I am trying to use the OD Arc wizard under Mach3 turn to cut a radius on the end of a rod. Here is the scenario:
I have a piece of hex bar that I want to cut a radius on the end of. I am making a few wheel nuts.
The bar is 20.4mm across the points of the hex. I want a radius that is 3mm below the edges of the hex, and covers all of the end of the bar. I am fairly sure that I have done this type of thing successfully in the past, and I seem to have in my mind that I specified a sphere diameter that was larger than the end of the bar, then used the graphic in the wizard that shows where it will cut, to fine tune the arc until it covered the end.
I am using these parameters: Z center 0, Z start 10.2, Z end 7.2. X start 10.2 X end 0
With the sphere diameter set to 20.4mm, the wizard does what I would expect, and proposes cutting a 1/2 sphere, finishing 10.2mm down the nut.
If I put a larger sphere diameter into the wizard, the image on the screen in the preview, is nothing that I am able to understand.

Actually, I was searching for, but didn't find, some doco that covers the turning wizards. Does such a thing exist?

There is no documentation on how to use the turn wizards.
Some work only in radius or diameter mode and not both modes.

I assume you are using the OD ARC WIZARD.

I'll post something quick and dirty for you on how to use.

RICH

The attached should  be of help for you.

RICH

Thank you Rich, sadly I have tried most of the points that you mention in your PDF, although I hadn't tried switching from radius mode (my current mode) to diameter mode instead. I have made the nuts that I wanted using the OD fillet2 wizard, but for the future, I'd still like to get my head around the OD  Arc wizard.
Given that my preview screen is messed up when I use a sphere diameter larger than 29mm, (my job is 20.4mm diameter, or 10.2mm in radius), I suspect that perhaps changing to diameter mode might resolve at least this issue.
Thanks again
Dave

Switching between Radius and diameter mode did not fix the issue. Here is a screenshot of the problem, the first is the issue, which happens after I increase the radius or diameter by 1 mm. The second is the ok version.

I get the same result on my end  per the first pic of inputs you posted.

The circle is a crop circle and to get rid of it untick Reversed Arcs in Front Tool Post
in configuration.

After you post code  in the wizard, exit back to the turn screen, zoom in  the graphics screen, and step through the gcode and watch the tool movements.

If all you want to do is put a radius on the end of the stock use a different wizard.

Note ....... "These wizards are donated by users ....., they are unsupported, but found to be usefull."   

RICH

Thanks Rich, that's as I thought, but I had a vague memory of it working despite the garbled graphic. I hear what you are saying about the unsupported wizards, and you suggest that I use a different wizard. Which wizard specifically would you suggest? I am happy to use anything that works. What would you use to put a radius on the end of a job? Other than a file of course.

I suggest you try all the wizards and gain an understanding for  their application to what you want to do.

It's all part of the learning experience,

RICh

Cheers Rich, but in your message yesterday, you said "If all you want to do is put a radius on the end of the stock use a different wizard" I realise that trying things is all part of growing up, but I think that over the last 10 years or more I have had the opportunity to try most of the wizards included in Mach3. I don't recall one that puts a radius on the end of a shaft. I thought that since you made the statement above, you might have known of one.
Regards
Dave