How do I start programming with a true fourth axis?

[DavidSV]

We have 2 rotary indexers right now. I control them currently with a manual entry function. Usually, when I program a part for them I will use a different WCS for each index position and program everything in the top tool plane for each WCS. Later this week we are having a true fourth axis installed on one of our machines. How would I program that to use the post to control the fourth axis?

 

Thanks

[Namliek_J@TheeCircle™]

Axis Substitution.

[Justin Beebe at Folsom Tool]

DavidSV

 

Leave WCS set to top for all operations and create new TC/planes for each side of the part you want to machine. The TC/planes will give you the rotation. Since you stated that you have been programming in the top plane, I am assuming you have vertical milling machines with The A-axis rotating about the X-axis. Always program from the center of rotation. Meaning Y0 and Z0 are at the center of rotation. X0 can be anywhere you choose. Depending on you machine I would also download a copy of mpmaster 4-axis mill post. It works great.

 

HTH

[YoDoug®]

As others have mentioned the Mpmaster works great for 4 axis work. I use it all the time with the advanced 5 axis swarf set to 4 axis outpur for milling windows in trolling reel frames. It will even post inverse feed time feed rates. If you are interested I can send you a sample file that has the toolpath I am talking about.

[Colin Gilchrist]

As others have stated, it makes it so much easier if you program from the center of your rotary axis. To do this you need to calculate these numbers on your actual machine, then measure from the center to your work offset location in XYZ (X is optional). Position your geometry in Mastercam so that the location your are going to use as your offset is at those numbers.

 

To expand on Doug's example, say you are programming a vertical machining center with a live fourth axis. To make your life easier, you've installed a fixture block on the 4th, with a live center at the other end.

 

Let's say this fixture block is 6" square and 30" long, and has a series of tapped holes for bolt down locations. You faced all 4 sides of the rectangle to make the block totally square and true and now it measures 5.920 exactly across each side.

 

Your centerline distance in Z is half that, or 2.96.

 

Now you decide to add a vise to your block, so you mount it and square it up. You decide that this job will use parallels and a work stop, so you mount those as well. Now from the top of the face to the top of the parallels, you measure 2.1483. Add this distance to your block centerline measurement and you get a Z distance of 5.1083. Then you measure the distance from the centerline in Y and you get 3.1281.

 

This is where you would model your 'XYZ zero' point, and draw all your geometry from. Like others have said, create one WCS, and then create rotated tool and contruction planes by rotating the WCS about the X axis. Mastercam uses these planes to automatically calculate the correct A rotation angle and outputs it to the NC code. All of this is for rotatry axis positioning...

 

For true live 4th cutting, you will want to use one of the multi-axis toolpaths (curve and swarf are the two easiest to use and learn) set to only 4 axis output. You might need a multi-axis license to use these toolpaths.

[Matthew Hajicek - Singularity]

For indexing I use multiple planes with different origins, putting the origins somewhere the operator can indicate them in. This way the part doesn't have to be in the same place in the real world as in my computer relative to the rotary axis, which is especially important for second or third ops. For live rotary though you need the origin to be on the rotary axis, and everything has to be where it's modeled.

[DavidSV]

Thanks for the replies. I did a test program and it seemed to work when I created new planes, but did not make them a WCS.

 

I guess the only issue is now if I run an old program on the new fourth axis, where all the indexing was with manual entry. There is no easy way I have found to change the operations WCS to top while leaving the T/C planes the same.

[Colin Gilchrist]

No easy way, but you can do multiple operations at the same time.

 

Select the affected operations and right-click, edit selected operations, change common parameters, activate and click on the planes button. Set your WCS to top, turn off the "display relative to WCS" check box, and change your C/T planes to what ever plane you need.

[DavidSV]

Thats a good idea Colin, Thanks