Early prints - need some tuning advice

Hi All, with your help we are now printing and my daughter presented the project at school to many intrigued and astounded faces.

I'm moving on to a real application now but it is quite evident I still need quite a lot of tuning to get the print quality up to something useful.

I have drawn up the following thing on FreeCAD:
[www.thingiverse.com]

Here is what is needs to look like ,

This is what I'm getting ,

I dont really have enough experience yet to know what to adjust first :-\

I am running black 3mm PLA from vic through a 0.35mm Jhead at 185C, layer height is .3102, feed rate has been calibrated. I have tried print speeds of 10-30mm/s. The adhesion between strands on the upper part looks poor so higher temp ? The density on the base where the fill is 100% seems to be spilling up between strands and looks too much but the density for the upper part is very poor. What to change is not obvious to me.

Any advice would be very welcome...

Lastly looking at the detail on the top face I am not at all confident that this can be printed given the support that is available whether the face is printed on the bed or on the top. At present I am simply printing a disc and intend to machine the face. Thoughts ?

Cheers all,
P

Your base looks OK, so I guess that the taller part is not getting enough time to cool between layers.
Try printing 2 or even 4 at a time and see if there is any improvement. Or add a fan.

I'd loved to have seen the faces of those kids watching the magic unfolding in their eyes!
Anyway, yes, that's good advice above, I never print small objects singularly with PLA - print at least 2 and get a fan of some sorts blowing in the direction of the model. By the way, your thingiverse upload is not public so we can't see it. I would be happy to see how it prints.

AL

The gaps between the filament loops is too great so something is wrong with the filament size or the nozzle. The heat won't cause this and yours looks about right anyway - I normally run 200 for the first layer then 185 after that.

You may be doing all this but just in case:-
Avoid using the scaling fudge factor to try to correct this, you should be able to get it right if you put the right numbers in.
Measure your filament with a digital vernier and use that figure instead of 3mm, it is normally 2.85 +/- 3mm
Make sure you have the correct nozzle size entered in Slic3r, it defaults to .5mm

Also, while you are finie-tuning a design I would reduce your fill to 30% or even 20% for test prints, it will still print and is a lot quicker for testing.
I usually increase it for the final print after I have ironed out the bugs of early designs.
The bottom void is probably too far to bridge so leave it out all together.

Edited 1 time(s). Last edit at 05/16/2013 09:16PM by Wired1.

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Richmond, New Zealand
Thingiverse ~ YouTube

Tis published now. I will try out these suggestion this arvo...
Thx for all so far

Temp seem a little warm to me, Vics PLA normaly prints at 165-175

Also your layer height seems very high, with a .35 nozzel I normaly print at .25 or .2 if you want finer layers

I had a look at the STL and was quite intrigued so thought I'd give it a go. The main portion of the part is much like the 0.5mm thin wall calibration cube, although i think the CAD is about 1mm?
Anyway, I measured my print at about 0.55mm so maybe I need to tweak my new PLA filament if its meant to be 1mm. Definitely needs active cooling and at least 2 at a time.

Making some progress finally. I setup 2 pieces and added a fan, and dropped the upper layer temp to 170. The first results were disasterous - found that after lowering the temp I was hitting EXTRUDER_MINTEMP in the firmware. Fixed that and slowed WAY down to 10mm/s and produced this cube

Which is mostly ok but it looks like the print quit early. It seems to have an unfinished layer and no top shell (1 layer). Also is measures 10.3x10.3x9.9
Hollow cube looks promising now although dimensionally also seems a layer short. Walls are 1.3 - design is 1.0

My part now looks like:

Which has room for improvement but is probably useable

Thanks for all the advice, anything further certainly still welcome.
Cheers
P

Edited 2 time(s). Last edit at 05/19/2013 05:08PM by pouakai.

I would suggest that you switch to a maximum of 0.25mm layer height for an 0.35mm nozzle. I would also verify your hot end temperatures to make sure they are what you think they are. It is possible to be 10° out with component variation or a damaged thermistor.

Your CAD model looks fine and I can't see any reason why it wouldn't print just fine.
Have you verified your Z-axis steps per mm?

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