I have been 3D-printing some Lego Technic pieces on my Bambu Labs P1S printer using Bambu Studio but the holes are little bit too small. I can drill round holes but I can’t make “X” shaped holes bigger. Any suggestions?
Despite not wanting the ‘holes’ on ‘X’ to get bigger, i guess it safe to offer advice for lego…
A small flat file should work, or cut down a nail file to fit the slots, and use that to widen them.
Most plastic responds well to a nail file, they are what I use for most cleanup work on 3d printed parts. And they can be trimmed and folded for awkward jobs.
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Go into the Advanced settings and try enabling the “exterior perimeters first” option.
Believe it or not, the inside of a hole is a perimeter and if you have the machine print it first, if there’s enough cooling the next perimeter will not push enough on the first perimeter to cause it to close up.
What usually happens is the inner most perimeter of the hole is printed, then the next one outside of that and finally the outside perimeter and there is only one place for the plastic to go if there’s not the perfect amount of plastic extruded.
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I don’t see “exterior perimeters first” option but I see “Order of walls” option.
Which slicer are you using?
Exterior parameters first is the slicer-family (Prusa-slicer, orca-slicer, etc) expression of this facility.
Bambu Studio.
OK, I avoid Bambu so I don’t have direct experience here.
You might want to try Inner/Outer there.
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Sounds like you understand the effect needed, hopefully you can find the setting which applies that technique and see if it helps with the accuracy of the holes.
If you have the CAD files for the designs you are printing then you can add tolerances to those parts giving your printer problems.
I love my Bambu.
The [order of walls] option is what you are looking for in equivalency in Bambu studio.
But my first thought is to redo the 3d objects and add the correct tolerances that you want so you don’t need to mess with all this.
P.S. I was unfamiliar with this lego technic system so just looked them up and…Holy Cow! I think these plastic parts are made from gold. Those are some pricey kits!
No, injection molded ABS made to very fine tolerances which are rigorously tested for, and when a mold wears to the point the parts are not fit, it is pulled and destroyed.
Consider the economics:
- each year the company can make so many molds
- run so many injection molding machines for so long for each mold to make a certain quantity of parts
- the parts need to be stored
- a kit then needs to be collected out of stored parts with the parts sorted into bags which match the instructions, and the bags and instructions placed into a box (and it is also necessary to arrange to have the bags made, and instructions and boxes printed, and for the box, folded and glued)
I have Lego bricks which I had when I was young from very early kits and they still fit perfectly with current production — Lego bricks are really the best value in toys, and I hope the company continues to make them for a very long time (says the AFoL who has a Saturn V which he “launches” each day on arrival at his office and then restores to the horizontal stand on leaving).
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I heard or read some time ago (so I don’t know whether it is true) that many years ago, they tried to license production, but even US military contractors couldn’t reliably hit Lego’s required precision.
I’ve been assuming that the 3d-printed variants depend on distorting layer ridges for fit, instead of precision.
A bit of discussion of one attempt here:
The problem isn’t getting the parts made, so much as getting them made at an acceptable price…
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Ah, the story I heard of was at least purporting to be about history from many decades ago. But I have no references.
The technique I use is to make the holes larger in cad because the plastic shrinks and the holes when printed to their correct dimensions always shrink slightly on the actual model. if it is a 3mm hole for instance try increasing it to 3.25mm in cad and then test it when it is printed