Extend+contour+turn

[FROZEN]

Anyone having trouble extending an arc contour in turn with 2017? Extending a line contour seems to work fine.

extending contour.mcam

[JoshC]

The last entity chained in your Finish Contour toolpath is an Arc, If you keep extending an arc eventually it will become a closed circle. I think the best solution here to increase the length of that finish toolpath is to re-chain and include the line. If you want to run along the line slightly perhaps include the line in the chain and use the Shorten End of chain setting.

[FROZEN]

So, you can not extend a arc in turn??? You can in mill. I thought the point of being able to extend a contour is so you do not have to draw more geometry.

 

[JoshC]

I was not saying draw anything, just chain Additional geometry that you already have in your file. Like add the other Arc or the line to your chain because you can always Shorten that chain if you chain additional geometry. Or you can use the Add line extension setting on your lead out page and that should work without any trouble. There are probably other methods too that wouldn't require any geometry creation but with the brief glance I had at your part I would chain more geometry since your chain stops halfway up that Radii.

[crazy^millman]

I think the better question is what are you trying to accomplish here? Why stop half way on the arc? Why not complete the arc? I wouldn't cut a lathe part they way you are going about so please explain the thought process and maybe someone can better understand how to help you accomplish the task. Far as I know you cannot extend an arc in lathe the way you are trying to go about it. I would again never approach it the way you are trying to approach it. If you extended it the .5 you have then I would expect a major problem as the rest of the arc is only .0.29452 long. Please give a little more detail of the task you are trying to accomplish and maybe someone can help you.

[FROZEN]

The file downloaded here was a quick experiment to see if you can extend an arc. I extended the arc by .5 so you can see the difference without zooming in. The job I'm working on has a full radii I'm trying to blend from main spindle to the sub spindle. I broke the arc in quadrants and extend the contour by .05. But Mastercam did not extend the arc. I can not upload the file for the job per customer.

[FROZEN]

Thanks for the help.

[crazy^millman]

1 hour ago, FROZEN said:

The file downloaded here was a quick experiment to see if you can extend an arc. I extended the arc by .5 so you can see the difference without zooming in. The job I'm working on has a full radii I'm trying to blend from main spindle to the sub spindle. I broke the arc in quadrants and extend the contour by .05. But Mastercam did not extend the arc. I can not upload the file for the job per customer.

This is the way I would approach it. Yes it would be nice to extend an arc, but as you have found out lathe is not mill and in lathe you sometimes have to do a little more to accomplish the same task.