Print dimensions don't match design

[daveinhull]

Hi,

I've now got my V3 upgraded printer working and the prints look very good in deed. No more z-axis wobble; nice clean surfaces

However, I'm seeing some minor problems with dimension where the print size does not match the design size (I'm using Creo Elements as the design package). There is just a small difference, but enough to make the prints unstable at times.

Some differences seen
20mm = 18mm, about 90%
8mm = 7mm, about 87.5%
3mm = 2.25mm(ish), about 75%

So I suspect the actual size difference is around 87 to 90% mark.

Can this be adjusted in software?

Many thanks
Dave

[Hugues]

Yes it can,

i used to do it this way:

- extract a bit of plastic and remove it, but let the rest ooze out slowly
- bring the extruder down to touch the build plate, you should have a little plastic spot
- move your extruder by 200mm in X (or 150,..) using the sofwtare
- bring down the extruder again to mark a second plastic spot
- move the extruder out of the way
- measure the distance between the 2 plastic spot, it should match your 200 or 150mm move
- if not, you can adjust the number of steps in the software menu
- i don't have the soft open now, but it's in one of the first menu, called firmware i think, you can see how many encoder steps per mm and you can change that value
- decrease or increase it proportionally to your measured error
- repeat the procedure again until you are satisfied
- then do the Y axis
- for Z, just measure a fix spot on the build plate

[daveinhull]

Hi Hugues,

Many thanks. I sort of found the setting and was trying with a pen mark but your idea is far better.

Thanks
Dave

[Hugues]

Also remember to measure your model once it has cool down, because it will shrink a bit.

Normally, the first layer printed on the bed might measure a bit more because it is often "squahed" down on the plate, measure above the first layers preferably.

[salman550]

this is very nice post

[olce]

Hi,

just for reference.

here is a nice and good calibration method and fairly detailed.
Model + instructions: http://www.thingiverse.com/thing:195604

it may involve some test prints before calibration is completely done.

O.

[seaton]

Hi,

I've now got my V3 upgraded printer working and the prints look very good in deed. No more z-axis wobble; nice clean surfaces

However, I'm seeing some minor problems with dimension where the print size does not match the design size (I'm using Creo Elements as the design package). There is just a small difference, but enough to make the prints unstable at times.

Some differences seen
20mm = 18mm, about 90%
8mm = 7mm, about 87.5%
3mm = 2.25mm(ish), about 75%

So I suspect the actual size difference is around 87 to 90% mark.

Can this be adjusted in software?

Many thanks
Dave

If performing the calibration checks where you normally print, or try at different spot on both X and Y, I had problem where the belts had stretched and my calibrations were fine in one spot but out terribly in another, it was then I realised my belts had stretched in that spot it was out.

[mrcncap]

remember that plastic shrinks as it cools so don't forget to scale your model to the shrink rate of the material you are using.

Hi,

I've now got my V3 upgraded printer working and the prints look very good in deed. No more z-axis wobble; nice clean surfaces

However, I'm seeing some minor problems with dimension where the print size does not match the design size (I'm using Creo Elements as the design package). There is just a small difference, but enough to make the prints unstable at times.

Some differences seen
20mm = 18mm, about 90%
8mm = 7mm, about 87.5%
3mm = 2.25mm(ish), about 75%

So I suspect the actual size difference is around 87 to 90% mark.

Can this be adjusted in software?

Many thanks
Dave