CNC ABS Build - To Vapor Wash or Not to Vapor Wash...that is the question...

I’m just getting started printing out the myriad of parts needed to construct this beast of a machine. I’ve opted for ABS because I have tons of it laying around and have never had shrinkage/warpage issues during printing (Rostock Max V2 Ed.4). My question is whether or not anyone else has ever tried doing an Acetone Vapor wash of the printed parts prior to assembly? It would certainly make it look cleaner (no layer lines), and in theory would strengthen it a bit, but I’m unsure if the vapor wash could possibly push things out of wack in terms of hole positions, etc. I don’t mind not washing it, but wanted to see if anyone else had tried this in the past with success and/or failure. I’ve had drooping on different parts in the past when in the vapor wash, but those are a little more extreme cases then what the parts for the CNC look like.

I wouldn’t bother but I didn’t even color coordinate my parts. I just want it to work and don’t care what it looks like and I don’t think vapor polishing is going to add any functionality.

I figure if I’m going to spend hours building/tuning/using a system, it might as well be appealing to the eye, but that’s just a personal preference of course. I’ve found that in some cases an Acetone wash can strengthen the part as it makes it harder for the layers to break part due to the lack of layer lines. This isn’t always the case, but it’s anecdotal information I’ve gathered from printing ABS for as long as I have. I’m just trying to ensure that if I choose to do so that it won’t corrupt the parts enough to throw everything out of wack. I don’t believe so, but was hoping someone else had been brave enough to try it before me…

Vapour washing may change the interior dimensions of the parts, which could translate to issues later on. I personally would not risk it after spending all the time and money printing it.

What you could so is with a small thing paint brush, brush the outsides of the parts where it does not matter. That may actually make them stronger by melting the layers together.

I’ve had issues with using the brush-on method before, specifically the brush lines appearing in the print afterwards, which is why I stick with the Vapor washes. However you do bring up a good point about internal dimensions becoming corrupted, which was what my original concern was. The most egregious of these errors would most likely appear near the bearing mount locations as the prints have very small (by comparison to the overall part) torus’ that hold the bearings in place. If those were to become misshapen, well, most certainly chaos would ensue. Perhaps the safest bet is to build a full unit without the washes, figure out its inner workings, then replace the parts a few at a time with vapor washed versions and see what goes wrong. The feet I don’t think there’d be a problem with, but anything with a bearing or a belt guide could be problematic.