fine tuning tool paths for production

[donek]

We've been cutting a lot of ski cores for mass production rather than our usual custom work. The cutting force when cutting cross grain is much large than when cutting parallel to the grain. As a result high speed cuts are more likely to push a core around on the vac table when making cross grain cuts. I've manually edited the code to change move speeds during cross grain operations while running at maximum on cuts parallel to the grain. Is there any way of doing this sort of thing in Aspire or another CAM program?

Possibly setting a MS that applies for the x-axis, but is different for the y-axis. Or just selecting portions of the tool path and altering the move speed in that zone.

It's not all that difficult to edit the code manually, but it would be kind of cool to isolate the x and y axis or to change the speed in certain zones within the CAM software.

[bleeth]

You can't do that when cutting out an object but if you were simply cutting lines you could set up two toolpaths; one for the with grain vectors and one for the cross grain.
So if you wanted to cut out a rectangle, offset it the radius of your bit, explode it, create your toolpaths cutting on vector, and then use toolpath ordering to try to get your cuts efficient as possible.

[donek]

You can't do that when cutting out an object but if you were simply cutting lines you could set up two toolpaths; one for the with grain vectors and one for the cross grain.
So if you wanted to cut out a rectangle, offset it the radius of your bit, explode it, create your toolpaths cutting on vector, and then use toolpath ordering to try to get your cuts efficient as possible.

Not really a viable solution when you're doing production. The object is the shortest and fastest too path, yet refined to the material. Your approach results in up and down movements of the z between the paths. Time is money (ie. an employee twiddling his thumbs).

[gundog]

Not really a viable solution when you're doing production. The object is the shortest and fastest too path, yet refined to the material. Your approach results in up and down movements of the z between the paths. Time is money (ie. an employee twiddling his thumbs).

You can stop the up and down movement by drawing the lines as a poly line connecting the ends and making it one big poly line vector. This is fairly easy to do if the cuts are flat 2d but if the cuts are 3d with the Z axis moving constantly which I suspect is the case not so simple.

[donek]

You can stop the up and down movement by drawing the lines as a poly line connecting the ends and making it one big poly line vector. This is fairly easy to do if the cuts are flat 2d but if the cuts are 3d with the Z axis moving constantly which I suspect is the case not so simple.

I think you've missed the point. We already have closed tool paths, but wanted a way to alter the feed rate during certain portions of that path. The only way to do this in vectric is to break the tool path, resulting in separate tool paths with z moves and even jogs home if you don't edit the post processor. At this point the best way to accomplish the task is to manually edit the shopbot code, which isn't all that difficult, but does require you hunt for the correct locations to insert the codes.

The more I think on this, the more I like the idea of being able to independently set feed rates for the x and y axis.

[Sk8MFG]

I think you've missed the point. We already have closed tool paths, but wanted a way to alter the feed rate during certain portions of that path. The only way to do this in vectric is to break the tool path, resulting in separate tool paths with z moves and even jogs home if you don't edit the post processor. At this point the best way to accomplish the task is to manually edit the shopbot code, which isn't all that difficult, but does require you hunt for the correct locations to insert the codes.

The more I think on this, the more I like the idea of being able to independently set feed rates for the x and y axis.

Easy, but you can't do it in Aspire.

We optimize our toolpaths for production. We usually add loops to cut down on time between cycles, change feeds, modify peck drilling to only withdraw what it needs to, modified safe Z during moves so it just clears the object.

Have to do it in code.

Find the line in code where you want to change feed and add an MS command.

*edit. Didn't catch the bit where you want to isolate x and y feeds... can't help there.

[gundog]

I think you've missed the point. We already have closed tool paths, but wanted a way to alter the feed rate during certain portions of that path. The only way to do this in vectric is to break the tool path, resulting in separate tool paths with z moves and even jogs home if you don't edit the post processor. At this point the best way to accomplish the task is to manually edit the shopbot code, which isn't all that difficult, but does require you hunt for the correct locations to insert the codes.

The more I think on this, the more I like the idea of being able to independently set feed rates for the x and y axis.

I guess I was not very clear as I see it in my mind but did not explain it well. If the part machines better in the x axis lay the parts out to machine a raster using the x axis you may have to create your own raster but try not to do much machining in Y and any machining needed in the Y direction done as a second tool path at a different speed.

[carlcnc]

Sean
I use a cadcam called Millwrite, should do what you want
few years ago the author added a feature that lets you set a different feedrate for radius/circles
works well. , IF your ends are arcs,
reach me at cncbuilder[at]comcast dot net
Carl

[adrianm]

If the parts do have arcs the speed change could be made via Aspire as well as the Post Processor has a separate section for arc moves.

[Ajcoholic]

What about a stronger vacuum? Wouldn't that allow the same fast cutting without moving? Not slowing down at all = less time = more $$ :)

[donek]

What about a stronger vacuum? Wouldn't that allow the same fast cutting without moving? Not slowing down at all = less time = more $$ :)
It might help, but they are ski cores which are long and narrow, so the holding force in the cross grain direction is compromised by the shape of the blank.

[donek]

If the parts do have arcs the speed change could be made via Aspire as well as the Post Processor has a separate section for arc moves.
That's a great idea, however, the sidecut of the ski is a large circular arc as well. It could be broken into line segments, but still not the ideal solution.

[Burkhardt]

It might help, but they are ski cores which are long and narrow, so the holding force in the cross grain direction is compromised by the shape of the blank.

How about a custom shape long and narrow vac pod? It could even have fences or dowel stops to prevent the blanks from moving. After all, the surface area of that ski core should give you over 1000 pounds of holding force at high vacuum (e.g. > 20" Hg). Would also allow running at very modest electrical power.

[donek]

If the parts do have arcs the speed change could be made via Aspire as well as the Post Processor has a separate section for arc moves.


How about a custom shape long and narrow vac pod? It could even have fences or dowel stops to prevent the blanks from moving. After all, the surface area of that ski core should give you over 1000 pounds of holding force at high vacuum (e.g. > 20" Hg). Would also allow running at very modest electrical power.

That's not a bad idea. Perhaps we'll use it next season.