topic Re: Machining time calculation in Fusion Manufacture Forum

Machining time calculation

Martema — Sat, 12 Oct 2019 19:01:16 GMT

Hello all,

Does everyone has this problem with bad calculation times or is it just me? If I add up all operation times I get 222 seconds or 3 mins 42 seconds. Machining time shows 2 mins 16 seconds. So this time is 1.63 times shorter then the actual machining time. What can be done to have more accurate machining time predictions, if any? And this problem is not with this part. I saw that this happens quite often. Is it very hard to program a sum of several numbers or what?

Re: Machining time calculation

Martema — Sat, 12 Oct 2019 19:20:07 GMT

And what is wrong with tool changes calculation? Why there is always only one tool change?

Re: Machining time calculation

daniel_lyall — Sat, 12 Oct 2019 22:19:51 GMT

It is a best guess and that is all, a lot more info would be needed to get it bang-on and at this stage, it can not be done.

Re: Machining time calculation

engineguy — Sat, 12 Oct 2019 23:02:23 GMT

@Martema

Tool change is an easy answer, in your file you have all your tools numbered as T1, if you number them as T1,T2,T3,T4 then it will show as 4 tool changes in your simulation.

Regards

Rob

Re: Machining time calculation

engineguy — Sun, 13 Oct 2019 22:42:15 GMT

@Martema

@daniel_lyall

Well folks, I have had a play around with the numbers and it is possible to get reasonably close to Machine times for a single operation but it is a pretty dreadful system for sure and multiple operations are near impossible as @daniel_lyall rightly points out !!

One it doesn`t seem to add in rapids or tool change times, to be fair it does say "Machining Time" so it only covers the actual cut and any leadin/out distances.

As one would expect there is a direct correlation between the "Machining Distance" value shown in the simulation "Statistics" tab and the feed rate set for the operation, if for example the "Machining Distance" shown is 242.698mm as in the example attached setting a feed rate of 242.698 mm/min for ALL the moves in the operation then the mill should take 1.0min to make the leadin/out and the cut not including the rapid to start position and a tool change so those would have to be added for real accuracy 🙂

It actually comes out at 1.01min !!

Well, that looks simple enough you say, just use multiples of the 242.698 value eg x2 then you should have 30 seconds or whatever, not so simple, there is another variable to play with and that is the "Feedrate Ratio %" under the "Machining Time" tab in the Machine configuration which is set to 100% by default, adjusting this value allows you to adjust the actual time shown for the operation to the correct figure for the feed rates used !!

BTW I have no idea where the odd .698mm came from, the distance should have been 242.0mm, could be something to do with length of the Vertical arc ??

Once you start using different feedrates for stuff like the leadin/outs/ramps/helical etc, etc then you are spending way too much time with a calculator and not getting any real work done !!

Is it worth the effort ?? Not IMHO that`s for sure but it was fun playing around with it 🙂 🙂

Maybe if some enterprising genius could come up with for example something like a small XL type file or an "App" that could do it for us that would be great 🙂 Ah, wait, that would be the Development Dept wouldn`t it, but I certainly don`t see it as an essential "get it done any time soon" thing so I for one won`t be pressing them for it !!!!!!

How sad can we get doing stuff like this ? 🙂 ? 🙂 ? 🙂

P.S. There are plenty of good Backplot softwares out there, some free ones as well that you can input your generated G code into that will give you a pretty accurate time for your job!!

Regards

Rob

Re: Machining time calculation

Anonymous — Tue, 02 Jun 2020 11:46:14 GMT

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