Long Delays Before Print?

[HighlandStorm]

Hi guys,

Sorry if this question has been answered before, but I've googled a lot and can't find anything on it.

I'm using a Davinci 1.0a with repetier firmware and S3D.

When I try to print, there is a long delay before the printer does anything - around 20 minutes. Is this normal?

When the printer does eventually start to print, there are lots of delays between layers.

Any idea what could be causing this?

Thanks.

[brian442]

Go to Tools > Machine Control Panel, and watch the Communication tab when you start the print. That should allow you to see what commands are being sent back and forth and it might give a clue as to what is happening.

PS - preheating my machine can take about 10 minuets, so that might be part of the time

[HighlandStorm]

Thanks for the reply.

I did what you suggested, and it's really weird. The printer heats up, and then all the GCode flies through on the communication window, but the printer doesn't move at all. Essentially, it's like S3D yells all the commands at the 3d printer as quickly as possible, and the 3d printer just ignores them.

Any idea why it could be doing this?

[HighlandStorm]

This is what it does.

https://youtu.be/BQY_EUq3uc0

[cmarko]

Long pre-heat cycles can have more than one cause.

Make sure temperature sensor in contact with the print bed.
Double check the connections between the controller and the heated bed. If a terminal is not screwed down securely on a bare wire it could reduce the current going to the heated platform. This can result in burning out a connector.

I'm not familiar with the davinci firmware but If you can run a PID calibration on the heated bed, you may reduce the time needed for pre-heat. This is a simple g-code driven calculation on arduino based printers using marlin firmware.
This post may help: http://reprap.org/wiki/PID_Tuning

I've had one other instance where the heated bed got to temperature but would not start the print for a random amount of time. Sometimes the print would start in 10 minutes other times it took 50 and others it never started. If your print start time is more random, I would suggest looking in your firmware for settings similar to the one below.

// Actual temperature must be close to target for this long before M109 returns success
#define TEMP_RESIDENCY_TIME 10 // (seconds)
#define TEMP_HYSTERESIS 1 // (degC) range of +/- temperatures considered "close" to the target one


The random start times was caused by the "RESIDENCY" set to "10" with the "HYSTERESIS" set to 1. So the bed had to hold its temperature within 1 degree for 10 seconds before the print could start. We were printing ABS and with the bed temperature set to 110^, the fluctuation was more than 2 degrees.

After the printer was run through PID tuning it was able to hold a temp to +-1^, but it was still faster to start printing when the the "RESIDENCY" was changed to "2" and the "HYSTERESIS" set to "3".

// Actual temperature must be close to target for this long before M109 returns success
#define TEMP_RESIDENCY_TIME 2 // (seconds)
#define TEMP_HYSTERESIS 3 // (degC) range of +/- temperatures considered "close" to the target one

Try the PID tuning first, this will most likely solve the problem before you have to get into anything deeper.

[HighlandStorm]

Thanks for the suggestions.

The printer is moving and heating up in time now, but it's also setting Z axis to 15mm for every print.

I've tried using the z offset in the software, but it's making no difference at all.

ah well