Issue With Preheating

[joesoap583]

I haven't verified the following fully, however I think it might be a problem that needs looking into. Perhaps someone else could try the same to confirm?

I designed a job to print with my left extruder. I then pre-heated te left side to 235 degrees, and executed print over USB.

As the left extruder was already sitting at the required temperature it was held there by S3D whilst the bed came up to 105 degrees. Once the bed reached temperature no further progress was made.

I think, but am not sure, that if the extruder temperature is already at the required value then S3D doesn't need to heat the extruder, and it goes into a loop which it never comes out of - because there is no event to suggest that the required temperature has been reached.

If I execute the same job without preheating then it works fine.

[TenKOhms]

I usually have my printer pre-heating while I prepare a print. Hot end usually hits temp pretty quick, and by the time I initiate printing over USB, the bed is still climbing. I have yet to experience this problem, I'm printing with a RAMPS 1.4 board over USB.

[joesoap583]

I don't usually have my bot preheated. It was just unusual yesterday when I tried.

It might not be a problem, I would be grateful if someone else could confirm.

[horst.w]

Preheat or not,
when I set temp-point for the sec extruder to zero because it is not in use, than the display shows the real temperature of e.g. 20 degr of the room.
Starting now printing with the sd-card, the heated bed heat an after this the primery extruder heat but in a never ending loop under flickering in the display between 1st and 2nd extruder.

When I set now the temperature for the sec extruder e.g. to 30° (higher than the real temperature), the printer will run without problems.
Zeroing the option >Wait for temperature controller to stabilize ... shows the same fault.

I think that is a bug in s3d

[JoeJ]

I'm guessing your starting script has commands which tell the printer to wait until the temperature is stabilized. So when you tell it to print at 15 degrees, it can never stabilize at that low of a temperature (since room temp is more like 25C), and the firmware isn't smart enough to realize this is okay and continue. So it keeps waiting.

But thankfully it is a very easy fix - don't tell it to print at a temperature below 25C, or use the preconfigured profiles that S3D provides that specifically do NOT try to stabilize an unused extruder. For example, if you are printing with the left extruder, don't have a command that tells the right extruder to wait until it has reached the target temp

[horst.w]

Thanks.

I'm owner of a brandnew Mankati Full XT, coming with Mankati-Cura and this programm doesn't show this problem. The g-code of both in the starting-sequence are nearly equal.
The starting-script is origin of S3D and hook on >Wait ...< doesn't make a difference.

I have solved the problem with heating the sec Extruder to 40°, so that anytime the temperature of room is overlaied. In a second step I put down the temperature to 20° but the extruder hold the 40° for the whole time. Thats also ok for me.

It is only important to know, why the printer hangs in a loop and doesn't print.


H.