Sounds good, now i look at it, I can see it really is a 2d form but with a known depth so i guess thats why they call it 2.5D ??

I have 2D cad ok, I use a couple of apps for that and can do all i need, they export DXF files.

What do i pass them to for the CAM part?

I have fusion360 setup and I see its free for hobbyists so thats good. Will that be the app to take the the DXF, add tool sizes etc and spit out g-code??

My 2D workflow is CAD -> SheetCam -> Mach3 Plasma

My 3D printer is CAD -> Slic3r -> Printer (proprietary system but runs G-code)

So 2.5D will be CAD -> ? -> Mach3 Mill

If you already use SheetCAM, then you don't need anything else.
CAD -> SheetCAM -> Mach3

2.5 or 3d ??  Well that dep[ends on what you entend to cut on your machine (;-). If it is just parts and pieces then 2.5 works just fine . IF you plan on doing any carvings,etc then you will need 3d.

For the most part on 2.5  Scam will get you by.

(;-) TP

If you already use SheetCAM, then you don't need anything else.
CAD -> SheetCAM -> Mach3

BOY, AM I SOME SORT OF BLINKERED IDIOT !

I love sheetcam, quite good at messing with that from my plasma table, I can honestly say I never knew it anything other than sheet cam as in plasma etc !!!

Even though it shows a milling tool as a splash-screen!

I have my install set for flame/jet only so all the goodies are hidden away from me - just turned it on and already have some code ready for armchair scrutiny

Sheetcam and a speed/feed calc will do 90% of what i need to start with - brilliant.

Thanks for poking me with the sharp stick

Question - do i need to change post processors ?

Yes you do need to change your Post to reflect what you are doing with Scam. AND if you had the Feed/Speeds plugin for Scam then you would be set ? 

(;-) TP

Actually that is an OLD plugin. I need to redo it like I did one for UCCNC.

(;-)

Are these plugins still available?

want, want, want........

Is there a good post? I see I have one called "Mach3" or various other machine names.

Been messing with my Scam and it all makes sense when you get to an app your'e familiar with

Specific question,
I have one job in mind that is ally, 3mm thick and has some 3mm dia holes in it, if I had say a 2mm single flute cutter in, would i change to a drill or just plunge-cut with the mill and open out to 3mm in a circular pass??

You could do it ether way but teh drill is designed to do a controlled plunge cut, straight down. With a single flute cutter cutting ALUM they do not do a straight plunge well because of only having 1 flute. So in that case you do a ramped spiral cut in a circle that way everything moves in a very controlled motion for a single flute cutter in ALUM. 

Cutting Alum at router spindle speeds can be a challenge because at teh spindle speeds of a router your feedrate will have to be very high .

For your MP ( Multi purpose) machine I would consider a Spindle with a seperate motor and a multi speed pulley setup. That way you can gear it for the best speed for each type of cutting.   You copuld have Super high for engraving, High for router and lower for metal.

Just a thought, (;-) TP

Thanks again TP,

Its all falling slowly into place now, once that happens i can get a grip on things

I will save the multi speed head for an upgrade, the spindle I have coming is 2.2kw and supposed to run from 8,000 to 24,000rpm

From what speed/feed calc i have dabbled with so far (not many) the feed rates seem fine.

Any recommendations on a Scam post??

Standard Mach3 post ( with arcs) for 3 axis  (;-)

(;-) TP