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Mhackney Calibration box tests: - after partial rebuild / full recalibration
I think I'm using the correct calibration box now..
Here's the kind of mhackney hollow box tests I'm getting: (temps written on boxes)

It's hard to measure the walls due to the poor quality, but on the one area that was smooth I got .54mm
with my calipers. So I guess the right amount of plastic is being extruded.

The same old corner artefacts are there as ever.. Can't seem to shift them
Also sagging, shrinking inwards towards top, and all the usual problems I have been seeing.

Settings:
; layer_height = .2
; perimeters = 1
; top_solid_layers = 0
; bottom_solid_layers = 1
; fill_density = 0
; perimeter_speed = 20
; infill_speed = 20
; travel_speed = 20
; nozzle_diameter = 0.5
; filament_diameter = 1.68
; extrusion_multiplier = 1.0
; perimeters extrusion width = 0.55mm
; infill extrusion width = 0.55mm
; solid infill extrusion width = 0.55mm
; top infill extrusion width = 0.55mm
; first layer extrusion width = 0.55mm

G21 ; set units to millimeters
M190 S75 ; wait for bed temperature to be reached
M104 S235 ; set temperature

Ok, I saw my name and had to reply!


It really looks like one problem is you are way too hot. I'm assuming this is ABS at those temps?

Here's what I'd like you to do...

warm up your hot end to 220°C
extrude 10mm of filament

Did it extrude nicely? If not, raise the temp 5° and try it again. Repeat until you get good extrusion. However, I'm guessing it extrudes fine at 220°, so LOWER the temp 5°. Extrude 10mm? How does it extrude? Repeat lowering until you get to a point where it just doesn't seem to extrude nicely. Once there, add 5° and report back here what that temperature was.

Also, slow WAYYYYY down when doing this test, 20mm/s is too fast. Go down to 5mm/s. It crawls but that's the point. Print after you find the best temp as above and slow down as just stated and then let us know what happened (with a photo please!).

Give it a shot. I'm also avail to chat today if that would help.

Cool - will try that, and document the results ot the "lowest extrudable temperature"

Yes, it's abs - I bouight more high quality filament - The temps I am using are based on median temperatures within in the range recomended by the manufacturer of the filament (Formfutura.com)

Just an observation, - original post (i'd thought it was you, but it was Polygonhell) about performing this test says this:
"I set all of the speeds to the same relatively low value of 20mm/s"
His machine was making beutiful cubes at that speed!! I wish I knew how to get even half that good!

It's Saturday night here so I going out to try and be a functional human in the outside world, but I may well be around later.

As always, I really appreciate the support I'm getting

Great. Our recommendation when things are not going just right is to slow down. You can then start bumping up the speed.

Bear in mind, the temp you measure (your thermistor reading) may not be the actual temperature due to a lot of variables. The manufacture recommended melt range was likely done on calibrated equipment. It is very possible that you could be measuring temps too low. So, it is good practice to do an extrusion test like the one above on new materials to find its sweet spot. I do this on every new roll of filament I get. Saves aggravation!

If I get through this without giving up I may draw a flow-chart for those that come after me...

That would be great and you WILL get past this. It's way too cool to be able to make your own stuff!

analog_banana wrote:If I get through this without giving up I may draw a flow-chart for those that come after me...

Please don't give up. There are hundreds perhaps thousands that have made this stuff work. They go into it with the attitude that
they WILL make it work and they make it work. As you have seen it takes a lot of research, a lot of repetitive test prints, a lot of time and
most important of all, it takes an I will not fail attitude.

I did those tests: Do you think the filament is coming out too thick for a .5mm nozzle?

temps: 195 - 225
extruding 10mm @ 100mm/min

195 = length:33mm diameter:0.93mm **SKIPPING EXTRUDER**

200 = length:44mm diameter:0.91mm

205 = length:44mm diameter:0.91mm

210 = length:45mm diameter:0.89mm

215 = length:48mm diameter:0.85mm

220 = length:50mm diameter:0.85mm

225 = length:51mm diameter:0.82mm

All lengths and diameters are based on the rough average of four extrusions per temperature.

Ok, so it looks like 200-205°C should be good for slow-moderate speeds. As you speed up (later when things are sorted) you usually have to bump up the temperature a bit because the filament doesn't have a long enough residence time in the hot zone.

For now, lets use 205° 0 which is a lot lower than you used in the prints above. Slow down to 5 to 10mm/s and let's see what happens. Don't worry about the filament diameter right now, especially since you got reasonable wall thicknesses above.

This is 205@ 5mm/second speed.
It is neater with the ultra-slow speed.

As always the corners are quite bumped up, with the nozzle grazing over each previous layer,
causing the corners to deform.

BTW - wall thickness measures ok at around .55 / .57 mm