Issue after the first print of the day

[mrmonisimo]

My first print of the day on a flashforge creator pro using Simplify 3D always comes out perfect, but every print after always shows gaps on the first layer and under extrusion throughout the print. It also prints differently than the first time (some new and different curves).
There was a time when this never used to happen but this problem started a few days ago.
I've tried letting the machine totally cool down to room temp after the first print before starting the next one, but when I print I still have the issue.
If I leave the machine off and get back to it again the next day, the first print comes out perfect and then I get botched subsequent prints.

Any ideas?
Thanks

[Geoff]

Depends on what material you are printing in, and also the environment essentially.

If you are printing in ABS and are getting small splits between some layers, what's happening is you are probably getting some backdraft somewhere, any cool air blowing on an ABS print can cause these splits, also not printing hot enough - raise temp by 1 or 2 degrees and also make sure hot bed is as hot as you can get. Ideally ABS you want to keep warm and cosy when printing.

If you are getting layer splitting with PLA (which loves to be cooled down when printing) it's very possible one of your belts is loose.

I would try printing a bed calibration model and see what the print is like across the bed - even a badly levelled hotbed can cause the splits - as the nozzle prints close to the model, then slightly far away..

Imagine you are printing a cylinder on a bed that's not level.

The first few layers will look fine, but the machine doesn't know about the bed level, so it just keeps printing. Let's say the back of your plate is lower than the front...

This means the front layers will look compacted, and the back of the cylinder will not be printing each layer close enough. If its a small object you don't often notice it but on taller items it becomes apparent pretty fast if your bed's not level. "Sort of level" is not ok...

I often put 6 x 1cm cubes on the build plate, 4 in each corner and 3 across the middle.

When it's printing all 6 uniformly, and they are identical - then I know I'm level.

4 thumbscrews are not terribly accurate sadly and often will lose their way when you pull hard stuck objects off the build platform.

[curious aardvark]

I get a similiar issue with certain colour flexible filaments. White is fine, yellow and orange can be buggers.
Personally I think it's temperature creep going up from the extruder melting chamber to the filament entering the chamber.
It warms up too much and becomes just too soft to be pushed through properly.
I don't get it with any of the stiffer filaments.

Could also be an issue with the hobbed bolt cog being a bit clogged so it's not got a very good grip when pushing the filament through.

I'm going to dismantle the extruder and see if I can do anything about it, as it's quite annoying :-)

[EagleSeven]

My first print of the day on a flashforge creator pro using Simplify 3D always comes out perfect, but every print after always shows gaps on the first layer and under extrusion throughout the print. It also prints differently than the first time (some new and different curves).
There was a time when this never used to happen but this problem started a few days ago.
I've tried letting the machine totally cool down to room temp after the first print before starting the next one, but when I print I still have the issue.
If I leave the machine off and get back to it again the next day, the first print comes out perfect and then I get botched subsequent prints.

Any ideas?
Thanks

Could be a Voltage Drop to stepper-motors.
Caused by the Power-supply or Mother-board problem.
(I would first try an different power-supply)
Make sure Fans are working at both PSU and Mobo.

Or it could be a stepper-motor overheating and failing.
I've read about that happening and causing problem like yours.
(touching motors, after about an hour of printing, will let you know if Too hot)
(I have fan on X & Y motors to prevent that)

[Geoff]

Could be a Voltage Drop to stepper-motors.
Caused by the Power-supply or Mother-board problem.
(I would first try an different power-supply)
Make sure Fans are working at both PSU and Mobo.

Or it could be a stepper-motor overheating and failing.
I've read about that happening and causing problem like yours.
(touching motors, after about an hour of printing, will let you know if Too hot)
(I have fan on X & Y motors to prevent that)

Yeah it does sort of point toward a possibly dying stepper motor or driver, I just didn't want to freak him out

The fact that you can get one print out of it and then subsequent prints it starts to happen - then yeah Eagleseven is right, either the stepper is getting tired and dying or the driver is, I would lean toward the motor first and the stepper driver later ..

ironically this happened to me last week also, and now I think about it it was causing me very similar issues but
I did not let it print that far because I could see the inconsistent extrusion when I was loading filament. It would extrude.. .then sort of thin out then go thick again etc.

I thought blockage, but I cleaned it out completely. Replaced the stepper motor and all problems ceased. The motor had done over 3000 hours of printing, so it had a good life.

[mrmonisimo]

Yeah it does sort of point toward a possibly dying stepper motor or driver, I just didn't want to freak him out

The fact that you can get one print out of it and then subsequent prints it starts to happen - then yeah Eagleseven is right, either the stepper is getting tired and dying or the driver is, I would lean toward the motor first and the stepper driver later ..

ironically this happened to me last week also, and now I think about it it was causing me very similar issues but
I did not let it print that far because I could see the inconsistent extrusion when I was loading filament. It would extrude.. .then sort of thin out then go thick again etc.

I thought blockage, but I cleaned it out completely. Replaced the stepper motor and all problems ceased. The motor had done over 3000 hours of printing, so it had a good life.

So it has been a while but I was horribly busy with work and didn't have very much time for printing. Thanks for the replies. The problem got worse and I think you guys were right. I changed the nozzle, the tube and switched the motors. I still had the same problem even after all of that on the same right extruder. The filament just seems to get lazy and doesn't want to come out. If I push the filament through it goes fine but when I let go it doesn't extrude anymore.

So that leads me to believe that if I switched the motors and I'm having feeding issues on the same right extruder then the problem must be the driver? Is this on the motherboard? I have to look this up to see how to change it. I've been fixing issues on the extruders (clogs, leveling the heads, switched the motors) but I've never tackled an issue with the motherboard.

[mrmonisimo]

In preparation, I've opened the bottom panel and have found the stepper motor. Does the right extruder (while facing the front of the machine) correspond to stepper motor driver A?

[mrmonisimo]

So I put in the new stepper motor driver and the problem still persists. I'm getting pretty frustrated.
Apparently the issue isn't with the stepper motor or driver then. The filament is grinding and skipping and not feeding when I'm loading it. But this is with a new nozzle and tube so there definitely isn't a clog.
Anybody have any ideas out there?

[curious aardvark]

maybe new stepper motor ?

Does your left nozzle work okay ?

If so swap the plugs or motors and see if the left one works with the right connections.

[Geoff]

So I put in the new stepper motor driver and the problem still persists. I'm getting pretty frustrated.
Apparently the issue isn't with the stepper motor or driver then. The filament is grinding and skipping and not feeding when I'm loading it. But this is with a new nozzle and tube so there definitely isn't a clog.
Anybody have any ideas out there?

hmm frustrating I can imagine, Can you at least push it through by hand and see it extrude at all? if you can't push it down by hand then there is little chance the stepper motor is going to be able to.