sizes of a print producr issue

[duvdev]

Hello,

I just ended a aketch in solid works 2014.
the height of the object in the program is 2.6mm and the heihgt of the printted one is 2.9mm

why? and how can I solve it?

thanks

[critical_limit]

It depends.

What are your slicer settings?

Count your Layers in your slicer and multiply it with your Layer hight you printing with.
Dont forget, if you have a bigger first Layerhight, to add this. And, maybe you have a little offset due to your calibrated Z0.

I´m printing most with first Layer 0.15mm and Layers 0.1mm. My Slicer is slicing 200 Layers on a 20mm part. So I end up with 199x0.1mm + 1x0.15mm. So my part is 20.05. Sometimes little more du to Z0 is not exactly zero. Don´t expect the Parts are exactly that hight you are constructing it. Calculate your Parts Hight on a "Layerbase", not on mm´s.

Most Times my Parts are dimensionally correct within 0.05-0.1mm in Hight, but horizontally I have 0.2-0.4mm off.

And have a look to the settings for the stl output in Solidworks. You can adjust it. It makes a difference if you have a circle printed in 8 lines or if is printed in 256 lines!

Hope that helps

cheers
Dirk

[Russ]

Also check your actual filament width with a caliper. My lovely 1.75mm Makerbot True White PLA roll is actually 1.83-2.00 mm, which causes printing issues. If you enter 1.75 mm for your filament size in Slice3r but your filament is actually larger, you will extrude more plastic then intended, and this will cause your printed item to be larger than intended.

Cheers,

[teoman]

I had % 10 growth in the Z dimension and 2 percent in the x and y.

I redid the calibration process thoroughly. And now i am close to 1-2% in every dimension.

[critical_limit]

I had % 10 growth in the Z dimension....

I think that´s nearly impossible.

You printed a part which is 10mm in Z, you got it in 11mm. Ok, that´s possible.
You printed a part which is 100mm tall, you got it in 110mm???? Think, that´s impossible.

Let´s think about that.
Let´s say you have a Layerhight of 0,5mm. To print a part of 10mm hight, you need 20 Layers.
When you print a Part of 100mm, you need 200 Layers. You said, that your part of 100mm is coming out 110mm. That´s 20 Layers more.
Where are the 20 Layers coming from?

The only I can imagine is, that your pulleys are not set correctly in the firmware:

#define PULLEY_TEETH 20
#define PULLEY_CIRCUMFERENCE (BELT_PITCH * PULLEY_TEETH)

and because of that, the machine is adding a small amount each Layer. But that results in Layerseparation the higher the part gets. And that is no longer printable from that Layer, where is doesnt adhere to the last Layer. And your horizontal dimensions would be far off too.
So. Absolutly impossible.

As far as I can tell from my experience, all Slicers are in Z-off within 1-2 Layerhights. Depends how correct your Z0 is set.
You can check that when you put a part into the slicer which is 1mm tall. Set 0.4mm Layerhight. Is it printing 2 Layers? It will come out in 0.8mm. If the Slicer prints 3 Layers it will come out 1.2mm. And what happens, when you set the Layerheight to 0.35mm? Not every Slicer reacts the same way. Check it before planning and printing a part and you won´t be disapointed after the print not matching your dimensions...



cheers
Dirk

[teoman]

26mm part (peek fan) was coming out as 29mm. Other dimensions were OK. Re-did the entire firmware and calibration and it was much better.