Cnc Machine Undercuts With Picker Head

[krustykrab]

Does anyone know the most fool proof way to program/cnc undercuts using a picker head?

What I'd like to do is cnc cut a fixture from the top, then put in the picker head with the tool at 90 degrees to the z-axis and 180 degrees to the y-axis.

I am using a Fadal 3-axis vmc.

Programming with Powermill

[HuFlungDung]

Foolproof? I'd be surprised if there is anything remotely close to foolprool for that, but I haven't seen everything

I think just a carefully crafted, hand-written program would be simpler than trying to force it out of a cam program. You can use the cam to figure out the position of the toolpath, and execute a cut along said line, but approach and depart will most likely be up to you to design.

Do you have a good reference point that you can pick up on the part, when moving from normal "Z spindle" to "Y spindle"?

[krustykrab]

I am looking to run 3d toolpaths to cnc cut remaining form in undercut areas.

Using ball cutters, I would expect to be picking up the center of a tooling ball as my xyz reference.

I wonder if it's just a case of swapping axis designation?

I haven't tried any of it, but it would save an awful lot of time in multiple setups using angle plates and sine plates.

[Dan B]

We have been machining undercuts on fixtures for years using this method. We don't use the picker-head quite as much now that we have a Tri-tech head and a Hermle 5-axis machine, however.

What specifically are you finding difficult? We use WorkNC, and it's quite simple. Create a toolpath in the desired axis, and post it from the center of the tool (ballnose tools are your only option for picking up). We have our WorkNC post set up to list the set-up angle for the machine operator.

I know PowerMill's 3+2 axis capabilities are almost as good as WorkNC's so you should be able to do it.

Hope this helps,

Dan

[krustykrab]

I guess what I find difficult is understanding the fundamentals of changing the tool axis and using workplanes.

My guess is that when you create a cutterpath with the picker head set at 90 degrees to the table, then you would set the axis for that tool in Powermill as such.

However what I'm confused about is being able to draw boundaries and calculate the toolpaths in a manner that when the toolpath is posted the x is still the x, the y is still the y and the z is still the z.

I guess I'll just have to play around and see what I get.

Anymore input will also be greatly appreciated.

Thanks guys

[Dan B]

It sounds like your questions are all "how-to" questions for PowerMill users. I don't know enough about it to be helpful.

In WorkNC I can create a view in any plane and that will be the direction my toolpath is created in. I can apply that view and create whatever boundries are necessary. It's no harder than programming from the Z axis.

From what I remember from our brief time with PowerMill, you can do the same thing, although it requires a few more steps. Beyond that, I can't help. (It was almost 2 years ago that we briefly owned PowerMill before returning it for a refund. However, I do remember creating some 3+2 paths while we had it.)

Dan

[krustykrab]

Thanks Dan,

Yes, I can create a workplane in powermil which will allow me to create boundaries and toolpaths in whatever view that workplane is.

I am just not sure what the resulting output would be when the program is posted out.

I guess I could grab some wood and give it a try.