Tell me what I'm doing wrong, please.

[kdurbs]

I've had my FF for about three weeks now. Learned enough from this forum to print several items with success. My son and I are now attempting to print him a Cyborg Beast prosthetic hand. We started simple, trying to print a thumb, but we keep getting variations of what you see below. Some specifics:
PLA
Nozzle 230c
50% fill (have tried as little as 10%)
Number of shells 5 (started with 1)
Build plate 30c
Three point leveling with post it note before each print.
Tried with support, and without.

It's supposed to look like the blue picture. Unfortunately, they don't tell you in the instructions what settings to use, some I'm flying blind.
Any help would be appreciated.


DSC_0735.jpgDSC_0734.jpgThumb_Finger_w_Bumps_preview_tinycard.jpg

[Ghosty]

hi, welcome,

from what i have learnt, 230c at nozzle is way to hot for PLA,

try
nozzle = 195 (even thats to hot but works for me)
infill = 10% - 15%
shells = 2
build plate at 65c
movement speed 40
travel speed at 70

these will give you some quality results, except on hugh overhangs, still trying to figure that one out, but i did print an iphone 5 case last night and came out perfect with those settings

[stevekr2]

Hi. No expert but PLA usually is around the 200 mark.
It looks to me that it is air printing off the raft??
In what ever slicer you are using make sure to drop model onto table, then ensure that there is no settings set to have a big gap between raft and model.
Another suggestion would be to turn the model 45* on the table.
Highly recommend simplfy3d if you are happy to pay $140.
A trial version is not necessary it works! Much better finish that SK/forge or slic3r.

[Geoff]

Yeah way too hot,

Run PLA at 200-205c
Hotbed at 65c

And Ghosty's right, more shells. When it prints shells or 'walls' it does them from the inside to the outside which makes the exterior wall more rigid.

Movement and Travel I would go anywhere from 50-60ms feed to 70ms feed, travel 100-120ms

[curious aardvark]

I've got a roll of pla that won't even extrude at 190. Needs 220 to print clean. But it's definitely the exception - only mentioned it because that's also white. Pretty much all the other colours I print at 195.
So for this white pla 230 might not be massively too hot. Maybe knock it down to 210 - 215 and try a cube or sphere. Or my favourite test shape a cube with sphere removed :-)

Printing too hot will give you runny pla, that just won't build up properly.

Printing too cool will give you sticky pla that makes a lot of spiderwebs and doesn't laminate properly.

Once you've found the happy medium - pla is brilliant stuff.

If you can afford ploymakr pla-max - it can also be tougher and more durable than abs.
Although that said, I've found the reprapper brand pla I'm using to be at least as durable as the abs and not at all brittle.

Test sphere cube thing attached. If you can print this cleanly - you should be able to print pretty much anything.
Also it only uses a couple grams at most :-)

It tests everything from precision to bridging to under hangs and over hangs in one very compact, quick to print and material light little shape :-)test-sphere-cube.stl

test-spherecube-thing.jpg

And if you want to make different sized ones it's this openscad file:

$fn=100; difference() {


cube (20,center=true);
sphere(d=26);
}

Just change the cube size (20) and the sphere size (26) to get different sizes and thickness of the supports. Numbers are in millimetres.

***

Just loaded my white pla and had to up the preheat temp to 230 before it would even load.
And yes I'm sure it's pla. It sticks to cold tape, smells like maple syrup and has a pla sticker on it.

Currently done a test print at 225 and it worked well. So now printing a larger part at same temp.

[kdurbs]

Thanks for all the suggestions. Trying some of them now. I'll let you know.

[jfkansas]

Have you tried to dip the "white PLA" into acetone?

I've got a roll of pla that won't even extrude at 190. Needs 220 to print clean. But it's definitely the exception - only mentioned it because that's also white. Pretty much all the other colours I print at 195.
So for this white pla 230 might not be massively too hot. Maybe knock it down to 210 - 215 and try a cube or sphere. Or my favourite test shape a cube with sphere removed :-)

Printing too hot will give you runny pla, that just won't build up properly.

Printing too cool will give you sticky pla that makes a lot of spiderwebs and doesn't laminate properly.

Once you've found the happy medium - pla is brilliant stuff.

If you can afford ploymakr pla-max - it can also be tougher and more durable than abs.
Although that said, I've found the reprapper brand pla I'm using to be at least as durable as the abs and not at all brittle.

Test sphere cube thing attached. If you can print this cleanly - you should be able to print pretty much anything.
Also it only uses a couple grams at most :-)

It tests everything from precision to bridging to under hangs and over hangs in one very compact, quick to print and material light little shape :-)test-sphere-cube.stl

test-spherecube-thing.jpg

And if you want to make different sized ones it's this openscad file:

Just change the cube size (20) and the sphere size (26) to get different sizes and thickness of the supports. Numbers are in millimetres.

***

Just loaded my white pla and had to up the preheat temp to 230 before it would even load.
And yes I'm sure it's pla. It sticks to cold tape, smells like maple syrup and has a pla sticker on it.

Currently done a test print at 225 and it worked well. So now printing a larger part at same temp.

[Geoff]

You should be able to tell ABS from PLA pretty easily, they have completely different characteristics, PLA you can snap like a piece of spaghetti almost, ABS takes a little bit of back and forth to actually snap off a piece.

I wonder why your flashforge hates ABS so much and all of ours loves it , weird.