Chadd
Posts: 9
Joined: Mon Jun 08, 2015 3:25 pm

Print time estimates way off.

Fri Sep 25, 2015 4:46 pm

My print times are way off from what S3D estimates the print time to be. Currently running a print that was estimated at 8 hours 48 minutes. It has been printing for 16 hours 44 minutes and shows to be 96% compete on the machine control panel.

Why is it so far off on the estimates? It may not seem like a bit deal but I don't like to leave the printer unattended and when you expect something to be completed in just under 9 hours and it takes closer to 18 hours that is an issue.

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dkightley
Posts: 2282
Joined: Tue Mar 10, 2015 4:09 pm

Re: Print time estimates way off.

Fri Sep 25, 2015 5:22 pm

Do a search on the forum and you'll find several threads on the subject.......and reading them will give you all the information there is.
Doug Kightley
Volunteer at the National Tramway Museum http://www.tramway.co.uk
Railway modeller and webmaster at http://www.talkingtgauge.net

Chadd
Posts: 9
Joined: Mon Jun 08, 2015 3:25 pm

Re: Print time estimates way off.

Fri Sep 25, 2015 11:48 pm

dkightley wrote:Do a search on the forum and you'll find several threads on the subject.......and reading them will give you all the information there is.
I did search before posting and none of the threads had any info in them. Just people saying the estimates were way off.

Was hoping to hear something from S3D as to why the times are so wildly off and if they are working on it or of there is a work around.

dsegel
Posts: 159
Joined: Tue Sep 30, 2014 5:37 pm

Re: Print time estimates way off.

Sat Sep 26, 2015 12:09 am

They're off because there's no way for S3D to know what kind of acceleration or jerk settings your printer has defined in firmware, or how those settings affect the actual speed your printer's motors are able to achieve. The best it can do is estimate based on actual linear motion and feed rates. There's simply no way for it to be 100% accurate.

Chadd
Posts: 9
Joined: Mon Jun 08, 2015 3:25 pm

Re: Print time estimates way off.

Sat Sep 26, 2015 9:14 pm

dsegel wrote:They're off because there's no way for S3D to know what kind of acceleration or jerk settings your printer has defined in firmware, or how those settings affect the actual speed your printer's motors are able to achieve. The best it can do is estimate based on actual linear motion and feed rates. There's simply no way for it to be 100% accurate.
I understand that it can't be 100% accurate but to estimate less than 9 hours and it actually takes 18 hours? Jerk settings aren't going to add 9 hours to a print.

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kiwisam
Posts: 9
Joined: Tue Jun 23, 2015 5:33 am

Re: Print time estimates way off.

Sun Sep 27, 2015 4:29 am

I did search before posting and none of the threads had any info in them. Just people saying the estimates were way off.
Maybe you never noticed this thread. viewtopic.php?f=8&t=3435

A look at the attached file from a spreadsheet should give you some idea as to why estimated times can be so different from actual print times.
My only observation is that the complexity of the print is a major contributor to extended print times and it is almost impossible to calculate an estimated time from any known factor or group of factors.
Not much help I know, but that's the way it is.

Cheers

Sam

tmorris9
Posts: 43
Joined: Thu Apr 24, 2014 11:30 pm

Re: Print time estimates way off.

Tue Sep 29, 2015 12:06 am

I have the same issue.

Other slicers allow an estimate change. They could do a value of 100% as default (for the current setting) and allow you to make the number larger or smaller to adjust the estimate, after a few prints it would at least be close.

I had a 12 hour estimate the other day that ended up actually taking closer to 19 hours.

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Viceman
Posts: 29
Joined: Wed Sep 23, 2015 3:47 am
Location: Finland

Re: Print time estimates way off.

Tue Sep 29, 2015 6:31 am

Maybe there could be an option to simply scale print time? I am going to make my own timer and multiple the estimated S3D time regarding my own prints. Afterall this would be nice to have adjusted somehow.

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jimc
Posts: 1124
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Location: mullica, nj
Contact: Website

Re: Print time estimates way off.

Tue Sep 29, 2015 8:23 am

the problem is the time that s3d estimates is not the same for all prints so simply adjusting the time 50% longer for instance wont work. you may have one print that is 50% longs and another that is only 10% longer then the next 75% and so on. generally it depends on acceleration and how many travel movements, retractions you have in your print.

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dkightley
Posts: 2282
Joined: Tue Mar 10, 2015 4:09 pm

Re: Print time estimates way off.

Tue Sep 29, 2015 9:41 am

This is something that will never die, I'm afraid......

One dictionary definition of the word estimate is: "an approximate calculation or judgement of the value, number, quantity, or extent of something."

The problem with computers is that neither can they make an "approximate calculation" nor can they make a "judgement" .....so its going to be impossible....without a good injection of AI.....for any algorithm to be able to come up with an accurate "estimate" of print time.

And looking at this from another perspective......from a business point of view. You ask a builder to let you know what it will cost to build an extension. Would you be expecting an estimate.....or a quotation? An estimate would be "In the order of £xxxx." whereas the quotation would be "It will be £zzzz."Are S3D users expecting an estimate or a quotation??

Perhaps instead of the Build Statistics having "Build time: 0 hours 24 minutes", it should be changed to "Rough estimate of what the build time might be based on information available: 0 hours 24 minutes."
Doug Kightley
Volunteer at the National Tramway Museum http://www.tramway.co.uk
Railway modeller and webmaster at http://www.talkingtgauge.net

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