First Layer - How should a first layer should look?  

Re: First Layer - How should a first layer should look?

My belts have good tension on them, still my 20mmx20mmx20mm cube prints 19.8mm, 19.8mm, 19.8mm, any tips regarding that?
1% accuracy is quite good.

But I'm working with parts that needs to fit together now, then 0.2mm is to much 🙁
I'll try another one with slight raised Extrusion Multiplyer

Re: First Layer - How should a first layer should look?

I'm afraid you cannot achieve lego-like accuracy with hobby FDM printer, there are too many factors taken into account. Filament string is not always 1.75mm, nozzle is not exactly 0.4mm, nozzle temperature, bed temperature, air temperature and humidity, all changes with time.

Re: First Layer - How should a first layer should look?

I'm afraid you cannot achieve lego-like accuracy with hobby FDM printer, there are too many factors taken into account. Filament string is not always 1.75mm, nozzle is not exactly 0.4mm, nozzle temperature, bed temperature, air temperature and humidity, all changes with time.

no lego here, I'm just trying to get a cylinder to fit inside a circle hole 😀

Re: First Layer - How should a first layer should look?

Hi Patrik

You could try with a different slicer; you could ensure that the outside perimeter is printed first, you could try different extrusion widths and of course, you could adjust the step count.

All this would have to assume that you have the same accuracy consistently. If your accuracy varies then you have to find what is causing the variation.

However, as David says, 1% accuracy is something to be very pleased about. When I want to fit one model inside the other, I usually allow a 0.4mm clearance adjustment.

Peter

Re: First Layer - How should a first layer should look?

Even the frame of printer itself changes dimension with temperature. 300mm of steel/iron extends by 0.1mm per 20°C. Aluminium alloy is even worse. If you start printing at 20°C and let the printer warm up to 40°C during few hours of printing ... guess what. 😉

Re: First Layer - How should a first layer should look?

OK then, I'll settle with my 0.2 mm error 🙂

Re: First Layer - How should a first layer should look?

One more fact (regarding your note about cylinders fit into round holes) - filament string tends to cut the curves short, that's why all printed holes usually come out a little smaller. Every time I want to print a hole which has to be of exact dimension (for example for a screw or some shaft), I make it 0.2mm larger in diameter. For example, I print 3.2mm hole for M3 screw. Then I usually don't need to finish it by drill or any other tool.

Re: First Layer - How should a first layer should look?

Hey guys!
Damnit, it's frustrating. Today, i tought i would follow the advice of david and lower the Z-Axis further. So i started printing my job from yesterday and set Z in Liveadjust to -0,503.
After the job finished, i can't realize what was going wrong: The first layer looked like the first print from yesterday. I've changed nothing.
So i just started to print the same job 2 times again, without tune parameters - see the attachement.

So, i have the following ideas, why the first jobs seem rough:
- The room was a little bit colder as yesterday (maybe 2-3 degrees°?)
- The heatbed was colder (the sensor may not measure the TOP of the heatbed)
- ...?

My problem now: If it's a problem with the "heat up" of the printer; i've to calibrate it correctly print 10-15 minutes a job. Has anyone other this problem?

Yesterday night i printed the LCD Frontcover (i posted 2 pics in my first post) and it seems quite good; ways better that before my live-z-adjustments.

Re: First Layer - How should a first layer should look?

Hey. I readjusted (fixed) the PINDA-Probe, and than had to readjust the Live-Z-Height. Printed bigger parts (3x3cm), and finaly got a better result than every (very plain firstlayer).

Re: First Layer - How should a first layer should look?

Hi,

I just want to trow in my results here and wonder what you think ?
is this ok or too squishy?

Thanks to ALL