New chitu boards and the locking out of other slicers


Yeah, for some reason my account doesn’t show up if you use the searchbox in Github.

If you google using the searchterms “github” and “fcollingwood”, you’ll find it


@formware, I see the following in the latest release notes:

" * Added: features for .ctb files version 4, extra speed control variable for retract speed"

Does this mean that Formware now writes the encrypted .ctb files?


no it does not (not yet).

.ctb had added some extra speed variable for bottom retract. I’ve added that.


Does the SDK allow for the implementation of other features described by Chitubox? I’m interested in the possibility of slicing multiple objects on a build plate using different resin profiles (exposure times and tolerances). Would there be a way to also allow for the over exposure of supports? The public documentation of the SDK isn’t very extensive, so I’m not sure what is and isn’t allowed.


Short update; we have the SDK working. So it’s coming probably end of next week live.
It took a little because we had to port some C++ code.

The SDK, as far as I can see, is very basic. So no advanced functoinality to specify muliple profiles per layer.
It accepts slices and per layer variables. And some newer settings to give your axis different speeds at the same layer; to speed up the print.

kind regards


I’ve added a release V1040 that includes the CTB SDK to output the .ctb files needed for the encrypted machines.

The SDK does not provide functionality to use different profiles/settings within one layer.
It does allow for adaptive layer thickness (that is now also integrated in our software). This does require your machine to be upgraded to the latest CTB firmware according to chitubox.



Can I assume the software will still slicer ok for true older chitu boards. I have several machines that are not upgraded


@formware - there are quite a few features missing from the print profile for V4 .ctb

Rest Time Before Lift
Rest Time After Lift
Rest Time After Retract
Peel Distance
Peel Speed (Slow speed in the peel lift section)
Lift Distance (Peel Distance + Fast Lift distance)
Lift Speed (Speed in fast lift section)
Slow Retract distance
Slow Retract speed

Chitubox can set these, and I can set them too when I run a v3 .ctb through my hacked version of LiberatingMars, so it should be easy for them to be added to v4 .ctb print profiles in Formware. Have a look at the v4 print profile tab in Chitubox 1.9.0, and you’ll see just how much can actually be set.

Really, the only new feature added in is the ability to write v4 .ctb files natively. I don’t find this useful at all, I’d rather keep on using the hacked LiberatingMars to post process v3 files, as it adds so much more versatility…


I have made a new slice setup format called (CTB SDK) which is over the SDK export. The older one remains unchanged exactly for this reason.



Yes i’m aware of that. I’ll have a look at all these settings.

in the CTB interface I found them rather confusing to be honest…that is a recipe for things going wrong. Functionally they are wrong… why does a user need to be bothered by settings to speed up the print process with multiple speeds per layer
That should be in the hardware of their closed system including proper management of the acceleration. So it always feels a bit counter intuitive programming interfaces for settings you would fundamentally disagree with…

So I will probably extend the speeds/exposure dialog to include these somehow… make them optional one way or the other…


@formware they are actually VERY useful settings.

You want slow lift for the first 5-7mm (I use 30mm/m) so that the print peels correctly (Especially on the large format machines) rather than either rips the fep or rips the print off the supports. You then want fast lift for the rest of the lift (~300mm/m) to help clear partially cured resin off the B side of the print to improve B side quality

You want fast retract until 3-4 mm above print position, again, to help B side quality. You then want slow retract to print position (Again, I use 30mm/m) in order to allow the resin to settle and stop flowing. Coupled with a 1 second rest before exposure, the resin has had a chance to mostly stop moving before exposure.

The above two principles are well known and proven from the first days of the Wanhao D7

Regarding the CTB interface, I hear you on it being confusing. It was for me too, until I read the TSMC section here:

After that it was pretty easy to understand.

Also, calculating light off delay is a pain in the arse and it’s not flexible. It’s much easier to just specify the three rest times.

I set up two stage lift via firmware settings in my Mighty 4Ks (I did not upgrade the firmware on these to use v4 .ctbs) and while it was easy to do, it’s not flexible. I like being able to do it in the slicer.


cool thx for your input. I’ll try and manage to wheel them in there one way or the other.



Rest Time Before Lift
Rest Time After Lift
Rest Time After Retract

Which of these are being used?

I read the ‘off time section’ on the CTB website. Seems to me as nobody every understood that. So everybody is entering a value for off time and thinks the printer is waiting that amount. Only to find out it’s substracting the time of the movement from that.
I think most of our other OEMs are using this variable in Formware as a delay variable. So I propose we just skip this in the CTB exports and shift to the Rest time implementation for V4 and onwards.

Rest time before list -> does this have any purpose? I could imagine you want to cool down large surfaces of some kind? But hard to find this has any effect… probably the glass plate gets hot anyway over time. So it would not be a reliable paramter?

Rest time after lift -> same question? what’s the purpose?

Rest time after retract -> ok this has a clear purpose, allowing resin to settle.


fyi, almost done with the two stage motion option. Update coming early next week. Probably tuesday.
I think for the latest anycubic machines this is also relevant. They seem to have some option in photon workshop as well to control the motion in 2 parts. I’ve added dynamic changing images to clearify all the values.


As in other thread:
I’ve just uploaded V1041 to the website.

It has:

  • rest time variables.
  • transition layers implemented
  • all height/speed variables for 2 stage movement including (imho intuitive) UI.

All variables visible in the image below are exported to the CTB SDK .ctb format.
The offtime variables are not used anymore in this case; only rest time variables.

Will be adding the other machines that are supported with this next couple of days.


Thanks, I was waiting for transition layers for long time


the transition layer work in sonic 4k? (no mini)
because it’s not working for me


Hi Nano,

Not 100% sure. The hardware needs to support it.
You can try to do the following:
switch the slice output from CTB to CTB V4 SDK (machine config, slice tab).
This makes sure that the file is generated with the CTB SDK (which we purchased from CTB).
Then try that file on the machine.

Otherwise please check with Phrozen.



now is working
thanks for including this improvement
I was waiting long time for this
No more chitubox!!!