wirlybird
Posts: 1015
Joined: Sun Jul 17, 2016 12:32 pm

S3D Misses The Mark On Weight And Time Esimates By A Lot!

Mon Feb 11, 2019 5:53 pm

Just finished one of 4 parts I am doing in ABS.
The part has rough dimensions of X=202, Y=117 and Z=132mm
It is pretty straight forward. No odd overhangs or things like that and no supports.

It could almost be just a big rectangle with a few vertical holes all the way through.

4 perimeters, 5 top/bottom layers with full honeycomb at 50% infill.

It estimated at 540 grams and 45 hours to print.
It ended up at 630 grams and 58 hours to print!

This isn't really a complaint but more an observation since I do give price estimates based on the estimates S3D provides.

zemlin
Posts: 251
Joined: Mon Feb 01, 2016 11:36 am

Re: S3D Misses The Mark On Weight And Time Esimates By A Lot!

Mon Feb 11, 2019 10:26 pm

Make sure the DENSITY of the filament you are using is set correctly. When I've checked part weight predictions they've been spot on. That calculation is a cake walk compared to print time.
Last edited by zemlin on Tue Feb 12, 2019 8:21 am, edited 1 time in total.

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Re: S3D Misses The Mark On Weight And Time Esimates By A Lot!

Tue Feb 12, 2019 3:28 am

That is indeed very annoying. It's the one part I really hate about Simplify3D, the terribible undercalculation of time.

And for the last update they promised great improvements in time calculation and even showed a stopwatch like it's spot on - it's still not!

It's not uncommon for my prints to take up to 30% more time than calculated which is very annoying when you run a business and work with deadlines.

wirlybird
Posts: 1015
Joined: Sun Jul 17, 2016 12:32 pm

Re: S3D Misses The Mark On Weight And Time Esimates By A Lot!

Tue Feb 12, 2019 6:39 am

zemlin wrote:
Mon Feb 11, 2019 10:26 pm
Make sure the DENSITY of the filament you are using is set correctly. When I've checked part weight predictions they've been spot on. That's calculation is a cake walk compared to print time.
Thanks, I checked it and it was at 104 for ABS but I'll make a change and see what happens. Maybe it needs a nudge.
I'm not as worried about the time being off a little as the weight estimate. I figure weight should be pretty straight forward for the most part.

wirlybird
Posts: 1015
Joined: Sun Jul 17, 2016 12:32 pm

Re: S3D Misses The Mark On Weight And Time Esimates By A Lot!

Wed Feb 13, 2019 4:47 pm

I have been able to improve the weight estimate but only by entering bad numbers. I set the ABS density to 85 and it gets a pretty good estimate compared to the actual part.

Time estimates are still no way near close.

Part took 52 hours (rounded off) and the estimate was 36. So time and weight estimates are still pretty much useless.

horst.w
Posts: 707
Joined: Fri Oct 17, 2014 4:00 pm

Re: S3D Misses The Mark On Weight And Time Esimates By A Lot!

Thu Feb 14, 2019 4:58 am

I think, the calculation of print time doesn't consider the acceleration and jerk, because the program can not know them. But if it would be known, on my printers I have reduce the values in behalf of print quality.

I have test it with 5 objekts, always 1 mm height:

square 100 x 100 mm
square 50 x 50 mm (will be 25% of the 100 x 100)
circle diameter 113 mm (will be nearly 10,000 mm² ~ 100 x 100)
circle diameter 56,5 mm (will be nearly 2,500 mm² ~ 50 x 50 or 25% of 100 x 100)
rectagle 250 x 40 mm (will be same as 100 x 100)

print time is 59 min and 15 min (4 x 15 = 60)
material is ~ 1,540 and 400 mm (4 x 400 = 1,600) filament (2,83)

This shows, that acceleration and jerk can not be considered, because the objects have all the same volume / surface or 25% of it. But the lines to print are very different, from very long running (rectangle) over the squares and very short lines printing the circles. That can not be realistic but it provides a base to make a own calculation comparing the real print time .
For this I have set all values for the Firstlayer and Infill to 100 so that the the conditions are comparable.

The influence of M-codes for acceleration and jerk, inserted into the start-script, I have not tested now, but would be very interesting.
The given values of the firmware are unknown to the program.

horst.w
GER

wirlybird
Posts: 1015
Joined: Sun Jul 17, 2016 12:32 pm

Re: S3D Misses The Mark On Weight And Time Esimates By A Lot!

Thu Feb 14, 2019 7:39 am

horst.w wrote:
Thu Feb 14, 2019 4:58 am
I think, the calculation of print time doesn't consider the acceleration and jerk, because the program can not know them. But if it would be known, on my printers I have reduce the values in behalf of print quality.

I have test it with 5 objekts, always 1 mm height:

square 100 x 100 mm
square 50 x 50 mm (will be 25% of the 100 x 100)
circle diameter 113 mm (will be nearly 10,000 mm² ~ 100 x 100)
circle diameter 56,5 mm (will be nearly 2,500 mm² ~ 50 x 50 or 25% of 100 x 100)
rectagle 250 x 40 mm (will be same as 100 x 100)

print time is 59 min and 15 min (4 x 15 = 60)
material is ~ 1,540 and 400 mm (4 x 400 = 1,600) filament (2,83)

This shows, that acceleration and jerk can not be considered, because the objects have all the same volume / surface or 25% of it. But the lines to print are very different, from very long running (rectangle) over the squares and very short lines printing the circles. That can not be realistic but it provides a base to make a own calculation comparing the real print time .
For this I have set all values for the Firstlayer and Infill to 100 so that the the conditions are comparable.

The influence of M-codes for acceleration and jerk, inserted into the start-script, I have not tested now, but would be very interesting.
The given values of the firmware are unknown to the program.

horst.w
GER

I think you are probably correct with this assumption. It would make sense and the larger the print the larger the error could be.

Honestly, I am more concerned with reasonably accurate material weight estimates than print times.
I use the weight estimate to quote customer costs.
I use the time estimates more for guaging print order for large parts. I usually do the smaller, shorter time prints of the order first to make sure everything is running good and settings are ok before launching a 60 hour print!

horst.w
Posts: 707
Joined: Fri Oct 17, 2014 4:00 pm

Re: S3D Misses The Mark On Weight And Time Esimates By A Lot!

Thu Feb 14, 2019 3:09 pm

Yes I know.
But at the moment I have to gloss some prints and can't weigh them. Also the identical prints are different with perimeters and infill what I havn't stored .
But the theory says, that the weight and the length of filament, S3D has calculated, is corresponding with the diameter of the filament and the specific weight. So I guess, that the sum of all E-values amount to the outgiven length and weight.

If there are so much differences between the calculated values and the real weight, there must be a serious defect however where it is.

An other irritation is the use of Mesh-Calculate-Volume. The length of the filament is 6370 mm, may be 43,5 gr by 2.85 mm dia and 1.07 spec weight. The volume be expected with 55,4 ccm and I don't know what they mean with it. The volume of the printed material is clearly minor (may be round about 40 ccm) and it is not the volume of X-Y-Z ( > 100 ccm).
Compared with the results of statistics of the CAD the volume is 44,7 ccm * 1.07 = 47,8 gr. Less infill, the declarated weight of 43,5 gr seems realistic.

H.

zemlin
Posts: 251
Joined: Mon Feb 01, 2016 11:36 am

Re: S3D Misses The Mark On Weight And Time Esimates By A Lot!

Fri Feb 15, 2019 5:32 pm

I ran some parts last night on my Raise 3D N2+ with an aftermarket Bondtech extruder.
Looking up ABS density it ranges from 1.06-1.08 g/cc.
If I enter the density as 1.07 the predicted weight for the print is 314.8.
With a density of 1.08 the predicted weight for the print is 317.7
Measured weight is 316.8.
That's accurate to -0.6%-+0.3%.
I'd say that's pretty good.

4.0 & 4.01 predict about 5g less than 4.11 - so the accuracy is better with the newer version, but it wasn't bad before.

wirlybird
Posts: 1015
Joined: Sun Jul 17, 2016 12:32 pm

Re: S3D Misses The Mark On Weight And Time Esimates By A Lot!

Sat Feb 16, 2019 7:46 am

That is pretty good especially on a larger weight print.
I am still exploring this to see why I am getting less than great results on weight.

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