[subnoize]

Hello!

Some time back there was talk about supporting G93 Inverse Timing in madCAM. I was wondering how that was coming? The alternative driver software I'm using to get G94 mode to work with my 4 axis machine is just butt ugly on so many levels it isn't even funny! When I cut 3 axis using LinuxCNC the surface quality is just stunning. Madcam's output is very accurate and true to the model. I cut in 4 axis using "somebody else's" controller and it looks like a two year old's first clay sculpture.

So, it would be nice to know what is up with G93 support in Madcam? Is it even still an option?

Thanks!

[Gregore]

I am surprised that you are getting such bad results , my 4th axis without g93 is as good as my 3 axis finish. My friend set it up with a Kflop board by dynomotion. My friend was already to make his own controller boards until he found this one that had pretty much all the stuff he wanted.
He did not use their controller software he ended writing his own. But I still hope joakim will get it done soon as when we go to 5 axis the finish may suffer a little.

[subnoize]

Not only bad results but the short little pulses a smooth G93 move would make is reduce to thousands of tiny straight lines that cause tremendous vibration in my machine. I can't afford it but a friend generates the g-code g93 in Autocad and the mill is wisper quite and runs 6 or 7 times faster.

My hardware is a little more expensive than what you have but that shouldn't even matter. The CAM software is what makes the difference which is why such a wonderfull mill turning out such crap is a sad thing indeed.

[Dan B]

G93 functionality is on the list of new features being added to madCAM. Watch for it in a future service release.

Dan

[subnoize]

Thanks, Dan! I was jealous of the stuff a friend of my keeps turning out on my machine. Its like "my machine" but it works for everyone but me :-(

[loddie]

G93 inverse timing was discussed here and another thread a while back. Does anyone know if it was added to MadCAM 5? Thanks!

[subnoize]

G93 inverse timing was discussed here and another thread a while back. Does anyone know if it was added to MadCAM 5? Thanks!

No, no progress. I have been waiting for well over a year. It's not a high priorit I guess.

--jb

[subnoize]

No, no progress. I have been waiting for well over a year. It's not a high priorit I guess.

--jb

Make that 3 years so it isn't going to bappen....

[svenakela]

Make that 3 years so it isn't going to bappen....

There are things happening.
The status around G93 I don't know but I do know there are some really nice refactoring happening that starts with 2D and hopefully will come into play in 3D cutting in a not-too-far-away future. And those changes will affect your machine in a good way I'm sure.

Your machine, does it support G64 commands? If that's the case it will blend curves and a lot of the stop-n-go vibrations will go away (if not all). I use G64 P0.01 in the post processor for one of my machines and that tiny change makes a uge difference. Some controllers support G64 without the tolerance setting though and sometimes the tolerance is configured in a settings menu or file.

[loddie]

There are things happening.
Your machine, does it support G64 commands? If that's the case it will blend curves and a lot of the stop-n-go vibrations will go away (if not all). I use G64 P0.01 in the post processor for one of my machines and that tiny change makes a uge difference. Some controllers support G64 without the tolerance setting though and sometimes the tolerance is configured in a settings menu or file.

Svenakela, thanks for this tip. My EdingCNC controller does support G64, so I'm going to give this a try.

[Gregore]

I really do not understand why G93 inverse time feed rate would make it any less choppy the only thing it is doing from my understanding of it is slowing down the X,Y,Z feeds to match the speed of the rotary from any give center point , and really the only reason for this is to not take too much or too little chip load . If every one was cutting butter then G93 would not be needed as butter has a huge chip load range .

You mention that your friends cam produces smoother code for your machine , and I suspect that it is not the same post processor coding , so my thought is that maybe the post processor in madcam could be tweaked to not give you those choppy little codes

It sounds to me more like you are talking about arc moves that your friends machine is putting out

I think you should post some of the code here from madcam and your friends machine and see if anyone notices something that could be fixed

[Gregore]

I found a cleaner way of saying what G93 is really doing

The tool tip can be in a constant state of change relative to the center of each axis when in 5 axis mode and G93 is a formula that allows xyz to be sped up or slowed down to keep the feed speed at the tool tip constant to the request feed rate

I am not sure how not having that would creat shorter choppy moves

If it turns out to be arc moves that your friends machine is putting out then your in luck as there is a program that takes Gcodes and produces arc moves from it .

Metacut is the company and metacut finish is the product

[subnoize]

I am not sure how not having that would creat shorter choppy moves

It doesn't matter anymore because I use a G-Code genertaor from AutoDesk that fully supports G93 and LinuxCNC.

If I remember correctly the guy who set up your machine set the A axis to a constant speed. That was the other way of getting it to "sort of" work. That said, it was cheaper and easier to simply get software that fully supported LinuxCNC. In a bind I use that Mach3 crap and have a dual boot feature on my machine.

Maybe MadCAM will catch up and implement the Next Gen features and that would be nice! I do like the 3 axis output.


--jb

[svenakela]

It doesn't matter anymore because I use a G-Code genertaor from AutoDesk that fully supports G93 and LinuxCNC.

If I remember correctly the guy who set up your machine set the A axis to a constant speed. That was the other way of getting it to "sort of" work. That said, it was cheaper and easier to simply get software that fully supported LinuxCNC. In a bind I use that Mach3 crap and have a dual boot feature on my machine.

Maybe MadCAM will catch up and implement the Next Gen features and that would be nice! I do like the 3 axis output.


--jb

I run several heavy LinuxCNC machines with massive acceleration and the MadCAM output runs just fine. Don't understand why you need G93 for LinuxCNC, but on the other hand I haven't seen your machine.

[subnoize]

I run several heavy LinuxCNC machines with massive acceleration and the MadCAM output runs just fine. Don't understand why you need G93 for LinuxCNC, but on the other hand I haven't seen your machine.

As you are aware LinuxCNC requires G93 input for angular axis and linear axis to be used together. My machine is 4 axis. I did configure the system to use a constant speed on the A axis but it got real expensive either by breaking end mills or by taking a bloody week to do tiny projects.

I will be upgrading to the newest LinuxCNC v2.7.4 here in the next week, actually. I don't think they slipped in G94 to G93 interpretation while I wasn't looking. G93 is the next generation of G-Code so it is the future. Anything less is the past!

--jb

[Gregore]

Subnoize. Do you mind mentioning what you payed and poining t a link to it so I can look into it


Thanks

[svenakela]

. G93 is the next generation of G-Code so it is the future. Anything less is the past!

I say anything less than NURBS is the past.

[svenakela]

As you are aware LinuxCNC requires G93 input for angular axis and linear axis to be used together. My machine is 4 axis. I did configure the system to use a constant speed on the A axis but it got real expensive either by breaking end mills or by taking a bloody week to do tiny projects.
...

I see your problem now. Actually, LCNC doesn't need G93 for this to happen but your machine might need it. I remember there was a similar discussion at the EMC2 mailing list, it was more than two years ago and much has happened since then. I know the old trajectory planner didn't blend lines in rotational axis movements but as I said it was long time ago and the code has changed since then. What version of LCNC are you running? It might be worth an upgrade of the controller.

[subnoize]

Subnoize. Do you mind mentioning what you payed and poining t a link to it so I can look into it


Thanks

Uh, not sure what you are asking.

[subnoize]

I say anything less than NURBS is the past.

Which is exactly why I would love to see G93 in MadCAM.

Let's just be frank here, MadCAM's 3 axis output is beautiful. Very comparable to software costing 5 or even 10 times its price, Rhino3D included. (and for those who haven't priced this stuff, don't believe me and go price it yourself!)

I am sure the output for 4 and 5 axis is equally beautiful on controllers that can interpret angular and linear motion from G94 mode.

My machine needs G93 to run 3 linear axis with a A rotary axis. I am sad I don't have MadCAM beauty in all 4 axis.