Help needed for a 3d part gcode for mach3

[irving2008]

@Jazzcnc hi Dean, long post but invaluable content! For us mere mortals following this with interest but no way to open the OPs original file please, if possible, could you post one if your Solidworks renders so we have an idea what this part looks like?

[magicniner]

Problem with this approach Nick is the time factor involved

Always with the negative waves Moriarti

[John S]

Yes I know this has I've Been using Bobcad for 6yrs now so I know it inside out, Unfortunately it's also why I know it's rubbish at 3D.!!

What version you on Jazz ?

[JAZZCNC]

@Jazzcnc hi Dean, long post but invaluable content! For us mere mortals following this with interest but no way to open the OPs original file please, if possible, could you post one if your Solidworks renders so we have an idea what this part looks like?

Here you go Irving and yes long post but how the hell do you try to explain 2D/3D Cam in 10 words or less. . .Lol

Always with the negative waves Moriarti

Ah ah great Film and times precious in my world just like the gold in film.!!

What version you on Jazz ?

Version 24 John but only because they upgraded me Free due to there skanking sales man promising one thing and delivering another with all my protests and emails ignored.!!

[irving2008]

Here you go Irving and yes long post but how the hell do you try to explain 2D/3D Cam in 10 words or less. . .Lol

Right, now I see. Def 2D for the slots and flats and roughing out the curves, then 3D for the rest, any other approach is crazy IMHO.

Only other comments I'd add is the need for a jig to allow part to be flipped accurately and, depending on the size, consider whether several parts can be machined as one then separated in one final pass, which would decrease overall manufacturing time.

[magicniner]

Only other comments I'd add is the need for a jig to allow part to be flipped accurately.

Fixture or Jig?
A bit like the difference between cannot and may not but both important distinctions IMHO;-)

[JAZZCNC]

Fixture or Jig?
A bit like the difference between cannot and may not but both important distinctions IMHO;-)

Know what your meaning has Fixture is very different to Jig and actually often a fixture holds a Jig.!!. . . but Neither are needed actually.?

Because the slot tops are all on same plane there's a flat surface for when flipped, if the outer profile is done at same time has slots then It's a simple rectangle so when flipped new work coordinates are taken from the corner and material lower surface. No special indexing or jigs are required. . . . The Difficult bit will be work holding and even then that's not too difficult has it can be held in vice or clamped from the ends.

Thou like Irving says because of it's small size then chances are longer lengths will be machined then cut to length.? . . . . . .That's how I would do it anyway.

[magicniner]

Getting back to the OP's original request and stepping away from the Tangents this topic has spawned I've had a fiddle in BobCad Cam V25 Build 996
Before posting code I'll wait for preferred tooling size, advance per flute and spindle speed from the OP, but here's how you could get there -

1. import and reposition (translate) the model
2. Create a new layer and select it as active, then used Extract Edges From Solid to create a wireframe in the new layer, which can then be viewed satndalone by turning off the original layer (with the model in it).
3. Use Profile for the flat edge, select the line where the flat meets the vertical for geometry.
4. Use Profile to take the curved edge down to the upper vertex of the curved suface where it meets the vertical, select the line where the curved surface meets the vertical for geometry.
5 Use Pocket with outside edge lines set as dotted lines (allows the tool to pass the edge of the work) to make the operation Open Pocket for the two middle slots.

Now you're into the curved surface, you'll probably use a function requiring a Boundary and selection of the surface in the solid model layer to be selected as the geometry.

To make your boundary create another new layer, set it as active and use CAD Line drawing based on Extracted Edges to construct a Boundary for the operation, usually 1/2 the tool diameter smaller than the surface to machine.

When you Compute paths you'll get something like this -



CAM is a lot more in depth than I ever imagined before diving into CNC, I've missed out all the detail of selecting tooling options, top & bottom of work where required and multiple other options within the functions, hopefully the above shows why it's rarely the case that a request for G-Code from a solid model is met. There can be quite a lot of work for what looks like a simple job and it's rarely simply a case of feeding a model to the software and getting G-Code out,
Best Regards,
Nick

[John S]

Personally if I had to make these and , big AND here, in this quantity I'd setup on a 4th axis and using a tailstock to support a mounting plate mill enough out to cut up into as many pieces as possible.

The flat parts can be done with normal milling cutters either lying flat or stood up and using woodruff cutters.

The curves sections which as causing all the problems could be cut with an old end mill or router cutter [ more later ] with one flute ground back for clearance and the cutting flute ground for the radius needed.

The cutter could be ground to a CAD generated cardboard template as these curves are just clearance profiles and not critical to microns. Commercial ones are often die cast.

The reason I mentioned router cutters is that they are usually straight flute and grinding a profile into a straight flute is far easier than trying to follow the helix on an end mill.

I'm betting that grinding a couple of cutters is far quicker than drawing and coding the same part plus the time saved over one pass as opposed to many small step passes makes this a dead certainty.

All the passes can either be run manually or under CNC but the code for the CNC will be just power feed type passes.

3D CAD / CAM has is place but often and especially when quantity is involved a couple of jigs and special tools will be more cost effective as regards time and cash.

[irving2008]

John,

I agree in principle with the idea of a specialized cutter for the curves, and it would certainly be faster from a production perspective but as I have no idea of the size of the curved sections it's hard to say whether it's practical or not.