Print is good, except for .5 mm too tall

[phiatt]

Hello Everyone,

My name is Philip Hiatt, I am a fairly new user of S3D, and I always try to figure things out for myself unless I get stumped, which is why I am posting here.

Duplicator i3
.4 mm nozzle
Bed @ 85 C
Extruder @ 260 C
ABS

The problem:

My prints come out very good, length and width are spot on, except for height, It is .5 mm too tall. If some of you may feel that I am being anal about this .5 mm, I am not, since I have had this printer I have been able to keep my tolerances within 50 micron. But the height issue is really bugging me. If anyone has any ideas or suggestion I am all ears, Thanks.

[CompoundCarl]

Well what is your layer height? If your layer height was 0.3mm for example, you really can't expect to control the Z-axis print height any better than that.

Another thing that can easily affect this is first layer positioning. If the nozzle is too close to the bed, you could easily print 2-3 layers that are very squished against the bed. These layers would print smaller than the software expected them to, since the bed was so close. Again, that's another place where you could easily generate 0.1-0.2mm of error depending on your bed positioning.

You might also want to verify your Z-axis steps/mm just to rule that out. Tell the Z-axis to move 100mm, and measure to make sure it moves exactly that much.

[mroek]

For the i3, the correct value for steps/mm on the Z-axis is 400. No need to measure anything. The older versions come with a slightly wrong setting for this value (405, I think), and it may be that Wanhao hasn't bothered fixing this. It really doesn't matter much, as the error is really small, but entering the correct value doesn't hurt either.

[phiatt]

Hi,

And thanks for the responses, layer height is .2 mm, Z axis steps per mm were something like 405.9000 blah blah, after my attempt at calibration I came up with 402. and some decimals. So, mroek, you say 400 is the correct value? I have yet another test print going right now. I verified Z level, and set the nozzle .2 mm above the build plate. I will try a different value when this print finishes. Thanks

Philip

[phiatt]

After my last test print, there was a slight decrease in height, about .2 mm. I went ahead and changed the steps /mm as mroek sugessted, the test was much better. So, here is what I did to get my print within .1 mm height.

Changed the steps / mm per mroek suggestion
Set nozzle height at .2 mm above bed
Layer width at .48 mm
Layer height .2 mm
Z offset at -.2mm

I had tried the Z offset before to no avail. Changing the steps per mm seemed to be the main culprit. Thanks everyone for your help, after my last print cooled down, it was within +-.02 mm which I feel is pretty good.

[KC_703]

After calibrating your e-steps, try lowering the extrusion multiplier by 2-5%. This will compensate for filament which may not be a consistent diameter or various fillers which may be in the filament.

Best way to check if you're under or over-extruding is to print an object which should fit on a standard object... for instance a socket cap screwhead. I use the attached M3 or M5 thumbscrews which should snap onto standard socket caps.

Hope that helps.