wardjr wrote:

Yeah, for a part like that you want to use a .3 layer there is no benefit to a .1
You want to use the proper z height for those as well.  The SD comes with a 5/16" Z rod so you need values that actaully match up to the metric nature of the rest of the system.  This is very important and is often over looked.
.3=.2963
.2=.1976
.1=.09878

What should the first layer height be for each of those layer heights?

Thanks!

That all depends on preference, I like to run my first layer height at the same height to keep things simple.  I then adjust my z end stop to achieve the proper amount of squish on that first layer.  I have found that by decreasing the extrusion width of the first layer to something like .36 will greatly improve adhesion.  I know others that use a higher first layer height for the same reason but I haven't found that to be as reliable.

Yeah, for a part like that you want to use a .3 layer there is no benefit to a .1
You want to use the proper z height for those as well.  The SD comes with a 5/16" Z rod so you need values that actaully match up to the metric nature of the rest of the system.  This is very important and is often over looked.
.3=.2963
.2=.1976
.1=.09878

What should the first layer height be for each of those layer heights?

Thanks!

TickTock wrote:

Don't touch the Z constant.  It *is* moving 1mm when you say 1mm.  You are changing the layer height so it moves .2963 *instead* of 0.3000.  This is to ensure that the stepper stops at an integer step since the fractional steps are prone to non-linearity. You can see variation from layer to layer if it stops at a different fractional step each layer so using the numbers wardjr provided avoids this error.

Ah, now I get it, thanks!

And do I need to recalibrate the flow rate?

NO

Don't touch the Z constant.  It *is* moving 1mm when you say 1mm.  You are changing the layer height so it moves .2963 *instead* of 0.3000.  This is to ensure that the stepper stops at an integer step since the fractional steps are prone to non-linearity. You can see variation from layer to layer if it stops at a different fractional step each layer so using the numbers wardjr provided avoids this error.

Ah, now I get it, thanks!

And do I need to recalibrate the flow rate?

Don't touch the Z constant.  It *is* moving 1mm when you say 1mm.  You are changing the layer height so it moves .2963 *instead* of 0.3000.  This is to ensure that the stepper stops at an integer step since the fractional steps are prone to non-linearity. You can see variation from layer to layer if it stops at a different fractional step each layer so using the numbers wardjr provided avoids this error.

Thank You for the explanation I'm on the phone ordering computers sooo....

Yeah, for a part like that you want to use a .3 layer there is no benefit to a .1
You want to use the proper z height for those as well.  The SD comes with a 5/16" Z rod so you need values that actaully match up to the metric nature of the rest of the system.  This is very important and is often over looked.
.3=.2963
.2=.1976
.1=.09878

OK, I'll switch to 0.3mm layer height when the current print is done.  I assume I need to recalibrate flow rate?

Should I just use those layer heights, or should I calibrate the Z axis and change the M92 constant in the firmware so it's really moving 1.0000mm when I tell it to move 1.0000mm?

The Z constant is currently 2268.0 steps per unit, if that means anything

Does the 'modern' (got it in Nov) SD4 have the same problem, or do I not know without calibrating it?  What's the best way to calibrate, tell it to move 100mm and see what it actually does, or use a dial indicator on a 1mm movement?

Thanks!

That is a very close up image so it is difficult to judge things.  You may be slightly over extruding but other than that and a few blobs there is no smoking gun here.  That area of the print will not affect fit or performance so it is usable as is.
That doesn't make it correct but it sounds like you're doing everything right.  It could just be that particular roll of filament.
And as Jago said, go get a cheap thin piece of hardware store glass cut to size for a few bucks.
Are you using .2963 for your layer height?

Yeah, my kid's cheap USB microscope starts at 10X, and my iPhone doesn't do well on closeups.

My glass is on order.  8*)

Layer Height is 0.1mm
First Layer is 0.35mm

Try a thinner sheet of glass, it can't hurt. I use cheap $2 glass at the hardware store. Your bed should reach 105. Maybe check the plugs for a good connection and take up the aluminum to make sure there isn't an air pocket around the bed thermistor.

I've got some thinner glass on order, so that might help.

But that kind of distortion doesn't immediately say <something> specific?  Everyone's thinking bed temperature?