3D Printers

[steinra]

I took a quick look at the printer, it looks like it has a screw adjustment for the z-limit switch for hte zero process. That may need some adjusting.

The first layer should be smooshed a little bit against the glass.

As for speeds, in the printer and filament section

Print speeds should be the normals speeds you can run at. I found on my Prusa I can do 40 mm/s on perimeters without and issue and a 50 mm/s infill.

But, in the bottom of that box you will see a setting for bottom layer speed ratio. Set this to .5 or higher as it will slow the initial layer and not go to fast building that initial layer.

The other speed to watch is the travel speed. If the travel speed is too high and the current is not high enough to the stepper motors they will skip steps.

60 mm/s is what I have had good luck with.

[steinra]

A feeler gauge would work. .2 mm is a typical layer height so somewhere between .1 and .2 mm would be a good starting point.

[steinra]

You will know when you get the first layer right is when is is smooth and consistent and does not "plow" through other plastic already laid down.

Sometimes it takes a little tuning to get just right.

Make sure you turn the skirt feature on as it gives a rough idea of the evenness of the bed. That is usually where I run into issues, but that printer may be fixed bed height.

Don't be afraid to stop the print if the first couple of layers don't look right.

[EricH]

Originally Posted by steinra

Sometimes it takes a little tuning to get just right.

Don't be afraid to stop the print if the first couple of layers don't look right.

Best advice I can give. We run a 3-layer shell, and if the first three layers come out, we're good until much later in the build unless something goes badly wrong like a jammed tip. If the first three don't come out, we'll stop and tune.

Protip: find a small, 10-15 minute build. Maybe something you can do as a giveaway. If you make a machine settings change, or a machine change, run one and see if it turns out right. We use turtles.

[ksafin]

Wow, the nozzle has to be that close?

You know.. this is starting to make sense.

Perhaps the reason why the top layers turn out better is because at that point, the height of the object we're printing is > 5 mm, and thus the nozzle can get super close to it. Whereas the first few layers are super far from the nozzle and thus turn out noodl-ey.

[EricH]

Originally Posted by ksafin

Wow, the nozzle has to be that close?

You know.. this is starting to make sense.

Perhaps the reason why the top layers turn out better is because at that point, the height of the object we're printing is > 5 mm, and thus the nozzle can get super close to it. Whereas the first few layers are super far from the nozzle and thus turn out noodl-ey.

Exactly!

What's happening is: You're starting so high up that the material won't stick. But, what does stick forms a base. As you get closer to the head, the material sticks better, and forms the shape better. So by the end of the part, it looks really good. But at the beginning, ugh.

I've seen that when I've pulled material from one part in a 4-part build--eventually, I got high enough that it wouldn't act up, then it built almost normally, then other stuff happened (that I won't go into here).

Use that height-adjustment screw set--it's your friend--but once you get good parts, you don't want to touch it unless you absolutely have to.

[steinra]

As you get into this a little further take a look at skeinforge. it is a bit more complex, but if has some more features over slic3r. One of the things it can do is print a raft which is a couple of layers of plastic that is used to offset the part. When I had some initial layer issues the raft really helped make some great parts. But after really tuning it, I don't need it very often.

Good luck, looking forward to seeing your parts you produce.