is there a Post Processor for 4th axis in Inventor HSM 2016

[mirza623]

Hi,

We have a 4-axis CNC gantry machine. I have attached a picture of the machine. We have recently downloaded a trial version of Inventor HSM 2016 for evaluation and potential purchase of a seat. Could anyone suggest that what would be the nearest Post Processor for our machine in the existing list of postprocessors in HSM?

As you can see in the picture, we have two cutting tools installed on our machine. One is Router and other one is Saw.

The blue vertical shaft carrying the saw has the ability to rotate 360, so we are looking at a 4-axis CNC Panel Cutting Machine.

We are having problem in post processing for the Saw which is installed on the rotary axis.

Any suggestions will be highly regarded.

Thanks,

Mirza.

[AchimN]

We definitely need more information for this. Which controller is installed on the machine?

[Laurens-3DTechDraw]

Achim wrote:
We definitely need more information for this. Which controller is installed on the machine?

Indeed and info on how you plan on programming the saw.

[mirza623]

Hi Achim and Laurens,

Thanks for a prompt response.

Controller is Weihong NK300A.

http://en.weihong.com.cn/products_detail/&productId=c022d973-7d1d-46c1-bde3-506ca3fadb91.html

I have attached some pictures representing axes directions and relative distances between the too shafts (Router and Saw).

All dimensions are in millimetres.

The pivot distance for the Saw is 304mm as shown in Pic4.

The Saw program is done as follows:

Once the job is placed in the machine, reference is set with respect to the Router spindle(X=0, Y=0) as shown in Pic2. The G codes for the Saw should be generated with respect to the same reference. Pic1 shows the Default location for the Saw (A=0 degrees). We dial our saw rotating in positive direction then set A=0 and only rotate it in positive direction when run by the program to avoid any backlash effect. Maximum angle we go is 270 degrees.

I am more than happy to share any other information you guys need to know help us out. Let me know if any other info is needed.

Thanks a lot guys,

Mirza.

[scottmoyse]

Hi Mirza,

Are you able to share some sample code from a typical program please? Also do you use that saw in & around nested parts on the machine? If so could you share a typical nest please?

[mirza623]

Hi Scott,

Thanks for your response.

I have attached a sample program.

We don't use nested parts setup. The process is one part per program. Normally the program is between 15 to 20 lines. The program is small but it is equally complex to get the right coordinates.

Saw cutting workflow is as follows:
We always start the first cut at A=0 degree. So, we don't give that command (G01A0F300) in the program. Also we first finish all the cuts that need to be done at A=0. Then we rotate the Saw for next cuts. I have attached a picture showing that.

In some cases cut at an angle also needs to be done.

Any help would be much appreciated.

Thanks,

Mirza.

[scottmoyse]

Excellent, thanks for the info. Out of curiosity, is the length of the 1st cut greater than the diameter of the saw? If it isn't how do you typically deal with that?

[mirza623]

Hi Scott,

Very relevant question indeed.

Normally, each part needs to be cut from both sides. Meaning, we perform the cuts on one side of the part then flip it up side down and finish the cuts on the other side. Cutting from one side would leave material at the bottom surface anyway. I have attached a picture showing that.

So, In case the cut length is smaller than the Saw diameter (which happens quite frequent), we reduce the depth of cut. I have attached a picture showing that.

Thanks,

Mirza.

[scottmoyse]

Ok, so how do you detach the offcut when its being held on with the red areas?



Part of the difficulty here, and Laurens touched on it, is how to create the toolpaths in Inventor HSM in the first place. I'd love to figure it out and will spend some time on it tomorrow.

[mirza623]

Hi Scott,

In this case the detachment is done in a separate process in the QC department and not on the machine under discussion.

Thanks,

Mirza.

[scottmoyse]

Mirza wrote:
Hi Scott, In this case the detachment is done in a separate process in the QC department and not on the machine under discussion. Thanks, Mirza.

Ok, excellent, I just wanted to make sure I wasn't missing anything. Cheers.

[Laurens-3DTechDraw]

scottmoyse wrote:
Ok, excellent, I just wanted to make sure I wasn't missing anything. Cheers.

Since we are talking a full version and not Express I guess scott that you could look at changing the tool orientation to be so that the Z would 90 degrees from the side you want to saw. That way you can find saw moves in the post(Since oriented) and make the program understand how far it can cut into the model when you define the diameter of the saw as a slotting tool. It will be some serious post editing though. Since it has an offset from the main spindle and you would need to make the post understand it's not actually oriented(Not that hard just something to think about.)

[scottmoyse]

I was curious if we could treat it as machining a slot. We would have to capture each rotation of the operation origin each time with some kind of marker that is a saw cut. Then trigger that special routine in the post. Achim, do you think this is feasible at your end?

[Laurens-3DTechDraw]

scottmoyse wrote:
I was curious if we could treat it as machining a slot. We would have to capture each rotation of the operation origin each time with some kind of marker that is a saw cut. Then trigger that special routine in the post. Achim, do you think this is feasible at your end?

Biggest problem is that you have to calculate how deep you need to cut with the saw yourself. (Since simulation doesn't work either)
So that's why I thought going the way it actually can calculate this for you and simulate correctly is the way to go.

[mirza623]

Hi Guys,

I simulated the tool path in Inventor HSM. I have attached a video file showing the path. Tool path is not optimized between cuts but that we can fix later. This is just to represent what we are looking for to be converted into G codes.

Thanks,

Mirza.

[scottmoyse]

Mirza wrote:
Hi Guys, I simulated the tool path in Inventor HSM. I have attached a video file showing the path. Tool path is not optimized between cuts but that we can fix later. This is just to represent what we are looking for to be converted into G codes. Thanks, Mirza.

I was just about to try this out.. but looks like you have already nailed it!! Well done.