milling a very simple feature on a CNC mill?

[Black Forest]

When I get finished with the CNC conversion to my mill what hoops will I have to jump through to mill something as simple as a short slot in flat material? Will it be as simple as load the correct to in the spindle and then go to the MDI input and enter some short g-code strings? I sure don't want to have to go into Fusion 360 and model a part and then output a file in the CAM program, then load the program onto the mill control. This mill will have a Centroid controll. Right now I would mount the workpiece on the mill. Use my 3D taster to find the X and Y edges and then use the DRO to job to the correct location and either plunge a center cutting end mill or drill a hole first and then use the end mill to mill the slot. So say I wanted a 25mm long slot 10mm wide through 10mm flat steel plate using either a 10mm endmill or and 8mm endmill. How complicated would the g-code be to accomplish that without CAM?

[metalfixer]

I have been using "Mill Wizard" for 4 or 5 years, and it does everything that I need.
The website says it's Beta, but it's been that way for years.
Newfangled Solutions LLC - Mill Wizard

[Toolguy]

The Centroid control reportedly has a good conversational program. In that case you would ignore the G code and either mill it manually like normal, using the handwheel on the control panel, or you would write a program in conversational with a start page, a mill page, and an end page. On each page, you fill in the blanks in the language you want to work in. This can be done on the control panel or offline on a desktop or laptop computer. When you write the conversational program, it automatically writes the corresponding G code for you. The machine runs off of the G code.
It would take me about 5 minutes to write that program on my mill, at the mill control. You will need to set Z zero for each tool you will be using. Normally the top of the workpiece, with a .001 shim under the tool, handwheel the tool down close to the shim, then work down in .001 increments till it traps the shim. Pause between each .001 click on the handwheel till you get there.

Make sure to verify the program on the screen before you run it to catch anything you don't want it to do. Until you know the control pretty well, it's a good idea to run it the first time in air, maybe with the tool out of the spindle to make sure it's doing what you meant, not just what you said. During the first run, keep your hand over the E stop in case it does something you don't like. You WILL break some tools on a CNC machine. Sometimes a new expensive solid carbide one. That is part of the learning curve. You always pay for your education one way or another. Everyone hates that part.

By this time next year, you will be an old pro, easily making anything you want to on it. One of the best things about a CNC machine (there are many), is thread milling. You can thread mill any thread you want, right, left, inside, outside, straight, tapered, any pitch, etc.

[elf]

Less than 3 minutes to create the toolpath in Fusion 360....

[Doc Nickel]

This is the big sticky point to home-shop CNC.

Once you're used to the process, a fellow can make a simple cut with a CNC almost as fast as a guy can set it up and cut it on a manual mill.

But it's that getting used to the process thing that trips up a lot of people.

Centroid has, as noted, a pretty decent "conversational" system, and with not too much practice, you can do fairly simple bits relatively quickly. But it won't be overnight.

You'll basically "find" your part, tell it where to start the slot and where to end it, the feed rate and RPM and all that. The manual can walk you through it, and for my Centroid lathe, I made up some "cheat sheets" to help.

Doc.

[polaraligned]

Yeah, Centroid has a good conversational, but on my machine I often just use the MPG to do a simple slot or facing. Just crank it and you can see your IPM speed on the display. Full speed cranking gets me about 8 to 10 IPM with the MPG.

[elf]

How hard is it to add a roughing pass on each stepdown in converstional? A simple slot isn't that simple if your tolerances are tight.

[Toolguy]

I use my smaller CNC manually about 1/2 the time. It's the easy way to just square the end of a part, drill & tap a hole, face off the top of something, etc. My MPG handwheel can be set to 14 different amounts per click of the handwheel, including .0001, .0005, .001, .002, .003, .004, .005, .006, .008, .010, .012, .015, .0175, and .020. For general manual milling, the .005 works pretty well. For doing setups, edge finding, tool setting, and indicating, the finer settings are the best.

[skunkworks]

find out what you are comfortable with.. I mostly write small gcode programs to do stuff like this...

sam

[Toolguy]

How hard is it to add a roughing pass on each stepdown in converstional? A simple slot isn't that simple if your tolerances are tight.

I use an undersize endmill for making slots. Just write a page to start a certain depth, end a certain depth, with whatever incremental steps you want in between, running down the middle. That takes out all the meat, then a page to go full depth down one side, move over down the other side, and done. If close tolerance, I do the sides a bit undersize with a spring pass or 2, measure, edit the page to do the same again, taking off the diff between the measured size and the finish size. In 22 years of making everything I needed to make, I ended up never learning G code because the conversational has always done anything I needed.

[Bented]

This depends entirely on the control.

I have never used a Centroid control so do not know if it has a conversational mode.

A conversational control requires no G-Code for simple operations such as slots, pockets, bolt circles, circles, radii, hole patterns and rigid tapping.

[Toolguy]

This depends entirely on the control.

I have never used a Centroid control so do not know if it has a conversational mode.

A conversational control requires no G-Code for simple operations such as slots, pockets, bolt circles, circles, radii, hole patterns and rigid tapping.

You are talking about canned cycles. A real conversational control allows you to program toolpaths or anything you want without G code. The only thing that really requires a downloaded G code program is 3D contouring. But then, no one writes G code for that anyway. That is always done with CAD/CAM. My conversational will even do limited 3D contouring, as well.

[lakeside53]

I use the Acurite Millpwr in conversational mode. Sure, it can run G-code but I've made some awfully complex parts in conversational mode. Never have has to resort to G-code in 10 years, might never. It even directly imports DFX for layout if needed. A slot? Maybe 30 seconds to enter the parameters. On mine I can specify a finish pass, stepover, everything... If my tools are wearing I just measure the result, add that into the tool size and hey, spot on.

[macona]

For a lot of simple stuff I just use jog and the MDI. MDI to get to the starting point and then jog to take the cut. Or if I know exactly what I want to do Ill just enter all of it in the MDI.

Once there is anything like a curve or pocket then I will just blast it out in cad and cam. Does not take very long at all. Seems more of a hassle than it really is.

[Bented]

You are talking about canned cycles. A real conversational control allows you to program toolpaths or anything you want without G code. The only thing that really requires a downloaded G code program is 3D contouring. But then, no one writes G code for that anyway. That is always done with CAD/CAM. My conversational will even do limited 3D contouring, as well.

Indeed, the OP asked a question about producing a simple pocket (slot) this is a canned cycle and requires little or no code.