3d confusion.

[artie]

I've had my printer for a little while now and very impressed with it and myself.

There's one niggle, when I design something say 220mm long. export it as .stl, slice it, print it, and measure it. It will be a few mm short.
Is there a handy fix, Or will experience show me how much to increase the design length to compensate.

 

[MorrisWoodman12]

In my understanding the printed filament shrinks as it cools. My CEL Robox allows you to dial in a percentage increase/decrease adjustment to compensate (many reckon the Robox was years ahead of its time) though I believe lots of printers/slicers still don't have that feature. Which printer are you using and is the shrinkage in just one direction?
Martin

 

[artie]

I'm using the ender 5 plus. I think it's in all directions, but I'll check.
I'm trying it today enclosed, so the temp is much higher, maybe that will make a difference.
Most things don't matter for a few mm but some do.

 

[ChaiLatte]

You need to quantify your problem.

For an object of 220mm dimension, how much exactly is "a few mm"? 22mm would be 10%; 2.2mm would be 1%.

Are the "few mm" the same absolute number or the same proportion if you make the object 110mm dimension?

And what do you mean by "short"? It is called a 3D printer for a good reason - it prints in three dimensions, conventionally X, Y and Z. Does the shortness occur equally in all three axes?

Look on any 3D printing site: there are specific test objects that you can download to measure the performance of your machine and which will aid in troubleshooting.

When you bring the object into the slicer, does it report the same dimensions as the program in which you have 3D modelled it?

 

[artie]

The slicer reports the same size as onshape.

A test cube I did 20 by 20 by 20mm turned out so close it's not worth mentioning.

The part in the pic is supposed to be 218 by 114 by 13 with 94mm diameter holes.

The actual dimensions are 216.5 by 111.4 by 12.84 with two 91mm d holes.

I printed a ruler to compare with my steel ruler. over 290mm (x) it comes up 1mm short 20mm wide ( y ) instead of 22.9 and 3mm thick (z) instead of 3.2

 

[paulrbarnard]

The slicer reports the same size as onshape.

A test cube I did 20 by 20 by 20mm turned out so close it's not worth mentioning.

The part in the pic is supposed to be 218 by 114 by 13 with 94mm diameter holes.

The actual dimensions are 216.5 by 111.4 by 12.84 with two 91mm d holes.

I printed a ruler to compare with my steel ruler. over 290mm (x) it comes up 1mm short 20mm wide instead of 22.9 and 3mm thick (z) instead of 3.2
View attachment 174177

1% of 20mm is 0.2mm. 1% of 200mm is 2mm. Same error different perception of a problem. The part you just printed should give you the amount to scale for x and y.

To add it’s not just shrinkage it’s also possible that the steps to distance calibration of the printer is a little out. That can either be compensated by scaling or you can change the calibration of the printer. Depending on your printer that can be easier said than done.

 

[HamsterJam]

There should be a scaling setting in the slicer you can use to calibrate your workflow. Pretty sure there is one in Cura.

 

[artie]

Thanks, I have a print going which won't be done for another day.
Then I'll experiment with the scale settings on the slicer.

I'm running it enclosed, the temp is <> 28c I'll se if that helps.

 

[MorrisWoodman12]

Ah! The temperature is <>28c! What is it then?
That's enough of me being pedantic
I guess you mean about or ~28c. I have always read <> as not equal to.

I've got my coat on, just need to find my hat.

 

[artie]

Ah! The temperature is <>28c! What is it then?

It varies around 28c

I've got it in a tent it's printing much better. Spare room temp is ~14.


Never knew Tilde was on my keyboard.

Everyday's a school day.

 

[donturner]

I'd start by checking the printer calibration, specifically the steps/mm values for the X, Y and Z stepper motors. This is as simple as printing a 20mm calibration cube, measuring each axis with calipers or micrometer, then calculating the new steps/mm values based on the existing values and setting them via the touch screen menu.

This video does a pretty good job of explaining it:

I have an Ender 3 Pro and after calibration is it dimensionally accurate to within 0.1mm over 200mm. I would guess your Ender 5 is capable of similar accuracy.

Much better to have a well calibrated machine then rely on scaling in your slicer.

 

[artie]

Much better to have a well calibrated machine then rely on scaling in your slicer.

Thank you that is great information.
When I enter settings and selected motor control, a X appeared accross the button and I couldn't progress.
utube or a google search brings up nothing.

 

[donturner]

Not sure what's causing that. Afaik Creality don't lock any configuration settings. Could you post photos of the menu screens?

 

[artie]

Not sure what's causing that. Afaik Creality don't lock any configuration settings. Could you post photos of the menu screens?

Main screen.



and settings screen.




The motor control was clear like the rest till I tried to access it.

 

[donturner]

I think that's just indicating that you can disable the stepper motors if you want. This can be useful if you want to manually move the print head around.

What's on the Move and Printer Info screens?

If setting the steps/mm isn't available through the LCD menu you may need to connect the machine to a computer and send the relevant commands via the terminal.

 

[artie]

The print screen just let's me pick the file.



There seems to be some input available on the move screen

 

[TRITON]

Thats excellent, you've 3D printed a couple of holes.

If I ever need to measure the diameter of some air, you've got the job

 

[donturner]

It seems that the touch screen on the Ender 5 is missing a lot of functionality (source: this video and page 28 of the manual https://img.staticdj.com/cdda0a7c7a...f19-4b75-b385-97e124a91853.nav_link_store_1.1). I would suggest plugging it into your computer and using something like Pronterface to execute the G-Code commands to set the steps/mm values directly.

Here's a getting started guide: Using Pronterface to send GCode to your Printer - TH3D Studio Help Center.

You'll need to send an M92 command to set the steps/mm, then save the settings (so that they are read each time the machine is powered on) using M500.

In more detail, I would do the following:

1. M503 - Read all the machine settings, copy these to a text file so if you screw anything up you can easily restore the machine to factory settings.
2. Print your calibration cube and calculate the new steps/mm values
3. M92 X<new X value> Y<new Y value>
4. M500 save settings

Repeat steps 2-4 until your dimensional accuracy is fixed.

 

[artie]

1. M503 - Read all the machine settings, copy these to a text file so if you screw anything up you can easily restore the machine to factory settings.

Yes Don. That's the important bit.
Thank you for this valuable information. I have lots of pieces to print which don't require a great degree of accuracy.
So I'll put this on the long finger for now.
Your help is appreciated.

 

[donturner]

No problem. I design and print a lot of dust extraction adapters where 0.5mm can be the difference between "way too loose" and "nice airtight fit". If you're doing anything like that it's well worth the pain of calibration.