Object with incorrect dimensions

Vertex 3D Printer Vertex - Your printer, creations, and ideas for im
1

Hey guys,

couple of weeks ago i bought also a K8400 and right now i am trying to upgrade the printer with some parts.
The printer works pretty good, also the quality of the surface is amazing for such a low budget printer but i got a problem and i don’t have any idea what does it cause…

Right now i am printing the bearing clamp with bigger holes (thingiverse.com/thing:874862)

The outer dimension is right at 29,00 mm so far so good, but the inner diameter of the hole for the bearing is 9,4 mm and it should be at 10,0 mm.
Don’t have any idea how i can fix this.

Using S3D for slicing and PLA filament. Seems like something is going wrong but i am just wondering about what, because like is said the outer dimension is correct, or actually every dimension is correct, only the inner diameter is a bit to small.

So maybe someone got the clue…

Thanks 4 help.

Greetings,
Dani2k

2

Hi,

It’s a well known issue with those printers. Causes are multiple and it’s not easy to get rid of it.

Easiest solution : drill the hole afterwards with a bit of the desired diameter.

If you have time to spend to fine tune your printer you can have a look at this [color=#408040]website[/color].

3

[quote=“raby”]Hi,

It’s a well known issue with those printers. Causes are multiple and it’s not easy to get rid of it.

Easiest solution : drill the hole afterwards with a bit of the desired diameter.

If you have time to spend to fine tune your printer you can have a look at this [color=#408040]website[/color].[/quote]

Hi,
raby is right.
It’s a known issue.
I use the K8400 since one and a half year, and I have the same problem.
I did not find realy a solution. You can change a little bit the nozzle diameter and the floating.
It is not a issue by the slicer, because I tried it with cura, slic3r and simplify3D and it is always the same problem.
I think it is a firmware issue, because the outer dimensions are very accurate.
I also did not found a comment from Velleman.

If I design the parts by myself, I design the holes a little bit bigger.
But it is very frustrating, if you download some parts and they dose not fit.

Sorry for a lot of words and no solutions.

egm

4

Hi Dany2k,

as an engineer of plastic technology i can tell you that this is inherent to the system.
All shaping technics with heat and temperature differences have this effect, especially plastics. (think about shrinking, tensions, fading …) Sintering technologies less, injection molding with very high pressure in the middle and additive melting technics more.

And you can optimize a production system only in one direction, not in two opposed ways simultaneously.
So also slicers are optimized for the outer dimensions, wich makes more sense.

You have to consider this in your designs. Nearly all parameters of your 3d-printing process have influence, so there can’t be a simple formula.
But with time you will get more and more experience how you have to modify the inside dimensions to get perfect results with your materials and you will do not have to refinish you parts.

Bert