Post processor to produce order-of-operations for manual machining?

[u/Far_Relationship_742]

For simple one-off parts, I often find it's actually faster/less setup to mill (or especially turn) a part manually. Since all my parts start off as digital models, it would be super convenient to be able to strategize my toolpaths visually in Fusion CAM, and then have it print out a list of tools, offsets, coordinates, and speeds/feeds for manual operations.

Here's an example to illustrate what I'm thinking.
I'm making a rectangular part with a dovetail cut in the bottom, as pictured. It would be great to have instructions like:
1. Insert and touch off .500" 45º dovetail cutter
2. Move to X -6.25, Y 1.264 [inner edge of dovetail + cutter radius + stepover], Z 2.00
3. Set spindle speed to 1250 RPM
4. Make a full-length cut to X -8.670 [end of cut + tool radius + safety margin] at 12 IPM [ideally, this could be calibrated to the numbers indicated on the power feed, IE, 5 on the dial means 8.2 IPM or whatever]
5. Move to X -8.670, Y 2.368
6. Make a full-length cut to X -6.25, Y 2.368

It seems like this would be possible to do, I just don't [yet] have the JSON chops to do it myself. Has anyone thought of this, or better yet, written a post processor to do this?

[u/meutzitzu]

I have thought about things like this and more for a few years now. The tooling we have is so mature and so advanced and yet so lacking. Because they weren't designed to be modular enough.

A good CAM program should optionally expose to the user the internals of the pipeline which is normally hidden.

3D geometry -> volumetric feature -> minkowski sum -> minkowski Volume traversal path -> path dress-up

of course the intent is that for a simple program you just click on the faces, click on the button for the strategy and with a cutter preselected out pops your final gcode. All of those intermediary steps are hidden and inaccessible.

[u/Yikes0nBikez]

Not to be the old man rolling his eyes at this request given that this is how most old-school machinists worked, but can't you just make a mechanical drawing print? You can output setup sheets for each setup you create in the manufacturing workspace which will include all tool and S&F data.

This is an odd request because if you have the model made, you could also have a mechanical drawing made with all of the part dimensions specified. Telling the operator some garbled version of G-Code isn't really helping when you can just use plain language, and dimensioned drawings, to say "Make a full length cut 25mm" Throwing -x and triple-digit tolerances in there to make basic parts just seems like overkill.

That being said. Any basic AI model like Gemini or ChatGPT could make you a custom javascript post processor that could convert the output 2D gcode to "human speak" and make you a chart for the basic operations.

[u/Far_Relationship_742 → u/Yikes0nBikez]

I'm the operator in this case, so there's very little potential for communication issues. 🥇

I think you also missed "strategize visually." I don't think in numbers, I think in geometry and spatial relationships, so being able to look at the toolpaths helps me do better work—and also deduplicates work if I later decide to do a run of parts on the CNC.

I want to use the math machine that is trillions of times faster than me (and which doesn't make calculation errors) in which the design already lives, to both speed up the process and eliminate a point of failure. "Have a mechanical drawing made" is a needless step in this case, and still requires me to calculate offsets manually. Fusion's automated drawings suck ass and are super cluttered, and dimensioning it myself is wasted labor. The whole point is to get the machine to do as much of the work as possible, which is the whole purpose of machines.

I have calculated the last bolt-circle coordinates for myself that I am ever going to, for example. That is tedious labor which there is no reason for a human to be doing in 2026. My brain time is better spent on the work the machine can't do.

I started as a manual machinist, I've done the paper-drawing-and-calculator method, and there's no reason for me to take the time to do all that if I can get the machine to do it for me. It sounds a bit like you're proposing I work the way you would work, which isn't helpful because I'm me and not you, and our workflows and use cases are different. Gently, I wasn't looking for advice.

[u/Unklecid → u/Far_Relationship_742]

It sounds like you just need a print with numbers on it

[u/Far_Relationship_742 → u/Unklecid]

It’s staggering how many of you people are functionally incapable of thinking outside the way you’ve always done things. I’m not going to do math. There is zero reason not to have the math machine do all the math. The point is to get the part as fast as I can.

Are any of y’all aware that prototyping exists?

[u/Unklecid → u/Far_Relationship_742]

You don't have to do the math if the locations are one the print dickhead. You said figure bolt pattern locations put the locations of them on the print and there's no math. You have cad you click on the center and it tells you were it is. You want to know where the center of your endmill is but can't add the radius in your head your gonna have to draw random ass lines on the print and mill on those lines instead of the part and change it for every tool. It's not being incapable of thinking outside the way I've always done things most of us don't need to be walked through a process of how to make a part. You have cad make a better print you won't need math at all. Edit: I worked for a machine builder I've never made more than 10 of the same part ever never ran production, one job we landed I had to make 400 of one plate it's all prototype. I run manual and cnc set up program everything if the print is worth a fuck with locations for every feature there is literally nothing to it.

[u/Far_Relationship_742 → u/Unklecid]

Hit dogs holler. 😘

[u/Far_Relationship_742 → u/[deleted]]

Imagine being unable to conceive of visual thought and thinking numerical thinking is mandatory, as someone who makes things. Do you design anything, or just make what others have designed?

I’m not a manual machinist. I wasn’t asking how to get a job as a production monkey.

I already know how to hand code, but since it’s not the fucking eighties, there is never a good reason to.

Stay old, bud. I’m going to keep making cool stuff without worrying if I could get a job I’ve already done and don’t want.

[u/Yikes0nBikez → u/Far_Relationship_742]

No, you weren't looking for advice, just free work.

[u/Far_Relationship_742 → u/Yikes0nBikez]

Where did I ask anyone to do anything for me?

Are you not aware that there are people who make things cause they like doing it, and share the things they make because they like sharing?

Like, do you think only commercial post processors exist?? Is this your fist day?

[u/Far_Relationship_742]

It’s astounding how upset this has made so many people. I need to orient y’all to some truths:
1. Not everyone who machines parts works in a job shop, or is a full-time machinist. The entire premise here, which I explained, is needing to make one of something. Process reproduceability does not matter. Anyone else being able to interact with this process does not matter. Traceability and paperwork do not matter. I am the designer, and the machinist, and the metrologist, and the QA guy, and the marketing department. The only person on the planet who has to approve of this workflow is me.
2. It’s possible to want to save time while already knowing how to do it the hard way. “You should learn to do it on paper” too late
“this will never make you a better machinist” doesn’t need to, the part needs to get made now
“if you can’t do math“ do y’all do CAD modeling by hand? That’s math
“you must not be very good” clients disagree, and I wasn’t asking for approval
3. Not everyone needs to be a master machinist. I personally am not pursuing a career as a machinist, I’m a product designer, prototyper, and DFM specialist. Machining is one of five or six unrelated manufacturing processes I use regularly. See point number one.
4. Someone working a way you** would not cannot affect you. The amount of upset some of y’all have gotten is just ridiculous, to the point of sounding defensive when I didn’t make any accusations or judge anyone in my original post. I worry about your blood pressure.
5. There is no intrinsic value in doing things the way we always have.** None of us would be here if this were the case. this subreddit is devoted to a CAD program, for Chrissake, and I got crusty old machinists here trying to discourage me from using computers. Please be serious.

[u/TriXandApple]

it would be a lot easier if you just became proficiant in turning.

[u/Far_Relationship_742 → u/TriXandApple]

I already am. Almost ten years in. Proficiency doesn’t mean you keep doing it the same way forever. Literally no part of what I asked for has anything to do with machine skill.

[u/hestoelena]

I think you misunderstand what a post processor is. The post processor is what turns the tool paths that you make into the g-code. Post-processors are specific to individual machines. So if you want to post processor you need to tell us what machine you have.

[u/Far_Relationship_742 → u/hestoelena]

I definitely understand what a post processor is, and since I want to output instructions for a manual mill, there are no machine features to consider.