# Print Time Accuracy
**URL:** https://forum.formlabs.com/t/print-time-accuracy/11111
**Category:** General Discussion
**Created:** [December 28, 2016, 12:42am UTC](https://forum.formlabs.com/t/print-time-accuracy/11111 "2016-12-28T00:42:17Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@rclaborne](https://forum.formlabs.com/u/rclaborne)
#### Post date: [December 28, 2016, 12:42am UTC](https://forum.formlabs.com/t/print-time-accuracy/11111/1 "2016-12-28T00:42:17Z")
Am I the only one that notices that PreForm is pretty bad at calculating the print time for a build for the Form2 but pretty good at calculating it for the Form1+ ? Form2 calculation is typically 1 hour less than actual on the Form2 but pretty much right on for the same build on a Form1+. That is to say, the calculation is the same either way but the Form2 consistently takes longer to build.
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### Author:  [@kevinduhe](https://forum.formlabs.com/u/kevinduhe)
#### Post date: [December 28, 2016, 12:49am UTC](https://forum.formlabs.com/t/print-time-accuracy/11111/2 "2016-12-28T00:49:06Z")
I do not own a Form 1+ so I cannot comment on that. But from my experience, I too have noticed time estimates can be pretty far off. I posted about it once before and was told the wiper, resin sensing/dispensing, and even the pre-heating time (does that get calculated in the overall time?) all account for longer build times. Since the form 1+ doesn’t have a wiper or auto resin sensing/filling, perhaps they just need to adjust the software to better account for those factors?
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### Author:  [@Drewwerd](https://forum.formlabs.com/u/Drewwerd)
#### Post date: [December 28, 2016, 7:12am UTC](https://forum.formlabs.com/t/print-time-accuracy/11111/3 "2016-12-28T07:12:31Z")
I too saw some pretty drastic errors in the time calculation on my Form 2. I recently finished a print that Preform stated would be 15hr 50min and the nice email alerting me to a jobs completion totaled the job at 19hr 9min. My assumption was that preheat time was not figured in as Preform has no idea how warm the vat and therefore no idea how long the heating process will take, in my experience it take 15 ish min, to heat up (which tangentially begs the question, why cant we start the tank warming as soon as we fire up Preform), the other time suck I assume is tank refill. Preform does seem to have a calculation for wiping time as evident by the print time change if you move all parts closer to or farther from the wiper.
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### Author:  [@kevinduhe](https://forum.formlabs.com/u/kevinduhe)
#### Post date: [December 28, 2016, 5:34pm UTC](https://forum.formlabs.com/t/print-time-accuracy/11111/4 "2016-12-28T17:34:59Z")
> [@Drewwerd](#):
>
> Preform does seem to have a calculation for wiping time as evident by the print time change if you move all parts closer to or farther from the wiper.
I stand corrected there sir! You are right on this.
Here was my suggestion to FL a while ago. This ability would give the printer a head start at warming up while the user imports, orients and builds supports for his/her item.
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### Author:  [@rclaborne](https://forum.formlabs.com/u/rclaborne)
#### Post date: [December 28, 2016, 10:32pm UTC](https://forum.formlabs.com/t/print-time-accuracy/11111/5 "2016-12-28T22:32:02Z")
Preheating does not seem to account for the vast inaccuracy.
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### Author:  [@kevinduhe](https://forum.formlabs.com/u/kevinduhe)
#### Post date: [December 28, 2016, 11:01pm UTC](https://forum.formlabs.com/t/print-time-accuracy/11111/6 "2016-12-28T23:01:17Z")
I think the MAIN reason for the inaccuracy is the “resin sensing” and refilling. On my printer it can take up to 2 mins for it to sense, then dispense. If it has to do this a dozen times during a multi-hour print, it could easily add 30 min to the print time.
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### Author:  [@rclaborne](https://forum.formlabs.com/u/rclaborne)
#### Post date: [December 29, 2016, 11:02pm UTC](https://forum.formlabs.com/t/print-time-accuracy/11111/7 "2016-12-29T23:02:48Z")
This doesn’t account for it either. My latest print went +1:15 on a 3:45 calculation. That’s a 25% error. Maybe after heating, wiping and filling it all adds up but the bottom line is that my F1+ printed the same job within 1 minute of calculation.
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### Author:  [@kevinduhe](https://forum.formlabs.com/u/kevinduhe)
#### Post date: [December 29, 2016, 11:09pm UTC](https://forum.formlabs.com/t/print-time-accuracy/11111/8 "2016-12-29T23:09:30Z")
Hmm, that is pretty far off. I could see how my theories could account for 10% or so, but being off by 25% …something else is going on there.
Maybe someone else can chime in with any other differences between the two printers that might account for the time Δ.
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### Author:  [@fantasy2](https://forum.formlabs.com/u/fantasy2)
#### Post date: [January 14, 2017, 3:01pm UTC](https://forum.formlabs.com/t/print-time-accuracy/11111/9 "2017-01-14T15:01:37Z")
Experiencing the same. I had an 11 hour print, it took almost 13.5 hour to finish. The resin was warm at start.
Resin sensing takes long, and it is surprising to me that it has to sense the resin every time it needs to top up. The machine knows how much resin in consumes every x layers, so why not sense the resin every x_2 or x_4 layers and just dispense a few mil every x layers?
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### Author:  [@fantasy2](https://forum.formlabs.com/u/fantasy2)
#### Post date: [February 2, 2017, 7:16am UTC](https://forum.formlabs.com/t/print-time-accuracy/11111/10 "2017-02-02T07:16:11Z")
Got another one of those prints. Printing in flexible resin.
Duration according to preform: 9h40m so I expected it to be almost ready this morning as it is printing for 8h34m already.
The dashboard is saying: 5h14m remaining.
So the print time calculation is off by roughly 4 hours. That gets close to 50% off.
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### Author:  [@drp34](https://forum.formlabs.com/u/drp34)
#### Post date: [May 17, 2018, 10:29pm UTC](https://forum.formlabs.com/t/print-time-accuracy/11111/11 "2018-05-17T22:29:36Z")
This is still a pretty big problem for us. I’m currently stuck at work because our print said it would finish 2 hours earlier than it is actually finishing. When you have multiple prints to do, it can really mess with your planning.
It would be nice for an improvement to the print time estimate. Hopefully Formlabs is working on it…???
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### Author:  [@JohnHue](https://forum.formlabs.com/u/JohnHue)
#### Post date: [May 18, 2018, 6:02am UTC](https://forum.formlabs.com/t/print-time-accuracy/11111/12 "2018-05-18T06:02:28Z")
Are Preform and the printer’s Formware up to date ? They _recently_ made corrections to the print time estimate, I think it was around the big 17’ December update.
Things have been better on that front for me since, my last print took a bit more than 10 hours and Preform estimated 10h17’ so we’re spot on. It was a “shallow” print though, only 483 layers @0.1mm layer height, but the XY plane was full which is why it was quite long.
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### Author:  [@drp34](https://forum.formlabs.com/u/drp34)
#### Post date: [May 18, 2018, 4:49pm UTC](https://forum.formlabs.com/t/print-time-accuracy/11111/13 "2018-05-18T16:49:43Z")
We updated everything yesterday, so we’re all good there. It was our first print with Grey Pro, so maybe it is just that. We’ll see how the next print in standard Grey goes.
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### Author:  [@waveformer](https://forum.formlabs.com/u/waveformer)
#### Post date: [June 5, 2018, 5:36pm UTC](https://forum.formlabs.com/t/print-time-accuracy/11111/14 "2018-06-05T17:36:04Z")
I had a print yesterday that was estimated to take 3.5 hours, but ended up being over 5.5 hours (newest update installed), so there’s definitely something to this.
\*edited to note that I was using Clear resin
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### Author:  [@MIdlands3D](https://forum.formlabs.com/u/MIdlands3D)
#### Post date: [June 11, 2018, 12:45pm UTC](https://forum.formlabs.com/t/print-time-accuracy/11111/15 "2018-06-11T12:45:29Z")
I have a brand new machine and updated firmware installed. My prints are also considerably out from the estimate. Estimated 3.5 and took 4.5 if I recall correctly…it was certainly an hour out anyway.
Any thoughts on what is driving this? I plan to use the estimated print time as a basis for estimating print costs for clients and need it to be reliable.
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### Author:  [@billb](https://forum.formlabs.com/u/billb)
#### Post date: [June 12, 2018, 10:58am UTC](https://forum.formlabs.com/t/print-time-accuracy/11111/16 "2018-06-12T10:58:47Z")
The more layers there are, the greater the time discrepancy. So it has to do with the algorithm that calculates the time the build platform lifts and falls.
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### Author:  [@johnd](https://forum.formlabs.com/u/johnd)
#### Post date: [June 15, 2018, 2:54pm UTC](https://forum.formlabs.com/t/print-time-accuracy/11111/17 "2018-06-15T14:54:59Z")
This is definitely an ongoing issue. Currently printing a big model on Form 2 in gray resin - initial estimate was 18 hours 34 minutes. I got in this morning to find it still had 1.5 hours to go (it’s been two hours since then, now it says 30 minutes). So total print time is actually more than 21 hours.
This has been a consistent issue - even since the latest firmware update.
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### Author:  [@McGlashan](https://forum.formlabs.com/u/McGlashan)
#### Post date: [June 18, 2018, 4:01pm UTC](https://forum.formlabs.com/t/print-time-accuracy/11111/18 "2018-06-18T16:01:14Z")
I’m waiting for a print that was estimated at just over 12 hours and which is currently looking like it’ll finish in 14. It’s so consistently wrong that I just mentally add 2 hours to the estimate every time I print now.
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### Author:  [@RafPic](https://forum.formlabs.com/u/RafPic)
#### Post date: [June 18, 2018, 8:51pm UTC](https://forum.formlabs.com/t/print-time-accuracy/11111/19 "2018-06-18T20:51:44Z")
Hi, I noticed those estimated time errors. These are my last prints:
| Firmware | Layers | Resolution | Volume | Prevision | Effective | Diff | Perc. error |
| 1.17.7 | 579 | 50µm | 1.9mL | 01:52 | 02:58 | 01:38 | 58,93% |
| 1.17.7 | 1211 | 50µm | 86.6mL | 04:56 | 06:34 | 01:38 | 33,11% |
| 1.17.7 | 1425 | 50µm | 102.6mL | 06:35 | 08:32 | 01:57 | 29,62% |
| 1.17.7 | 1333 | 25µm | 10.3mL | 04:40 | 06:38 | 01:58 | 42,14% |
| 1.17.7 | 296 | 25µm | 2.1mL | 01:14 | 01:46 | 00:32 | 43,24% |
| 1.17.7 | 310 | 25µm | 25.7mL | 02:40 | 03:07 | 01:21 | 16,88% |
| 1.17.10 | 833 | 50µm | 21.8mL | 03:47 | 05:08 | 01:21 | 35,68% |
| 1.17.10 | 1989 | 25µm | 43.5mL | 10:03 | 12:37 | 02:34 | 25,54% |
Raf
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### Author:  [@shawny2005](https://forum.formlabs.com/u/shawny2005)
#### Post date: [June 19, 2018, 4:38am UTC](https://forum.formlabs.com/t/print-time-accuracy/11111/20 "2018-06-19T04:38:24Z")
The data doesn’t lie 😂😂😂
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