Light Off Delay finally explained, understand this setting for 3d resin printing!
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- Опубликовано: 3 окт 2024
- Finally got around to this video after seeing so many different explanation and theories on his this works. I explain how this interacts with your other settings as well.
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They should rename this setting to ‘delay before next layer exposure’ or similar, much less confusing. Thanks for doing this research!
except you can still have your screen turning off, and as long as its not longer than the movement of your plate, up and down, then there wouldn't be any delay. It only delays your next exposure, if the off time exceeds your plates movement time.
@@AnunnakiAaron Not necessarily so . . . perhaps on the printer you'd tested, but, not on mine. Please see my comment from today. My printer's "Time-Off Delay" (time between ceasing motion of the Build Plate and turning-on the light source) is the amount I've entered into the slicer PLUS the 1.0sec that Anycubic programmed into my Mono X. If I use "0 sec" of Light-Off Delay, I still get a 1sec pause between the Retract cycle and the Exposure cycle.
Newbs everywhere applauding
I know I'm late to this video, but I just want to thank you for making it. This really helped me.
Thanks a lot man! Awesome video and totally on spot.
You can find the exact time when extra light off time really makes sense at any speeds by: 1) Check with zero light off time, slice and write that time down. 2) Increase Light Off time, the first increase can be about 6 seconds, slice and possibly the total print time will remain the same. 3) Increase light off a bit more, like to 8 seconds, now it possibly increased the total print time, if it happens then you can reduce Light Off time a bit and keep comparing total print times. If you are efficient in a couple of minutes you can determine the lowest time where Light Off have no effect (I stop at one decimal, no need for more precision). Let's call this MinTimeOff.
After you have the MinTimeOff, any extra time you add will be the time used to let the resin settle a bit after the print reached its new low.
In my case I determined the MinTimeOff to be 6.4 seconds and I wanted another two seconds for the resin to settle so I set the Time Off to 8.4 seconds.
Sorry if It sounds a bit cumbersome, but is actually quite easy and only takes a couple of minutes.
The amount of time you save me on a regular basis... Genuine thanks.
I messed around with this a bit this evening with my Mars Pro in an effort to pinpoint the timing aspect of my machine as it relates to my Chitubox slicer. I used a pretty basic base as a test, then set my layer height to .04, Bottom Layer Count to 5, Exposure Time to 60, Bottom Lift & Lifting Distance both set to 6, Bottom Lift Speed & Lifting Speed set to 45, and Retract Speed set to 150. As an initial test I set the Light-off & Bottom Light-off display time 8 seconds and hit SLICE. I then hit the “BACK” button and continued to up the Light-Off Delay settings by 1 second until my Print Time changed. I then halfed the time, so it changed between 10 seconds & 11 seconds, so I tried 10.5 - same as 10, so I tried 10.75 - same as 10 & 10.5, so I tried 10.88 and there I saw the time of the print change. So I kept tinkering around with it until I came up with 10.807 seconds as when the print time noticed a difference (meaning that with my settings I would need to hit that mark before it would even matter). I then did the Math, on 45mm/min = .75mm/second - then 6mm/.75mm/sec = 8 second travel time before retracting. Then 150mm/60 = 2.5mm/sec retract speed - so 6mm/2.5mm/sec = 2.4second retract speed. Added those together (8 + 2.4 = 10.4). Then took my calculated time of 10.807sec - 10.4sec to determine my “machine + slicing software” accounted for .407seconds.
What does this all mean? It meant I could use my findings of 10.807 seconds + Greg’s recommendation of adding a minimum of 2 seconds & a maximum of 3 seconds to give my Light-off range at 12.807sec - 13.807sec, which I took the middle ground at 13.307sec. It also meant I could do this calculation for any combination as long as I computed the math of my lift distance in relation to my lifting & retracting speeds + .407Seconds for Machine.
Just a fun little math exercise while waiting for my prints!
Me want make things in pretty box. No tell me math work... brain no like!
HOLY SHIT, IM never going to be able to get a print to stick to the plate, I have to do all of that math? I'm screwed
Using the 70/30 formula I called out in my comment above gives me exactly 10.4 as well. Seems to be pretty close.
Hi Greg, I just backed your Kickstarter.
I figured after all the great advice you've given to us, I owed it to you to back your KS.
I encourage other folks that have found Greg's tips useful to do the same. Let's pass on the good Karma, and support those that contribute towards our community! 🙂
Thanks for trying to explain this "Light Off Delay" (LOD) feature, which Lychee Slicer describes as "Delay before print normal layer". But, some of your description didn't match some of what I'd read elsewhere, particularly about the LOD being meaningless if it wasn't at least longer than the sum of the lift and retract intervals. I find it hard to believe that the developers of these printers and slicers would make this parameter that obtuse and cumbersome, and that it doesn't truly represent the time between the retract cycle ending and the exposure cycle starting. So, I decided to experiment with my Anycubic Photo Mono X (4k) with the latest firmware installed. Obviously the results might be different on different printers, and I suggest you (and your other viewers) try this on their own printers . . .
Slicer settings:
Z-lift Height: 8mm
Lift Speed: 2mm/sec (thus, in theory, 4.0sec lift time)
Retract Speed: 2mm/sec (thus, in theory, 4.0sec retract (drop) time)
Bottom Layers: 1
Bottom Exposure: 4.0sec
Normal Exposure: 4.0sec
Light-Off Delay: 0sec, 2sec, 10sec (3 different test files)
An interesting thing I noticed on my printer is that the "Lift" and "Retract" cycles are both broken into 2 sub-cycles.
Lift: Initially slow, then fast
Retract: Initially fast, then slow
In other words, as the Build Plate approaches-towards or recedes-from the FEP it is slow, and when some distance from the FEP it moves faster. You can visually observe these 2 speed-zones as well as audibly (different tones in the different zones) My theory is it initially lifts slower in order to allow the print to peel off from the FEP gently, and then get up quickly so that fresh resin can fill-in the area . . . and then it slows-down as it approaches the FEP so that there's less motion of the resin as exposure time approaches; something you discussed in your video as the purpose of LOD.
I observed the "printing" process with the Build Plate and Resin Vat removed, and a piece of copy paper placed over the LCD screen. I used a "stop watch" app on my phone to record the times. The test piece was a simple 25mm cube.
Test Results:
In all 3 test cases, the average times were:
Slow Lift Fast Lift Fast Retract Slow Retract Exposure Post-Exposure Delay
2.0sec 3.1sec 3.0sec 2.0sec 4.0sec 0.0sec
So, no matter what the Light-Off Delay is, the lift/retract behavior is the same . . . as one would expect. It's interesting that approximately 75% of the calculated lift/retract interval (4.0sec) is spent at high speed (presumably the 2mm/sec that I told it to do) and that some extra time was spent at a lower speed when the part was close to the FEP. In fact, one could estimate that about 6mm of the 8mm lift-height was at full speed and that the remaining 2mm was at slow speed; 2mm/2sec=1mm/sec or 50% of the commanded lift/retract speed. More experimentation would be needed in order to verify that the slow speed is always 50% of the commanded speed or if it's always a fixed 1mm/sec (regardless of commanded speed). I'm not interested enough to run the experiment :-) Just suffice it to say that on this model of printer, you can't simply estimate the lift/retract times by dividing the distance by the commanded speed . . . expect it to be roughly 25% longer.
You will notice that the Build Plate always starts to lift immediately as the exposure cycle ceases (the light goes off); the Post-Exposure Delay in my measurements above. I personally would prefer there to be a slight delay before movement begins as this would allow the UV-induced chemical reaction to subside before fluidic motion begins, but, perhaps that's not really an issue.
Where the differences appeared were in the Pre-Exposure Delay . . . the time between the Retract cycle ending and the Exposure cycle beginning. This is that crucial interval of time where you want resin motion to have ceased before exposure begins (at you correctly stated in your video).
Light-Off Delay Pre-Exposure Delay
0sec 0.91sec (probably actually 1sec)
2sec 2.90sec (probably actually 3sec)
10sec 11.0sec
It would seem that the Mono X's firmware already has a pre-programmed 1.0sec delay from the time the Build Plate stops moving until the UV light turns on; presumably this is intended to allow the resin to stop churning-about. Any Light-Off Delay you add-in via the slicer simply extends this forced 1sec delay. So in the case of this printer I automatically get some delay before the light turns on, so, the Anycubic-recommended Light-Off Delay times (or "Off Time" as they call it) of 0.5sec to 1.0sec seems to be icing on the 1.0sec cake they've already provided.
Again, this is one make/model of printer . . . your mileage might vary . . . which is why I'd suggest everyone perform this type of experiment on their printer so that they can conclusively understand how Light-Off Delay behaves on their printer.
Cheers! :-)
With my Mono, the light off delay (LOD) is added before the printing layer. No math needed. I confirmed this behavior by removing the vat and watching the light through the enclosure. I was slicing with Lychee running an Anycubic Mono on stock firmware v0.17.
I believe that printer also has "exposure off compensation" which let's the firmware determine the light off delay depending on how large the layer was.
3. Exposure off compensation
Exposure off time is the interval between printing platform retracts to the lowest point and UV light turns on. When the exposure area is large during printing process, due to the surface tension and resin characteristic, there may be problems such as delay of z-axis or delay of resin reflowing, causing print failure. It is suggested to enable exposure off compensation to improve success rate.
The compensation only works on bottom layers and layers with large area. In normal layers, off time is automatically added according to the area of layers; the larger the area, the longer the off time.
For large print objects, the compensation can reduce the risk of layers separation or base falling off to avoid print failure. For the smalls, it can prevent their bases from thickening.
Exposure off compensation, which is enabled by default, adds print time. If the print object or its area of layers is small, you can disable the function in Set up.
First, you are 100% correct when it comes to the printers. They are hard-coded to have specific lift/speed settings, I have two different versions of the Anycubic Photon (OG & Fauxton) the Fauxton moves faster than the Photon, I can start prints at the EXACT same time with the EXACT same files, and the Fauxton finishes 20-30 mins earlier
Also I changed Off-time in Chitubox, I had 1s and a print was 1h 45m, changed it to 2,3,4,5,6,7 and each time the estimate time was 1h 45m. Only time it changed was when I put it to 8s and it now it outputs 1h 51m
So in Chitubox it automatically calculates what you said... also I just found out by hovering over the input box it explains the
"True Machine light-off time = maximum (total time of Z-axis up and down movement, configured light-off delay)"
I know this video is two years old, but it still helped me figure this stuff out. And just a tip to anyone who decides to do this tip themselves, use your phone to record the test and count the frames, or have a stop watch going beside it so you can count the miliseconds accurately.
Awesome!!! Keep doing videos like this that explains what the settings mean, and how they're used.
Thanks for this information, its very usefull about this mystery setting which do makes sense now!😊
I think the different times on different machines altough using the same settings can be explained easily, listen for a moment:
Not all machines use the same electromotor, nor spinder, nor the same motor controller.
Even if used the same components, other brands of printers can use the controller differently, that alone would be enough to see a time difference between machines. For instance, the lifts and retract speed with the same settings , where one brand could set the ramp up more steep, which means it accelerates faster to the platforms coordinate and setspeed. Also, the ramp down could be set less or more steep, meaning it will brake slower or very abrupt before coming to a full stop for a coordinate.
There could be other delays on telling the controller to go up or down, for instance, just using another software which waits for a certain step to happen in memory before telling the controller to move the electromotor, although the hardware being identical, results will be different.
Now with different spindels, gear ratios, or a elektromotor with a different nominal rational speed means achieving the same speeds, is done completely different on a electrotechinal level. A machine may relatively having steeper ramp up or downs, or a machine could try to reach and move from a coordinate very gently. Maybe you can spot the difference if you let those machines, run next to each other and find out what aspect makes the machine quicker or slower.
So that being said I hope you understand why different machines still can have different behaviours in some sense, even with the same settings. That being said, printer companies, if you want your printer to print faster than the concurrent, set your ramps steep bro, or ramp steep after a certain moment.
Much appreciated…finally someone who could make it clear
Thank you again! Your videos are gold for noobs like me who are struggling a little to get things dialed-in
Thanks man, wondered about that one myself.
I guess it makes sense if you think of it as "Minimum light off time". In practise, you could just chose a good time, such as 12 seconds, and stick to that instead of adding to the time observed.. It should not matter if that time is spent lifting or waiting.
Exactly what I was thinking. It’s just a minimum light off time.
You must be reading my mind...I just asked myself today what this meant after looking at a resin settings table.
thanks alot, iv never understood anything about the setings untill now after watching you video..
Thanks for this explanation. Been messing around with my Peopoly printers lately to try and remove bloom problems I have been having, turns out my Light Off delay wasn't even doing anything! Had to adjust it up to 8.5 seconds to get about a second of light off delay, getting perfect prints now.
The odd behaviour where certain printers are taking longer to move than expected, I think it's something to do with the firmware not allowing the printer to move faster than some predetermined speed that the manufacturer put as a speed limit in the code. I had heard this somewhere before when updating the firmware on my original Anycubic Photon, I believe it increased the speed limit so that the printer was allowed to move faster.
Its not a thermodynamic reaction, its a free radical exothermic polymerisation.
Thermodynamic reaction would be to adjust the reaction pathway based upon thermodynamic or kinetic control.
English please! hehehe :)
Thanks for the video. These have helped me when I messed up a setting and got some failed prints.
For the scientific jargon.
Thermodynamic is the relationship between heat energy, time, material, and other variables. It can mean transfer of heat and also transfer of cold.
The resin goes through an exothermic reaction which is specific to the release of heat energy due to the chemical reactions "the chemical boogaloo".
Very interesting. The conclusion to adjust relative to the "minimum" off-time seems odd though. Seems to me like if you're getting off time from plate movement that's just as good as from the setting for the screen & the resin cooling? Guess the resin settling after the plate descends theory might matter, but I feel like the off time for the machine for heat/screen stuff doesn't matter if it comes from lift speeds or off time (Though even then my "gut" feel is that most of the resin disturbance happens from rising...).
That's some super helpful info! Thank you! Some of it I kinda figured, but you confirmed and expanded.
great video my man. help me so much with the issues i was having
You get different up and down times because the up and down for each machine has different acceleration times of the motor called "jerk". The motor doesn't go instantaneously to 5 or 6mm/min. Your math is assuming instant acceleration. One machine may reach 5mm/min slower than another. Same with the down. If the jerk setting is set high, the movement may never hit 5mm/min before it reaches the 5mm movement.
I know my Photon (OG) vs Fauxton, the Fauxton is faster with its up/down compared to the OG ones
Its so fast sometimes the SAME print started at the SAME time, the Fauxton finishes about 20-30 minutes earlier
On my Mars there is a file called "Machine parameters.gcode" and in here you can alter the acceleration speeds as well as max speeds etc. @3DPrintingPro I imagine if you check this file on the printers that were slower than expected then the acceleration will be a lot lower, the command is M8008 Ixxx with xxx being the acceleration in mm/s^2 this being 1000 on my mars.
Very good point about heat killing LCDs. Most regular LCDs are rated for a max of about 50C and high temp industrial/extreme environment LCDs are rated usually for max 85C and they don't come in 4K resolution as far as I know (just took a quick look at DigiKey, didn't see any 4K extreme temp LCDs). With high powered UV lights being used, I'm sure the LCDs are being exposed to temps much higher than the typical 50C max during a typical print. Do that long enough and it'll definitely kill the LCD. This then brings up the thermal management/design considerations for the UV light and LCD when reviewing MSLA printers as thermal management will become even more important especially as manufacturers start to cram more powerful UV lights to get cure time down.
@H D indeed, yet they are bumping up the power each generation.
Thank you! I was just wondering what that number means and your video popped up! I feel like this was so helpful, hopefully my prints will work next try🤞
Below are my findings for my Elegoo Saturn using the Lychee slicer.
I used my default print settings to conduct the test.
Exposure time: 2,5 s. Lift after print: 7 mm. Lifting speed: 100 mm/min. Lowering speed: 150 mm/min.
With 0 seconds Light-off delay, screen was off for 8,3 seconds.
With 8 seconds Light-off delay, screen was off for 9 seconds.
With 10.3 seconds Light-off delay (original result + 2), screen was off for 11,3 seconds.
It seems, in other words, that the total time off in my case is the Light-off delay setting + 1 second, if this value exceeds the non-adjusted light off time.
Awesome! 👍
Love channels like this that are full of useful information! Well done and thank you!
Thanks for the info. Id imagine the difference in times between printers would be attributed to acceleration. Some printers will accelerate the build plate faster than others because their motors have more torque. That time might also be affected by the amount of resin currently attached to the build plate, since greater mass takes longer to accelerate. (?)
Man I have an Elegoo Mars pro2 and I'm just sitting on it. I think I'm just nervous that I'm going to break something and have wasted my money. But I really want to use this thing so I'm watching everything on proper operations and what not.
You're a monster of 3D! congrats
This is exactly what is stated in the Chitubox manual under light off delay. Light off time has to be in addition to the total Z up and down times.
If your ambient temperature is hot and the resin viscosity is thin, these times can be kept low, but if the ambient cools off during your print and cools/thickens the resin you'll want more off delay to give time for the build plate to get to the right height and displace extra resin. If you're seeing extra thick rafts or oddly thick layer lines in areas this could be why.
my ambient room temp is 28-30 degreees celcius. So i can keep the light off delay low right?
@@richieyumnam8646 I wrote my comment when it was still relatively cool during the day. After a really hot summer, I think it really depends on the temperature of the resin. Seems like I have more issues with print inconsistency when it's HOT. Like 25C+. It gets bad when it's 30C+. I generally run 1s for both fields, but should probably add time when it gets really hot out to give the resin and screen at least a little time to cool down.
My setup is in the garage, so I stopped trying to print during the day if I see the ambient daytime temp will get much over 25C. I get the best results overnight when it's cool out. Might do the opposite in the winter when it starts getting down to near freezing at night, but 20-25 during the day.
@@HuntingHeresy agreed. Ill be printing at night times too then, keeping the delay somewhere in between. Not too long not too short. Mostly a little longer due to the average temp being around 28C
My printer was heating up more the more off time I was adding so much that the USB was warm so back down to 3 seconds and it's cool again! Could have been another setting causing this but the change of this 1 setting cooled the printer but it's this new elgoo 2.0 abs rubbish I'm using at the moment having to double your exposure time to 5 seconds from the normal like abs before so could have a serious effect on screen ware
@@Emtbtoday I’m running ABS-Like 2.0 on three Saturn 2s. 2.5 second exposure with 1s delay. No idea why you’re having issues.
Now that my printers are in a temperature controlled basement, I’m no longer having issues. Just make sure to mix the resin really well if it sits for more than an afternoon. You’ll see swirls if it needs to be mixed up.
Already been said I'm sure but the actual lift/retract speed will vary depending on the z driver /firmware acceleration and jerk settings
Awesome video. The extra one or two seconds to get your printer in position might be the acceleration (positive and negative acceleration) of the motor. Because it physically can not jump from 0mm/min to 50mm/min in no time (it needs time to speed up and slow down again).
Literally had all these problems with my printer during winter, changed my off time from 0.5 to 1 and now I don't have the failures I had before. In any other season I had no problems.
I think the off-time controls the light on/off ratio which affects the heat and lifetime in a long term. And also controls the time for the resin to stop flowing which affects printing quality. Maybe the bottom layer should have more off-time.
chitubox (for me) doesn't calculate the off-time correctly, I put my offtime at 8 seconds (because that's when i saw the time change), eventually sliced, ~1.5 hours, but on the Photon it showed 2 hours :P This video really helped understanding it! Thanks!
Excellent! Thank you for explaining this.
Thanks again for the advice! Joining the Kickstarter here soon
IMO the main reason for using off time is for detailed intricate parts, especially if using a more flexible resin like Blu or Tenacious. If you're using a flexible resin and these delicate tendrils are moving through the resin, they're bound to move/bend as they move through the fluid to get into position. Obviously the machine isn't going to automatically compensate for this because it just knows what layer and layer height it is at, so you need the off time for the model to reform back into its original cured position and settle down. Obviously with using harder resins this isn't as much of an issue if any because they're much less likely to deform. Same goes for less detailed areas that likely wouldn't deform. So you could potentially adjust your settings in slicer (Lychee allows for changes at different layers) to adjust the off time depending on the area of the model and thus save time in some areas that don't need long off times.
thank you for the advice toretto
Why would one use off-time instead of just decreasing lift speed? Seems like decreasing lift speed would provide the same extra off-time while also being more gentle on your supports.
need more like this mate thanks
Thank you for explaining this!!
I was looking for information on this setting in lychee for my Anycubic Mono 4k, though this is a somewhat old video it seems to be what i wanted to know. I do not know if this setting has evolved in the three years since this video was released but i tested it out.
For my test i set a basic cube model with a burn of 1 layer 2 seconds 6mm and 4mm of lift height with 1mm/s and 2mm/s Retraction at 6mm and 4mm at 2mm/s and 1mm/s
Giving a total lift of 10mm around 8 seconds which was near enough right. With a 1 second light off i wasn't quick enough to time it but with a 10 second light off i timed 9.87 seconds.
So with my Mono 4k and the latest version of lychee at the time of this comment, the light off time appears to be an actual number separate to the lift and lower times
Thanks for the video
I'd be interested to know what temperature the screen peeks at during a print. I couldn't find info based on a brief Google search. Just info on operating room temperature.
If the main goal was extending screen life. Keeping it under the operating temperature of the panel or at least minimizing the maximum peek temperature should be what you were aiming for. Based on info for a replacement screen operating temp was listed at -20 to 70C on panelook .
It seems like Mars 2 Pro is blending the lift speed and the retract speed going up and down. From my measurements (admittedly rough), it seems to be about a 70/30 split going up AND down. Going up, I'm seeing 70% lift speed, then 30% retract speed (at the top). Going down, I'm seeing 70% retract speed, then 30% lift speed (at the vat). This may not be exact, but it's close enough that I can dial in my 2-3 seconds of off time pretty reliably.
Brilliant talk through im trying to figure out this myself but i use Lychee pro and in the
lift distance
Lift speed
Retract speed
There are 2 stages i dont understand its not like chitubox just having that 1 setting per setting for example the
Lift Distance stage 1, 6 stage 2, 6 mm/m
Lift speed stage 1, 50 stage 2 180 mm/m
Retract speed stage 1 50 stage 2 180 mm/m
This is the way the menu setting is layed out so its damb near impossible when new at this to know what one of these stages does what! The h9ver over info says The lift distance is in two stages, first and second distance can have different values. Distances are connected with speed values! I mean if thats not double dutch i dont know what is! I absolutely lost with these 2 stage settings for 1 setting, maybe you can shine some light on this?
These are interesting facts to calculate 👍 Anyway the phrozen shuffle doesn't care for the settings in chitubox because you had to set those times including motor acceleration in profiles at the build in nanoDlp interface. In this case the printer only uses the zipped bunch of png images from the slider.
Kickstarter is looking great👍🖖
I'm having mixed results of testing this out on my Anycubic Mono. If I slice the same file in Chitubox and Photon workshop I get different print times (all the settings are the same). In Photon worskhop the Off Time starts changing the print time from the beginning (any change Off Time is resulting in a lower/shorter print time).
Whereas in Chitubox the printtime stays the same until I go over 3 seconds off time before changing the final print time.
So it seems that Photon workshops Off Time works more like a Off Time should work logically.
I would love to test this more in practice but since Chitubox yet doesn't slice to the Mono's
proprietary format I can't test it cross program.
Just coming here to add this same comment. It would seem the different slicers may work differently with regards to off time. I was testing this on my Mono X using Photon Workshop and it is exactly as you say...off time is a true “delayed” off time that starts after the plate settles back to the “home”/bottom position. What I find interesting is that you need to check this from the back of the printer to verify it. If you watch just the touch screen on the front of the printer, the layer image comes on as soon as the plate is returned to the FEP and that image is displayed for both the off/delay time and the exposure time. But if you look through the fan opening in the back and do your timing check based on the actual light coming on, then it all works out as expected: plate returns to FEP, off delay time starts/completes, and then light comes on for the correct exposure time. I’m curious if Lychee and other slicers are this way (Photon Workshop looks more like Lychee than Chitubox).
Anyways, thanks for the video Greg...loving the content you put out!
A bit late to the party, but could zero seconds be an auto-setting? In some other applications (obviously not all) the application is written (on a coding level) to have an effect when a new setting is turned on, but a zero time would be the same as "off", so it is written to adjust based on partnering settings/variables. Your personal testing of 2 seconds above the calculated travel time matches the outcome in terms of time. But the travel is slowed to adjust, instead of the delay (likely to give the appearance of not stalling? Though that's just a guess) just a couple of thoughts.
Is there any reason why the people at Chitubox couldn’t change it so the light off delay is just the pause before the light comes on? I don’t see why it would need to include the up and down time. Might be a good request for a future update.
Because the up and down time is a variable. What would be awesome is if the math was built into the printers default profile so your light off delay gets automatically adjusted when you change those variables
myself i have always used off time of 6.5 for prints under 7 hours on my original V1 photon. and set to 13 for prints over 7 hours. also i have my off time for the burn in 3/4 of the base exposure for the burn in. i keep telling people to set there off time. it annoys me when slicers defaults are always set to 0. having to constantly remind people to set there off time to 4.5 for the photon-s motherboards and 6.5 for the classic photons. and people complain there screen is dead i ask them for there settings and then to find out there off time is 0. as stated by yourself it sets to default off time as in the time it takes to raise and lower the bed. had my photon since its release and still on the original screen. and also it gives cold resin that thickens time to flow and move between layers very handy when your using a lot of supports it gives the cold resin chance to move and flow with a good cover.
Thanks for tip. I have the PhotonS
How about matching the on time with the off time?
I feel like it could be beneficial, to match it instead of using a set time.
In the case of a long on time, you'll have created more heat, so matching would make sense.
Great informative video, but not enough table banging. 😅
Congrats on the successful kickstarter, I'm looking forward to printing those models! 👍
super useful, thank you SO MUCH!!
Great video as always. I know you moved over to Lychee now, but can you make a video on the "Waiting Mode During Printing" option. Explaining the different rest times and your recommendations? Thanks
I wonder if the slicer software will start calculating the off time based on other print settings to make the settings more intuitive
Chitubox should do the math for you based on lift / retract speed / distance and let you just punch in actual seconds for off delay time…and default the settings to 2 & 3 seconds. I just watched my printer UV lights through the air holes on the back and listened to the stepper motor stop retracting and there’s about 1/2 second delay before the lights turn on with the light delay settings at zero. So there’s already a slight “off time delay” by default.
Basically:
What is the minimum amount of time that you want the light to remain off?
If the cycle time (lift + lower) meets or exceeds your minimum, then printing will resume as soon as the cycle completes.
If the cycle time is less than your minimum, then it will wait until the total time (cycle + wait) meets your minimum before resuming.
definition at 3:33
thank you very much!
I have three Epaxes, an orginal Epax x1, a Epax x1n and a Epax 10 mono 4k. The Epax original matches the Chitubox time printing estimation after slicing and the newer Epaxes don't. The newer models always take longer to print the models then estimated. After watching this, I have a feeling it has something to do with the light off delay not matching chituboxes settings.
I'm new to 3D printing and trying to understand all the different setting, especially light off. This is a good insight. In regards to how the light go on or off would that damage the light because constant power up the light?
I really wish somewhere there were the perfect settings for the Kingroon KP6 Mono 😩. Off to Reddit! Lol
It is my understanding that "off time" is the time between when the LED turns off and when the Z lifts and is to allow the chemical process initiated by the UV light resin exposure to complete ( before the z lifts) As we know the LED light process activates the hardening process in the resin but only time allows it to complete. It stands to reason that different resins with different compositions need different "off time" It would be a good subject for Goobertown Hobbies to throw some light (excuse the pun) on !!!
Easy enough to test. Reslice your favorite print, but change the off time to something sufficiently large (60s?). Then just remove your vat and build plate, put a paper over the screen, and run a print using that new slice. See when there's a ridiculously long wait with the printer doing nothing. (Hint: the long delay won't be between the light going off and the plate rising)
Do you think that the low exposure time of the mono screen heat up the screen less than an normal lcd . You can also check the heat of the screen with a thermometer gun to see if it's hot
its down to acceleration settings, if you watch carefully all of them slow start lift and slow start retract adding to the extra time
So this should be interesting an helpful
Hello, i'm a bit more confused then before... is there any difference between LIGHT-OFF DELAY and OFF TIME? apparently looks the same things but in the suggest parameter of my anycubic m3max the say 2 second OFF TIME, it's a huge and useless difference listening your explication, could you clear it me?
i would also say if up and down time are combined to 10 seconds, adding 2 seconds of time is added is 20%, so that's your screen saving time ie 2000 hours your adding 200 hours to your screen time in theory, but not really as screen time is measured in on screen time so its still 2000 hours
I think you did not get it - this about giving the LCD screen time to cool off which should extend the displays life time.
in the print settings there is a second column for distance and speed for bottom, normal, and retract in version 1.9.4 do you know what the second column is for? hovering over area boxes doesnt explain what that setting does like some the other areas in chitubox
Ho there id like to consult with you on a problem that i have to see what possible solutions you have to offer...ive currently exhausted every option i could think of...
Thanks for the video. One question, have you found that the predicted print time is accurate, as you play around with the light off setting? I have a very hard time getting remotely close predictions from chitubox for my Longer Orange 30. It usually takes much longer than predicted. I think finding out the correct time for my machine may be helpful in getting accurate predictions.
would it not allow better cooling of the lcd and resin, if the up and down time were increased (I.e. slow them down) so the the lcd and build plate/model spend the least amount of time next to each other. Gives resin more air exposure to cool also. So you wouldn’t use light off setting at all.
That's very odd as the gcode generated should be a G4 P#### which is a dwell for #### ms. Can you check if that is in your generated code? If so is the slicer doing the calculation and modifying the time to what it thinks it should be?
Will you print more models by doing this or the same amount but your lcd screen lasts longer? If you get the same number of models it doesn’t matter, so I think that’s important to know. In other words, a third option is it’s neither detrimental nor beneficial.
@3DPrintingPro could you do a video on this for CHITUBOX 1.9, please?
is he talking about bottom light- off delay and light-delay off? Im using the
Can I ask something? Why the models after printed its like increasing the size? Ex. The prongs set 0.8mm but after printed it become to 1.4mm. Also all diamond holes are become smaller.
Hy. I m new in resin printing and i just bought one Weistek 5501. Can you recomand me what expouser time to use? I start with 6 seconds. I think the majufacture of the same resin recomand 8. I print two item same time. Was ok except some parts of a piece at start of the print were i dont have layers on the piece. And i cant explain why. Was like a missing layers there. Do you recomand me to lower the cure time? I dont need extra details on my part. I can print on 0.1 layer height. If the layer is heigher i must increase or decrease the cure time? Thank you
Challenge Accepted
I just dont have the funding to run a proper test. xD
good info thanks
What I would prefer is an off time after the layer is exposed where the build plate stays put and then raises up. During layer exposure the resin gets warm to hot. Introducing a delay after exposure, the resin has time to cool off a bit before it tries to pull the layer off the FEP. For some reason it appears the firmware on my Saturn actually does this rather than pause before the next layer is exposed and as a result I'm finding the ripping sound as it peels off is far less than all the other printers we have in the office using the same resin and all calibrated.
On the suggestion that having the resin moving during exposure of the layers buggers up the layer curing, I actually experimented with this by having the resin flowing across the vat with an external pump (tried diaphragm and large peristaltic) at a reasonable speed to see what the effect was. Interestingly the models were greatly improved by doing this. The usual issue of stagnate resin caking onto the model surfaces between the build plate and model and around the dense supports was greatly reduced while still retaining all the exact details of the model. The eiffel tower model printed about 40mm high, retained all of the details (AA on) and had zero extra resin trapped in between the fine structures. Another side effect that comes back to my first point is that it helps carry away the heat buildup and I did find the FEP peel off less dramatic.
Interesting findings on moving the resin! I'd love for someone to do a deeper dive on that! how much testing did you actually do?
My saturn has a delay when the light goes off before lifting. Then when retracting, the first little bit it goes really slow, then speeds up to whatever my retract setting was. Weird!
I hope you're able to figure this out from the manufacturers, you're helping us all out!
I am thinking that the Printers have hardcoded settings for the lift speeds and what not, as I have the EXACT same settings for two versions of the Anycubic Photon but the Newer variant (Fauxton) moves faster than the older one
Got an Anycubic mono X. With larger print beds the peel forces can be higher. Supports probably depend on the part size. Can you weigh in?
Any chance you can share you Elegoo Mars pro 2 Print settings?
is this still a thing? I am not finding that off time setting anywhere? on chitubox at least.
My settings I found online have been giving me great prints. But I never see anyone else’s setting like this and have no idea what they mean enough to go changing them. Is anything weird or unnecessary in here:
Phrozen sonic mini (not 4K)
Layer height 0.04
Bottom layer count: 8
Exposure: 9s
Bottom exposure: 70s
Light off AND bottom light off delay: 0s
Bottom lift distance 5mm
Lifting distance 5mm
Bottom lift speed: 300mm/min
Lifting speed: 300mm/min
Retract speed: 300mm/min
I’m using a castable resin and getting good results but no idea what the settings do enough go changing. Anything stand out as odd or overkill maybe?
Whats the difference between the Light-off and Bottom Light-off? Should both be set to the same value or do i only use the Light-off?
Bottom light off is for the bottom layers/base layers
so the offtime is an addition to the time it is already off while moving up and down? so if its 8 seconds to go up and down and you add 1 second of offtime. whats the benefit of that 1 extra second of off time if its already been off 8 seconds? is there a minimum amount of offtime that is beneficial?
It's let's the resin settle (still not sure if this really matters, even the major companies are all over the place on it) and it also allows an extra bit of cooling
question are those settings just for testing or are those recommended for printing?
bottom layer 1
exp time 2
bottom exp 2
light off delay 11
bottom light off delay 11
that was for test purposes only!
Does anyone else find the Chitubox build plate offsets backwards. A/!B affect C/D and visa versa.
My man, you have a camera and video editing software. You can obtain a much more precise measurement with those tools.
Unsure how you could confirm the off time conjecture.
Would be too much work and expensive, better to take a vacation if you need some off time benefit.
Also the light on time will vary likely due to how long it takes for the uvled driver to be powered up and supply the power to the LEDs.... I could be wrong 😅
Normally it takes a high power LED driver a fraction of a millisecond to power up or down. If you perceive a LED to be powered up gradually its a soft start to make it more comfortable to humans.
Yes know this to be true from the charged driver to the LEDs but I was not sure about the boards delay or time it takes for the signal to be received by the led driver and wether or not the led power supply is already charged or active at all times or only once the signal is received then it receives power from the board
17:45 the printer needs time to accelerate and decelerate
This setting would be best called "Minimum Light Off Time"
And as such, it is the real world off time!
You keep talking about being only 2 seconds off time, but it's not. By your own description of how it works, it will always have the z up and down travel time, which was 7+ seconds.
Now if you are saying it needs/should have a real world off time of 10+sec, then that's fine. But it's not like it is running continuous, it's already getting 7+s off time after every layer.
it'll likely take years for the lcd to give out and when it does a replacement is lik £100. so who cares? but youre right if there's no huge downside, why not, right?