E3d V6-Lite + PLA = Trouble?

[shark_fan_94]

Hello all!

I have read through the other E3D threads but haven't found a true solution for what I am looking for. So the hotend prints fine, when it prints. But, I am having trouble when I print PLA with it. I have a Metal Simple and a Metal Plus, both with Buildtak on the build platform. Now, with the Ubis , on my simple, I have no problems at all with the prints. But when I use the E3D V6-Lite, my prints don't stick as well. Even though the nozzle tip is just above the Buildtak. What happens is the first few perimeters stick, but after the 3 or 4th they start to warp up a little and then the nozzle catches on them and the print is toast.

So, my two thoughts 1) too many perimeters or 2) I need to have a fan aimed at the build surface at all times.

Does anyone else have any suggestions? I would like to add a E3D V6-lite to my simple as well but I want to make sure it will work first..

I run a 3d printing prototype business for local machine shops/engineering firms so I would like to get this sorted out ASAP. So if anyone has any suggestions feel free to chime in and then future people can use them too!

[RetireeJay]

Clearance between the nozzle and the bed is critical. Try this: with the Ubis, start a print and then kill it before the second layer starts. Peel the print off the bed and measure the thickness of the layer with a digital caliper. Then do the same with the E3D. You will want to adjust your bed clearance so that the first layer is the same thickness as your good setting with the Ubis. Tenths of a millimeter matter here!

Besides that, maybe try raising the temperature for the first layer only. There are also other tricks within the slicer to make the first layer "fatter" and more likely to stick well. Good luck!

[Mooselake]

You need a fan with PLA, but turn it off for the first few layers. With a bit of googling I found a number of comments about fan use while printing PLA. Richrap recommends no cooling for the first 3 layers, then adjusting the fan speed after that for just the right amount of cooling. If your fan won't go slow enough try some masking tape (like that blue stuff) over part of the fan opening to reduce the volume; might need some thicker paper under it to prevent the proverbial hitting the fan. A different fan shroud design might help you too; I'm partial to ducted fan shrouds so the airflow surrounds the print and you don't get the one side is better than the other issue.

The if you still have problems after Jay's suggestions and tweaking the fan try increasing your printed filament width (under the advanced settings in slic3r, you might need to fake Cura out by increasing the nozzle size) a bit, say 5 or 10% at at a time. Plastic can be stretched as it prints, then shrink and try to pull back when it cools. It's more of an issue with ABS, but it's worth a try with PLA.

The actual amount of plastic the slicer will extrude depends on the incoming filament volume (diameter and extruder speed), and not the nozzle size. However, the slicers will use the nozzle diameter as a starting point for the width of your extruded plastic, and vary both the the distance the extruder moves the incoming filament, along with the distance the X and Y axes move the print head. Increasing the width that's laid down will decrease the amount the plastic filament needs to be pulled (think how a rubber band gets narrower as you stretch it) to adjust it's width to the desired size. It gets worse on thinner layers (less height so more pull) so thicker layers can help; try a thicker first layer. At 3 or 4 layers infill width shouldn't be a factor, but increase the infill extrusion width (which has the side benefit of improving print speed a little). If you're using slic3r set the infill every n layers to 99 and it'll decide how many perimeters it can print before doing an infill layer. Since many objects spend more time infilling than printing perimeters it'll make a difference in total print time, along with reducing and stretch.

And just from curiosity, how's that prototype business going? There's been some discussion here about what to charge, so if you haven't already you should search the forum for it.

Good Luck!

Kirk

[shark_fan_94]

[Mooselake]

I have the Printrbot (sort of) equivalent all metal Ubis that's being used as a temporary test (of both the AMU and dual geared beta extruder) until I've put a dent in my 1.75mm collection. After that I'll be going back to my original 3mm Ubis and Wades extruder. If the non-metal Ubis packs it in I'll probably keep the Wades and get a 3mm E3d.

Kirk

[bbrown64]

With the E3D-V6 or the Ubis hotend it is critical to make sure you set up the Z-Probe to the right height. But first you have to have the gap between the bed and nozzle the correct distant. The instructions say use a piece of paper as a make shift feel gauge. I found it cumbersome to use a sheet of paper. I bought a feeler gauge set, I use .013mm gauge for the nozzle gap. Once that is set I use the plastic feel gauge that come with the printer to set the Z-Probe height.
Then you have to go through the process of setting of the Z-Probe height in the software. Usually my measurement there ends up somewhere near Z-1.2 to Z-1.25. I print PLA temp between 200-210 with a bed temp at 60-70. All my prints stick just fine without any other help.