1 Topic by DLM

  • DLM
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Topic: Tolerances for 1mm hole

Hi all,

I have a delta printer with pretty decent calibration. I print with 1.75 ABS. Looking to see if anyone out there has experience printing an object with lots of tiny little holes. I'm looking to print cylindrical holes, 1mm in diameter by about 1.5mm deep. They would be part of a larger print and located in a section that is 100% infill. Ideally, they would be about 2mm apart from each other on all X/Y axis. To elaborate on intent: I want to sink these tiny 1mm diameter x 1mm long magnets into a solid slab of printing.

So the question is more on the design end. If you were going to make something like this, would you make the holes 1.5mm in diameter in the STL to account for expansion and any potential over extrusion? I have faith in my printer, but tolerances in most filament are not great for this type of high precision work, which means sooner or later int he print I'll get some over extrusion.

I'm typically a trial and error type of guy, but I have a feeling these prints are going to take forever. Looking for a second opinion on this one before I start.

2 Reply by tonyno

  • tonyno
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Re: Tolerances for 1mm hole

I print a lot of small things with a 0.4mm nozzle and always add around 0.8mm to hole sizes to start.  Create a small part to test first. wink

3 Reply by heartless

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Re: Tolerances for 1mm hole

a lot does depend on how well calibrated things are, including filament.. type of filament also makes a difference. some have higher shrink rates than others.  i typically give about 0.5mm extra - at minimum.

I am with tonyno - make a small, quick & easy test print, with say 4 holes, and each hole a slightly different tolerance for testing purposes, see what works best for you, your printer, and the filament being used

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4 Reply by mark.giblin (edited by mark.giblin 2018-09-23 21:14:01)

  • mark.giblin
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Re: Tolerances for 1mm hole

Whats the hole for?

I think that the use of the hole will really dictate what you need to consider.

I was going to suggest you have a simple solid fill behind the hole through to the shell on the opposing surface and leave a dimple like X marks the spot and drill it with a 1mm bit to the required depth.

Assuming that the position and location is accessible.

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5 Reply by Grendel

  • Grendel
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Re: Tolerances for 1mm hole

I think it depends on the printer, but I typically add 0.4mm (the size of my nozzle) to any interior holes, and only occasionally do I need to ream them to size with a drill bit, by placing the hole you get a solid wall around it, no matter what % fill you use.