Mastercam Cycle Time Versus Machine Cycle Time

[Bill Sutton@Accurate Machine]

We have programmed a part and the mastercam cycle time of the part was 6 min 12 seconds. Got it on the machine and the cycle time was 8 min 58 seconds. Some of the time is used by tools changes. Where is this time being lost at. What can we do to get the times to match up.

 

 

Thanks

[medaq]

I personaly dont think mastercam can get it right. Since mastercam does not know your tool lengths and what z travel down time is. It only knows the actual program cutting time, and that one is a little funny sometimes to. There are other factors it can not compensate. Accel and deaccel. Mastercam invisions 10g machines

 

Jim

[chris m]

There are numbered questions in your post for avg toolchange time and rapid traverse rate, you might want to play around with and see if that helps

[Müřlıń®]

One cause...

 

Slide driver voltages will drift over time and need to be adjusted in order to maintain proper IPM.

 

 

Another I have found....

 

If you are using helix entry and are outputting lines instead of helix, the time will not be right.

 

I run 18 hr programs and Mastercam computes cycletimes within a couple min.

 

I set the rapids to a given IPM in my post so it knows.....

[heeler]

We have adjusted the tool change and rapids in our post, and it is pretty close unless you are drilling alot of holes. The machine has acc/dec where as mastercam just figures distance divided by speed equals time.

 

HTH

 

Glenn

[Bill Sutton@Accurate Machine]

Where can I add the time for Pallet change Time

 

 

Thanks

Bill

[wildcat99]

I take Mastercam time and add 30sec. That gets me suprisingly close on cycle times similar to yours.

 

Most of your difference is probably from tool changes. Measure your tool change time and put it in the post like chris suggested. It will make a world of difference.

 

This may be stating the obvious, but make sure feedrates are not edited on the floor and the feed override is at 100%.

HTH

[Chad M]

+1 wildcat99.

When I add tool change time to MC time it is right on the $.

[Tom Dorgan from American Precision]

I have my rapids and tool changes in my post and my programs times are so close we use my times for quoting purposes.

[Mike Mattera - TFM]

If your machine has a rapid rate of 1000 ipm and your moving .750 between holes, your machine will never hit the 1000ipm.

 

If your drill is pecking up and down, same thing. Lots of motion never hitting Max rapid rate.

 

If you try to moxe X 10" Y5" and Z2", your machine will adjust (lower) the rapid rate so all 3 axes hit the target at the same time. Because if all 3 were moving at 1000ipm the Z would reach target first, the Y second and the X last. It would not be a straight line.

 

All of these are small, but they add up with lots of holes, lots of rapids and lots of toolchanges.

 

Mike Mattera

[chris m]

Agreed that you'll never hit your max rapid in short moves, I'd try some downward adjustment in the MC rapid rate if you are looking at a lot of little moves

 

On your 2nd point, most CNC machines don't rapid in a straight line

 

C

[heeler]

quote:

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On your 2nd point, most CNC machines don't rapid in a straight line

 

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I know on the fanuc there is a parameter to have them by sync'ed or not.

 

Glenn