4th axis G-code question, maybe not UCCNC

[cncdrive]

And here A reaches A90-re and Z starts going to Z2.1225.

[spumco]

Balazs - thank for the analysis. Good to know.

However, Terry's analysis proved to be right on the money. It was clearly a programmer defect and not a controller or hardware issue. I clearly need to learn how to edit the Fusion post so it doesn't do stupid things, and also learn to recognize stupid things. Second more important that the first.

The part came out great, including the peck drilling and tapping, after fiddling with the code per Terry's guidance.

How quickly can I learn this stuff without breaking too many things...

Maybe I should get some rubber end mills and drills and test every program with my CNC equivalent of a hockey helmet on:)

Spider chuck 4th asi

[cncdrive]

Hi Spumco,

Ok.
Yep, learning new CNC controller and new CAM is always time consuming.
Maybe get a rubber CNC for training, I saw something like that on Alibaba.

[spumco]

Hi Spumco,

Ok.
Yep, learning new CNC controller and new CAM is always time consuming.
Maybe get a rubber CNC for training, I saw something like that on Alibaba.

It's not just controller and CAM. It's everything - no machining or electrical/electronics experience beyond a manual lathe before last summer. I'd be dead if it weren't for you guys and the internet.

[cncdrive]

What you need for operating a CNC is nothing more than logical thinking.
If you have that then you can learn it pretty fast.
And I know you have it, because you quickly figured out the possible cause for the rigid tapping earlier issue which was a type of issue that someone who has no good logic could never figure out.
So, I'm sure you will quickly learn these and will have success in CNC-ing.

[mrprecise]

I have been using 4th axis for many years, and it behaves in strange ways in the three different systems I own. It is always wise to do a dry run with no tool in the spindle for starters.

In the situation here, I would post a short dwell after the A rotation command. The command following the A rotation should not start until after the dwell period, which could be a 1 or 2 seconds. It it does move before the A rotation is finished with a dwell inserted, "we have a problem."

Looking at the code, I would think is would not move Z until the previous line completed.

Another option is insert a stop command, M1, to be totally safe. Go to Z clearance, rotate A axis, Stop, Continue progam.

Also, there does not seem to be a place to input the 4th axis material part radius in UCCNC yet, or else I have not found it. This has a great affect on the cutting speed if the tool is cutting with X,Z, A moving simultaneously. The feedrate will not be the same as a cut in X and Y making a vector cut.

Debugging programs using X,Y, and A is a huge time sink, as opposed to a flat plane with no 4th axis of rotation.

John