CamBam / FreeCAD 2D/3D MOP question Please help

Ok. I can mill 2D objects no probs.

I wanted to mill a simple semi circle slot along the horizontal plain of the material. The circular slot is to be 120mm long / 11.113mm deep
Attachment 12877

This picture is just an example I made so you can see what I am trying to do. I have milled the object all apart from the slot on the left.
What is the simplest way to do this ?. I have today tried to create a 3D version in FreeCAD software, but when imported to Cambam, I have no Idea what to do with it. Especialy as I only want the slot. Maybe there is a way in Cambam, that lets me do this without getting into 3D ?

whats the radius of the slot? or is it a true semicircle so diameter = 22.226mm (spurious level of accuracy aside), or 7/8". Maybe you can find a 7/8" ball nose cutter.

Hi irving,
The Dia is 7/8" . I have 6mm ball nose cutters. I can't fathom out how to cut a semi circle slot. Cambam just creates a rectangular pocket. Obviously I am missing a vital bit of info. My DOC is only 1.5mm in aluminium

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Originally Posted by irving2008

whats the radius of the slot? or is it a true semicircle so radius = 11.113mm (spurious level of accuracy aside), or 7/16". Maybe you can find a 7/16" ball nose cutter, like this one (scroll down 1/2 way)

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Edited my post, but not quickly enough.. got my radii and diameters confused (its the heat). Don't think cambam can do that. If you can find a 7/8 cutter and get it in your spindle the doc isn't an issue, just go round and round.

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Originally Posted by dudz

Hi irving,
The full circle would be 7/8". I have 6mm ball nose cutters. I can't fathom out how to cut a semi circle slot. Cambam just creates a rectangular pocket. Obviously I am missing a vital bit of info. My DOC is only 1.5mm in aluminium

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Hhhmm chinese spindle. I dont know if the speed will cope too low with such a large endmill . If Cambam wont do it, what software will ?

Or maybe something inside Mach3 ??

But you aren't trying to cut a semi-circular slot, you are trying to cut a semi-circular slot with something at the ends so the software knows what to do when it gets there. The tool needs to know where it can overhang.
Given half a chance any self respecting software will not view this as a pocket sinking exercise. That way it can cut the outline when it reaches the end. Simples.
The easiest way is to write a quick program that spits out a G code, that way you can be sure you get a finishing cut that increments to the face rather than the depth.

OK thx.

I just tryed the trial version of Meshcam. It was simple to do (on the pc)
Pitty I cant get Cambam to do it though.

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Originally Posted by dudz

OK thx.

I just tryed the trial version of Meshcam. It was simple to do (on the pc)
Pitty I cant get Cambam to do it though.

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Have you tried the CamBam forum? There are some very knowledgeable people on there.

Quote:

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Originally Posted by dudz

I wanted to mill a simple semi circle slot along the horizontal plain of the material. The circular slot is to be 120mm long / 11.113mm deep
Attachment 12877

This picture is just an example I made so you can see what I am trying to do. I have milled the object all apart from the slot on the left.
What is the simplest way to do this ?.

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I would draw the slot as a line longer than you need draw a semi-circle to the size you want and extrude the semi C along the line, create your tool path using a bull-nosed cutter, using center line of where you want to put slot across the part, use this as XYZ = 0 set your cutter & g-code to run from there, it should cut a semi-circle across the part.

Phill

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Originally Posted by phill05

I would draw the slot as a line longer than you need draw a semi-circle to the size you want and extrude the semi C along the line

Phill

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This is the bit, Im not sure how to do ?