Help with first print

hello - just received the Lulzbot mini today and tried to print the rocktopus. First frustration was El Capitan - but sorted that by using an old computer. The print turned out pretty poorly but trying to convince the skeptics in the house that it is worth trouble shooting before we return.

Its seems the PLA did not adhere well to the base. The tip moved several “rounds” before anything came out. Then it came out rather stringy and did not stick down well. The end result was OK. By far the poorest 3D object I have ever held in my hands. The legs weren’t solid, were stringy and overall quite a disappointment. i know we have a lot to learn but it seems this demo has been quite successful for most people.

your help is appreciated!

Could you post some photos of your print including one of the bottom of your print and of your toolhead with filament loaded and the idler latched? It sounds like this will be either a first layer problem or an under-extrusion problem those pictures should help narrow it down a bit.

Thanks - some more playing today. When we push the extrude 10 it extrudes filament but it does seem like there is a delay in extrusion during printing.

I will attach pics you requested here

try 2

toolheadsm.jpg455×586 47.3 KB

oh and the skirt didn’t print - the head went through the motions but nothing came out…

Did you manually extrude filament until it was flowing from the nozzle before you started printing?

These are the steps I take after selecting a filament to use and turning the printer on.

1. Use the LCD (or CuraLE printer control) to set the extruder temperature to the suggested temperature for that filament
2. Insert the filament as far as I can manually
3. Use the LCD (or CuraLE printer control) to extrude filament until I get a nice string coming out of the nozzle
4. Use tweezers to remove the string (more than once if it oozes)
5. Start the print

Watch the skirt or brim or raft start to print (I usually do skirts). If the skirt doesn’t start appearing right away or doesn’t stick to the bed then something is wrong and I stop the print and figure out what needs to be changed. The nozzle temperature, the bed temperature, and sometimes the speed of the first layer may need to be adjusted (usually in that order).

The first layer of the print is the most important layer. If there is anything wrong with the first layer, there’s a very good chance that the rest of the print will have bigger problems.

Yes we did extrude. My son figured out for one print to pause the print, manually extrude, then resume print and it works. But it won’t extrude again during the print.

Part of the reason to buy this printer was it more “plug and play” compared to others. At what point to we say we have a dud and should send it back?

At what temperature should the nozzle begin to move? We find that it starts to move around 196C - I am wondering if it isn’t hot enough at the beginning of the print.

We extrude, but the nozzle cools while it goes through the brushing/leveling steps, then when it heats up again the print starts before 200C. No filament flows. However, if we pause the print, extrude again, resume, the filament flows.

Any ideas?

Is your nozzle temperature set to 200? if so, initial movement at 196 might be normal, the last couple degrees should finish within maybe 5-10 seconds. It might be expecting the last couple degrees quickly near the start of the print.

To test your theory about nozzle temperature, you could also just re-slice with a temperature set to 205 and then see if there’s a change in how that first layer goes. (assuming it would move around 200-201 then.)

You can also try to slow down the first layer, or increase thickness of first layer, etc…

So far, you’re using a default profile? I assume the bed is heating up?

It might also be that a lower z-offset would help get the first layer to stick more. Is there filament coming out at the start that isn’t squishing and sticking to the bed? This seems possible on the legs. Can search to find more instructions about z-offset if this seems like the issue.

You could go down into the skirt settings and tell it to do an extra (or a few more) skirt line(s) to be sure the extruder is more primed before it starts the model. Looking at the skirt can help determine if z-offset is good. (If it is sticking down but not too flat then it’s probably good. If anything you might be not sticking down enough…)

From extruder pic, I think it looks like the idler tension is about right (?) but you can also take steps to make sure it isn’t slipping and that e-steps are correct. To do this, measure how much filament is pulled through when you instruct it to pull a certain amount. (Normal instruction is measure and mark 120mm up from top of extruder, tell it to extrude 100mm, and then confirm there are 20mm left above the extruder.) If there are more than 20mm left, then it is under-extruding and the fix could be to increase esteps (or tighten the idler arm screws more on the filament to help stop slipping.)

If you forget to prime the extruder, then you can also do some quick trick at around 185-190 before the print starts… after wiping and bed leveling, wait until ~185-190 and then open the idler and push in a bit more filament… Then quickly re-latch it before it starts to move to print. I’ll sometimes do this to jump start it if I forgot to prime the extruder, for example after restarting a print. Before wiping, it backs out some filament, and then it extrudes some more to make up for it, but if it wasn’t primed to begin with then it isn’t enough and without that, it takes longer for the filament to start flowing.

Anyway, sorry if this seems like a lot… pick or choose what sounds good…

Any other details you share might give more ideas if not overwhelmed already.