Holes smaller than model

[Polecalex 0]

Hello All!

 

I have recently started using Cura, which I absolutley love! I am getting better prints than I ever did before and It's so easy to use!

 

Although it is amazing, I am having a little difficulty while printing. I am trying to print out a spotify code as a key ring. I am trying to make one piece as the outline and the other as the code which they will then both slide into each other to create the full code. The models like up perfectly in blender and I have printed the first piece. Now I am printing the second piece, the outline part which will go around the code, however, while it is printing I have noticed the holes are very small! I doubt they will even fit around the first part as they're way too small.

 

Obviously, I haven't really played around with the software but I am just looking for some advice on what it might be? Do I need to change the model slightly? Is it the wall thickness? Something to do with the bed leveling? I am using the Makerbot replica, "CTC 3D Printer" so the printer isn't perfect but surely it should print the right sizes?

 

Here are the images of the print and model.

https://imgur.com/9TC8nqM

https://imgur.com/1NsTjwL

 

Many thanks!

[Mari 33]

Did you calibrate your printer extruder e-steps?

Edited June 13, 2020 by Mari

[GregValiant 986]

The image does appear to be severely over-extruded.  That would push the sides of the slots in.  When you say "way to small" what does that mean.  How wide are the slots as designed?  It's hard to get a sense of scale from the images.

[Polecalex 0]

On 6/13/2020 at 2:09 PM, Mari said:

Did you calibrate your printer extruder e-steps?

 

I have no clue what this means?

 

On 6/13/2020 at 2:50 PM, GregValiant said:

The image does appear to be severely over-extruded.  That would push the sides of the slots in.  When you say "way to small" what does that mean.  How wide are the slots as designed?  It's hard to get a sense of scale from the images.

 

I'd assume this is what is causing the issue then. I mean that the inner gaps should be larger in order for the other piece to slot together. The piece that slots into the holes are way too big in order to slot together even though they fit together in blender.

[Mari 33]

... printer has to know how many steps the extruder has to make to extrude 100mm of material... with less steps you get underextrusion, with more steps you get overextrusion! Therefore you need to calibrate this!

 

--> https://www.thingiverse.com/groups/ctc-3d-printer-owners/forums/general/topic:7915

[GregValiant 986]

Another thing would be how much clearance you left (in the model file) between the raised portions of the yellow piece and the slots in the black piece.

[Polecalex 0]

On 6/16/2020 at 7:08 PM, Mari said:

... printer has to know how many steps the extruder has to make to extrude 100mm of material... with less steps you get underextrusion, with more steps you get overextrusion! Therefore you need to calibrate this!

 

--> https://www.thingiverse.com/groups/ctc-3d-printer-owners/forums/general/topic:7915

 

I have used a guide to check the steps and it all works out perfect, it doesn't extrude too much or too little.

 

On 6/16/2020 at 10:48 PM, GregValiant said:

Another thing would be how much clearance you left (in the model file) between the raised portions of the yellow piece and the slots in the black piece.

 

I have made space between them but the outer piece's holes are still too small no matter what.

[GregValiant 986]

I would start with the slots clear of the raised areas by .25mm constant all the way around.  So if a raised area is 1mm x 5mm I would have the slot at 1.5mm x 5.5mm.  You can make up a small test piece with some slots on one half and matching raised areas on the other half.  Print it and cut it apart and test fit them together so you don't have to print both of the real pieces.  If things still don't fit together go to .35 all the way around.  Once you have it dialed in then make adjustments to the real parts and print them up.

Edited June 18, 2020 by GregValiant