Haas G-Code for 4th axis

[CJH]

We are going to be getting a 4th axis for our TM-1 soon. I have been exploring the use of Artcam Pro that we are using for some of the work. I have seen that we can do some 4th axis work with it. But don't know exactly what our G-Code should like for this type of work. I wanted to look at our posts and see if they are capable of producing rotary moves. So I am going to be trying some of them and also contacting our reseller for assistance as well.

What I am interested in getting help with from this forum is getting a few lines of sample code so that I can have a reference when I am trying our posts. This way I have something to compare our posted code to.

Would any of you guys have some sample lines that you could post to help me out?

Any help would be appreciated.

Thanks, CJH

[HuFlungDung]

Well, an A is the axis description, and represents an angle in degrees. Big help, huh?

Probably the main problem is getting appropriate feedrate commands out of your CAM. Haas is pretty easy that way, as it has a setting in which you tell the control what diameter is the main diameter of your 4th axis job. There is only one diameter allowed per job, but this does cover a lot of 4th axis type work anyway.

From that diameter input, the control can auto-calculate the appropriate A feed from a common linear feedrate command. So if X is moving at 10 ipm, and you write
A90 F10.
the control will calculate the feedrate in degrees (in the background) and turn the rotary so that the circumference is traversing the tool at 10ipm at that diameter input.

Compound moves like Xx.xxxx Aa.aaa will execute simultaneously, at the current linear feedrate as well. Both axis begin and end motion simultaneously, so a linear feedrate command will work.

Now if you have widely varying diameters to the job, then you'll probably want to invoke inverse time feedrates, and you can read about this in the Haas programming workbook. I don't know how fancy of a CAM system you'd need to calculate inverse time for varying diameter A axis work, but probably pretty expensive. I've never needed that myself, so I haven't looked. I'd probably hand edit some code if it really needed it.

The ability to do 4th axis continuous is usually tied to a 4th axis wrap ability in the CAM. This involves creation of a 2d map layout of the surface features in CAD, then by a trick in the post, the Y moves are converted to A moves with a simple formula applied. This type of continuous 4th programming usually forbids use of Y at all during the course of running the program, because the tool is assumed to be centered over the rotary axis and to remain there for the duration.

[CJH]

Hu,

Thanks for replying. I did know about the A Axis description. I just wasn't sure how it would be designated in the code, or if there were other variables that would be posted that I should be looking for. I figured that it would be better to ask a question first and then do some simple research in order to better educte myself. I have used manual indexers before on our mill, and always break up the programs for each side, and just manually turn them. But the programs can be quite long, and having an atuomated A axis will be a nice addition.

Since there is only one diameter allowed per job I would figure that it would be largest diameter of the stock, and anything smaller than that would just be included in the overall code created by the CAM software. I don't know why I would need to use inverse time feedrates, but sounds like I should at least look into them.

Some of the things that we would be machining are highly complex objects coming from scanned data. We could be maching things like human skulls, artifact statues, or all sorts of things, in addition to mechanical parts.

I am posting a pic of one such things from a while back that I machined, just to give an idea of some of thing we do in our shop.

[HuFlungDung]

Probably that kind of work might fall under 4th axis positional, which is a fairly simple implementation of 4th axis where you rotate the work to a suitable access angle, basically giving you the ability to make 3d toolpaths at the new A angle, without further A moves for the duration of those operations.
Rotate and repeat as required to gain tool access to all areas possible on a 4th.

Since I am familiar with OneCNC but not Artcam, I don't know what capabilities the latter has. But in OneCNC, for that job, I might rough as just described, then opt for a finishing routine, which is like a planar finishing routine, with tiny incremental A axis movements between each pass. So to visualize this, the tool would be moving along in X and Z to follow the model, then at the end, the tool would lift to clearance, the model would be rotated a fraction of a degree, and another pass would follow, in X and Z to the other end of the model, always parallel to the rotary axis.

[CJH]

The indexable approach is what I did origonally since it was done manually. I had to machine it from 6 different directions, the top of the skull, underside to access the roof of the mouth and skull base region, then on the manual index head for the rest of it, turning it 90 degrees each time. I just used that skull as an example of things we will be doing on the new rotary. We have Esprit, which is what I origonally programmed this in, but don't have an A axis license and it is a considerable upgrade cost to get one. We also have Mastercam for the new router we just bought. Not sure if the 4th axis license was purchased for that one, since we just bought it and haven't used it yet. I know it's capable of a lot though. I just wanted to have a little background info when expirimenting with Artcam and also talking with our reseller.

The skull job was a whole series, for forensic reconstruction sculptures for an exhibit, set to open early next year. The 4th axis is going to afford us the luxury of doing a lot more of this type of work.

Your approach you described if done in OneCNC sounds, like one of many different ways to approach it. I wouldn't consider doing this as a continuous interpolated rotation job, since there is just way to many things that could go wrong, plus it would probably be a massive program and take forever. But it's nice to have other opinions on how people are approaching work, since it probably differs from my way of things. As anybody would say there are probbaly 100's of ways of going about machining. Some just yield better results than others depending on the parts.

So while I'm thinking of it I'll ask another question. Are there any limitaions on the feedrate in which a 4th axis can turn and still yield good quality surface results? I know there will be variables like material and cutters that need to be taken into account.

Well I have to get going, I'll check back in on this thread when I'm back at work on Monday.

[Donkey Hotey]

The Mastercam question depends on which version you got. I'm pretty sure that after MCX came out, 4th axis was optional. In fact: that's why I bought MC9 when I did. It meant that I got 4th axis included and my MCX license grandfathered that capability.

So the question is: was your Mastercam license purchased back in the MC9 days and just updated, or was it bought under the new pricing model?

I'm interested in this thread and what you learn. I've got a T5C trunion rotary (HA5C rotary bolted to the HRT210 rotary).

I plan to use each of the rotaries alone (as you're suggesting) and in 5-axis combination. I'm working a project right now where I'm going to eventually put that thing in the machine and figure all of this out.

[Barney]

Hi I have Haas HS1-RP and need the quickcode file for it, does anyone know where I can get the file emailed to me or download it, my machine is a 1996 model. Thanks in advance for anyone who can help me. Please email it to me if you have the file saved somewhere, thanks! barney