Problem with accuracy

[EdMann]

I have been printing for a little over a week and the printer has been working great since the first print. But I discovered an issue today with prints being slightly off from the design. I tried to print a USB holder I created in CAD. The print was to be 20mm by 20mm, which was slightly off at 19.51mm. The big issue is with the width. I set it to 12mm but printed at 9.61mm. Is there something I need to adjust in the slicer (Slic3r) or do I need to re-calibrate the machine?

[Elysio]

Hi Edmann

Please post some more material.
Printsettings of your print programm/ slicer
Maybe CAD file. Photos, Filament etc.....

[Jimustanguitar]

ABS will shrink as it cools. This might be part of what you're seeing.

[EdMann]

I'm using the Rostock Max V2 with 1.75 ABS and w/o modifications.

After printing several items from Thingiverse I thought I take a shot at developing my own using FreeCAD. Once the small USB holder was complete I exported the FCStd as a stl, opened it in Repetier-Host, sliced and printed it. On the upside, all 3 prints are very consistent but they are not even close to getting a USB to fit. They measure approx. 9.8mm by 3.6mm.

Attached are all the files and settings I employed.

[Jimustanguitar]

I forget who brought this up the other day (I can't take credit for this tip) but sometimes the slicing programs will have trouble when the perimeters are thick and the infill area is small. Try reducing your shell thickness and give it another slice.

[EdMann]

Same result, sort of. it's no longer a cube 19.35 X 18. The interior width of the slots is down slightly to 9.3. But I like where you are going. So I chiseled out the inner wall of one of the slots. Now it measures 12.3 x 5.8 and the USB fits, all be it tight.

So do you think is my issue lies in the slicer or does the machine need calibration?

[Elysio]

Hello

I saw you have settings for the layer with 0.4mm, I guess with 0.1mm this will become better.
I just can imagine that thicker layer has to absorbe more heat which leads more to shrinking or deformation.

Are you using the fan?

[EdMann]

I'll try adjusting the setting.

I'm not using either fan since there was nothing in the instructions on how to mount them. As you might have guessed, I'm new to this and many posters have said they never use a fan for ABS. Anyway I have both set of wires connected to the board and running to the extruder head. Any info on how to mount and aim the fans would be appreciated.

[Eaglezsoar]

I'll try adjusting the setting.

I'm not using either fan since there was nothing in the instructions on how to mount them. As you might have guessed, I'm new to this and many posters have said they never use a fan for ABS. Anyway I have both set of wires connected to the board and running to the extruder head. Any info on how to mount and aim the fans would be appreciated.

The fans pretty much aim themselves once you have printed out the shrouds and install them. If you continue to run without the Peek fan you will be investing in new parts for your Hotend very soon.

[EdMann]

Your fan question spurred me to download the latest copy of the assembly manual. It now contains the fan shroud and mounting information.

I'll reprint and post the latest pic of my USB cube after I get the fans into position.

Thanks for the assist!

[EdMann]

Success!

OK, I took several steps back. I downloaded the latest version of the manual. I started with the new fan shroud section and re-calibrated everything. I was able to print and mount both fan shrouds with fans. I reconfigured the slicer with the supplied files.

No my prints are meeting the specs I set in FreeCAD. My only issue is boxes are slightly racked and circles are not quite round. Do I need to re-calibrate each tower again?

[Eaglezsoar]

Success!

OK, I took several steps back. I downloaded the latest version of the manual. I started with the new fan shroud section and re-calibrated everything. I was able to print and mount both fan shrouds with fans. I reconfigured the slicer with the supplied files.

No my prints are meeting the specs I set in FreeCAD. My only issue is boxes are slightly racked and circles are not quite round. Do I need to re-calibrate each tower again?

The answer is probably yes, depending on whether you can live with the issue. A calibration error is usually the cause of out of round circles and racked rectangles.

[geneb]

I'd check to make sure you don't have any serious binding issues going on. Out of round and "Racking" is usually caused by one or more axes dragging a little behind due to excessive friction.

g.

[lordbinky]

Depending on how small 'slightly' is, don't forget to check belt tension too in case one of the adjusters drifted and your pulleys.