is confusing me.

[Anonymous]

i think i might have found how to align the a axis where i want it in my set up only now all of the z heights and y positions have completely changed in my posted program yet all i changed was the z axis orientation in the set up.

[seth.madore]

Do you have a Renishaw probe on your machine? I'd set my origin to center of rotation and probe one of my flats to orient it correctly. I don't think Fusion yet has the ability to orient parts along the A axis, but this can be handled at the control or after you post your code. An example of the code is below:

N6G0G54.1P1A-10.
N7G0G90G54.1P1A0.X-.135Y0.
N8M10
N9G43H30Z2.T21
G65P9832
G65P9810Z1.F100.
G65P9810Z.7F20.
G65P9818Y1.Z.425S101.B10.
G65P9810Z1.F200.
G65P9810Z2.5F200.
G0G54.1P1M11
G0A-10.
A0.
M10
G54.1P1X-.135Y0.A0.
G65P9810Z2.5F200.
G65P9810Z1.F200.
G65P9818Y1.Z.425S101.B.125
G65P9810Z1.F200.
G0Z2.5

It's the P9818 that we're looking at. Breakdown:

Y value is the distance we are probing across, Z value is the Z location of that surface, S is the offset being updated, B is the angular tolerance permitted. In the example above, I'm running that cycle twice, 1st time to rough locate it, second time to fine tune it.

[Anonymous]

hello, sadly i don't have a probe in my machine and all i have is the top hole position in the component as we are now using this for a drive pin, i also have no flats in correct position to clock along as the component span as i was machining it, which i knew it would but im not paid enough to think for myself!! 

the only option i see is to position the pin at a known angle and set my fourth axis as that known angle is there no way i can just display the a axis zero in fusion and see where this pin is relative to it? 

[Anonymous · Accepted solution]

back to long hand programming then. nice dream while it lasted.

[seth.madore · Accepted solution]

G54 is going to be center of rotation, left side of part (for edge finding)

Assuming hole is finished, insert .7485 pin in hole.

Install 10mm gage pin into toolholder

Rapid to G54 X0 Y-.5711

Feed to an appropriate Z height.

Clock part against backside of pin. 

Tighten 4th axis workholding

Go make some chips.

 

[Anonymous · Accepted solution]

im really sorry for being so crabby this morning, but that still doesnt help me to set the A axis zero position as i cannot tell what angle the model is at in that orientation, i did essentially the same by clocking the pin in the top hole true to the fourth axis centreline @ 12 o'clock position, but i still dont know what angle that is relative to the program.

In the nc prog that was produced the face where you have the little purple line was being machined at A zero but when i set the fourth axis (with pin at 12 oclock positon) as the angular difference between the two and move the fourth axis to A zero it doesnt move to the position i expect. 

Its ok i have just pulled the program apart and started to manually program the fourth axis. I must have made some mistakes that are messing me up.

I will get there oneday, time to go and brush up on my online courses i think.

thankyou for all your help.

[johnswetz1982 · Accepted solution]

If I am understanding your problem, use a good old fashioned indicator and change your A angle until you get no indicator change when you are moving about that plane. I think Seth's original suggestion was pretty much the same thing, just jogging the Z axis up and down to indicate the vertical portion of the part and then rotate it by whatever your angle value is. 

[Anonymous]

im really sorry people. i dont know what i was doing yesterday got myself in a tizz and couldnt see the wood for the tree's! as soon as i left my machine it dawned on me that i was completely setting everything wrong, using the wrong side of angles etc. in future im not going to rush to jump on the forums and start acting like a petulant child until i have taken a step back and looked at what im actually doing! thankyou for your help

[seth.madore]

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@Anonymous wrote:

...in future im not going to rush to jump on the forums and start acting like a petulant child until i have taken a step back and looked at what im actually doing! thankyou for your help

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Hey, we're used to that behavior around here 🤣😁