Help with A axis.

[on7tim7]

I am new and learning to use my mill. I just build a rotary table and its works perfectly when I write the code for simple cuts but when use LazyCam I got into problems. There is something that I am not doing well, either on Mach3 V2 or on LazyCam. I have a GPEG image of a round medallion that I want to cut on my rotary table flat. I load the image on LazyCam and use the spiral cut for the gcode generation. I got the gcode on Mach3 it’s and looks OK but on X,Y coordinates not on A axis. To do that I use the Wrapper program to convert the Y axis to A axis and it doest it good but the converted gcode is weir and doesn’t correspond with the medallion cuts. I read somewhere that I could use the Indexer wizard at Mach3 to generate the code but I don’t have an idea of how to use that wizard. Please help me with any idea to get on track. Thanks.

[HuFlungDung]

I think your concept is incorrect, unless you are engraving something on the edge of a medallion. There is no application for the 4th axis, facing up towards the tool, that cannot be handled with XY movements.

[Tweakie]

As has already been said - the wrapper program is intended for working on the surface of a cylinder not a flat disc.

Tweakie.

[on7tim7]

Thank you HuFlung and Tweakie for your answers but I wonder what I have to do or buy to be able to cut this medallion, its 5” diameter and ¼” thick. I went to Youtube and watched some cuttings like the one I wanted to do. The piece is hold on a rotary table like mine looking up, parallel to the Z axis and the movement are on the Y, the Z and the A axis. They use Mach3 software, you can see it. I am sure someone in the forum has cut something like this before. Thank you.

[Tweakie]

By all means clamp the part in your rotary axis and leave it stationary. The X Y Z movements of the standard GCode program should produce the part OK.

If I am missing something here perhaps you could post a picture of the part or your GCode for the medallion.

Tweakie.

[on7tim7]

Thanks. I'll try that.

[HuFlungDung]

Perhaps a picture of what you are trying to machine would help.

What wrap does is converts Y axis movement to A axis movement through a conversion/scaling/renaming axis trick. So it is limited to working with one circumference (on the OD of a cylinder), where, given a particular diameter, all the Y axis movements are calculated as linear distances 'wrapped' around that cylinder, and then scaled to fit as a fraction of 360°, and the letter Y is replaced with the letter A.

So you can imagine that face milling in your setup is not at all suitable for wrap, as you have an infinite number of different circumferences, with small likelihood that any moves actually require the table to rotate while the tool dwells, as this is simply cutting an arc, which is a simple interpolated movement done without a rotary axis.

[ErnieD]

Hi,

Forgive my ignorance but I think that you should be able to do this medallion without a rotary table. Just treat it as if you were doing any flat engraving and let the x, y and Z axies do their thing.

Ernie

Edit Sorry Hu I did not see the very last part of your post. My apologies.

[on7tim7]

Thanks, I'll give it a try using the three axes, it should work. I always thought that in a case of a round object a circular cut would be more precise than the three axes method. It’s a challenge for me and I’ll keep looking of a solution after all. Thanks