Messages

261

General Mach Discussion / Re: G16 and G83 interaction (again)

« on: December 04, 2017, 03:31:13 PM »

Hi Rich

From my experiments, I would say that the restrictions on 10-20, that you can only use G0 and G1 within a G16/G15 scope, ARE correct.
But the example included in the manual which uses the G83 instruction withing a G16/G15 scope is NOT correct. (I tried it out.)

My suspicion is that EITHER the example was written down but never checked, OR that the example may have worked a few years/versions ago, OR that the NIST Standard meant it to work but it was never implemented correctly. Dunno which one. I note that the same text and example are found in the Mach2Mill manual.

On the other hand, the G16 instruction is not listed in the HAAS manual for the VF/-HS series. HAAS do list a couple of bolt holes in a circle codes.

Cheers
Roger

262

General Mach Discussion / Re: Real 4th axis software for tilting spindle? Not trunnion table way...

« on: December 03, 2017, 03:47:24 PM »

Hi Frank

When I first looked at Fusion it was cloud-only (if I remember correctly!), and I wanted something to also use on my CNC PC - which is of course NOT on any network. Since then I have written my own g-code, very much in a 'programmer' style (parameters, subroutines etc). For a lot of my work that has produced superior code and superior product - and been adaptable to a semi-production environment making 10-off at a time.

Yes, I know CNC tool kit. When I first looked at it some years ago it was a bit bare-bones. And I didn't need the STL capabilities anyhow.

My machine is not home built per se: it is a limited production Australian two-spindle machine which initially sold for around $30k. I bought it 2nd-hand, mostly unused, and had soon to replace ALL the electronics. The original was DOS-based with large plug-in cards! Fortunately I have more than enough electronics experience for that.

But the original machine was 3-axis designed for steel and aluminium, not stone, and for dry machining, no coolant (MQL these days actually). I added a good 4th axis to that - written up at http://www.cnczone.com/forums/linear-and-rotary-motion/261174-cnc-engineering.html - that was MYOG.

Since there is so much steel in the machine, I have had to add a 'bathtub' system to it so I can use diamond tooling with water coolant (1st photo). In the limited volume of my mill that has been tricky. I must be up to V3 or v4 so far. But note: my mill is MUCH smaller than your machines! A little bigger than 'desktop', but able to handle steel and titanium.

How do I use Autosketch for 3D? Well ... I guess you would have to say I don't. I use it in 2D - and i am fairly good at using it, but the 3D stuff happens first and in my head. But that is because the things I make can be done that way. They are not 'the head of Julius Caesar' as it were. One day maybe I will have to learn how to carve heads ... In the meantime, geometrical things. The 2nd photo shows a wood prototype from some time ago.

Finally, tooling. At present all the tooling I use for rock is diamond: no carbide. But that is because I am (so far) machining basalt and granite. I dare say that if I was working marble or limestone I could use carbide. I use larger diameter hole drills for roughing out as they can be used as a diamond disk to some degree (ie side on), but my spindle is vertical with no tilt. At this stage I am still learning!

Cheers
Roger

263

General Mach Discussion / Re: Real 4th axis software for tilting spindle? Not trunnion table way...

« on: December 02, 2017, 09:43:23 PM »

Only 3
I stopped spending.

Cheers
Roger

264

General Mach Discussion / Re: Real 4th axis software for tilting spindle? Not trunnion table way...

« on: December 02, 2017, 08:01:03 PM »

I see. Thanks.
Mind you, right now I have about 3 different CAD systems, and they are all horribly slow compared to doing the design in my head and with AutoSketch, but that's me.

Cheers
Roger

265

General Mach Discussion / Re: Real 4th axis software for tilting spindle? Not trunnion table way...

« on: December 02, 2017, 05:55:20 PM »

Hi dude1

No interest in indexing, only in genuine 4 and 5 axis stuff. After all, Mach3 handles full 6 axis work.

Do I understand correctly? Fusion can handle continuous 5 axis but not continuous 4 axis? How ... odd.
When you say two 5-axis toolpaths  with more coming: does this refer to the different ways of physically arranging the hardware? (As in trunnion mount and nodding spindle etc)

Cheers
Roger

266

General Mach Discussion / Re: A-axis rotary lathe question for Mach 3

« on: December 02, 2017, 05:02:34 PM »

Yes, Mach3 can do polar coordinates using G16, but while in that mode it can ONLY handle G0 and G1.
Unfortunately the manual promptly shows code using G83, which violates the restriction and DOES NOT WORK - at least with V.062. This is due to how Mach3 handles default values and polar mode. It's a bug in a way, but a very esoteric bug.

I did not understand your question #2 - sorry.

Cheers
Roger

267

General Mach Discussion / Re: Real 4th axis software for tilting spindle? Not trunnion table way...

« on: December 02, 2017, 04:54:43 PM »

Hi Frank

Of great interest!
I am currently using a 4-axis machine to machine granite and basalt, but that is still in the early stages. The 4th axis is a B axis (parallel to y axis), although I usually call it the A axis. Mach3 does not seem to notice the difference. I am now adding a different 4th axis to the table - a sort of C axis as that can make some things MUCH easier to program.

I have looked at the options for a tilting spindle, but I was not able to find affordable CAM SW with that option, at the time. Ideas?

Your web site does not have an English version! Sob. A lot of work to add it, but ...

Cheers
Roger

268

General Mach Discussion / G16 and G83 interaction (again)

« on: December 02, 2017, 01:20:26 AM »

Hi all.

The Mach3Mill manuals states (10-19) that you can put Mach3 into polar mode, but that this only works for G0 and G1 instructions (Note 1, 10-20). I have no problems so far.

But the same part of the manual goes on to provide an example which drills holes on a circle using a G83 instruction, ignoring the restriction in Note 1. At least on my system, programming a ring of holes this way produces a screenful of rubbish. Trying to run the code does likewise. Changing the G83 instruction (or G81) to a simple G1 results in the program working perfectly.

My interpretation is that the command sets a flag saying 'polar', but that only G0 and G1 check this flag. Executing G0 x10 y20 works fine, and saves 10 and 20 in the 'current X&Y registers'. But note that these are POLAR values. If you then issue a G83 z-5 instruction, the interpreter first sends the spindle to X=10 Y=20 and then does the peck drill. But these are CARTESIAN coordinates!

This is as expected if you believe the restriction in Note 1 that polar coords only work for G0 and G1 instructions. It is a pity that the example in the manual violates that restriction.

Or do others get different results?

Cheers
Roger
PS: Brian Barker's hole drilling wizard uses the G83 instruction - but does NOT use polar coords. Of course it works fine.

269

General Mach Discussion / Re: Alright fellow campers...a frankenstein moment!!

« on: November 20, 2017, 06:06:53 AM »

OK, I understand both the theory and the economics. Fully.

Cheers
Roger

270

General Mach Discussion / Re: Alright fellow campers...a frankenstein moment!!

« on: November 20, 2017, 01:55:43 AM »

For large (20 kW+) I can see line reactors being necessary, but are they really needed for little hobby-class VFDs? I ask because I do not know.

Cheers
Roger