Cutting time differs in create and motion

Hey folks, I feel dumb but I can’t figure out if something changed, my software versions are different, or I’m doing something wrong! But, when I setup a job in Carbide Create it will give me a time to cut, say it’s 15 minutes, then it will have a different time in Motion. Quite a bit different too.

Any suggestions?

I have always had that issue. CM initially will show the estimate from CC but when the job starts it will increase by 10-20%. I don’t think everyone has that experience but I do.


Second on @CullenS comment. I have been using CC since v3 and it has always been wrong. In CM the time is likely correct for the actual cutting but it does not seem to account for rapids and bit changes. So take the estimates with a grain of salt.

I would suppose if the software engineers could give a more accurate time they would. Under the covers the CC and CM are quite complicated.

I’ve never quite understood this either. 2 applications from the same company giving disparaging results for the same calculation.

Time = distance traveled * feedrate. “Basic” time estimate is that simple.

One difference between CC & CM would be that CM should know the rapid feedrate, where CC would not know the parameter you set on your machine. So, logically the CM estimate should be a bit more accurate.

Some more robust/comprehensive software does take into account acceleration/deceleration, tool change time, pallet change, rotary axis feedrates ( degrees per minute ), etc… to get more accurate times. For what we do, this should not be necessary. For a big production environment where seconds count, it does.

I jotted down CC & CM times in the past & compared them to actual cut time on the machine. It was far enough off that I no longer pay attention to the times. I do sometimes compare “relative” time. i.e. I’ll make a change to the toolpath & compare the change in the estimated time, knowing that neither number is very accurate, but the relation between them is relevant. If my change goes from 100 minutes to 60 minutes, the actual cut time might go from 50 minutes to 30 minutes. A 40% reduction in time.