When to Use Absolute vs Incremental Coordinates - Quick Machining Tip #22

In my video where I discussed machine tool coordinates, G. Tucker asked for examples of when to use absolute and incremental positioning and this is my response. Enjoy!

If you like my videos, please consider supporting my channel on Patreon. You'll get access to gag reels and I'll give you a shout out in my videos.

[vMercury]

Recently I was listening to someone who was criticizing learning on the internet because "there was no chapter one" the idea being that important fundamentals are missed because producers are making only advanced lessons. Thanks for this great chapter 1 lesson.

[KW-eipi]

Hi Stuart. Thank you very much for all of your very helpful videos. Over the years, I have picked up a lot of tips as well as very valuable information. You have made a few videos on the DRO that you installed on your mill that have been extremely informative. I would like to encourage you to make more videos regarding the setup and use of these import DRO's. Most of us that have them find the documentation limited or difficult to understand the poor manuals. The settings menu contains settings that I, at least, have no clue as to what they are or which buttons to push to change things. I'm sure many would find such videos very helpful. Thanks.

[seanwolfe]

I think many people use the abs/inc feature on digital calipers (well, I do) but just never seem to on my machines. Makes great sense as does tool offsets. I use this all the time when using my CNC mill, but never on my manual mill. Why? Fear? Intimidation? I don’t know but this has motivated me for sure. Thanks Stu!

[captcarlos]

I recently had a job for several thousand small aluminium upstands for which I would love to have had a small CNC lathe.
I made a HSS form tool which had all the features of one end, chamfers, diameter etc, including the part off.
I used several tool offsets to simplify this brain numbing exercise.
Tool 1: Part off and end diameter exact..
At X:0, Z:0.
Then drilled with tailstock drill to just break through so the part off left a clean face.
Tool 2: at Z:0 was the stock stop.
Tool 3: at X:0 was the OD turning diameter going to Z:0.
Revert to tool 1, into X:0, parting off, rinse repeat.
My point, on the same tool I listed 3 offsets and each had a simple to remember TARGET number of zero(0) which produced thousands of these little with less than 1% reject rate, simply.

[Steve_]

My question is a perfect example of Nicholas's statement "There is no chapter 1"

The place i work at has several Southwestern Industries machines, including a SMX 2500 mill with Prototrak control.
Staffing problems being what they are, we no longer have any 'expert CNC'ers' working for us, so I'm trying to learn on my own.

I know the Prototrak software inside-out, I've used it on a daily basis for the last 7 years, and am extremely comfortable with it, but I'd like to take the next step and be able to run G-Code on it. Ideally I'd like to output Aspire toolpaths and import them into the machine.

My problem is I've never used G or M codes before - I'm in the position of not even knowing what it is I should be learning!

[joell]

Thank you - that helps reinforce the concept 👍😎👍

[brucewilliams]

Thanks for the video. I have a DRO like the one you have on your mill. I am trying to setup the "Absolute Reference Point" in case of power failure. I follow the instruction and it says put it in REF mode, select the axis and move that axis until it "beeps". Mine doesn't and I suspect that it is because of the cheap scales and therefore they don't have the reference mark. So, have you tried it and if so did it work? If not do you know what the AB-Ref, LEF_AB references do? Thank you for all you do!